Micron-Size Silicon Monoxide Asymmetric Membranes for Highly Stable Lithium Ion Battery Anode

To meet the increasing demand for high energy density lithium ion batteries for electric vehicles and mobile electronics, it is mandatory to make revolutionary changes in electrode materials and chemistry. In this report, micron-size silicon monoxide powders are utilized to fabricate asymmetric membranes via a phase inversion method. We investigate the effects of carbonization temperature, silicon monoxide concentration and glues on membrane microstructure and electrochemical performance. It iss also observed that silicon monoxide powders in the membranes consist of silicon with multiple oxidation states. All silicon monoxide asymmetric membrane electrodes are characteristic of significantly improved cycling stability as compared to the control silicon monoxide electrode. The best cycling performance is achieved from the asymmetric membrane with lower silicon monoxide content and using carboxymethyl cellulose as the glue. 95% initial capacity can be retained after 110 cycles at 400 mA g⁻¹ for the membrane with ∼33 wt.% silicon monoxide. Its initial capacity loss is only 23.1% with an average coulombic efficiency of 99.82% over 110 cycles.