A Review on Mechanical, Electrical, Chemical, and Electrochemical Properties of Coating Materials for Silicon Anodes in Lithium-Ion Batteries.

Silicon (Si) has emerged as a highly promising anode material for next-generation lithium-ion batteries of high energy density. Nevertheless, its commercial adoption remains hindered by the disastrous huge volumetric evolution during repeated de-/lithiation cycles. Full coating of Si has proven effective in addressing these intrinsic limitations. Since coating properties directly govern electrochemical performance, optimizing coating characteristics must be pursued synergistically with Si structural engineering to finally realize commercially viable Si anodes. While previous reviews have predominantly examined coated electrode characteristics and coating techniques, a critical knowledge gap persists in systematically evaluating fundamental coating properties, particularly regarding electron/ion transport capability and mechanical/chemical/electrochemical durability. Addressing this gap is a key focus of this review. Another focus involves elucidating the key performance determinants of various types of coatings through rigorous examination of representative coated architectures, an aspect often overlooked in previous reviews on coated Si anodes. Finally, the review concludes with evidence-based insights and a forward-looking perspective outlining strategic research priorities to accelerate Si anode commercialization.