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IN THE UNITED STATES DISTRICT COURT

FOR THE EASTERN DISTRICT OF TEXAS

MARSHALL DIVISION

SK NEXILIS CO., LTD.,

Plaintiff,

v.

SOLUS ADVANCED MATERIALS CO., 

LTD., VOLTA ENERGY SOLUTIONS 

S.A.R.L., VOLTA ENERGY SOLUTIONS 

EUROPE KFT., VOLTA ENERGY 

SOLUTIONS HUNGARY KFT., AND 

VOLTA ENERGY SOLUTIONS 

CANADA INC.,

Defendants.

Civil Action No. _______

JURY TRIAL DEMANDED

COMPLAINT

Plaintiff SK nexilis Co., Ltd. (“SKn” or “Plaintiff”), by and through the undersigned 

attorneys, complains and alleges the following against Defendants Solus Advanced Materials Co., 

Ltd, Volta Energy Solutions S.A.R.L., Volta Energy Solutions Europe KFT., Volta Energy 

Solutions Hungary KFT., and Volta Energy Solutions Canada Inc. (“Defendants”).

NATURE OF THE ACTION

1. This is an action for patent infringement. These claims arise under at least the 

patent laws of the United States, 35 U.S.C. §§ 1, et seq.

2. SKn has filed this lawsuit to respond to Defendants’ unlawful infringement of 

SKn’s patented inventions, including U.S. Patent Nos. 10,480,090 (“the ’090 Patent), 10,811,689 

(“the ’689 Patent”), 11,346,014 (“the ’014 Patent”), and 11,591,706 (“the ’706 Patent”)

(collectively, the “Asserted Patents”), and to obtain damages and other relief as appropriate.

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THE PARTIES

3. Plaintiff SKn is a corporation organized and existing under the laws of the Republic 

of Korea, with its principal place of business at 2 3sandan 2-gil, Buk-myeon, Jeongeup-si, 

Jeollabuk-do, 56137, Republic of Korea. SKn is a market leader in the research, development, 

and manufacture of battery copper foils.

4. Upon information and belief, Solus Advanced Materials Co., Ltd. (“Solus”) is a 

corporation organized and existing under the laws of the Republic of Korea with its principal place 

of business located at 627 Seodong-ro, Iksan-si, Jeollabuk-do, 54584 Republic of Korea.

5. Upon information and belief, Volta Energy Solutions S.A.R.L. (“Volta”) is a 

company organized and existing under the laws of Luxembourg, with its principal place of 

business at 6, Salzbaach, Wiltz, Luxembourg. Solus owns a controlling stake in Volta Energy 

Solutions S.A.R.L. See Ex. 1, Solus Advanced Materials Co., Ltd. 2023 2Q Earnings Report, July 

2023 (“Solus 2Q Earnings Report”), at 17 (“Domestic & Overseas Corporations”), 

https://www.solusadvancedmaterials.com/download/ir/%EC%86%94%EB%A3%A8%EC%8A

%A4%EC%B2%A8%EB%8B%A8%EC%86%8C%EC%9E%AC_2Q.'23%20%EC%8B%A4%

EC%A0%81%EC%9E%90%EB%A3%8C_20230726_EN_vf.pdf (last visited November 21, 

2023). Upon information and belief, Volta is directed and controlled by Solus.

6. Upon information and belief, Volta Energy Solutions Europe KFT. (“Volta 

Europe”) is a company organized and existing under the laws of Hungary, with its principal place 

of business at Környe, Üveggyár u., 2851, Hungary. Upon information and belief, Volta Europe 

is a wholly-owned subsidiary of Volta Energy Solutions S.A.R.L., and is directed and controlled 

by Solus and/or Volta Energy Solutions S.A.R.L. Id.

7. Upon information and belief, Volta Energy Solutions Hungary KFT. (“Volta 

Hungary”) is a company organized and existing under the laws of Hungary, with its principal place 

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of business at Környe, Üveggyár u., 2851, Hungary. Upon information and belief, Volta Hungary 

is a wholly-owned subsidiary of Volta Europe, and is directed and controlled by Solus, Volta 

Energy Solutions S.A.R.L., and/or Volta Europe. Id.

8. Upon information and belief, Volta Energy Solutions Canada Inc. (“Volta Canada”) 

is a company organized and existing under the laws of Canada, with its principal place of business 

at 625 rue du Luxembourg, Granby, Quebec, J2J 2S9, Canada. Upon information and belief, Volta 

Canada is a wholly-owned subsidiary of Volta Energy Solutions S.A.R.L., and is directed and 

controlled by Solus and/or Volta Energy Solutions S.A.R.L. Id.

9. Defendants act in concert or individually to design, manufacture, sell, and offer for 

sale in the United States and/or import into the United States battery copper foils including standard 

battery copper foil (BF-PLSP), high-elongation battery copper foil (SR-PLSP), and high-strength 

battery foil (HTS-PLSP) products (the “Accused Products”). See Ex. 2,

https://www.solusadvancedmaterials.com/en/business/b-foil/#anchor-1 (last visited November 21, 

2023); see also Ex. 1 at 7 (“Battery copper foil_Expansion of the battery copper foil production 

capacity in North America and the EU”), 12 (“Consolidated Statement of Comprehensive Income”), 

14 (“Company & Business Introduction”), and 16 (“Business Sites”).

10. Both SKn and Defendants compete in the market supplying battery copper foils for 

use in electrical vehicle (“EV”) batteries. See, e.g., 

https://www.kedglobal.com/batteries/newsView/ked202309060002 (“The ground-breaking 

ceremony held in Granby, Quebec comes as South Korean EVs and battery makers, including its 

bigger rival SK Nexilis Co., are ramping up production in North America so that buyers of their 

cars are eligible for US tax credits under the US Inflation Reduction Act.”) (last visited November 

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21, 2023); see also https://www.just-auto.com/news/solus-breaks-ground-on-canada-copper-foilplant (last visited November 21, 2023). 

JURISDICTION AND VENUE

11. This Court has subject matter jurisdiction over the claims for patent infringement

(COUNTS I-IV) pursuant to 28 U.S.C. §§ 1331 and 1338(a) because this is a civil action arising 

under the Patent Act.

12. This Court has personal jurisdiction over Defendants. Defendants have established 

minimum contacts with the United States as a whole and with Texas such that subjecting them to 

personal jurisdiction in this Court will not offend traditional notions of fair play and substantial 

justice. Defendants purposely availed themselves of the laws and protections of the United States 

and the State of Texas by knowingly supplying, contracting to supply, shipping, distributing, offering 

for sale, selling, and/or advertising battery copper foils in State of Texas. Defendants have targeted 

the United States and the State of Texas by conducting regular business therein, and have placed and 

continue to place their products into the stream of commerce through an established distribution 

channel with the expectation and/or knowledge that they will be purchased by consumers in the 

United States, the State of Texas, and this District. SKn’s claims for patent infringement arise 

directly from and/or relate to this activity.

13. For example, Defendants have offered for sale and sold the Accused Products to EV 

manufactures, such as Tesla, Inc, located in Texas. See https://www.kedglobal.com/batterymaterials/newsView/ked202202160014 (“Tesla to use Solus’ products to meet 70% of its demand 

for next-generation battery production in Texas.”) (last visited November 16, 2023); see also

https://www.kedglobal.com/batteries/newsView/ked202309060002 (“The ground-breaking 

ceremony held in Granby, Quebec comes as South Korean EVs and battery makers, including its 

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bigger rival SK Nexilis Co., are ramping up production in North America so that buyers of their cars 

are eligible for US tax credits under the US Inflation Reduction Act.”) (last visited October 12, 2023); 

https://www.mk.co.kr/economy/view.php?sc=50000001&year=2022&no=152967 (last visited 

November 21, 2023). 

14. Defendants have also entered into contracts with existing U.S. customers to increase 

the supply of the Accused Products into the United States, including in Texas. See Ex. 3, Solus 

Advanced Materials, 

https://www.solusadvancedmaterials.com/download/main/2023_%EC%86%94%EB%A3%A8%E

C%8A%A4%EC%B2%A8%EB%8B%A8%EC%86%8C%EC%9E%AC_%ED%9A%8C%EC%

82%AC%EC%86%8C%EA%B0%9C%EC%84%9C_(EN)_v2.pdf (last visited November 21, 

2023), at 15 (stating that Solus expects to “make additional long-term supply agreement with existing 

customers” and “[i]ncrease local demand at existing/new plants in North America under USMCA.”). 

15. As another example, Defendants’ 2023 First Quarter Earnings Report states that they 

are engaged in a “[c]onsistent pursuit[] of new and additional supply contracts for North American 

and EU customer” as part of their “[e]xpansion of operational capacity for Battery copper foil.” Ex. 

4, Solus Advanced Materials Co., Ltd. 2023 1Q Earnings Report, April 2023, https://www.voltaenergysolutions.com/download/ir/(USD)%201Q%2023%20Earnings%20Report.pdf, at 7 (“Battery 

Copper Foil_Hungary PH2 Status and Plans”). Similarly, Defendants’ 2023 Second Quarter 

Earnings Report states: “[a]fter the USA IRA announcement, North America demands for EV 

batteries soared, and thus we must prepare to cope with such changes and conquer the local markets 

and maintain close relations with customers to gain a competitive edge.” Ex. 1 at 7 (“Expansion 

of the battery copper foil production capacity in North America and the EU”).

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16. Additionally, Defendants have purposefully availed themselves of the laws and 

protections of the United States and the State of Texas by filing and maintaining U.S. patents and 

trademarks. For example, Solus is the assignee of 51 unique U.S. patents and patent applications. 

17. As another example, Defendants have 14 registered U.S. trademarks and trademark 

applications, including “Solus,” “Solus Advanced Materials,” “Volta Energy Solutions,” and 

Volta’s logo. all registered to Solus. See e.g., SOLUS, Serial No. 90716913; SOLUS 

ADVANCED MATERIALS, Serial No. 90210109; SOLUS ADVANCED MATERIALS, Serial 

No. 90510553; VOLTA ENERGY SOLUTIONS, Registration No. 7159864; VOLTA ENERGY 

SOLUTIONS, Registration No. 7117560; Volta Two Triangle Design, Registration No. 7110030. 

These trademarks and trademark applications are registered to cover goods and services related to 

the Accused Products. 

18. Venue is proper in this District under 28 U.S.C. §§ 1391(a)-(d) and 1400(b). Each 

of Solus, Volta, Volta Europe, Volta Hungary, and Volta Canada is a foreign corporation that does

not reside in the United States, and thus may be sued in any judicial district pursuant to 28 U.S.C. 

§ 1391(c)(3).

19. Defendants are jointly and severally liable for infringing one or more of the claims 

of the Asserted Patents. Defendants’ liability stems from the same transactions or occurrences 

regarding the use, sale, and/or offer for sale in the United States and/or importation into the United 

States of the Accused Products. Consequently, this action involves questions of law and fact 

common to all Defendants.

SKn BATTERY COPPER FOIL

20. SKn is a market leader in the research, development, and manufacture of battery 

copper foils. See http://www.sknexilis.com/en/nexilis/introduction.php#self. 

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21. Battery copper foil is a key material of lithium-ion battery anodes for EVs and 

serves as a pathway for the electric current and the source to emit the heat generated by a battery. 

See

https://www.skc.kr/m/eng/creation/detailView.do?menuCd=002005&lang=eng&cate1=289&cat

e2=293&cate3=&cate4=#:~:text=CopperfoilisanAnode,copper20foilthinnerandwider.

22. With the rising demand for electric vehicles, the demand for lithium-ion batteries 

with higher capacity and reliability has also increased. The thinner the copper foil, the more active 

material that can be loaded into the anode. In turn, this reduces the weight of the battery, increases 

the battery capacity, reduces manufacturing costs, and minimizes environmental impact. The 

higher performing batteries lead to better and longer performance of EVs. The global copper foil 

market for EV batteries is expected to experience an annual growth rate of over 40 percent over 

the next several years. See

https://www.businesskorea.co.kr/news/articleView.html?idxno=203628. 

23. SKn has created industry-leading thin, long, and wide battery copper foils, which 

are critical for producing high-capacity, lightweight, and cost-efficient batteries. See

http://www.sknexilis.com/en/product/copper.php. 

24. SKn has expended considerable time, labor, skill, and money to create its market 

leading battery copper foils. SKn manufactures battery copper foils in a variety of types and sizes

including standard battery property battery copper foil (in thicknesses varying between 6-12μm), 

high elongation after high tensile strength battery copper foil (in thicknesses varying between 

6-12μm), heat resistant high tensile strength battery copper foil (in thicknesses varying between 

6-12μm), and ultra-thin battery copper foil (thicknesses less than 5μm). SKn’s commitment to 

research and development and use of its proprietary innovation has allowed SKn to provide to the 

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market the industry leading secondary battery copper foils that can be manufactured for use in 

various types of lithium-ion batteries such as pouch type, cylindrical type, and prismatic type. 

25. SKn’s innovations, which include optimization of key material properties 

associated with a battery copper foil such as peak count roughness, peak density and coefficient of 

thermal expansion, are instrumental in maintaining high charge/discharge capacity and reducing 

common manufacturing defects such as curls, bagginess, tearing, fusilli, MD buckles, and 

wrinkles. SKn’s innovations also enable manufacturing of wider and longer battery copper foils, 

which lead to increased production output and decreased production losses. For example, over the 

last decade, SKn’s manufacturing capacity has increased from 600-800 mm-wide and 8 km-long 

battery copper foil to 1200-1400 mm-wide and 77 km-long battery copper foil. Further, SKn’s 

innovations improve the transportation efficiencies of battery copper foil by enabling more

material to be transported per drum, which in turn results in reduced risks of damage during 

transportation.

26. SKn’s battery copper foil innovations have earned widespread recognition and 

praise. For example, in 2013 SKn was awarded the Silver Tower Order at the International 

Material & Components Industry Show for producing the world’s first 6μm copper foil. See SK 

Nexilis, History, http://www.sknexilis.com/en/nexilis/introduction.php#self (last visited 

November 21, 2023). In 2017, SKn was awarded the Ministry of Trade, Industry and Energy Prize 

for its development of 4μm copper foil. Id. In 2018, SKn was awarded the “Korean World-Class 

Product Award” for its copper foil products. Id. In 2020, the Korea Record Institute certified 

SKn’s battery copper foils as the longest, widest, and thinnest ever made in Korea. See 

https://www.skc.kr/m/eng/Conmmunication/news/newsDetail.do?seq=1187. Through its 

innovations, by 2021, SKn established itself as the world’s largest copper foil maker and has 

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earned the largest market share in the global copper film market. See

https://www.kedglobal.com/batteries/newsView/ked202208030007. 

THE ASSERTED PATENTS

27. U.S. Patent No. 10,480,090 is titled “Electrolytic copper foil, current collector 

comprising the same, electrode comprising the same, secondary battery comprising the same, and 

method for manufacturing the same.” The ’090 Patent was filed as PCT Application on April 28, 

2016 and issued by the United States Patent and Trademark Office on November 19, 2019. The 

inventors of the ’090 Patent are Seung Min Kim and Dae Young Kim. A true and correct copy of 

the ’090 Patent is attached as Exhibit 5. 

28. SKn is the sole owner by assignment of all right, title, and interest in the ’090

Patent.

29. U.S. Patent No. 10,811,689 is titled “Easily handleable electrolytic copper foil, 

electrode comprising the same, secondary battery comprising the same, and method for 

manufacturing the same,” and was filed with the United States Patent and Trademark Office on 

September 6, 2017 and issued on October 20, 2020. The inventor of the ’689 Patent is Seung Min 

Kim. A true and correct copy of the ’689 Patent is attached as Exhibit 6. 

30. SKn is the sole owner by assignment of all right, title, and interest in the ’689 

Patent.

31. U.S. Patent No. 11,346,014 is titled “Electrolytic copper foil, method for producing 

same, and high-capacity Li secondary battery negative electrode including same.” The ’014 Patent 

was filed as a PCT Application on August 24, 2018 and issued by the United States Patent and 

Trademark Office on May 31, 2022. The inventors of the ’014 Patent are Seung Min Kim and Ho 

Gun Kim. A true and correct copy of the ’014 Patent is attached as Exhibit 7. 

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32. SKn is the sole owner by assignment of all right, title, and interest in the ’014

Patent.

33. U.S. Patent No. 11,591,706 is titled “Electrolytic copper foil having excellent

handling characteristics in postprocessing, and manufacturing method therefor.” The ’706 Patent 

was filed as a PCT Application on January 25, 2019 and issued by the United States Patent and 

Trademark Office on February 28, 2023. The named inventors of the ’706 Patent are Seung Min 

Kim and Shan Hua Jin. A true and correct copy of the ’706 Patent is attached as Exhibit 8. 

34. SKn is the sole owner by assignment of all right, title, and interest in the ’706

Patent.

35. On September 27, 2023, SKn sent a letter to Solus, notifying it that Solus’ battery 

copper foil products were infringing SKn’s patents. Upon information and belief, Defendants 

should have therefore had knowledge of the Asserted Patents and their infringement of those 

patents at least since receiving the September 27, 2023 letter.

36. Defendants have also had knowledge of the Asserted Patents at least since the filing 

of this Complaint.

THE ACCUSED PRODUCTS

37. The Accused Products are battery copper foil products used, made, sold, offered 

for sale, and/or imported by Defendants, including battery copper foil products incorporated into 

EV batteries. The Accused Products include standard battery copper foil (“BF-PLSP”), highelongation battery copper foil (“SR-PLSP”), and high-strength battery foil (“HTS-PLSP”) 

products. See Solus Advanced Materials, Battery Copper Foil: Main Product, 

https://www.solusadvancedmaterials.com/en/business/b-foil/#anchor-1 (last visited November 21, 

2023).

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38. Solus was founded in October 2019, and Defendants did not begin manufacturing 

battery copper foils on a commercial scale until 2020—years after Plaintiff filed patent 

applications covering its battery copper foil innovations. See

https://www.solusadvancedmaterials.com/en/intro/history/; Ex. 9, Solus Advanced Materials 

Company Profile, at 4 (“Overview – Company Profile”), https://www.voltaenergysolutions.com/download/main/3Q%20%EC%86%94%EB%A3%A8%EC%8A%A4%EC

%B2%A8%EB%8B%A8%EC%86%8C%EC%9E%AC%20%ED%9A%8C%EC%82%AC%EC

%86%8C%EA%B0%9C%EC%84%9C_EN.pdf (last visited November 16, 2023). 

39. Defendants’ BF-PLSP products, for example, are used in electric vehicle batteries, 

are of “cylindrical,” “prismatic,” or “pouch” type, and have a thickness of 6-18μm. See

https://www.solusadvancedmaterials.com/en/business/b-foil/#anchor-1(last visited November 16, 

2023).

40. Defendants’ SR-PLSP products are of “cylindrical” and “prismatic” type, and have 

a thickness of 6-12μm. Id. Defendants characterize these products as “contributing to yield 

improvement by upgrading processability within the battery production process with high strength 

properties before heat treatment and increasing the life and stability of cylindrical and square 

batteries with high elongation properties after heat treatment.” Id. Defendants further characterize 

the “SR-PLSP” products as capable of “load[ing] much more active materials with high strength 

properties, contributing to the minimization of deformation at the time of battery charge and 

discharge by maintaining strength after heat treatment.” Id. 

41. Defendants’ HTS-PLSP products are of “pouch type” and have a thickness of 6-

12μm. Id. Defendants represent that the HTS-PLSP products can “load much more active 

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materials with high strength properties, contributing to the minimization of deformation at the time 

of battery charge and discharge by maintaining strength after heat treatment.” Id. 

42. Defendants “[m]anufacture [ ] battery copper foil products to individual customer 

specifications” and “[m]anufacture [ ] a wide range of battery copper foil products (e.g., thickness 

of 8μm or 6μm, high-strength, or high-elongation characteristics).” Ex. 4 at 6 (“Battery Copper

Foil/Copper Foil_Production Capacity Status & Plan”). 

43. Defendants’ 6μm battery copper foil products “can wind more than 30 km.” Ex. 

9, at 11 (“Battery Copper Foil”), https://www.voltaenergysolutions.com/download/main/3Q%20%EC%86%94%EB%A3%A8%EC%8A%A4%EC

%B2%A8%EB%8B%A8%EC%86%8C%EC%9E%AC%20%ED%9A%8C%EC%82%AC%EC

%86%8C%EA%B0%9C%EC%84%9C_EN.pdf (last visited November 16, 2023). 

44. Defendants’ Accused Products are designed to address the same problems solved by 

the Asserted Patents. For example, Defendants state that the Accused Products “[e]nhanc[e] yield 

by improving machining in battery manufacturing with high-strength battery copper foil before 

heat treatment” and “[m]inimiz[e] deformation during the charging/discharging of batteries by 

maintaining its high-strength properties even after heat treatment.” Id.

45. The Accused Products are developed, manufactured, and assembled by or for 

Defendants at facilities in Korea, Canada, and Hungary. Id. 6 (“Battery Copper Foil/Copper 

Foil_Production Capacity Status & Plan”), 14 (“Company & Business Introduction”), 16 

(“Business Sites”).

46. Defendants, directly or indirectly through their affiliates, subsidiaries, agents,

customers, or other representatives, sell and/or offer for sale the Accused Products in the United 

States, and/or import the Accused Products into the United States, including in connection with 

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supplying and selling the Accused Products to U.S. businesses for incorporation into products, 

such as EV batteries. Defendants manufacture the Accused products and sell them directly to 

“[g]lobal-tier battery manufacturer[s]” and “[g]lobal OEM company.” Id. at 6 (“Battery Copper 

Foil/Copper Foil_Production Capacity Status & Plan”).

COUNT I

DEFENDANTS’ INFRINGEMENT OF U.S. PATENT NO. 10,480,090

(35 U.S.C. § 271)

47. SKn incorporates by reference the preceding paragraphs as if fully set forth herein.

48. Defendants have infringed and continue to directly infringe the ’090 Patent by 

using, selling, and offering for sale in the United States and/or importing into the United States the 

Accused Products.

49. For example, independent claim 1 of the ’090 Patent recites: 

1. An electrolytic copper foil for a secondary battery, the electrolytic copper foil 

comprising:

a first surface; and

a second surface opposite to the first surface,

wherein each of the first and second surfaces has a peak count roughness Rpc of 

10 to 100,

wherein the peak count roughness Rpc of each of the first and second surfaces is 

an average of peak count roughness Rpc values measured at randomly-selected 

three points,

the peak count roughness Rpc of each point is the number of effective peaks 

which rise above an upper criteria line of 0.5 μm per unit sampling length of 4 

mm in a surface roughness profile obtained according to steel-iron test schedule 

(SEP 1940), and

there is at least one valley deeper than a lower criteria line of −0.5 μm between 

adjacent ones of the effective peaks.

50. The Accused Products meet each limitation of at least claim 1 of the ’090 Patent.

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51. For example, the Accused Products are electrolytic copper foil products for use in

secondary batteries such as the EV batteries. See

https://www.solusadvancedmaterials.com/en/business/b-foil/. As shown below (Figs. 1-3), the 

Accused Products comprise a first surface and a second surface opposite to the first surface. Id.

Figure 1

Figure 2

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52. As shown below in Fig. 3, the Accused Products have a “drum side” and an 

“electrolyte side.” Id.

Figure 3

53. Moreover, in each Accused Product, the first and second surfaces of the Accused 

Products have a peak count roughness (Rpc) of 10 and 100. For each Accused Product, measuring 

the peak count roughness Rpc values of each of the first and second surfaces at randomly-selected 

three points and averaging the three values results in peak count roughness Rpc of each of the first 

surface and second surfaces between 10 and 100 where the peak count roughness Rpc was the 

number of effective peaks which were above an upper criteria line of 0.5 μm per unit sampling 

length of 4 mm in a surface roughness profile obtained according to steel-iron test schedule (SEP 

1940), and there was at least one valley deeper than a lower criteria line of −0.5 μm between 

adjacent ones of the effective peaks. 

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54. By using, selling, and offering the Accused Products for sale in the United States 

and/or importing the Accused Products into the United States, Defendants directly infringe at least 

claim 1 of the ’090 Patent.

55. Defendants have derived substantial income from the manufacture and sale of their 

infringing battery copper foils in at least 2020, 2021, 2022, and 2023. See e.g. Ex 1, at 12 

(“Consolidated Statement of Comprehensive Income”).

56. Defendants have induced infringement of the ’090 Patent under 35 U.S.C. § 271(b) 

by knowingly and intentionally inducing others to directly infringe the ’090 Patent. Despite having 

notice of the ’090 Patent, Defendants have actively encouraged others to infringe the patent. For 

example, upon information and belief, Defendants have knowingly and intentionally induced thirdparty manufacturers, shippers, distributors, retailers, and/or customers to directly infringe (literally 

and/or under the doctrine of equivalents) the ’090 Patent by importing into the United States, using, 

and/or selling and offering to sell in the United States products containing the Accused Products. 

The Accused Products are specially designed to include features that infringe the ’090 Patent and 

have no substantial uses other than ones that infringe the ’090 Patent. 

57. Moreover, upon information and belief, Defendants take active steps, directly 

and/or through contractual relationships with others, with the specific intent to cause such persons 

to import, use, sell, and/or or offer to sell products containing the Accused Products. Upon 

information and belief, such steps by Defendants include, among other things, making and selling 

the Accused Products for importation into or sale in the United States, knowing that such 

importation or sale would occur. 

58. Defendants have also contributorily infringed the ’090 Patent under 35 U.S.C. § 

271(c) through its supply of the Accused Products and non-staple constituent parts thereof, which 

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are not suitable for substantial non-infringing use and which embody a material part of the 

inventions described in the ‘090 Patent. Defendants have engaged in these activities despite having 

notice of the ’090 Patent and knowing that the constituent parts are especially made and adapted 

for use in a manner that would infringe the ‘090 Patent. Defendants’ contributory infringement of 

the ’090 Patent is ongoing. 

59. Defendants’ infringement has been, and continues to be, willful. For example, 

Defendants have known or should have known about the ’090 Patent and their infringement of the 

’090 Patent since at least their receipt of SKn’s September 27, 2023 notice letter. Yet, Defendants 

have continued their infringing activities. 

60. SKn has suffered irreparable harm to its market share and its business opportunities 

as a result of Defendants offering competing battery copper foil products that infringe the ’090

Patent.

COUNT II

DEFENDANTS’ INFRINGEMENT OF U.S. PATENT NO. 10,811,689

(35 U.S.C. § 271)

61. SKn incorporates by reference the preceding paragraphs as if fully set forth herein.

62. Defendants have infringed and continue to directly infringe the ’689 Patent by 

using, selling, and offering for sale in the United States and/or importing into the United States the 

Accused Products.

63. For example, independent claim 1 of the ’689 Patent recites: 

1. An electrolytic copper foil, which includes a first surface and a second surface 

opposite the first surface, the electrolytic copper foil comprising:

a copper layer including a matte surface facing the first surface and a shiny 

surface facing the second surface;

a first protective layer on the matte surface of the copper layer; and

Case 2:23-cv-00539-JRG-RSP Document 1 Filed 11/21/23 Page 17 of 33 PageID #: 17
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a second protective layer on the shiny surface of the copper layer, wherein:

a coefficient of thermal expansion of the electrolytic copper foil, which is 

measured using a thermomechanical analyzer (TMA) while heating the 

electrolytic copper foil from 30° C. to 190° C. at a speed of 5° C./min, 

ranges from 16 to 22 μm/(m° C.),

a tensile strength of the electrolytic copper foil, which is measured after a 

heat treatment at a temperature of 190° C. for 1 hour, ranges from 21 to 36 

kgf/mm2,

a weight deviation of the electrolytic copper foil is 5% or less,

a peak count (Pc) of each of the first and second surfaces of the 

electrolytic copper foil ranges from 3 to 92, and

each of the first and second surfaces has a surface roughness (Rz) of 3.5 

μm or less.

64. The Accused Products meet each limitation of at least claim 1 of the ’689 Patent.

65. For example, the Accused Products are electrolytic copper foil products for use in 

secondary batteries such as EV batteries. See

https://www.solusadvancedmaterials.com/en/business/b-foil/. As shown below (Figs. 4-6), the 

Accused Products comprise a first surface and a second surface opposite to the first surface. Id.

Case 2:23-cv-00539-JRG-RSP Document 1 Filed 11/21/23 Page 18 of 33 PageID #: 18
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Figure 4

Figure 5

66. As shown below in Fig. 6, the Accused Products have a “drum side” and an 

“electrolyte side.” Id. Moreover, the Accused Products have a copper layer including a matte 

surface facing the first surface and a shiny surface facing the second surface, a first protective layer 

on the matte surface of the copper layer, and a second protective layer on the shiny surface of the 

copper layer. Id.

Case 2:23-cv-00539-JRG-RSP Document 1 Filed 11/21/23 Page 19 of 33 PageID #: 19
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Figure 6

67. In each Accused Product, the coefficient of thermal expansion of the electrolytic 

copper foil ranges from 16 to 22 μm/(m·° C.) where the coefficient of thermal expansion of the 

electrolytic copper foil is measured using a thermomechanical analyzer (TMA) while samples of the 

electrolytic copper foils are heated from 30° C. to 190° C. at a speed of 5° C./min. and the 

coefficient of thermal expansion is calculated using the equation: CTE=ΔL[LO×ΔT], where, CTE 

denotes a coefficient of thermal expansion, LO denotes an initial length (m) of a sample, ΔL 

denotes a change (μm) of the length of the sample, and ΔT denotes a temperature change (° C).

68. In each Accused Product, the tensile strength of the electrolytic copper foil, 

measured after a heat treatment at a temperature of 190° C. for 1 hour, ranges from 21 to 36 

kgf/mm2. 

69. In each Accused Product, the weight deviation of electric copper foil is 5% or less.

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70. In each Accused Product, each of the first surface and second surfaces of the 

electrolytic copper foil has a peak count between the range from 3 to 92, and each of the first 

surface and second surface of the electrolytic copper foil has a roughness (Rz) of 3.5μm or less.

71. By using, selling, and offering the Accused Products for sale in the United States 

and/or importing the Accused Products into the United States, Defendants directly infringe at least 

claim 1 of the ’689 Patent.

72. Defendants have derived substantial income from the manufacture and sale of their 

infringing battery copper foils in at least 2020, 2021, 2022, and 2023. See e.g. Ex 1, at 12 

(“Consolidated Statement of Comprehensive Income”).

73. Defendants have induced infringement of the ’689 Patent under 35 U.S.C. § 271(b) 

by knowingly and intentionally inducing others to directly infringe the ’689 Patent. Despite having 

notice of the ’689 Patent, Defendants have actively encouraged others to infringe the patent. For 

example, upon information and belief, Defendants have knowingly and intentionally induced thirdparty manufacturers, shippers, distributors, retailers, and/or customers to directly infringe (literally 

and/or under the doctrine of equivalents) the ’689 Patent by importing into the United States, using, 

and/or selling and offering to sell in the United States products containing the Accused Products. 

The Accused Products are specially designed to include features that infringe the ’689 Patent and 

have no substantial uses other than ones that infringe the ’689 Patent. 

74. Moreover, upon information and belief, Defendants take active steps, directly 

and/or through contractual relationships with others, with the specific intent to cause such persons 

to import, use, sell, and/or or offer to sell products containing the Accused Products. Upon 

information and belief, such steps by Defendants include, among other things, making and selling 

Case 2:23-cv-00539-JRG-RSP Document 1 Filed 11/21/23 Page 21 of 33 PageID #: 21
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the Accused Products for importation into or sale in the United States, knowing that such 

importation or sale would occur. 

75. Defendants have also contributorily infringed the ’689 Patent under 35 U.S.C. § 

271(c) through its supply of the Accused Products and non-staple constituent parts thereof, which 

are not suitable for substantial non-infringing use and which embody a material part of the 

inventions described in the ’689 Patent. Defendants have engaged in these activities despite having 

notice of the ’689 Patent and knowing that the constituent parts are especially made and adapted 

for use in a manner that would infringe the ’689 Patent. Defendants’ contributory infringement of 

the ’689 Patent is ongoing. 

76. Defendants infringement has been, and continues to be, willful. For example, 

Defendants have known or should have known about the ’689 Patent and their infringement of the 

’689 Patent since at least their receipt of SKn’s September 27, 2023 notice letter. Yet, Defendants 

have continued their infringing activities. 

77. SKn has suffered irreparable harm to its market share and its business opportunities 

as a result of Defendants offering competing battery copper foil products that infringe the ’689

Patent.

COUNT III

DEFENDANTS’ INFRINGEMENT OF U.S. PATENT NO. 11,346,014

(35 U.S.C. § 271)

78. SKn incorporates by reference the preceding paragraphs as if fully set forth herein.

79. Defendants have infringed and continue to directly infringe the ’014 Patent by 

using, selling, and offering for sale in the United States and/or importing into the United States the 

Accused Products.

80. For example, independent claim 1 of the ’014 Patent recites: 

Case 2:23-cv-00539-JRG-RSP Document 1 Filed 11/21/23 Page 22 of 33 PageID #: 22
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1. An electrolytic copper foil having a first surface and a second surface, the electrolytic 

copper foil comprising:

a first protective layer at the first surface;

a second protective layer at the second surface; and

a copper film disposed between the first and second protective layers, wherein

a binding coefficient of the electrolytic copper foil at the first surface or 

the second surface, defined as Mathematical Expression 1 below, is 1.5 to 

9.4,

(Mathematical Expression 1) Binding coefficient=Rp/μm+ peak 

density/30+ amount of attachment of Cr/(mg/m2)

(wherein the Rp (μm) is a peak height measured according to JIS B 0601 

(2001) standard, wherein the peak density is a number of peaks per unit 

length of 4 mm, wherein the peak density is measured according to ASME 

B46.1 (2009) standard with a peak count level of ±0.5 μm and wherein the 

amount of attachment of Cr (mg/m2) is measured by dissolving the first 

surface or the second surface of the electrolytic copper foil (110) with a 

nitric acid solution to obtain a dissolved solution, diluting the dissolved 

solution with water to obtain a diluted solution, and analyzing the diluted 

solution using an atomic absorption spectrometer).

81. The Accused Products meet each limitation of at least claim 1 of the ’014 Patent.

82. For example, the Accused Products are electrolytic copper foil products for use in 

secondary batteries such as EV batteries. See

https://www.solusadvancedmaterials.com/en/business/b-foil/. As shown below (Figs. 7-9), the 

Accused Products comprise a first surface and a second surface opposite to the first surface. Id.

Case 2:23-cv-00539-JRG-RSP Document 1 Filed 11/21/23 Page 23 of 33 PageID #: 23
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Figure 7

Figure 8

83. As shown below in Fig. 9, the Accused Products have a “drum side” and an 

“electrolyte side.” Id. Moreover, the Accused Products have a first protective layer at the first 

surface, a second protective layer at the second surface, and a copper film disposed between the 

first and second protective layers.

Case 2:23-cv-00539-JRG-RSP Document 1 Filed 11/21/23 Page 24 of 33 PageID #: 24
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Figure 9

84. In each Accused Product, the binding coefficient of the electrolytic copper foil at the 

first surface or the second surface is 1.5 to 9.4, where the binding coefficient of the electrolytic 

copper foil at the first surface or the second surface is calculated based on Rp/μm + peak density/30

+ the amount of attachment of Cr/(mg/m2), where the Rp (μm) is a peak height that was measured 

according to JIS B 0601 (2001) standard, the peak density is a number of peaks per unit length of 4 

mm when measured according to ASME B46.1 (2009) standard with a peak count level of ±0.5 μm,

and where the amount of attachment of Cr (mg/m2) is measured by dissolving the first surface or the 

second surface of the electrolytic copper foil with a nitric acid solution to obtain a dissolved solution, 

diluting the dissolved solution with water to obtain a diluted solution, and analyzing the diluted 

solution using an atomic absorption spectrometer.

85. By using, selling, and offering the Accused Products for sale in the United States 

and/or importing the Accused Products into the United States, Defendants directly infringe at least 

claim 1 of the ’014 Patent.

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86. Defendants have derived substantial income from the manufacture and sale of their 

infringing battery copper foils in at least 2020, 2021, 2022, and 2023. See e.g. Ex 1, at 12 

(“Consolidated Statement of Comprehensive Income”).

87. Defendants have induced infringement of the ’014 Patent under 35 U.S.C. § 271(b) 

by knowingly and intentionally inducing others to directly infringe the ’014 Patent. Despite having 

notice of the ’014 Patent, Defendants have actively encouraged others to infringe the patent. For 

example, upon information and belief, Defendants have knowingly and intentionally induced thirdparty manufacturers, shippers, distributors, retailers, and/or customers to directly infringe (literally 

and/or under the doctrine of equivalents) the ’014 Patent by importing into the United States, using, 

and/or selling and offering to sell in the United States products containing the Accused Products. 

The Accused Products are specially designed to include features that infringe the ’014 Patent and 

have no substantial uses other than ones that infringe the ’014 Patent. 

88. Moreover, upon information and belief, Defendants take active steps, directly 

and/or through contractual relationships with others, with the specific intent to cause such persons 

to import, use, sell, and/or or offer to sell products containing the Accused Products. Upon 

information and belief, such steps by Defendants include, among other things, making and selling 

the Accused Products for importation into or sale in the United States, knowing that such 

importation or sale would occur. 

89. Defendants have also contributorily infringed the ’014 Patent under 35 U.S.C. § 

271(c) through its supply of the Accused Products and non-staple constituent parts thereof, which 

are not suitable for substantial non-infringing use and which embody a material part of the 

inventions described in the ’014 Patent. Defendants have engaged in these activities despite having 

notice of the ’014 Patent and knowing that the constituent parts are especially made and adapted 

Case 2:23-cv-00539-JRG-RSP Document 1 Filed 11/21/23 Page 26 of 33 PageID #: 26
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for use in a manner that would infringe the ’014 Patent. Defendants’ contributory infringement of 

the ’014 Patent is ongoing. 

90. Defendants infringement has been, and continues to be, willful. For example, 

Defendants have known or should have known about the ’014 Patent and their infringement of the 

’014 Patent since at least their receipt of SKn’s September 27, 2023 notice letter. Yet, Defendants 

have continued their infringing activities. 

91. SKn has suffered irreparable harm to its market share and its business opportunities 

as a result of Defendants offering competing battery copper foil products that infringe the ’014

Patent.

COUNT IV

DEFENDANTS’ INFRINGEMENT OF U.S. PATENT NO. 11,591,706

(35 U.S.C. § 271)

92. SKn incorporates by reference the preceding paragraphs as if fully set forth herein.

93. Defendants have infringed and continue to directly infringe the ’706 Patent by 

using, selling, and offering for sale in the United States and/or importing into the United States the 

Accused Products.

94. For example, independent claim 1 of the ’706 Patent recites: 

1. An electrolytic copper foil having a first surface and a second surface, wherein

a texture coefficient of (220) plane of the electrolytic copper foil defined by 

Equation 1 below is 0.4 to 1.32,

a difference (|Δ(Rz/Ra)|) between Rz/Ra at the first surface of the electrolytic 

copper foil and Rz/Ra at the second surface of the electrolytic copper foil is less 

than 2.42, and

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a difference (|ΔPD|) between a peak density (PD) at the first surface of the 

electrolytic copper foil and a peak density (PD) at the second surface of the 

electrolytic copper foil is 96 ea or less.

95. The Accused Products meet each limitation of at least claim 1 of the ’706 Patent.

96. For example, the Accused Products are electrolytic copper foil products for use in 

secondary batteries such as EV batteries. See

https://www.solusadvancedmaterials.com/en/business/b-foil/. As shown below (Figs. 10-12), the 

Accused Products comprise a first surface and a second surface opposite to the first surface. Id.

Figure 10

Case 2:23-cv-00539-JRG-RSP Document 1 Filed 11/21/23 Page 28 of 33 PageID #: 28
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Figure 11

97. As shown below in Fig. 12, the Accused Products have a “drum side” and an 

“electrolyte side.” Id.

Figure 12

Case 2:23-cv-00539-JRG-RSP Document 1 Filed 11/21/23 Page 29 of 33 PageID #: 29
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98. In each Accused Product, the texture coefficient of plane (220) of the electrolytic 

copper foil is 0.4 to 1.32, where the texture coefficient of plane (220) of the electrolytic copper foil 

defined by Equation 1 below:

99. In each Accused Product, the difference (|Δ(Rz/Ra)|) between Rz/Ra at the first 

surface of the electrolytic copper foil and Rz/Ra at the second surface of the electrolytic copper 

foil is less than 2.42.

100. In each Accused Product, the difference (|ΔPD|) between a peak density (PD) at the 

first surface of the electrolytic copper foil and a peak density (PD) at the second surface of the 

electrolytic copper foil is 96 ea or less.

101. By using, selling, and offering the Accused Products for sale in the United States 

and/or importing the Accused Products into the United States, Defendants directly infringe at least 

claim 1 of the ’706 Patent.

102. Defendants have derived substantial income from the manufacture and sale of their 

infringing battery copper foils in at least 2020, 2021, 2022, and 2023. See e.g. Ex 1, at 12 

(“Consolidated Statement of Comprehensive Income”).

103. Upon information and belief, Defendants have induced infringement of the ’706 

Patent under 35 U.S.C. § 271(b) by knowingly and intentionally inducing others to directly infringe 

the ’706 Patent. Despite having notice of the ’706 Patent, Defendants have actively encouraged 

others to infringe the patent. For example, upon information and belief, Defendants have 

knowingly and intentionally induced third-party manufacturers, shippers, distributors, retailers, 

and/or customers to directly infringe (literally and/or under the doctrine of equivalents) the ’706

Case 2:23-cv-00539-JRG-RSP Document 1 Filed 11/21/23 Page 30 of 33 PageID #: 30
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Patent by importing into the United States, using, and/or selling and offering to sell in the United 

States products containing the Accused Products. The Accused Products are specially designed to 

include features that infringe the ’706 Patent and have no substantial uses other than ones that 

infringe the ’706 Patent. 

104. Moreover, upon information and belief, Defendants take active steps, directly 

and/or through contractual relationships with others, with the specific intent to cause such persons 

to import, use, sell, and/or or offer to sell products containing the Accused Products. Upon 

information and belief, such steps by Defendants include, among other things, making and selling 

the Accused Products for importation into or sale in the United States, knowing that such 

importation or sale would occur. 

105. Upon information and belief, Defendants have also contributorily infringed the 

’014 Patent under 35 U.S.C. § 271(c) through its supply of the Accused Products and non-staple 

constituent parts thereof, which are not suitable for substantial non-infringing use and which 

embody a material part of the inventions described in the ’706 Patent. Defendants have engaged 

in these activities despite having notice of the ’706 Patent and knowing that the constituent parts 

are especially made and adapted for use in a manner that would infringe the ’706 Patent. 

Defendants’ contributory infringement of the ’706 Patent is ongoing. 

106. Defendants infringement has been, and continues to be, willful. For example, 

Defendants have known or should have known about the ’706 Patent and their infringement of the 

’706 Patent since at least their receipt of SKn’s September 27, 2023 notice letter. Yet, Defendants 

have continued their infringing activities. 

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107. SKn has suffered irreparable harm to its market share and its business opportunities 

as a result of Defendants offering competing battery copper foil products that infringe the ’706

Patent.

PRAYER FOR RELIEF

108. WHEREFORE, Plaintiff SKn prays for relief as follows:

A. A judgment that each Defendant has willfully infringed, directly or 

indirectly, each of the Asserted Patents;

B. A permanent injunction enjoining Defendants and their officers, agents, 

servants, employees, attorneys, related business entities and those in active concert or 

participation with them from further infringement of the Asserted Patents.

C. Compensatory damages in an amount commensurate with Defendants’ 

infringement of the Asserted Patents, including without limitation lost profits and no less 

than a reasonable royalty;

D. Pre-judgment interest on all damages awarded to Plaintiff;

E. Post-judgment interest on all sums awarded to Plaintiff from the date of the 

judgment;

F. An award of treble damages pursuant to 35 U.S.C. § 284;

G. An award of reasonable attorneys’ fees pursuant to 35 U.S.C. § 285; and

H. Any and all other relief that the Court deems just and equitable.

JURY DEMAND 

109. Pursuant to Rule 38(b) of the Federal Rules of Civil Procedure, Plaintiff hereby 

demands a jury trial on all issues raised by this complaint.

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Dated: November 21, 2023 Respectfully submitted,

/s/ Deron R. Dacus____________

Deron R. Dacus

Texas Bar No. 00790553 Email: 

ddacus@dacusfirm.com

THE DACUS LAW FIRM, P.C.

821 ESE Loop 323, Suite 430 Tyler, TX 75701

Phone: (903) 705-1171

Fax: (903) 581-2543

D. James Pak

djamespak@quinnemanuel.com

David M. Elihu

davidelihu@quinnemanuel.com

QUINN EMANUEL URQUHART & SULLIVAN, LLP

865 S. Figueroa St, 10th Floor

Los Angeles, CA 90017

Tel: (213) 443-3000

Fax: (213) 443-3100

David A. Nelson

davenelson@quinnemanuel.com

Brianne M. Straka

briannestraka@quinnemanuel.com

Harrison B. Rose

harrisonrose@quinnemanuel.com

QUINN EMANUEL URQUHART & SULLIVAN, LLP

191 N. Wacker Drive, Suite 2700

Chicago, Illinois 60606

Tel: (312) 705-7400

Fax: (312) 705-7401

Sean Pak

seanpak@quinnemanuel.com

Kevin (Gyushik) Jang

kevinjang@quinnemanuel.com

QUINN EMANUEL URQUHART & SULLIVAN, LLP

50 California Street, 22nd Floor

San Francisco, California 94111-4788

Tel: (415) 875-6600

Fax: (415) 875-6700

Counsel for Plaintiff SK nexilis Co., Ltd.

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