(606f) Development of Nanoporous Si/Graphene Nanomaterial for High Performance Lithium Batteries

The interest in developing higher energy capacity and longer cycle life rechargeable lithium batteries is steadily increasing with the realization of its potential capabilities especially in electric vehicles. Recently, silicon-based anode materials are being explored as an anode material due to its low discharge potential and its theoretical capacity (highest known, 4,200 mAh/g) which is more than 10 folds of the traditional graphite anodes. However, due to the increased accommodated lithium ions, silicon's volume varies by 400% causing pulverization and loss of electrical contact. This study explores the use of electrochemically etched nanoporous silicon to maximize surface area for lithium alloying and to allow spaces for volume expansion. The material is then coated with graphene overlayers to enhance capacity retention and cyclability thru stabilization of the solid-electrolyte interface.