On September 24, 2024, the United States District Court for the Northern District of California threw out a trade secret suit brought by startup company Soelect Incorporated (“Soelect”) against Hyundai Motor Company (“Hyundai”). The court granted Hyundai’s motion to dismiss for lack of personal jurisdiction, improper venue, and failure to state a claim. Soelect Inc. v. Hyundai Motor Co., Case No. 3:23-cv-05405, Dkt. No. 52 (N.D. Cal. Sept. 24, 2024).
Soelect describes itself as “a corporation that develops revolutionary lithium anode battery technology for rechargeable lithium batteries for high energy applications, such as electric vehicles.” Soelect v. Hyundai, Case No. 3:23-cv-05405, Dkt. No. 1 at ¶ 4 (N.D. Cal. Oct. 20, 2023). There is no public information on the docket about what trade secrets Hyundai allegedly misappropriated, but a review of Soelect’s published U.S. patent applications may shed light on some of its lithium anode battery technology.
U.S. Patent Application 17/808,326 (“the ’326 application”)
The ’326 application, titled “Lithium Metal Anodes and Method of Making Same” and published on December 1, 2022, is directed to reducing dendrite formatting by laminating lithium metal anodes with particulate materials using a roller press process.
According to the ’326 application, lithium metal is one of the most promising high energy and power anode material for next generation electronic devices and electronic vehicles. The ’326 application at ¶ [0003]. But conventional battery technology causes lithium to form dendrites, which in turn reduces battery performance. Id.
Dendrites form due to the highly reactive nature of solid lithium. For example, one prior art process makes lithium metal anodes by plating lithium metal onto a solid electrolyte interphase (“SEI”) film. This process causes cracks in the SEI film. When additional lithium metal is plated, lithium dendrites form in those cracks. The ’326 application at ¶ [0004]. Moreover, during battery use, lithium dendrites accumulate into a layer of “dead” lithium on the surface of the plated SEI film, resulting in thickened film and a porous electrode. These properties reduce battery performance. Id.
The ’326 application proposes what it describes as a cost-effective process that reduces dendrite formation and creates more uniform surface topography. The ’326 application at ¶¶ [0005-9]. Specifically, the ’326 application proposes forming a lithium metal composite anode by adding particulate material to the anode. Id. at ¶ [0011]. Below are exemplary anodes:
The ’326 application, Figs. 1-3 (labels repositioned; annotated).
The particulate material can be one or a mixture of (1) polymers; (2) organic materials that can be used in any electrolyte materials; (3) inorganic materials that can be dissolved in solvents, polarizable lithium salts, non-polarizable lithium salts and combinations thereof; and (4) metallic and non-metallic lithiophilic materials. The ’326 application at ¶ [0011]; see also id. at ¶¶ [0033-39] (providing additional requirements for preferred particulate materials).
The ’326 application also provides two preferred manufacturing processes. One is a roll coating process using press rollers 340, 350 to press two film layers 300, 320 together. A feeder device 360 distributes particulate material 310 before the press, while a nip 330 sandwiches particulate material 310 between the two film layers after the press. The ’326 application at ¶¶ [0027 ,31].
The ’326 application, Fig 4 (labels repositioned; annotated).
The alternative process provides an additional step of evaporating all solvent and moisture from the first layer 400 before pressing the two layers 400, 420 together. The ’326 application at ¶ [0028].
The ’326 application, Fig 5 (labels repositioned; annotated).
To achieve the result illustrated in Figure 1 above, the second layer may be stripped away. To achieve the result illustrated in Figure 3 above, after stripping away the second layer, the first layer may be folded upon itself and then passed through the nip again one or more times to distribute the particulate material throughout the resulting anode. The ’326 application at ¶ [0029].
Lastly, the ’326 application provides exemplary battery cells and related manufacturing process. See, e.g., the ’326 application at ¶¶ [0040-55]. According to the ’326 application, these exemplary cells performed better and lasted longer than control cells. See id. at ¶¶ [0042-55].
Claim 1 of the ’326 application currently recites:
A lithium metal anode for a battery comprising at least a portion of lithium metal and one or more particulate material(s), wherein the one or more particulate material(s) are adhered or embedded on or in the portion of lithium metal, and wherein the one or more particulate material(s) inhibit or eliminate the formation of a dendrite.
U.S. Patent Application 18/571,869 (“the ’869 application”)
The ’869 application, titled “Semisolid Electrolyte Membrane and Method of Fabrication Thereof,” is directed to a membrane that can act as a separator and electrolyte conduit within a rechargeable battery.
According to the ’869 application, rechargeable energy storage devices that use liquid electrolytes suffer from certain shortcomings. For example, the liquid electrolytes themselves are generally volatile and potentially dangerous, particularly when the cell overheats. Further, liquid electrolytes can lead to unwanted side reactions and corrosion of the cathode, thereby limiting self-discharge and efficiency of the cell. The ’869 application at ¶ [0004].
On the other hand, rechargeable batteries using solid-state electrolyte films (solid-state batteries) also suffer from certain shortcomings. Conventional solid electrolytes include sulfide-based and oxide-based conductive polymers that exhibit poor ionic conductivity and interface resistance between the positive and negative electrodes and these polymers. The ’869 application at ¶¶ [0005-8]. These solid-state electrolytes are also rigid and prone to internal damage caused by external forces. Id. at ¶ [0009].
The purported invention of the ’869 application is a semisolid electrolyte membrane that can act as a separator and electrolyte conduit within a rechargeable battery. According to the ’869 application, the article is cheap to manufacture and exhibits flexibility and low rigidity after electrolyte induction, while permitting sufficient electrolyte transfer for safe and effective battery use. The ’869 application at ¶ [0011].
The semisolid electrolyte membrane is a swollen porous base material with two layers of electrolyte deposited on top. The ’869 application at ¶ [0012]; see also id. at ¶¶ [0015-17] (providing preferred materials for base material). The electrolyte deposition layers may include rotating molecules that can pass through the semisolid electrolyte membrane for charge and discharge. Id. at ¶ [0014] (providing preferred rotating molecules); see also id. at ¶¶ [0018-22] (providing preferred electrolyte formulations the electrolyte deposition layers).
The ’869 application, Fig. 3.
The ’869 application further provides that two distinct electrolyte deposition layers may be deposited on both sides of the base material, thereby creating a semisolid separator/electrolyte structure. This would drastically reduce or even eliminate the use of liquid electrolytes. The ’869 application at ¶ [0014].
The ’869 application, Fig. 4 (illustrating a semisolid electrolyte membrane being used as a separator); see also id. at ¶ [0042].
According to the ’869 application, compared to conventional cells, cells using a semisolid electrolyte membrane have an improved life span and limited unwanted dendrite formation. The ’869 application at ¶¶ [0053, 56].
Claim 1 of the ’869 application currently recites:
A semisolid electrolyte membrane exhibiting a tensile strength of from 1 to 50 MPa, wherein said membrane comprises a swollen porous base material having a top side and a bottom side and selected from hydrophilic fibers, hydrophilic films, and any combinations thereof, wherein said swollen porous base material comprises at least two layers of electrolyte deposited thereon at least one of said top and bottom side thereof, wherein a first layer of said electrolyte deposition resides within at least some of the pores as well as on the surface of said swollen porous base material and wherein a second layer of said electrolyte deposition resides on top of said first layer of said electrolyte deposition, and wherein said semisolid electrolyte membrane exhibits ionic conductivity of from 10-4 S/cm to 10-3 S/cm.