All Cell Technologies, LLC et al v. Chervon North America, Inc.

Filing 129

MEMORANDUM Opinion and Order Signed by the Honorable Rebecca R. Pallmeyer on 7/15/2021.(rbf, )

UNITED STATES DISTRICT COURT
NORTHERN DISTRICT OF ILLINOIS
EASTERN DIVISION
ALL CELL TECHNOLOGIES, LLC and,
ILLINOIS INSTITUTE OF TECHNOLOGY,
Plaintiffs,
v.
CHERVON NORTH AMERICA INC.,
Defendant.

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No. 18 C 1419
Judge Rebecca R. Pallmeyer

MEMORANDUM OPINION AND ORDER
A battery's performance can suffer if it gets too hot or too cold. For batteries to perform
optimally, it is helpful to ensure that their temperatures stay within relatively narrow ranges. The
four patents at issue in this lawsuit disclose power supply systems and methods of operation that
purport to improve thermal management in batteries and battery packs. Unlike systems and
methods that use active cooling mechanisms to regulate temperature, for example, the systems
and methods disclosed in the patents-in-suit rely on heat transfer between batteries and
surrounding material (such as paraffin wax).
Plaintiff All Cell Technologies, LLC, is an Illinois corporation that designs, markets, sells,
and provides support for batteries with advanced cooling systems. (First Am. Compl. [26] ¶ 2.)
All Cell is the assignee of one of the patents-in-suit: U.S. Patent No. 10,005,941 (the "'941
Patent"). Plaintiff Illinois Institute of Technology, an Illinois corporation, is a technology-focused
research university located in Chicago, Illinois. (Id. ¶ 3.) It is the assignee of the other three
patents-in-suit: U.S. Patent No. 6,468,689 (the "'689 Patent"); U.S. Patent No. 6,942,944 (the
"'944 Patent"); U.S. Patent No. 8,273,474 (the "'474 Patent"). Said Al-Hallaj is a named inventor
of all four patents, and Jan Robert Selman is a named inventor of the '689, '944, and '474 Patents. 1

Al-Hallaj is the founder and Chief Executive Officer of All Cell, and Selman is a
manager at All Cell. (See Al-Hallaj Decl., Ex. 1 to Pls.' Responsive Claim Construction Br. [751

Plaintiffs All Cell and IIT (collectively, "All Cell") have sued Defendant Chervon North
America, Inc. ("Chervon") for infringement of all four patents. Chervon is a Delaware corporation
with its principal place of business in Naperville, Illinois. (Id. ¶ 5.) The accused products are
Chervon's "EGO POWER+" electric garden tools (such as cordless chainsaws, hedge trimmers,
push mowers, handheld leaf blowers, and snow blowers) and the batteries sold with those
products. (See, e.g., id. ¶¶ 5, 17.) Chervon has asserted numerous affirmative defenses and
counterclaims, including counterclaims for declaratory judgment that each patent is invalid and
not infringed. (See Second Am. Counterclaims [31] ¶¶ 7–24, 144–49.)
The merits of these claims and defenses may turn on the interpretations of disputed terms
in the patents-in-suit. The court held a claim construction hearing by videoconference on October
23, 2020, and now addresses construction of the following disputed terms: "phase change
material"; "cell element"; "containment lattice member" / "lattice member"; "thermal contact"; and
"at elevated temperature" / "to a greater than ambient temperature." (Second Am. and Supp.
Joint Claim Construction Chart ("Second Cl. Constr. Chart") [120].) 2
BACKGROUND
A.

The Patented Inventions
The inventions disclosed in the '689, '944, and '474 Patents "relate[ ] generally to battery

power supply and, more particularly, to thermal management in such battery power supply
systems." ('689 Patent, Joint Appendix ("JA")-2 [69-2], col. 1, ll. 5–7; '944 Patent, JA-4 [69-4],

1] ¶¶ 3, 5; First Am. Compl. ¶ 2.) Both are professors at IIT. (First Am Compl. ¶ 2.) Al-Hallaj and
Selman are not themselves plaintiffs in this lawsuit.
In the Second Amended and Supplemental Joint Claim Construction Chart, the
parties informed the court that they resolved their disputes about the following terms: "thermal
management matrix," "carbon or graphite cloth matrix," "comprises graphite dispersed therein,"
"disposed at least in part in a heat conductive lattice member," "at least a portion of the supply of
phase change material disposed in a heat conductive lattice member," and "a polymer coating on
at least one surface." (See id. at PageID#: 4675.) The parties agree that these terms require no
construction. (See id. at PageID#: 4679.)
2

2

col. 1, ll. 15–17 (same); '474 Patent, JA-6 [69-6], col. 1, ll. 28–30 (same).) The Patents claim
battery power supply systems and/or methods of operating such systems. The specification for
the '689 Patent, which for most purposes is representative of the specifications for the '944 and
'474 Patents, explains that for some battery power supply systems, "a plurality of cells" is
"packag[ed] together . . . in a parallel or series configuration to form a battery module or
pack . . . ." ('689 Patent, col. 1, ll. 15–17.) Battery modules or packs are commonly used "as a
power supply for personal electronic devices such as cell phones, lap top computers, camcorders
or the like." (Id., col. 1, ll. 17–19.) New uses (such as for powering electric vehicles) are emerging,
as well. (See id., col. 1, ll. 20–30.) Thus, there is increasing demand for power supply systems
with improved thermal management. (Id., col. 2, ll. 18–28.)
The specification for the '689 Patent explains that "[d]uring operation and discharge, such
cells, battery modules or battery packs commonly produce or generate quantities of heat which
can significantly impact the performance resulting therefrom." (Id., col. 1, ll. 36–39.) For the cells,
modules, or packs to perform optimally, "it is generally important to maintain temperature of such
cells, battery module or battery packs within fairly narrow prescribed ranges." (Id., col. 1, ll. 39–
43.) The patented inventions address this issue. (See, e.g., id., col. 2, ll. 31–32 ("A general object
of the invention is to provide an improved power supply system and method of operation."); id.,
col. 2, ll. 43–46 ("The prior art generally fails to provide a power supply system and method of
operation which provides or results in thermal management which is either or both as effective
and efficient as may be desired.").)
1.

Method claims

The '689 and '944 Patents disclose methods of operating battery power supply systems.
Among other things, the methods use "phase change material" ("PCM"), one of the disputed claim
terms. Put simply, the PCM referenced in the asserted claims regulates temperature in battery
power supply systems by absorbing heat from discharging "cell elements" and later releasing heat
back into the cell elements. The claimed methods also disclose a subsequent discharge of cell
3

elements after they have absorbed heat from PCM. According to the '689 Patent specification,
keeping a battery "at a higher temperature than the surrounding temperature during relaxation"—
i.e, when it is not being used—can "increase the utilized capacity when the cell is then charged
or discharged." (See id., col. 6, ll. 27–36 (discussing one preferred embodiment).) Claim 1 of the
'689 Patent, an independent claim, recites:
A method of operating a power supply system, the method comprising:
discharging at least one cell element of a battery module to produce a quantity of
power and a quantity of heat,
absorbing at least a portion of the quantity of heat in a phase change material in
thermal contact with the discharging cell element,
following discharge, releasing at least a portion of the absorbed quantity of heat
from the phase change material to heat the at least one cell element, and
discharging the at least one cell element at elevated temperature.
(Id., col. 7, ll. 19–31.)
Claim 21 of the '944 Patent, also an independent claim, is similar. It recites:
A method of operating a power supply system, the method comprising:
discharging at least one cell element of a battery module to produce a quantity of
power and a quantity of heat,
absorbing at least a portion of the quantity of heat in a phase change material in
thermal contact with the discharging cell element with the phase change material
disposed in a plurality of openings in a heat conductive containment lattice
member,
following discharge, releasing at least a portion of the absorbed quantity of heat
from the phase change material to heat the at least one cell element to a greater
than ambient temperature, and
subsequently discharging the heated at least one cell element.
('944 Patent, col. 16 ll. 24–38).
Figure 1 of the '689 Patent, pictured below, "is a top view schematic of a battery module
incorporating a thermal management system in accordance with one embodiment of the
invention":
4

('689 Patent, fig.1 & col. 3, ll. 3–5.) 3 The number 10 identifies a battery module and the number
12 identifies a "cell package . . . composed of eight (8) cell elements." (Id., col. 3, ll. 35–37.) The
numbers 14, 16, 18, 20, 22, 24, 26, and 28 identify individual "cell elements." (See id.) There are
"void spaces," identified with the number 32, "between the various adjacent cell elements . . . of
the cell package." (Id., col. 3, ll. 49–52.) The PCM, identified with the number 34, fills those void
spaces "to facilitate desired thermal management . . . ." (Id., col. 3, ll. 54–59.) The PCM in the
figure "surrounds each of the cell elements" and "is in general thermal contact therewith." (Id.,
col. 3, ll. 60–62.)
2.

Power supply systems

In addition to disclosing methods, the '944 Patent discloses power supply systems.
Claim 1, an independent claim, recites:
A battery module comprising:
a housing;
a plurality of electrochemical cell elements contained within the housing, the
electrical cell elements capable of a heat-generating charge,
a supply of a phase change material also contained within the housing and in
thermal contact with at least one of the plurality of electrochemical cell elements
3

This figure also appears in the '944 and '474 Patents.
5

whereby the phase change material absorbs at least a portion of the heat
generated upon a charge or discharge of electric power from the at least one of
the plurality of electrochemical cell elements, the phase change material having a
thermal conductivity; and
a heat-conductive containment lattice member also contained within the housing,
the containment lattice member having a plurality of openings wherein at least a
portion of the supply of the phase change material is disposed.
('944 Patent, col. 15, ll. 20–38.)
Similarly, the '474 Patent claims various battery systems. Claim 1, an independent claim,
recites:
A battery system comprising:
an electrochemical cell array comprising a plurality of electrochemical cell
elements and
a thermal management matrix at least in part enveloping the electrochemical cell
array and in thermal contact therewith, the thermal management matrix comprising
a supply of phase change material disposed at least in part in a heat conductive
lattice member, the thermal management matrix dissipating at least a portion of
heat generated upon activation of at least a portion of the electrochemical cell array
enveloped by the thermal management matrix.
('474 Patent, col. 19, ll. 5–16.)
Claim 11, another independent claim, recites:
A thermally managed lithium-based battery system, the system comprising:
an electrochemical cell array
electrochemical cell elements and

comprising

a

plurality

of

lithium-based

a thermal management matrix at least in part in thermal contact with at least one
of the lithium-based electrochemical cell elements of the electrochemical cell array,
thermal management matrix comprising a supply of phase change material, at
least a portion of the supply of phase change material disposed in a heat
conductive lattice member.
('474 Patent, col. 19, l. 40–col. 20, ll. 1–5.)
3.

The '941 Patent

The '941 Patent is not in the same family as the other patents-in-suit but it, too, relates to
thermal management in battery systems. (See '941 Patent, JA-8 [69-8], col. 1, ll. 8–9.) Relevant
here, the '941 Patent discloses a "thermal management composite" consisting of a polymer6

coated carbon or graphite "matrix," which itself contains PCM. (See id., col. 11, ll. 30–37.)
According to the specification, "[t]he percentage weight of the PCM" in the composite can vary,
but "is between 30 to 80% . . . ." (Id., col. 3, ll. 47–48; col. 6, ll. 20–28.) "An object of the invention
is to improve flexibility and/or compressibility in PCM composites." (Id., col. 1, ll. 52–53.) Those
improvements enable the composites to "withstand higher mechanical stresses without breaking
apart or losing thermal contact with" cells, which in turn improves thermal management. (See,
e.g., id., col. 3, ll. 11–18.) Claim 1, an independent claim, recites:
A thermal management composite, comprising:
a carbon or graphite cloth matrix including knitted or woven carbon or graphite
fibers;
a phase change material disposed in voids between the fibers or bundles of the
fibers; and
a polymer coating on at least one surface of the composite, wherein the polymer
coating comprises graphite dispersed therein.
(Id., col. 11, ll. 30–37.)
Claim 13, another independent claim, recites:
A thermal management composite, comprising:
a flexible carbon or graphite cloth matrix of carbon or graphite fibers, wherein the
cloth is knitted or woven from the carbon or graphite fibers or bundles of the carbon
or graphite fibers; and
a phase change material disposed in voids between the fibers or the bundles of
the fibers; and a polymer coating on at least one surface of the composite, wherein
the polymer coating comprises graphite dispersed therein.
(Id., col. 12, ll. 28–37.) 4
B.

Prosecution History
The '689 Patent issued from U.S. Patent Application No. 09/515,268 (the "'268

Application"), which was filed on February 29, 2000. ('689 Patent at Cover.) The '268 Application
All Cell asserts additional claims from all four patents-in-suit that depend from the
independent claims discussed in this section of the opinion.
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originally recited the following independent method claim (labeled then as Claim 7):
A method of operating a power supply system, the method comprising:
discharging at least one cell element to produce a quantity of power and a quantity
of heat,
absorbing at least a portion of the quantity of heat in a phase change material in
thermal contact with the discharging cell element, and
subsequently releasing at least a portion of the absorbed quantity of heat from the
phase change material to heat the at least one cell element.
('268 Application, JA-1 [69-1] at 26.) In an Office Action dated July 31, 2001, the Patent Examiner
rejected the claim under 35 U.S.C. § 102(b) as anticipated by prior art: GB 2,289,976, a patent
issued in the United Kingdom (the "Bourne Patent"). (See July 31, 2001 Office Action, JA-1 at
56–57.) In response, the applicant amended the second clause of the claim to include "of a
battery module," such that the clause read, "discharging at least one cell element of a battery
module to produce a quantity of power and a quantity of heat."

(Oct. 17, 2001 Proposed

Amendment, JA-1 at 66 (emphasis added).) The Patent Examiner again rejected the claim,
determining that although the amendment overcame rejection for anticipation by the Bourne
Patent, the claim nonetheless was anticipated by U.S. Patent No. 4,883,726 (the "Peled Patent").
(See Apr. 3, 2002 Office Action, JA-1 at 155.)
The applicant amended the claim again. (See May 23, 2002 Proposed Amendment, JA1 at 171.) The second amended version is identical to what is now Claim 1 of the '689 Patent.
(See id.) On June 4, 2002, the Patent Examiner allowed the claim, stating, in relevant part: "The
prior art does not teach such a method wherein heat is stored in a phase-change material for a
period of time followed by reheating the same element for further discharge at an elevated
temperature." (June 4, 2002 Office Action, JA-1 at 175 (emphasis added).) The Patent Examiner
also stated:
It is noted that specific phase-change materials are disclosed in the instant
specification. These materials are shown to change phase during the discharge
of a battery element. Although any material may be considered a phase change
material at high temperatures (such as nickel battery casing), it is clear from the
8

applicant's specification that a [sic] phase-change materials are shown to be
materials which change phase at battery discharge temperatures, approximately
30-60° C as noted on page 10 of the specification. As such, a specific phasechange material is necessary for the method as compared to the simple discharge
of heat into the surrounding environment such as a casing.
(Id. at 176 (emphasis added).) Also relevant here, the Examiner distinguished the method
claimed in the '268 Application from the method disclosed in the Bourne Patent on the basis that
the cell elements in Bourne "are enclosed in . . . monoblocks and are not in contact with the
phase-change materials." (Id.) The '689 Patent issued on October 22, 2002. (See '689 Patent
at Cover.) The '944 Patent and the '474 Patent issued in September 2005 and September 2012,
respectively, from applications that were continuations-in-part of the '268 Application. (See '944
Patent at Cover; '474 Patent at Cover.) The '941 Patent, which issued in June 2018, is in a
different family of patents. (See '941 Patent at Cover.)
DISCUSSION
A patent's claims define the scope of the invention to which the patentee may exercise his
right of exclusivity. Phillips v. AWH Corp., 415 F.3d 1303, 1312 (Fed. Cir. 2005). Where the
meaning of a claim is disputed, the court must determine its proper construction as a matter of
law. Markman v. Westview Instruments, Inc., 517 U.S. 370, 391 (1996). In construing a claim
term, the court "look[s] to the words of the claim itself." Power Integrations, Inc. v. Fairchild
Semiconductor Int'l, Inc., 711 F.3d 1348, 1361 (Fed. Cir. 2013). The court generally should give
claim terms their "ordinary and customary meaning," which is "the meaning that the term would
have to a person of ordinary skill in the art in question at the time of the invention." Phillips, 415
F.3d at 1312–13 (internal quotation marks omitted). "[T]he person of ordinary skill in the art is
deemed to read the claim term not only in the context of the particular claim in which the disputed
term appears, but in the context of the entire patent, including the specification." Id. at 1313.
Sometimes, a term's ordinary meaning as understood by a person of ordinary skill in the
art ("POSITA") is equally apparent to a lay person. See id. at 1314. In that circumstance, claim
construction entails "little more than the application of the widely accepted meaning of commonly
9

understood words." Id. "[G]eneral purpose dictionaries may be helpful" for that exercise. Id. If
a claim term "does not have an ordinary meaning, and its meaning is not clear from a plain reading
of the claim," the court should look to other sources of intrinsic evidence for guidance. Power
Integrations, 711 F.3d at 1361; see also Phillips, 415 F.3d at 1314–19. The patent's specification
"is the single best guide to the meaning of a disputed term." Power Integrations, 711 F.3d at 1361
(quoting Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1582 (Fed. Cir. 1996)); see also
Phillips, 415 F.3d at 1315. The specification must include a "full, clear, concise, and exact"
description of the claimed invention. Phillips, 415 F.3d at 1316 (quoting 35 U.S.C. § 112). If the
specification reveals that the inventor has given a claim term a "special definition" that "differs
from the meaning it would otherwise possess," the "inventor's lexicography governs." Phillips,
415 F.3d at 1316. The same is true if the specification shows that the inventor has limited the
scope of the term. See id. Often, the specification "describes very specific embodiments of the
invention." Id. at 1323. But the Federal Circuit has "repeatedly warned against confining the
claims to those embodiments." Id.
The prosecution history is another helpful source of intrinsic evidence. See id. at 1317.
The prosecution history "consists of the complete record of the proceedings before the PTO
[Patent and Trademark Office] and includes the prior art cited during the examination of the
patent." Id. Because the prosecution history "represents an ongoing negotiation between the
PTO and the applicant," however, "it often lacks the clarity of the specification and thus is less
useful for claim construction purposes." Id. Finally, in some circumstances the court is permitted
to consider extrinsic evidence, so long as it is not used to contradict claim language that is
"unambiguous in light of the intrinsic evidence." Id. 1324; see also id. at 1318–19; Vitronics Corp.,
90 F.3d at 1583 (similar). Extrinsic evidence, which can include expert and inventor testimony,
technical dictionaries, and treatises, is generally thought "less reliable than the patent and its
prosecution history in determining how to read claim terms." Phillips, 415 F.3d at 1317, 1318.
"A patent's specification must 'conclude with one or more claims particularly pointing out
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and distinctly claiming the subject matter which the applicant regards as [the] invention.'" Teva
Pharm., USA, Inc. v. Sandoz, Inc., 789 F.3d 1335, 1340 (Fed. Cir. 2015) (quoting 35
U.S.C. § 112). "Section 112's definiteness requirement must take into account the inherent
limitations of language," but a patent nevertheless "must be precise enough to afford clear notice
of what is claimed . . . ." Nautilus, Inc. v. Biosig Instruments, Inc., 572 U.S. 898, 909 (2014). An
indefiniteness analysis is "inextricably intertwined with claim construction." Cox Commc'ns, Inc.
v. Sprint Commc'n Co., 838 F.3d 1224, 1232 (Fed. Cir. 2016) (quoting Atmel Corp. v. Info. Storage
Devices, Inc., 198 F.3d 1374, 1379 (Fed. Cir. 1999)). Thus, "if a person of ordinary skill in the art
cannot discern the scope of a claim with reasonable certainty, it may be because one or several
claim terms cannot be reliably construed." Cox, 838 F.3d at 1232. "[T]he dispositive question in
an indefiniteness inquiry," however, "is whether the 'claims,' not particular claim terms, 'read in
light of the specification delineating the patent, and the prosecution history, fail to inform, with
reasonable certainty, those skilled in the art about the scope of the invention.'" Id. at 1231
(emphasis added) (quoting Nautilus, 572 U.S. at 901). "Indefiniteness must be proven by clear
and convincing evidence." Sonix Tech. Co. v. Publ’ns Int'l, Ltd., 844 F.3d 1370, 1377 (Fed. Cir.
2017).
A.

"Phase change material"

Claim Term
"phase change material"
['689 Patent, Claims 1, 5;
'944 Patent, Claims 1, 3, 21,
22; '474 Patent, Claims 1, 11;
'941 Patent, Claims 1, 13]

Plaintiffs' Proposed
Construction
"a material having a melting
point in the range of between
about 30° C and 60° C"

Defendants' Proposed
Construction
No construction (plain and
ordinary meaning)

All Cell contends that the term "phase change material" should be construed as "a material
having a melting point in the range of between about 30° C and 60° C." (Second Cl. Constr. Chart
at 4.) Chervon maintains that the term needs no construction. (Id.) In support of its position, All
Cell emphasizes that the Patent Examiner offered a nearly identical description of PCM in the
notice of allowance for the method claim in the '268 Application. (See All Cell Responsive Claim
11

Construction Br. ("All Cell Br.") [75] at 4; June 4, 2002 Office Action, JA-1 at 176 ("[I]t is clear from
the applicant's specification that a [sic] phase-change materials are shown to be materials which
change phase at battery discharge temperatures, approximately 30-60° C as noted on page 10
of the specification."). For the reasons discussed here, the court agrees with All Cell that the term
"PCM" requires construction but declines to adopt All Cell's proposal. Instead, the court construes
"PCM" as "a material that changes phase at battery discharge temperatures."
The asserted method claims of the patents-in-suit describe how PCM functions: it absorbs
heat from a discharging cell element of a battery and later releases heat back to the cell element.
(See, e.g., '689 Patent, col. 7, ll. 23–38 (Claim 1) (disclosing a method that comprises, in part,
"absorbing at least a portion of the quantity of heat in a phase change material in thermal contact
with the discharging cell element" and "following discharge, releasing at least a portion of the
absorbed quantity of heat from the phase change material to heat the at least one cell element");
'944 Patent, col. 16, ll. 28–36 (Claim 21) (similar).) Claim 22 of the '944 Patent, moreover,
discloses the method recited in Claim 21 and further specifies that the PCM "changes from a solid
phase to a liquid phase during the absorbing step and from a liquid phase to a solid phase during
the releasing step." ('944 Patent, col. 16, ll. 40–42.) Other asserted claims disclose the location
of PCM within a battery system, module, or composite. (See, e.g., '474 Patent, col. 19, ll. 11–12
(Claim 1) (disclosing a battery system wherein a PCM is "disposed at least in part in a heat
conductive lattice member"); '941 Patent, col. 11, ll. 30–34 (Claim 1) (disclosing a "thermal
management composite" wherein a PCM is "disposed in voids between the fibers or bundles of
the fibers").) And some of the asserted claims provide examples of materials that can serve as
PCMs. (See '474 Patent, col. 19, ll. 34–35 (Claim 8) ("paraffin wax"); '941 Patent, col. 11, ll. 43–
44 (Claim 4) ("wax"); '941 Patent, col. 12, ll. 3–4 (Claim 6) ("microencapsulated wax").) None of
the asserted claims defines the melting point of a PCM.
The specifications of the '689, '944, and '474 Patents provide more information in that
regard. As both sides note, the specifications discuss "[v]arious phase change materials" that
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"can suitably be used in the practice" of the invention as well as their melting points. (See, e.g.,
'689 Patent, col. 4, ll. 17–21.) For example, the specification for the '689 Patent states that a
suitable PCM "for use in Li-ion [Lithium-ion] battery applications" "desirably will have a melting
point in the range of between about 30° C and 60° C . . . ." (Id., col. 4, ll. 19–21.) 5 According to
the specification, PCM suitable for this use is often made of wax. (See id., col. 4, ll. 27–32; see
also '474 Patent, col. 17, ll. 34–36 (stating that "paraffin waxes are preferred phase change
materials for particular applications in conjunction with Lithium-ion cells").) The '689 specification
also explains that "mixtures of chlorobenzene and bromobenzene may be suitable for particular
applications such as involving precise temperature control between 30° C to about 45° C." ('689
Patent, col. 4, ll. 37–40.) The specification further states that for purposes of the claimed
invention, suitable PCMs "may include stearic acid which has a melting point of about 70°, and
various commercially available esters of stearic acid with methyl, propyl and butyl alcohols, having
melting points in the range of about 17° C to about 34° C." (Id., col. 4, ll. 41–46.) Each of these
examples of suitable PCMs also appears on page 10 of the '268 Application, which the Patent
Examiner cited in describing the meaning of a PCM for purposes of the claimed invention. (See
'268 Application, JA-1 at 17; June 4, 2002 Office Action, JA-1 at 176.)
To summarize, the asserted claims and specifications teach that a PCM can be made of
various materials depending on the application of the invention. Further, it is apparent from the
specifications that a PCM can have a range of melting points. The examples of PCMs discussed
in the specifications have melting points between 17° C and 70° C. This means, according to
Chervon, that a POSITA would understand the plain and ordinary meaning of PCM to be "a
material that changes phase within a reasonable temperature range and under an appropriate set

The patents-in-suit do not define a Lithium-ion battery. One everyday definition is
"a rechargeable battery that uses lithium ions as the primary component of its electrolyte." Lithium
ion
battery,
Merriam-Webster.com,
https://www.merriam-webster.com/dictionary/lithiumion%20battery (last visited July 13, 2021).
5

13

of constraints" and, therefore, shows that no construction is required. (Chervon Br. at 5.) All Cell
responds that the term requires construction because "every material at a high enough, or low
enough, temperature will undergo a phase change between one of the three common states of
matter." (All Cell Br. at 3.) This concern is, in the court's view, a valid one, and PCM is not an
everyday term. The court therefore agrees that the term requires construction.
The court does not agree, however, that PCM is defined as material that has "a melting
point in the range of between about 30° C and 60° C." By so defining a PCM, All Cell imports a
limitation from one embodiment of the invention—specifically an embodiment used for Lithiumion battery applications. (See, e.g., 689 Patent, col. 4, ll. 18–29; '474 Patent, col. 6, ll. 56–59.) It
is improper to "confin[e] the claims" to particular embodiments discussed in the specification,
however. Phillips, 415 F.3d at 1323. More importantly, by importing this limitation, All Cell reads
out disclosed embodiments of the claimed invention. The specifications of the patents-in-suit
teach that stearic acid having a melting point of 70° C, and esters of stearic acid having melting
points of about 17° C to about 34° C, are suitable for the claimed invention. (See, e.g., '689
Patent, col. 4, ll. 41–46.) Any suggestion that 17° C is "about" 30° C or that 70° C is "about" 60° C
defies common sense. Even named inventor Al-Hallaj agreed during his deposition for this case
that those temperatures are outside the range of 30° C to 60° C. (See Al-Hallaj Dep., Ex. 19 to
Chervon Reply Claim Construction Br. [79-1] at 61:15–17, 79:1–3.)) A definition of a claim term
that leaves "a preferred . . . embodiment" outside the scope of the patent claims—as All Cell's
does—"is rarely, if ever, correct . . . ." Vitronics Corp., 90 F.3d at 1583; see also, e.g., Mattox v.
Infotopia, Inc., 136 F. App'x 366, 368 (Fed. Cir. 2005) ("Absent statements in the intrinsic record
to the contrary, where claim language is plainly susceptible to an interpretation that includes the
described embodiments, that interpretation is the better interpretation.") (citing Vitronics Corp., 90
F.3d at 1583).
All Cell responds that a POSITA reading the patents would recognize that the "reasonable
temperature range" for a suitable PCM's melting point is between about 30° C and 60° C. (All
14

Cell Br. at 4.) In support, it cites the declaration of Al-Hallaj, in which Al-Hallaj offers several
reasons why the asserted claims purportedly contemplate a PCM having a melting point in that
range. (See id. (citing Al-Hallaj Decl. ¶¶ 10–16).) First, Al-Hallaj states that the patents discuss
batteries constructed from Lithium-ion cells, which generally operate between 20° to 55° C. (AlHallaj Decl. ¶ 12.) But as Chervon emphasizes, it is undisputed that the asserted claims are not
limited to Lithium-ion battery applications. (See, e.g., Chervon Reply Claim Construction Br.
("Chervon Reply") [79] at 3–4 (emphasizing that Claims 8 and 9 of the '689 Patent recite methods
used with lithium cells and fuel cell batteries, respectively).) Thus, the patents' references to
Lithium-ion batteries do not, on their own, justify construing "PCM" as having a melting point in a
range only appropriate for Lithium-ion applications.
Al-Hallaj also states that a PCM should remain solid (that is, should not melt) at room
temperature (which is about 20° C) so that it "is in solid form when the electrochemical cell begins
to produce heat."

(Al-Hallaj Decl. ¶¶ 13–14.)

In addition, he states that a POSITA would

recognize that a PCM "needs to be below the temperature where significant damage occurs to
the cells." (Id. ¶ 15.) Importantly, however, according to the specifications, PCMs having melting
points well outside of the 30° C-to-60° C range can be used to practice the invention. Al-Hallaj's
declaration thus does not remedy the flaws in All Cell's proposed construction: it imports a
limitation from a preferred embodiment and reads out other disclosed embodiments. Nor does
All Cell overcome these flaws by suggesting that a POSITA would recognize that certain forms of
stearic acid have melting points at approximately 55.1° C or 60° C, rather than at 70° C. (See All
Cell Br. at 5–6.) Even if some forms of stearic acid have lower melting points, the specifications
unequivocally teach that stearic acid with a melting point at 70° C is a suitable PCM. All Cell's
proposed construction would put an application that uses the latter form of stearic acid outside
the scope of the claims.
All Cell's argument that its proposed construction finds support in the Patent Examiner's
statement of allowance is also unavailing. (See All Cell Br. at 4.) The Examiner—citing a page
15

of the '268 Application that disclosed the same examples of suitable PCMs that appear in the
'689, '944, and '474 Patents—stated that PCMs "are shown to be materials which change phase
at battery discharge temperatures, approximately 30-60° C." (June 4, 2002 Office Action, JA-1
at 176; '268 Application at JA-17.) Prosecution history can inform the meaning of a claim term,
but the court agrees with Chervon that in this case, the Examiner's statement cannot properly be
used to impose a proposed temperature range into the definition of "PCM". Prosecution history
"cannot be used to limit the scope of a claim unless the applicant took a position before the PTO
that would lead a competitor to believe that the applicant had disavowed coverage of the relevant
subject matter." Schwing GmbH v. Putzmeister Aktiengesellschaft, 305 F.3d 1318, 1324 (Fed.
Cir. 2002); see Chervon Br. at 8 n.2 (citing same). All Cell does not argue that during prosecution,
it represented that a PCM must have a melting point in the range of approximately 30° C to 60° C
or otherwise disavowed coverage of material with melting points outside that range. To the
contrary, All Cell explicitly disclosed examples of suitable PCMs having melting points at 17° C
and 70° C. All Cell urges that it cites the Examiner's statement not for disclaimer-related purposes
but rather to assist with claim construction. (See All Cell Br. at 5.) It also argues that, because
the Examiner has expertise in the relevant technical area, the court should defer to his
interpretation of the claim language. (See id. (citing Dickinson v. Zurko, 527 U.S. 150, 160 (1999)
("PTO is an expert body" whose factfinding "deserves deference" from the courts).) These
arguments sidestep the evidence that when applying for its patent, All Cell represented that PCMs
can have melting points outside the range of 30° to 60° C. Regardless of the Examiner's
expertise, adopting the temperature range the Examiner mentioned would, in this instance,
improperly limit the meaning of "PCM" in a manner that All Cell did not press during prosecution.
For these reasons, the court rejects All Cell's proposed construction of the term "PCM."
The more appropriate construction of this term is simpler: "a material that changes phase at
battery discharge temperatures." This construction reflects the function of a PCM as disclosed in
the claims and described in the specifications: a material that absorbs heat from a discharging
16

cell element of a battery and later releases heat back to the cell element. In addition, it is
consistent with the specifications' clear instruction that a PCM can be made of various materials
and can have a wide range of melting points, depending on the application. Finally, the asserted
claims are directed toward improving thermal management in batteries. The reference to "battery
discharge temperatures" in the court's construction places a context-appropriate limitation on the
range of melting points for a suitable PCM without improperly limiting the term to specific
embodiments. 6
B.

"Cell element"

Claim Term
"cell element" ['689 Patent,
Claims 1, 5, 8; '944 Patent,
Claims 1, 16, 21; '474 Patent,
Claims 1, 2, 3, 11, 12]

Plaintiffs' Proposed
Construction
"a galvanic structure
enclosing only one cathodeanode pair"

Defendant's Proposed
Construction
No construction (plain and
ordinary meaning)

As it did with the PCM term, Chervon contends that the term "cell element" requires no
construction and should be given its plain and ordinary meaning. (Second Cl. Constr. Chart at
4.) According to Chervon, the asserted claims of the '689, '944, and '474 Patents make clear that
a "'cell element' is a cell element in a battery (in some claims, one of a plurality of cell elements)
that can be discharged." (Chervon Br. at 9.) By contrast, All Cell argues that the court should
construe the term to mean "a galvanic structure enclosing only one cathode-anode pair." (Second
Cl. Constr. Chart at 4; see All Cell Br. at 10.) Here, the court concludes Chervon has the stronger
position.
Claim 1 of the '689 Patent and Claim 21 of the '944 Patent disclose methods that involve
"discharging at least one cell element of a battery module to produce a quantity of power and a

Given this conclusion, the court need not address Chervon's arguments that prior
art and other extrinsic evidence disclose PCMs having an even wider range of melting points than
those disclosed in the patents-in-suit. (See Chervon Br. at 6–8 (discussing, inter alia, the PCMs
disclosed in the Peled Patent).) Similarly, the court will not address Chervon's argument that the
word "about" in All Cell's proposed construction renders the term indefinite. (Id. at 8–9.)
6

17

quantity of heat . . . ." ('689 Patent, col. 7, ll. 21–22; see also '944 Patent, col. 16, ll. 26-27
(Claim 21) (same).) The '944 Patent also discloses battery modules that comprise, among other
things, "electrochemical cell elements" that are "capable of a heat-generating charge" and
"electrochemical cell elements" that generate heat "upon a charge or discharge of electric
power . . . ." ('944 Patent, col. 15, ll. 23–25, 30–32) (Claim 1). The '474 Patent similarly discloses
a battery system that contains "an electrochemical cell array comprising a plurality of
electrochemical cell elements" that can generate heat "upon activation . . . ." ('474 Patent, col.
19, ll. 6–7, 13–15) (Claim 1).) And the '474 Patent discloses a "thermally managed lithium-based
battery system" that contains "an electrochemical cell array comprising a plurality of lithium-based
electrochemical elements." (Id. col. 19, ll. 40–43 (Claim 11)). None of these claims expressly
defines a "cell element."
The specifications do not incorporate a definition, either.

For example, the '689

specification states that the "general object of the invention can be attained, at least in part,
through a power supply system which includes at least one cell element capable of a heatgenerating charge or discharge of electric power . . . ." ('689 Patent, col. 2, ll. 34–37.) It also
explains that "cell elements" can heat or cool more easily based on their location in a "cell pack
configuration." (Id., col. 1, ll. 51–57.) And the specification includes the following figures, which
illustrate a single cell element used in a battery module (figure 2) and multiple cell elements used
in a battery module (figure 3):

18

(See, e.g., id., col. 3, ll. 5–8 & figs. 2 & 3.) 7 These figures, however, are just examples; they do
not define the shape or composition of every cell element that could be suitable to practice the
invention. Indeed, as Chervon points out, the patent specifications instruct that figures 2 and 3
do not limit the scope of the term. (See, e.g., id., col. 3, ll. 39–45 (stating that although the
"cylindrical shape" of the cell elements in the figures "are common and well known, the broader
practice of the invention is not necessarily so limited as cell elements having other desired shapes
or sizes can, if desired, be used alone or in combination"); see also '944 Patent, col. 8, ll. 14–19
("Those skilled in the art" will "appreciate that the broader practice of the invention is not
necessarily limited by the size, shape, number, form or type of cell elements or the fashion or
technique by which two or more of such elements or module units may be joined or connected.");
'474 Patent, col. 9, ll. 62–67 (same); Oct. 23, 2020 Hr'g Tr. [122] at 58:13–15 (Counsel for
Chervon) ("[T]he specifications in the patents-in-suit recognize that there is a broad range of
accessible cell elements that could be used for the patented invention.").)
The asserted claims and patent specifications thus do not expressly define "cell element,"
but use the term in the context of battery systems, battery modules, and methods of operating
battery power supply systems. Additionally, the '268 applicant overcame rejection for anticipation
7

These figures also appear in the '944 and '474 Patents.
19

by the Bourne Patent by specifying that a cell element is a "cell element of a battery module."
(Oct. 17, 2001 Proposed Amendment, JA-1 at 66 (emphasis added); see Apr. 3, 2002 Office
Action, JA-1 at 155.) It is apparent, from this intrinsic evidence, that a cell element is a battery
cell. During the claim construction hearing, both sides made statements to this effect. (See Oct.
23, 2020 Hr'g Tr. at 56:3–5 (Counsel for Chervon) ("[B]attery cell is a perfectly acceptable
definition of what the plain and ordinary meaning of a 'cell element' is."); id. at 11:8–9 (Counsel
for All Cell) (referring to "battery cells" as "cell elements").) It is also apparent from the claim
language that a cell element is capable of discharge. The claim language, specification, and
prosecution history do not further limit the definition of the term. The court agrees with Chervon
that a POSITA reading the '689, '944, and '474 Patents would understand that "cell element"
means a battery cell capable of discharge. The term requires no construction.
Indeed, All Cell's proposed construction improperly narrows the meaning of the term.
First, the claims and specifications do not use the word "galvanic." During the claim construction
hearing, All Cell defined galvanic as "an electrochemical structure that generates electricity using
a single cathode-anode pair, a positive and a negative." (Oct. 23, 2020 Hr'g Tr. at 54:2–6.) Thus,
All Cell's proposed use of the word galvanic overlaps with its argument that a cell element
encloses only one cathode-anode pair. But the patents do not state that a cell element must have
only one cathode-anode pair; they do not refer to a cathode-anode pair at all. And although All
Cell argues that figures 2 and 3 in the patents depict cell elements having only one cathodeanode pair, the specifications make clear that a cell element need not have the characteristics of
those depicted in the figures. Therefore, defining "cell element" as galvanic and as having only
one cathode-anode pair is inconsistent with the intrinsic evidence.
Moreover, it is not at all clear to the court that a POSITA would understand "cell element"
to exclude the "pile-type bipolar electrode modules" disclosed in U.S. Patent No. 4,022,952 (the
"Fritts Patent"). (All Cell Br. at 10.) All Cell suggests that the modules disclosed in the Fritts
Patent cannot be cell elements because they are not cylindrical, "are not divisible," and "share a
20

common electrolyte." (See id.; see also Al-Hallaj Decl. ¶¶ 27-29 (offering similar analysis).) But
as already explained, the specifications of the asserted patents foreclose this argument; they
state that the claimed invention "is not necessarily limited by the size, shape, number, form or"
even "type of cell elements . . . ." ('944 Patent, col. 8, ll. 14–17 (emphasis added); '474 Patent,
col. 9, ll. 62–65 (same); see also '689 Patent, col. 3, ll. 39–45 (similar).). The court concludes that
by reading the claim language and specifications of the '689, '944, and '474 Patents, a POSITA
would understand "cell element" to mean a battery cell capable of discharge. The term, therefore,
needs no construction.
C.

"Containment lattice member" / "Lattice member"

Claim Term
"containment lattice member"
/ "lattice member" ['944
Patent, Claims 1, 3, 4, 5, 21;
'474 Patent, Claims 1, 11, 13]

Plaintiffs' Proposed
Construction
No construction (plain and
ordinary meaning)

Defendant's Proposed
Construction
"a framework structure that
contains and conducts heat" 8

All Cell contends that the terms "containment lattice member" and "lattice member" need
no construction. (Second Cl. Constr. Chart at 4.) Before the claim construction hearing, Chervon
maintained that both terms should be construed as "a framework structure that contains and
conducts heat." (Id.) At the hearing, Chervon agreed that "contains and conducts heat" can be
eliminated from its proposed construction.

(See Oct. 23, 2020 Hr'g Tr. at 74:18–19.)

It

represented that the only remaining dispute is whether "containment lattice member" (or "lattice
member") is a framework (see id. at 61:19–20), and suggested that the words "arrangement" or
"configuration" could be used instead of framework. (See id. at 65:2–5 (Counsel for Chervon)
("So long as there is some type of structure, arrangement, configuration, framework, that's the
crux of our argument.

We think there needs to be something like that in the court's

The parties' claim construction briefing addressed a proposed construction that
Chervon has now abandoned: "a structure made up of intersecting strips that contains and
conducts heat." (Chervon Br. at 10.) The court here relies on the arguments the parties made at
the claim construction hearing.
8

21

construction.").) Finally, Chervon stated that it has "no problem if the court feels it's necessary to
add" that the framework "could be uniform or nonuniform." (Id. at 74:21–23.) With the parties'
positions in mind, the court turns to the intrinsic evidence.
All Cell maintains that a POSITA would understand the meaning of the disputed terms by
reading the asserted claims. (See, e.g., id. at 70:8–10 (Counsel for All Cell) ("Claim 1 [of the '944
Patent] by itself recites sufficient structure of a 'lattice member' to a person of ordinary skill in the
art . . . .").) The court disagrees that the asserted claims by themselves establish this term's
meaning.

Claim 1 of the '944 Patent discloses a battery module comprised, in part, of a

"containment lattice member having a plurality of openings wherein at least a portion of the supply
of the phase change material is disposed." ('944 Patent, col. 15, ll. 35–38.) Claim 1 of the '474
Patent recites "a supply of phase change material disposed at least in part in a heat conductive
lattice member . . . ." ('474 Patent, col. 19, ll. 10–12; see also id., col. 20, ll. 2–5 (Claim 11)
(similar).) Several asserted dependent claims give examples of materials that a "lattice member"
can be made of. (See '944 Patent, col. 15, ll. 53–54 (Claim 5) ("graphite"); id., col. 16, ll. 3–4
(Claim 12) ("foam"); id., col. 16, ll. 5–6 (Claim 13) ("screen").) These claims make clear that a
"containment lattice member" or "lattice member" can hold a PCM and can be made of various
materials, but they do not clarify the meaning of "lattice."
The specifications of the '944 and '474 Patents state that "[t]he heat conductive
containment lattice member . . . is perhaps best viewed making reference to FIG. 11." ('944
Patent, col. 9, ll. 12–14; '474 Patent, col. 10, ll. 57–59.) Figure 11 is reproduced here:

22

('944 Patent, fig. 11.)
The specifications explain that in figure 11, containment lattice member is identified with
the number 164. (See id., col. 9, l. 15.) They describe the containment lattice member using
language very similar to that in the asserted claims. (See, e.g., id., col. 9, ll. 15–29 (stating that
a containment lattice member "desirably includes a plurality of openings or pores"; that PCM can
be disposed in the openings or pores; that a containment lattice member is "desirably formed of
a heat-conductive material"; and that for practicing the claimed invention, preferred materials for
a containment lattice member include "various screen and foam materials such as graphite
foam"); see also id., col. 10, ll. 5–13 (noting that a suitable containment lattice member can range
in "porosity or open volume").) The containment lattice member illustrated in figure 11 appears
to have a crosshatch structure, but the figure illustrates just one embodiment of the claimed
invention. By stating that a containment lattice member "desirably includes a plurality of openings
or pores" ('944 Patent, col. 9, ll. 15–16)—rather than describing it more specifically as having
openings in a crosshatch or intersecting pattern—the specifications indicate that not every

23

containment lattice member will have a crosshatch or even a uniform structure. By contrast,
several dictionary definitions of the term "lattice" reference crisscrossed or intersecting structures.
(See, e.g., Lattice, MCGRAW-HILL DICTIONARY OF SCI. & TECHNICAL TERMS (6th ed. 2003), Ex. 10
to Chervon Br. [70-10] at CHER0004728) (defining "lattice" as "[a] network of crisscrossed strips
of metal or wood") (first definition listed).) The court, therefore, agrees with Chervon that the word
"lattice" has a special meaning in the asserted patents, and that the terms "containment lattice
member" and "lattice member" require construction.
The court construes each term as "a structure having an arrangement of pores or
openings, uniform or non-uniform." Use of the words "uniform or non-uniform" in the construction
not only aligns with the intrinsic evidence, but also resolves All Cell's objection to Chervon's
proposed use of the word "framework." (See, e.g., Oct. 23, 2020 Hr'g Tr. at 66:9–10 (Counsel for
All Cell) ("The problem with 'framework' is, they are looking for uniformed structure, but that is not
what is required.").)
D.

"Thermal contact"

Claim Term
"thermal contact" ['689
Patent, Claim 1; '944 Patent,
Claim 1; '474 Patent, Claims
1, 11]

Plaintiffs' Proposed
Construction
"in direct or nearly direct
thermal contact"

Defendants' Proposed
Construction
Indefinite under 35
U.S.C. § 112

All Cell proposes construing the term "thermal contact" as "in direct or nearly direct thermal
contact." (Second Cl. Constr. Chart at 4.) Chervon maintains that the term is indefinite, primarily
because it is unclear whether "two objects [can] be in thermal contact if they are separated from
each other." (Oct. 23, 2020 Hr'g Tr. at 77:7–9; see also Chervon Br. at 21 (arguing that All Cell's
proposed use of "nearly direct" exacerbates that problem).) For the following reasons, the court
concludes that the term is not indefinite but rejects All Cell's proposed construction.
Claim 1 of the '689 Patent and Claim 1 of the '944 Patent disclose PCM "in thermal contact
with" one or more cell elements. ('689 Patent, col. 7, ll. 24–25; '944 Patent, col. 15, ll. 26–28.)
24

Claims 1 and 11 of the '474 Patent disclose a "thermal management matrix" "in thermal contact"
with an "electrochemical cell array" or with one or more "electrochemical cell elements" of the
array. ('474 Patent, col. 19, ll. 8–10; id., col. 19, l. 44–col. 20, l.1.) Most of the references to
"thermal contact" in the patent specifications mirror this claim language. (See, e.g., '689 Patent,
col. 2, ll. 38–39; '944 Patent, col. 3, ll. 24–26; '474 Patent, col. 4, ll. 43–46.) Other references to
"thermal contact" in the specifications speak of "general thermal contact." (See, e.g., '689 Patent,
col. 3, ll. 59–62 (stating that in the battery module illustrated in figure 1, "the phase change
material . . . surrounds each of the cell elements . . . and is in general thermal contact therewith");
'944 Patent, col. 4, ll. 55–58 (same); '474 Patent, col. 10, ll. 13–15 (stating that in some
embodiments, the PCM "desirably surrounds and is in general thermal contact with the cell
elements").) Neither the claim language nor the patent specifications expressly define "thermal
contact."
As noted, Chervon argues that the term is indefinite because it fails to explain whether
objects must be touching to be in thermal contact. Chervon also argues that a POSITA reading
the patents would have no idea how much heat exchange between objects must be possible for
them to be in thermal contact. (See, e.g., Chervon Br. at 20 (questioning whether a thermal
management matrix could be in "thermal contact" with "the furnace of the building in which it
sits").) And Chervon contends that the specifications further confuse the issue by suggesting that
"thermal contact" may or may not mean the same thing as "general thermal contact." (See id. at
21.) The court is not persuaded that the term "thermal contact" is ambiguous regarding these
issues. The asserted claims clearly teach that a PCM absorbs heat generated by one or more
discharging cell elements and subsequently releases heat to the cell element(s) as they cool. It
is apparent that regardless of whether the PCM is touching the cell elements—and regardless of
how much heat is exchanged between them—the temperature of the cell elements affects the
temperature of the PCM, and vice versa. Moreover, the specifications use the terms "thermal
contact" and "general thermal contact" interchangeably. Chervon has not pointed to anything in
25

the specifications suggesting that the terms have different meanings.
Chervon's discussion of the prosecution history and extrinsic evidence likewise does not
compel a conclusion that the term "thermal contact" is indefinite.

For example, Chervon

represents that during his deposition for this lawsuit, Al-Hallaj testified that "whether something is
in thermal contact depends on whether there is sufficient heat flux between two objects." (Oct.
23, 2020 Hr'g Tr. at 77:18–20.) Chervon argues that determining whether heat flux is sufficient is
inherently subjective, and emphasizes that the patents-in-suit do not refer to heat flux. (See id.
at 77:21–78:4; see also Chervon Reply at 13 (citing Al-Hallaj Dep. at 127:7–128:7 (testimony that
it is the designer's responsibility to determine whether pathways for heat transfer are sufficient for
a specific application of the invention)).) As the court reads Al-Hallaj's testimony, it does not show
that the term "thermal contact" leaves a POSITA unable to "discern the scope of [the asserted]
claim[s] with reasonable certainty." Cox, 838 F.3d at 1232. Rather, his testimony illustrates the
above-referenced concept that is easily understood from the patents: regardless of whether
objects are touching, they are in thermal contact when the temperature of one can influence the
temperature of the other. (See, e.g., Al-Hallaj Dep. at 114:20–23 (testifying that thermal contact
is "when you have direct contact or indirect contact that you facilitate the movement of heat"); id.
at 122:14–15 ("[T]hermal contact means there is a way to move heat from one to the other.").)
Chervon also argues that although All Cell now maintains that objects can be in thermal
contact without touching, it took the opposite position during prosecution to overcome anticipation
by the Bourne Patent. (See Oct. 23, 3030 Hr'g Tr. at 78:10–16; see also June 4, 2002 Office
Action, JA-1 at 176 (distinguishing Bourne on the ground that the disclosed cell elements "are
enclosed in . . . monoblocks and are not in contact with the phase-change materials").) In the
same vein, Chervon argues that All Cell has taken inconsistent positions on whether objects can
be in thermal contact if they are separated by an insulator. (See Oct. 23, 2020 Hr'g Tr. at 78:19–
79:3; see also id. at 79:4–11 (Counsel for Chervon) (arguing that Al-Hallaj made inconsistent
statements concerning this issue during his deposition).)
26

The court does not detect any

inconsistency. During the claim construction hearing, All Cell explained that a thermal insulator
prevents thermal contact, whereas non-thermal insulators, such as electric insulators, do not.
(See id. at 84:5–85:9.) In the statements and testimony Chervon cites, All Cell and All-Hallaj
distinguished between "thermal insulators" and other insulators. (See, e.g., All Cell Br. at 20
(stating that an example of "nearly direct" thermal contact is when an "electric insulator" is used
to avoid "electrical contact" between cell elements and a containment lattice member); Al-Hallaj
Dep. at 115:17–19, 125:1–7) (testifying that two objects can be in thermal contact if there is an
insulator between them, but not if the insulator provides "complete[ ]" insulation).) Similarly, as
All Cell explained during the claim construction hearing, the material separating the PCM from
the cell elements disclosed in the Bourne Patent was a thermal insulator. (See Oct. 23, 2020 Hr'g
Tr. at 85:10–11; see also All Cell Br. at 20.) All of this evidence reflects the intuitive concept that
thermal contact between objects is broken when there is a thermal insulator between them. It
does not support a conclusion that a POSITA would not know whether objects must be touching
to be in thermal contact.
That said, All Cell's proposed construction—particularly the reference to "nearly direct"—
inserts confusion into the term. The construction should reflect the patents' clear teaching that
thermal contact requires a capacity for heat exchange between objects, regardless of whether
they are touching. All Cell's proposed construction does not do so. Moreover, because the
prosecution history indicates that there was no thermal contact disclosed in the Bourne Patent
(given the thermal insulator between the PCM and cell elements), the court concludes that any
construction of the term should confirm that a thermal insulator between objects breaks thermal
contact. (Cf. Oct. 23, 2020 Hr'g Tr. at 82:17–20 (Counsel for Chervon) (arguing that if the court
construes the term, it should account for All Cell's position that "if something is placed in between
two objects, they can't be in thermal contact").) Guided by the intrinsic evidence, the court
construes "thermal contact" as follows: contact between objects, whether they are touching or not
touching, in which the temperature of one can influence the temperature of the other; and where
27

there is no thermal insulator between them.
E.

"At elevated temperature" / "To a greater than ambient temperature"

Claim Term
"at elevated temperature" /
"to a greater than ambient
temperature" ['689 Patent,
Claim 1; '944 Patent, Claim
21]

Plaintiffs' Proposed
Construction
No construction (plain and
ordinary meaning)

Defendants' Proposed
Construction
Indefinite under 35
U.S.C. § 112

Chervon argues that the terms "at elevated temperature" and "to a greater than ambient
temperature" render claims in which they are used indefinite "because they claim variable, relative
amounts . . . without clear objective boundaries." (Chervon Br. at 22.) The first term, Chervon
contends, "is a relative term that requires comparison to a baseline value." (Id.) According to
Chervon, the patents do not identify any baseline value. (See id.) Similarly, Chervon maintains
that "ambient" is "a variable value" for which the patents establish no boundaries. (Chervon Reply
at 13; see also Chevon Br. at 22 ("The temperature surrounding a battery (i.e., the ambient
temperature) is susceptible to constant change, as the patents explicitly point out."); '689 Patent,
col. 1, ll. 44–47 ("[T]emperature variations between individual cells can result from one or more
of a variety of different factors including, for example: 1) changes in ambient temperature . . . .");
Chervon Br. at 22.) All Cell responds that the terms need no construction. (See, e.g., All Cell Br.
at 22 (arguing that the patents clearly teach that the terms refer to temperature that "is elevated
relative to the temperature of the cell before the discharging occurred").) The court agrees with
All Cell that the terms do not require construction and that both have the same plain and ordinary
meaning.
Claim 1 of the '689 Patent recites, in part, "discharging the at least one cell element at
elevated temperature." ('689 Patent, col. 7, ll. 30–31.) Claim 21 of the '944 Patent recites, in part,
"following discharge, releasing at least a portion of the absorbed quantity of heat from the phase
change material to heat the at least one cell element to a greater than ambient temperature."
('944 Patent, col. 16, ll. 33–36.) True, the claim language does not define "elevated temperature"
28

or "ambient temperature," nor does it provide specific boundaries or baselines for those
temperatures. The specifications do not do so, either. But the first step of both claimed methods
is "discharging" at least one cell element—an action that generates heat. (See '689 Patent, col.
7, ll. 21–22; '944 Patent, col. 16, ll. 26–27.) Understood in this context, the baseline temperature
contemplated in both claim terms is the temperature of the battery before it is discharged. Thus,
"at elevated temperature" and "to a greater than ambient temperature" refer to a temperature
greater than the temperature of the battery before it was discharged. The fact that air temperature
can differ depending on location and other factors—which could, in turn, mean that the
temperature of the battery before it was discharged could vary based on those same factors—
does not affect the meaning of either term.

For these reasons, the terms do not raise

indefiniteness concerns and do not require construction.
CONCLUSION
The claim terms in the '689 Patent, '944 Patent, '474 Patent, and '941 Patent are construed
as follows:
Claim Term
"phase change material"
"cell element"
"containment lattice member" / "lattice
member"
"thermal contact"

"at elevated temperature" / "to a greater than
ambient temperature"

Construction
a material that changes phase at battery
discharge temperatures
no construction required
a structure having an arrangement of pores
or openings, uniform or non-uniform
contact between objects, whether they are
touching or not touching, in which the
temperature of one can influence the
temperature of the other; and where there is
no thermal insulator between them.
no construction required

ENTER:

Dated: July 15, 2021

_____________________________________
REBECCA R. PALLMEYER
United States District Judge

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