Towards efficient binders for silicon based lithium-ion battery anodes

Silicon (Si)-based anodes have been intensively pursued as one of the most promising candidates for next-generation high-capacity electrodes in lithium-ion batteries (LIBs) due to their ultra-high theoretical capacity. However, huge volumetric change associated with the insertion and extraction of lithium-ions is a major impediment to the deployment of Si anodes, which result in the pulverization of Si particles and the loss of electric contact, as well as parasitic side reactions; these transformations cause poor cyclic stability and fast capacity fading. Binders, with minor content in electrode systems, have demonstrated their pivotal role in electrodes, particularly in Si-based anodes. Present review aims at providing a thorough analysis of existing and emerging binders, which are either synthetic or biomass polymers, for Si-based LIB anodes in terms of their structures, properties, advantages, limitations, working principles, design rules, as well as associated electrochemical mechanisms to address the challenges of Si-based anodes. On the basis of current progress, a short perspective is provided on existing challenges and research directions on Si-based anodes for commercialization in the near future.