Improving the Cycling Stability of SnO₂–Graphite Electrodes

The combination of SnO2 and graphite in a composite electrode allows obtaining a Li-ion battery negative electrode with enhanced specific charge. However, the reported cycling stability of these electrodes is often rather poor. Here we report conditions under which long-term cycling for these electrodes can be achieved, determined by studying the effects of the electrode and electrolyte composition as well as of the cycling protocol on the cycling stability of SnO2–graphite electrodes. The amount and type of binder, in combination with an optimized amount of electrolyte additive and applied limitation to the delithiation cutoff potential, play a major role in stabilizing performance of these electrodes. A specific charge retention of 81.5% after 300 cycles was obtained for electrodes prepared with 50 wt % SnO2, KS6L graphite, and PAA:CMC binder cycled with FEC electrolyte additive by using a 1.0 V delithiation cutoff potential.