Optimization of Graphite–SiO blend electrodes for lithium-ion batteries: Stable cycling enabled by single-walled carbon nanotube conductive additive.

Lithium-alloying materials are of great interest to improve the gravimetric and volumetric energy density of lithium-ion batteries, though their associated volume fluctuation with cycling often leads to poor cycling performance. Active–inactive alloys and blending alloys with carbon materials are common strategies to accommodate volume fluctuation. Herein we set out to optimize graphite–SiO blend electrode formulations to eliminate rapid capacity fade. Electrodes with highly stable cycling were prepared by simple planetary mixing procedures, enabled by the use of just a fraction of a weight percent of commercial SWCNTs as the only conductive additive, and by the appropriate choice of binder/stabilizing agent. In fact, the use of SWCNTs allowed for graphite-free SiO electrodes with approximately 74% higher volumetric energy density relative to traditional graphite electrodes, and superior capacity retention in coin-type full-cell testing versus NMC532 cathodes. • Capacity retention of graphite–SiO blend electrodes is significantly improved by the use of a commercial single-walled carbon nanotube (SWCNT) product relative to carbon black. • Excellent cycling performance is achieved for a variety of blend formulations using only a fraction of a weight percent of SWCNT, and prepared with simple and scalable planetary mixing procedures. • The use of SWCNT conductive additive enables graphite-free SiO electrodes with 74% higher volumetric energy and superior full-cell cycling compared to graphite electrodes. [ABSTRACT FROM AUTHOR]