Hu Guangwu, Yu Ruohan, Liu Zhenhui, Yu Qiang, Zhang Yuanyuan, Chen Qiang, Wu Jinsong, Zhou Liang, Mai Liqiang
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, China.
Nanostructure Research Centre (NRC), Wuhan University of Technology, Wuhan 430070, China.
ACS Appl Mater Interfaces. 2021 Jan 27;13(3):3991-3998. doi: 10.1021/acsami.0c19673. Epub 2021 Jan 13.
Si is a well-known high-capacity lithium-ion battery anode material; however, it suffers from conductivity and volume expansion issues. Herein, we develop a "surface oxidation" strategy to introduce a SiO layer on Si nanoparticles for subsequent carbon coating. It is found that the surface SiO layer could facilitate the conformal resin coating process through strong interactions with phenolic resin, and well-defined core@double-shell-structured Si@SiO@C can be obtained after further carbonization. Without the surface SiO layer, only a negligible fraction of Si nanoparticles can be encapsulated into the carbon matrix. With enhanced conductivity and confined volume change, Si@SiO@C demonstrates high reversible capacity as well as long-term durability.
硅是一种著名的高容量锂离子电池负极材料；然而，它存在导电性和体积膨胀问题。在此，我们开发了一种“表面氧化”策略，在硅纳米颗粒上引入一层SiO层，以便后续进行碳包覆。研究发现，表面SiO层可通过与酚醛树脂的强相互作用促进保形树脂包覆过程，进一步碳化后可得到结构明确的核@双壳结构的Si@SiO@C。没有表面SiO层时，只有可忽略不计的一部分硅纳米颗粒能被封装到碳基体中。由于导电性增强和体积变化受限，Si@SiO@C表现出高可逆容量以及长期耐久性。
