QuantumScape has filed a patent for processes to create lithium-stuffed garnet oxides with passivated surfaces that resist the formation of unwanted substances. The patent also covers new materials made using these processes. GlobalData’s report on QuantumScape gives a 360-degree view of the company including its patenting strategy. Buy the report here.
According to GlobalData s company profile on QuantumScape, hydrogen storage alloys was a key innovation area identified from patents. QuantumScape's grant share as of June 2023 was 1%. Grant share is based on the ratio of number of grants to total number of patents.
Processes for making lithium-stuffed garnet oxides with passivated surfaces
A recently filed patent (Publication Number: US20230207868A1) describes a process for making a sintered lithium-stuffed garnet thin film or pellet. The process involves several steps, including providing a solution comprising a salt and a solvent, immersing the sintered lithium-stuffed garnet thin film or pellet in the solution, and removing the surface of the film or pellet from the solution. The temperature of the solution during immersion ranges from 0°C to 60°C.
The patent claims specify that the salt used in the solution can be selected from a group of salts including LiPF6, LIBETI, LiTFSI, LiBF4, LiAsF6, and LiFSI, among others. The concentration of the salt in the solution is stated to be between 0.5 M and 1.5 M.
The solvent used in the process can be chosen from a group of solvents including EC, DMC, PC, DEC, THF, GBL, FEC, FMEC, F-EMC, F-EPE, F-AEC, and others. The patent claims also mention specific solvents such as SCN, GLN, sulfolane, EC, and EMC. The solvent is required to have a water content of less than certain specified levels, ranging from less than 200 ppm to less than 10 ppm.
The patent claims also describe the characteristics of the lithium-stuffed garnet thin film or pellet before and after the process. The film or pellet is characterized by a specific chemical formula before the immersion step. After the immersion and removal steps, the surface of the film or pellet is said to have a fluorinated surface, with fluorine or fluoride present at a depth of penetration ranging from 0.5 µm to 1.5 µm. The surface may also have fluorine bonded to elements in the lithium-stuffed garnet.
The process aims to ensure that the surface of the film or pellet is free or substantially free of contaminants, with Li2CO3 being specifically mentioned as a contaminant to be avoided.
Overall, the patent describes a detailed process for making a sintered lithium-stuffed garnet thin film or pellet, providing specific instructions regarding the salt, solvent, temperature, and other parameters involved. The process aims to achieve a fluorinated surface and eliminate contaminants, potentially enhancing the performance and stability of the lithium-stuffed garnet material.