Pre-Lithiated Silicon As the Anode Material for the Next Generation of Lithium Ion Batteries

It is widely believed that next generation of lithium ion batteries (LIBs) needs non-graphite anodes.  Among all anode materials scrutinized to date, silicon (Si) is one of the most promising ones, because of its exceptionally high charge capacity, earth abundance, low cost, and well-developed industrial infrastructure.  However, silicon suffers from a poor cyclability due to the volume fluctuation induced electrode damage during the lithiation/delithiation cycles.  To date, many strategies have been attempted to tackle this problem.  Pre-lithiated silicon (lithium silicide, Li_xSi) holds the promise for alleviating the poor-cyclability problem, as the pre-occupied space by Li can provide adequate volume for the subsequent lithiation/delithiation processes.  However, Li_xSi has high reactivity, the challenge in electrode fabrication is to prevent surface damage prior to battery assembly.

In this presentation, we will report our tactics of overcoming the challenge, starting from materials synthesis, structural characterizations, surface modification, and performance assessments.  Compared with the un-lithiated Si electrodes, the Li_xSi electrodes show much better charge capacity, cyclability, and rate capability.