Evaluation of Silicon-Rich Anodes for Low-Temperature Applications

Silicon-rich anodes were investigated as promising alternatives to graphite for lithium-ion batteries operating at sub-zero temperatures. Micro-sized silicon particles were employed with a capacity-limitation strategy (1000 mAh g−1) to mitigate mechanical stress and volume expansion during cycling. Electrochemical performance was assessed in three-electrode half-cells and bi-layer pouch full-cells (Si - NMC811) at temperatures ranging from 25 °C down to −25 °C. Despite the increased polarization and hysteresis observed in the galvanostatic charge/discharge profiles at low temperatures, micro-Si anodes retained a reversible lithiation/delithiation behaviour and high coulombic efficiency. Full-cell response was mainly affected by the NMC cathode, while the Si anode exhibited good capacity retention. These results demonstrate that capacity-limited micro-silicon anodes enable stable and efficient operation under cold conditions, providing a scalable, safe, and cost-effective route toward next-generation lithium-ion batteries and reducing reliance on graphite now listed as a critical raw material in the EU.