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

ABSTRACT 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 0.8 Co 0.1 Mn 0.1 O 2 ‐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.