A breakthrough in lithium battery
HSINCHU, TAIWAN – The Industrial Technology Research Institute (ITRI), introduced a composite material named ChemSEI-Linker. ChemSEI-Linker is a paste and linking material applied to lithium battery electrodes, which increases battery life up to seventy percent and makes it easier to recycle lithium batteries. ITRI explained this in technical terms, ChemSEI-Linker is an artificial nanoscale solid electrolyte interface of unique composition and structure that stabilizes lithium battery electrodes.
ChemSEI-Linker covers lithium battery electrodes and protects them from a solid electrolyte interface (SEI) layer that forms on electrodes during the discharge or charge process. ChemSEI-Linker does this by modifying the destructive SEI layer on electrodes and eliminates battery degradation that is caused by the SEI layer, thus preserving the battery, and increasing its life. It also allows for the maintenance of high energy, enabling safety, high voltage endurance, low cost, and fast discharging and charging. Typically, the SEI layer accelerates battery aging, reduces discharge and charge cycles, and adds steps and expense to recycling due to cracks created on electrodes.
In an electric-vehicle application such as a Tesla Model S, the use of ChemSEI-Linker could increase its driving range by 15 percent and would extend the number of charges and discharge cycles by 70 percent. Battery cost would be reduced, which is currently more than 40 percent of the overall vehicle cost, just by decreasing the number of required Li-ion batteries.
ChemSEI-Linker reduces battery-recycling costs and also improves safety. Because the ChemSEI-Linker layer protects the active electrode material, the charge-discharge cycle microcracks are not produced. The intrinsic structure of the active electrode material is undamaged, allowing a manufacturer to extract the material and reuse it directly. Conventional electrodes, when recycled, must be turned into lithium carbonate and various metals by using intermediate physical and metallurgical recycling processes. ChemSEI-Linker eliminates the need for regeneration of electrode material, streamlines recycling operations, and reduces costs. ChemSEI-Linker improves battery safety, as batteries equipped with ChemSEI-Linker will pass the nail-penetration tests.
Since the 2015 United Nations Climate Change Conference passed the Paris Agreement Air pollution caused by fossil fuel-driven vehicles has been recognized, and there is a global challenge calling for solutions. Globally, Nations are actively developing industries and products related to electric cars. This includes safe, high-capacity, high-power, long-life, and low-cost lithium-ion batteries. Service life, energy density, power density, capacity, and safety are the most crucial technological challenges for efficient lithium-ion batteries. The current technology for large-scale lithium-ion battery production lacks sufficient technical maturity and is very expensive. Because there are so many factories that produce batteries with limited functionality, small capacity, and insufficient endurance ITRI developed ChemSEI-Linker to address environmental concerns and improve the performance, recyclability, and safety of lithium batteries, said Dr. Jing-Pin Pan, Chief Technology Officer of ITRI’s Material and Chemical Research Laboratories.
ChemSEI-Linker includes a self-forming chemical solid electrolyte interface modification technology called ChemSEI and an electrode paste with a linker called Chemlinkbat paste which is 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. Integrating 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, safety, and high voltage endurance. ChemSEI-Linker allows a protective film to form on the surface of the active electrode cathode and anode materials of the Chemlinkbat electrode paste during mixing.
This film provides stress-buffering and functional protection for the interfaces between the active electrode materials, electroconductive 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.
The chemlinkbat paste can be applied with two-sided precision coating and baking to manufacture ChemSEI-Linker electrodes with highly flexible SEI film that firmly adheres to the active electrode materials. These electrodes have high durability and excellent stability and can be assembled as a unique cell. ITRI says that “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 lithium-ion batteries designed for high energy density and long life. Batteries including ChemSEI-Linker provide a substantial advance in battery technology.”
ChemSEI-Linker is currently a finalist for the research and development of 100 Awards in the United States.