Increased Capacity Retention of Silicon Anodes for Lithium Batteries

This proposal offers a new approach to stabilizing the very high capacity Si to use for lithium ion anodes - the use of a LiSi alloy rather than only Si. By starting with a silicon alloy instead of pure silicon, the initial structure is already in a stable expanded state. Mathematically stresses encountered on charging and discharging are reduced when the silicon is partially lithiated. It has been shown experimentally, there is much irreversible loss in than is encountered in pure silicon.In fact, there will be an excess of lithium contributing to extended cycle life. Cells could even be built with non-lithiated cathode materials significantly reducing the stresses as there would be no expansion and controlling the lithium transfer.This approach has a high probability of success as the alloy is compositionally the same as a charged Si anode.The study includes different alloys and alloy ratios, different particle size distributions and even surface treatment to improve interface stability.Dr. Stanley Whittingham Professor at SUNY Binghamton, Director of NECCES and a celebrated pioneer in lithium ion is a supporter of this proposal.