Silicon Anodes for High‐Performance Storage Devices: Structural Design, Material Compounding, Advances in Electrolytes and Binders. Issue 5 (12th March 2020) - Li, Fangru
Abstract: Silicon has an extremely high theoretical capacity, a low voltage platform, and abundant natural reserves. It is considered to be one of the most promising anode materials for lithium‐ion batteries. However, there are still many problems with silicon as an anode material for lithium‐ion batteries. During the lithiation/delithiation of silicon, a huge volume expansion occurs, causing the silicon particles to pulverize and the capacity to drop sharply. Furthermore, the continuous increase in the silicon surface solid electrolyte interphase (SEI) films and the poor conductivity of silicon affect the specific capacity of the battery. Means to improve silicon‐based anodes with regard to electrode cycling performance and electrode capacity include structural design, composite preparation, or improvements in electrolytes and binders (for example, designing silicon nanomaterials of different dimensions from 0D to 3D, including silicon nanoparticles, nanowires, nanorods, thin films, porous silicon, and core‐shell structures). Silicon has been combined with different materials to buffer its own volume expansion, resulting in excellent performance. In addition, the design of a reasonable electrolyte solution, as well as the development of a self‐healing binder is one of the main methods to improve Si‐based anodes. In recent years, sodium/potassium ion batteries have been increasingly studied, and silicon and sodium/potassium can be alloyed. The corresponding theoretical capacity can reach 954 mAh g −1 and 955 mAh g −1, respectively. Advances in silicon‐based anodes for sodium/potassium ion storage are summarized herein. Abstract : This review discusses several improved methods for silicon‐based anodes. (a) During the lithiation/delithiation of silicon, a huge volume expansion occurs causing the silicon particles to pulverize and a continuous increase in the silicon surface solid electrolyte interphase (SEI) films. (b) The main means to improve the silicon anode include structural design, composite preparation, or improvements in electrolytes and binders.