Advanced binder design for high-performance silicon anodes

Silicon (Si)-based materials are one of the most promising anode materials owing their ultra-high capacity. However, the low conductivity and the drastic volume expansion of Si anodes during repeated lithiation/delithiation result in a sluggish Lithium-ion (Li-ion) migration rate and rapid capacity decay. These phenomena impede the application of Si anodes in the energy storage field. As a critical link for connecting different components in Si electrodes, binders considerably impact the coordinating electrode components and synchronously improve the reaction kinetics and cycling stability of Si anodes. This review systematically summarizes the recently significant efforts on functional binders for realizing high-rate and long-term Si anodes. In particular, molecular structures modification, the synthesis of novel functional binders, application principle of supramolecular polymeric and bio-related binders, were discussed. The mechanism of nanoscale multi-interfacial compatibility for stable Li-ion storage and efficient stress-buffering within Si anodes based on the various design principles of binders were thoroughly discussed and analyzed. Finally, challenges and possible solutions for advanced binder design in Si-based electrodes in future studies were discussed. This review aims to provide a new perspective for the rational design of next-generation high-energy-density lithium-ion batteries.