Thermal safety overview of silicon-carbon anode in lithium-ion batteries: Key parameters in determining the reactivity

The quest for high-energy-density lithium-ion batteries has led to the widespread adoption of silicon anodes, yet their safety, particularly regarding thermal runaway, remains a critical concern. Herein, the thermal safety overview of silicon-carbon anode is conducted to identify the determinants of materials reactivity and heat generation sources. In the hierarchical silicon-carbon anode, surface floating silicon without carbon protection is a serious hazard affecting the thermal safety, exhibiting a 77 % increase in heat release at 100 % state of charge. When the pouch cells with floating silicon are conducted in the test of accelerating rate calorimeter, the maximum temperature can be 875.2 °C (532.1 °C for samples without floating silicon). In addition, the thermal safety of graphite anodes blending with different ratios of silicon-carbon electrode are also explored, confirming the potential safety risks of high-silicon-content lithium-ion batteries. This work presents comprehensive understandings on the thermal features of the high-capacity silicon-carbon anode, which is pivotal for enhancing the safety of next-generation silicon-based high-energy-density batteries.