On September 9, 2024, Ningde Amperex Technology Limited (“Amperex”) sued Zhuhai CosMX Battery Company, Limited (“CosMX”) in the United States District Court for the Eastern District of Texas. Ningde Amperex Tech. Ltd. v. Zhuhai CosMX Battery Co., Ltd., Case No. 2:24-cv-00728, Dkt. No. 1 (E.D. Tex. Sept. 6, 2024). Amperex alleges infringement of the following 5 battery-related patents: U.S. Patent No. 11,575,148 (the “’148 patent”), U.S. Patent No. 11,769,910 (the “’910 patent”), U.S. Patent No. 11,799,131 (the “’131 patent”), U.S. Patent No. 10,964,927 (the “’927 patent”), and U.S. Patent No. 11,923,498 (the “’498 patent”).
According to the complaint, Amperex is “the world’s leading lithium-ion battery manufacturer for smartphones and one of the major lithium-ion battery manufacturers for all consumer electronics.” Amperex v. CosMX, Case No. 2:24-cv-00728, Dkt. No. 1 at ¶ 4. CosMX, Amperex alleges, touts itself as “one of worldwide major suppliers of consumer Li-ion batteries” that “has long served [the] world’s well-known customers in the field of PCs, notebooks, tablets, smart phones, smart wearables, power tools, drones and other fields.” Id. at ¶ 11 (edit in original).
Amperex lists as accused products CosMX cells in laptops and smartphones that are shipped to the United States and distributed through retailers such as Amazon.com, Best Buy, Walmart, and Newegg. Amperex v. CosMX, Case No. 2:24-cv-00728, Dkt. No. 1 at ¶ 18.
In January 2025, CosMX filed for inter partes review of all 5 asserted patents. Zhuhai CosMX Battery Co., Ltd. v. Ningde Amperex Tech. Ltd., IPR2025-00431, Paper 1 (Jan. 28, 2025) (petitioning for review of the ’131 patent); Zhuhai CosMX Battery Co., Ltd. v. Ningde Amperex Tech. Ltd., IPR2025-00385, Paper 2 (Jan. 16, 2025) (petitioning for review of the ’927 patent); Zhuhai CosMX Battery Co., Ltd. v. Ningde Amperex Tech. Ltd., IPR2025-00389, Paper 1 (Jan. 15, 2025) (petitioning for review of the ’498 patent); Zhuhai CosMX Battery Co., Ltd. v. Ningde Amperex Tech. Ltd., IPR2025-00432, Paper 2 (Jan. 10, 2025) (petitioning for review of the ’148 patent); Zhuhai CosMX Battery Co., Ltd. v. Ningde Amperex Tech. Ltd., IPR2025-00405, Paper 3 (Jan. 5, 2025) (petitioning for review of the ’910 patent).
The asserted patents are directed to lithium-ion batteries or sometimes more generally to electrochemical devices, and various components within. More details below.
The ’148 Patent
The ’148 patent, titled “Porous Film and Lithium-Ion Battery,” is directed to a porous film arranged on the surface of a positive electrode, a negative electrode, and/or a separator in a lithium-ion battery. The ’148 patent, 2:44-46.
According to the ’148 patent, the porous film includes a binder and inorganic particles fixed by the binder. The binder provides good adhesion, which can prevent the porous film from detaching during the use of the lithium-ion battery. The average pore size of the porous film is larger and the pore sizes are distributed uniformly to allow good electrolyte diffusion and absorption capability and high ionic conductivity. A low average wall thickness between the adjacent pores in the porous film prevents the binder from swelling in the electrolyte and blocking the pores. The inorganic particles in the porous film enhance the stability of the pore structure. These characteristics lead to improved battery performance. The ’148 patent, 3:16-51.
The ’148 patent, Fig. 1 (a 1000 times magnification of the pore structure of the lower surface of an exemplary porous film).
Amperex alleges infringement of at least Claim 1 of the ’148 patent, which recites:
A porous film, comprising:
a binder; and
inorganic particles;
wherein the porous film comprises pores formed by the binder, the pores at least comprises a part of the inorganic particles, wherein the inorganic particles have particle sizes that Dv10 is in a range of 0.015 μm to 3 μm, Dv50 is in a range of 0.2 μm to 5 μm, and Dv90 is in a range of 1 μm to 10 μm; Dv10 of the inorganic particles is less than Dv50 of the inorganic particles, and Dv50 of the inorganic particles is less than Dv90 of the inorganic particles, and the inorganic particles have particle sizes that the ratio of Dv90 to Dv10 is in a range of 2 to 100.
The ’148 patent, 25:33-46; Amperex v. CosMX, Case No. 2:24-cv-00728, Dkt. No. 1 at ¶ 34.
Amperex’s claim chart alleges that the CosMX CA386990G battery cell has a separator that includes a porous film with a binder and inorganic particles with particle sizes in the claimed ranges. Amperex v. CosMX, Case No. 2:24-cv-00728, Dkt. No. 1, Ex. J.
Amperex v. CosMX, Case No. 2:24-cv-00728, Dkt. No. 1, Ex. J at 4 (annotation in original).
The ’927 Patent
The ’927 patent, titled “Separator and Electrochemical Device,” is directed to a separator used in batteries that addresses “safety issues where the explosion of batteries is caused by external forces puncturing the battery when in use.” The ’927 patent, Abstract; id. at 1:22-27. The separator, according to the ’927 patent, includes a porous substrate and a porous layer disposed on at least one surface of the porous substrate. The porous layer includes a binder and inorganic particles. Id. at 5:27-30.
According to the ’927 patent, “in the safety evaluation of lithium ion batteries, a nail penetration test is employed to characterize the safety of the lithium ion battery under severe operating conditions.” The ’927 patent, 3:54-59. The ’927 patent discloses various ranges of thickness and porosity for the porous substrate, but specifies that “when the absolute plastic deformation rate satisfies the requisite of about 40% to about 1800%, the nail penetration test passing rate increases with increasing thickness of the porous substrate.” The ’927 patent, 5:66-6:3 (disclosing thickness ranges); id. at 6:8-13 (disclosing porosity ranges); id. at 6:3-17 (disclosing range of absolute plastic deformation rate).
The ’927 patent states that the purported invention has a porous substrate with “a large plastic deformation under external force, so that when the separator is pieced [sic] by a nail, the separator will have a large extensional deformation with the nail, thereby maintaining the effect in isolating the cathodes and anodes, preventing the internal short circuit in the lithium ion battery, and improving the safety of the lithium ion battery.” Id. at 4:41-47.
The ’927 patent, Fig. 1 (illustrating method for testing the plastic deformation rate of a porous substrate).
Amperex alleges infringement of at least claim 1 of the ’927 patent, which recites:
An electrochemical device, comprising:
a cathode;
an anode; and
a separator;
wherein, the separator comprises a porous substrate and
a porous layer;
wherein the porous layer is disposed on a surface of the porous substrate and comprises inorganic particles and a binder; and the porous substrate has an absolute plastic deformation rate in a first direction ranging from about 40% to about 1800%, and
wherein the absolute plastic deformation rate is calculated according to an equation (L2−L0)/L0×100%, where L0 refers to a length of the porous substrate before stretching and L2 refers to a length of the porous substrate after the porous substrate is stretched to breakage and docked along the fracture caused by the breakage and flattened.
The ’927 patent, 25:20-37; Amperex v. CosMX, Case No. 2:24-cv-00728, Dkt. No. 1 at ¶ 73.
Amperex’s claim chart alleges that the CosMX CA476588P-Q1 battery cell is an electrochemical device that satisfies the claim elements recited in claim 1 of the ’927 patent. Amperex v. CosMX, Case No. 2:24-cv-00728, Dkt. No. 1, Ex. M. For example, Amperex alleges CA476588P-Q1 includes a porous substrate and a porous layer:
Amperex v. CosMX, Case No. 2:24-cv-00728, Dkt. No. 1, Ex. M at 2.
The ’910 and’131 Patents
Both titled “Electrolyte and Electrochemical Device,” the ’910 and ’313 patents are from the same patent family, and are directed to an electrolyte used in “all kinds of primary batteries, secondary batteries, fuel cells, solar cells, or capacitors.” The ’910 patent, 19:16-18.
According to the ’910 patent, at a high voltage, the cathode material in electrochemical devices suffers an increase in oxidizability and a decrease in stability. The conventional solution, the patent states, is to “add a film-forming additive to the electrolyte, but doing so will cause an increase in the DC internal resistance of the battery, thereby resulting in a decrease in the cycle performance and a decrease in the capacity retention rate.” The electrolyte disclosed in the ’910 patent can purportedly be used to inhibit that increase in DC internal resistance. The ’910 patent, 22:57-23:5.
The electrolyte of the ’910 patent purportedly “comprises a dinitrile compound [X], a trinitrile compound [Y], and propyl propionate [Z]” wherein, based on the total weight of the electrolyte, the weight percentage of X, Y, and Z meet certain conditions. The ’910 patent, 6:1-11. In one formula, the condition is “about 2 wt %≤(X+Y)≤about 11 wt %” and in another formula, the condition is “about 0.1≤(X/Y)≤about 8”. Id. at 6:14-16.
The ’910 patent provides examples of dinitrile compounds such as butanedinitrile, glutaronitrile, adiponitrile, and many others, and examples of trinitrile compounds such as 1,3,5-pentanetricarbonitrile, 1,2,3-propanetrinitrile, 1,3,6-hexanetricarbonitrile, and many others. The ’910 patent, 7:19-44; id. at 7:45-8:34.
The ’910 patent discloses test results showing that “[t]he DC internal resistance of the battery was significantly increased after cycles” with the addition of butanedinitrile or 1,3,6-hexanetricarbonitrile but no propyl propionate. The ’910 patent, 25:10-27:43. But when all three were used simultaneously, “the increase in DC internal resistance of the battery after cycles was obviously inhibited.” Id. at 27:44-48.
Amperex alleges infringement of at least claim 20 of the ’910 patent, which recites:
An electrolyte, comprising a dinitrile compound, a trinitrile compound, and propyl propionate, wherein, based on a total weight of the electrolyte, a weight percentage of the dinitrile compound is X, a weight percentage of the trinitrile compound is Y and a weight percentage of the propyl propionate is Z; wherein,
about 2.2 wt %≤(X+Y)≤about 8 wt %,
about 0.1≤(X/Y)≤about 6,
5 wt %≤Z≤20 wt % or 30 wt %≤Z≤50 wt %, and
about 0.01≤(Y/Z)≤about 0.3;
wherein the dinitrile compound comprises at least one selected from the group consisting of butanedinitrile, adiponitrile, ethylene glycol bis(2-cyanoethyl) ether, and 1,4-dicyano-2-butene; and the trinitrile compound is one or more compounds selected from the group consisting of 1,3,6-hexanetricarbonitrile , 1,2,6-hexanetricarbonitrile and 1,2,3-tris(2-cyanoethoxy)propane;
wherein the electrolyte further comprises 1,3-propanesultone and fluoroethylene carbonate; wherein,
based on the total weight of the electrolyte, a weight percentage of the 1,3-propanesultone is not less than 0.1 wt %, and not greater than 3 wt %.
The ’910 patent, 36:49-37:7; Amperex v. CosMX, Case No. 2:24-cv-00728, Dkt. No. 1 at ¶ 47.
Amperex also alleges infringement of at least claim 1 of the ’131 patent, which recites:
An electrochemical device, comprising:
an electrode; and
an electrolyte comprising a dinitrile compound, a trinitrile compound, and propyl propionate; wherein,
based on a total weight of the electrolyte, a weight percentage of the dinitrile compound is X, and a weight percentage of the trinitrile compound is Y; wherein,
about 2 wt %≤(X+Y)≤about 8 wt %, and
about 0.1≤(X/Y)≤about 6; wherein,
the electrode comprises a current collector, a single-sided coating and a double-sided coating;
a first part of the current collector is provided with the single-sided coating and a second part of the current collector is provided with the double-sided coating; and
an electrode compaction density of the electrode corresponding to the first part with the single-sided coating is D1, and, an electrode compaction density of the electrode corresponding to the second part with the double-sided coating is D2, wherein, about 0.8≤D1/D2≤about 1.2;
wherein based on the total weight of the electrolyte, a weight percentage of the propyl propionate is Z; wherein,
about 0.01≤(Y/Z)≤about 0.3;
wherein the trinitrile compound is one selected from the group consisting of 1,3,5-pentanetricarbonitrile; 1,2,3-propanetrinitrile; 1,3,6-hexanetricarbonitrile; 1,2,6-hexanetricarbonitrile; 1,2,3-tris(2-cyanoethoxy)propane; 1,2,4-tris(2-cyanoethoxy)butane; 1,1,1-tris(cyanoethoxymethylene)ethane; 1,1,1-tris(cyanoethoxymethylene)propane; 3-methyl-1,3,5-tris(cyanoethoxy)pentane; 1,2,7-tris(cyanoethoxy)heptane; 1,2,6-tris(cyanoethoxy)hexane; 1,2,5-tris(cyanoethoxy)pentane; and any combination thereof.
The ’131 patent, 33:18-53; Amperex v. CosMX, Case No. 2:24-cv-00728, Dkt. No. 1 at ¶ 60.
Amperex’s claim chart alleges that the CosMX CA496485F-Q1 battery cell has an electrolyte that satisfies the claim elements listed above. Amperex v. CosMX, Case No. 2:24-cv-00728, Dkt. No. 1 Exs. K, L. Specifically, Amperex alleges the battery’s electrolyte includes the following weight percentages:
Amperex v. CosMX, Case No. 2:24-cv-00728, Dkt. No. 1, Ex. K at 2; see also id.at Ex. L at 2.
The ’498 Patent
The ’498 patent, titled “Lithium-Ion Battery Having Desirable Safety Performance,” is directed to the internal structure of a lithium-ion battery that uses a recess for its leads. The ’498 patent, Abstract.
According to the ’498 patent, conventional lithium-ion batteries feature a lead that is soldered on a current collector to conduct current. This structure increases the thickness of the lithium-ion battery. The ’489 patent references prior art disclosing a lithium-ion battery which defines a recess on one end of a positive and/or negative plate to receive a lead therein, which reduces the thickness. But the prior art recess structure is not ideal because “thickness variation around the recess is much larger than the thickness variation of the film afar from the recess” and “[t]he film around the corners is readily peeled off, especially when the negative active material adopts an expansive substance, such as silicon.” These problems, the ’498 patent states, affect the safety performance of the lithium-ion battery. The ’498 patent, 1:36-2:3.
The purported invention of a battery includes a positive plate 1, a negative plate 2, a separator 3 disposed in between the two plates and electrolyte (not shown). The ’498 patent, 4:66-5:3.
The ’498 patent, Fig. 5.
The positive plate 1 includes a positive current collector 11, a positive film 12, and a positive lead 13. The ’498 patent, 5:3-5.
The ’498 patent, Fig. 1.
The negative plate includes a negative current collector 21, a negative film 22 defining a first recess, and a negative lead 23. The positive lead 13 is soldered and seated in the first recess 14. The negative film 22 defines a second recess 24. The negative lead 23 is soldered and seated in the second recess 24. The ’498 patent, 5:5-12.
The ’498 patent, Fig. 3.
An upper surface and a lower surface of the positive lead 13 each is formed with a first insulating glue layer 15. A surface of the positive film 12 corresponding to the second recess 24 is pasted with a second insulating glue layer 16. The ’498 patent, 5:12-17.
The ’498 patent, Fig. 2; see also id. at Fig. 1.
The ’498 patent states that its purported invention “provide[s] a battery which has high energy density and desirable safety performance.” The ’498 patent, 2:10-12. According to its cycle test results, the insulating glue layers 15, 16 may improve the safety performance of the lithium-ion battery. The ’498 patent, 9:1-20. The structure of the positive plate and negative plate may overcome uneven thickness of the battery cell. Id. at 9:30-48. Further, the recesses 14, 24 may reduce abscission of active material. Id. at 9:56-10:25.
Amperex alleges infringement of at least claim 1 of the ’498 patent, which recites:
A lithium-ion battery, comprising:
a positive electrode comprising a positive current collector and a positive electrode active material layer containing LiCoO2, wherein the positive electrode active material layer is formed on the positive current collector, the positive electrode active material layer being provided with a first recess accommodating a positive lead being coupled with the positive current collector;
a negative electrode comprising a negative current collector and a negative electrode active material layer containing graphite or silicon, wherein the negative electrode active material layer is formed on the negative current collector, the negative electrode active material layer being provided with a second recess accommodating a negative lead being coupled with the negative current collector;
a separator disposed between the positive electrode and the negative electrode; and
an electrolyte,
wherein, a top surface of the positive lead is provided with a first insulating glue layer, a surface of the positive electrode active material layer opposite to the second recess across the separator in a thickness direction of the positive plate and the negative plate is pasted with a second insulating glue layer, the second insulating glue layer has a width larger than a width of the second recess, and the second insulating glue layer has a length larger than a length of the second recess.
The ’498 patent, 10:42-11:2; Amperex v. CosMX, Case No. 2:24-cv-00728, Dkt. No. 1 at ¶86.
Amperex’s claim chart alleges that the CosMX CA496485F-Q1 battery cell has the structure recited in claim 1 of the ’498 patent. Amperex v. CosMX, Case No. 2:24-cv-00728, Dkt. No. 1 Ex. N. For example, Amperex alleges CA496485F-Q1 includes positive and negative electrodes with a recess accommodations and blue adhesive tapes acting as an insulating glue layers:
Amperex v. CosMX, Case No. 2:24-cv-00728, Dkt. No. 1, Ex. N at 2, 5.
Amperex v. CosMX, Case No. 2:24-cv-00728, Dkt. No. 1, Ex. N at 3, 6.