Influence of electrolyte to silicon electrode volume ratio on the capacity of next generation lithium ion cells at low temperature

•Characteristics like electrode thickness and electrolyte volume affect performance.•Large electrolyte to electrode volume (20:1) significantly improves capacity.•Relationship between electrolyte and electrode volume needs to be understood. Silicon electrodes are being investigated as potential high-capacity replacements for graphite electrodes in lithium-ion batteries. Various factors affecting silicon electrodes need to be understood to maintain increased capacity and high performance at subzero temperatures. This work investigates electrode thickness and volume of electrolyte used that can affect performance of a copper modified silicon electrode at −20 °C. When electrolyte volume is large compared to electrode volume (20:1 ratio), the performance of these cells at low temperature is noticeably improved, retaining approximately 400 mAh/g capacity at −20 °C after 50 cycles.