United States Patent and Trademark Office >>
Jul. 30, 2020: StoreDot receives patent for anode preparation system applying dry etching treatment to the anodes.
Because of their outstanding energy density and long cycle life, lithium‐ion batteries (LIBs) are being used in an ever-increasing number of energy storage applications. Everything from grid energy storage, to consumer electronics, and electric vehicles are turning to LIBs.
And as the production volumes increase, manufacturers are looking for ways to simplify manufacturing, reduce costs and improve performance. Thus StoreDot’s patent describes efficient and economical processes and mechanisms for preparing anodes - especially metalloid-based anodes for fast-charging lithium-ion cells - that improves the technology driving energy storage.
The patent outlines a method of preparing a raw anode from oxidized active material particles, together with a supporting structure that includes electron conductive elements and ion conductive channels that interconnect the oxidized active material particles to each other and the surface of the raw anode. The process ensures the reduction (de-oxidation) takes place on the surface areas of the particles which are in contact with the ion-conductive channels, thereby ensuring a good ion conductivity of the anode.
In general, anode preparation takes place in an aqueous (water-based) environment, such as in a water-based slurry, or in any other potentially oxidizing atmosphere, such as air. Expediently, by oxidizing (followed by de-oxidation) the active material particles in the raw anode, the preparation processes can also be simplified significantly, thereby enhancing productivity and safety, as oxidized active material particles are much less reactive than prior art non-oxidized active material particles.
As part of the process, an RIE (Reactive-ion etching) treatment is applied to the raw anode to at least partly reduce the oxidized active material particles - whose conductivity is rather low when compared to non-oxidized particles - thereby enhancing electrical conductivity.
By following the methodology described in the patent manufacturers can simplify the manufacturing process and improve the performance and safety of the anode, and therefore of the battery.