With the mass proliferation of mobile devices, anything that extends battery life is most welcomed. Such is the case with ChemSEI-Linker, a composite material, paste, and linking material applied to lithium battery electrodes, that increases battery life up to 70% and makes lithium batteries easier to recycle. Created at the Industrial Technology Research Institute (ITRI), ChemSEI-Linker is an artificial nanoscale solid electrolyte interface of unique composition and structure that stabilizes lithium battery electrodes.
The materials cover lithium battery electrodes and protects them from a solid electrolyte interface (SEI) layer that forms on electrodes during the discharge/charge process. ChemSEI-Linker modifies the destructive SEI layer on electrodes and eliminates battery degradation that the SEI layer causes, thus preserving the battery, increasing its life, maintaining high energy, and enabling high safety, high voltage endurance, low cost, and fast charging and discharging. Normally, the SEI layer accelerates battery aging, reduces discharge/charge cycles, and adds steps and cost to recycling due to cracks that it creates on electrodes.
In an electric-vehicle application such as a Tesla Model S, the use of ChemSEI-Linker could increase its range by 15 percent and extend the number of charge-discharge cycles by 70 percent. It would also reduce battery cost, which is currently more than 40 percent of the overall vehicle cost, by decreasing the number of required batteries.
ChemSEI-Linker not only reduces battery-recycling costs but also improves safety. As a layer protects the active electrode material, the charge-discharge cycle does not produce microcracks. Since the intrinsic structure of the active electrode material is undamaged, a manufacturer can extract the material and reuse it directly. Conventional electrodes, when recycled, must be turned into lithium carbonate and various metals by intermediate physical and metallurgical recycling processes. ChemSEI-Linker eliminates this need for regeneration of electrode material and streamlines recycling operations and reduces costs. It also improves battery safety, as batteries equipped with ChemSEI-Linker pass nail-penetration tests.
ChemSEI-Linker includes a self-forming chemical solid electrolyte interface modification technology (ChemSEI) and an electrode paste with a linker (Chemlinkbat paste), integrated into a unique, multifunctional architecture. It combines in-situ organic hyperbranched polymer material with silane-type linkers, electro-conductive additives (graphite, carbon nanotubes, metallic flakes or fibers) and conductive metallic ion inorganic structural materials. These integrated technologies enable the design and development of battery electrodes called Chemlinkbat electrodes, which are integral to a lithium-ion battery that features high capacity, long service life, high safety, and high voltage endurance.
ChemSEI-Linker causes a protective film to form on the surface of the active electrode cathode and anode materials during the mixing of the Chemlinkbat electrode paste. This film provides stress buffering and functional protection for the interfaces between the active electrode materials, electro-conductive additives, and binders of the electrode paste. Without this protection, the various components would damage each other. ChemSEI-Linker protects the active electrode materials from being attacked and damaged by the electrolyte, and reduces the cumulative electrochemical damage of the SEI film.
Chemlinkbat paste can be applied with two-sided precision coating and baking to manufacture ChemSEI-Linker electrodes with excellent features, such as highly flexible SEI film that strongly adheres to the active electrode materials. These electrodes have high durability and great stability, and can be assembled into a unique cell.
ChemSEI-Linker can also be used as an adhesive to join active electrode particles, electro-conductive additives, and binders. Electrodes with ChemSEI-Linker show remarkably excellent structural intensity, flexibility, and stability, and can be used in batteries designed for high energy density and long life. Batteries including ChemSEI-Linker provide a substantial advance in battery technology.