Engineering molecular regulation for SiO x with long‐term stable cycle and high Coulombic efficiency as lithium‐ion battery anodes

Abstract In the current situation where the practical application of silicon anode materials encounters great challenges, silicon oxide (SiO x , 0 ≤ x ≤ 2) has attracted the attention of researchers due to its relatively small volume expansion, stable cycling performance, and low cost, which is possible to realize commercial applications earlier than silicon anode. However, it remains a challenge to prepare SiO x materials with long‐term stable cycling performance and high Coulombic efficiency using low‐cost methods. In this work, SiO x anode material with high Coulombic efficiency and good long‐term cycling stability was prepared at a low cost by hydrolysis of siloxane and in situ polymerization of phenolic resin. The hydrolysis of siloxane was further regulated by different silane coupling agents to regulate the size and microstructure of prepared SiO x materials, which displayed the substantially improved electrochemical performance. The excellent electrochemical performance of SiO x prepared by regulated hydrolysis of siloxane with silane coupling agents is attributed to the effect of silane coupling agent on size and microstructure of SiO x , revealing that the strategy of modulating the hydrolysis of siloxane by silane coupling agent is a potential method to prepare high‐performance SiO x materials.