All-in-One Interface Engineering From Bulk to Electrode Toward High-Performance Micro-Sized Silicon Anodes

Interface engineering that simultaneously targets the silicon particle surface and the electrode-level interfaces among silicon particles, binders, and conductive additives is a key direction for addressing the large volume expansion (∼300%) of silicon anodes, especially for low-cost microsized silicon (µ-Si). Herein, an integrated co-carbonized (ICC) electrode was successfully fabricated (µ-Si@C/ICCE) without organic binder and conductive additives. The surface of µ-Si particles and the interface of the electrode evenly distributed a uniform carbon layer, which is attributed to the ICC process of the pre-coated layer of µ-Si particles and the pre-binder of the electrode. This design regulates the µ-Si particles' surface and also robustifies the electrode interface. The µ-Si@C/ICCE exhibited a high initial coulombic efficiency of 86.88% and strong mechanical stability. The µ-Si@C/ICCE electrode was further cycled for 400 cycles and retained a capacity of 1355 mAh g^-1, corresponding to a capacity retention of 84%. In addition, the µ-Si@C+G/ICCE electrode delivered a high areal capacity of 6.13 mAh cm^-2 after 500 cycles with a capacity retention of 91%. More importantly, the matched LiNi_0.8Co_0.1Mn_0.1O₂-based pouch cell validated the practical applicability and commercialization potential of the µ-Si@C/ICCE electrode. This work provides an effective strategy to solve the instability of Si-based anodes from the bulk to electrode interface design.