Silicon as Emerging Anode in Solid-State Batteries

Silicon is one of the most promising anode materials due to its very high specific capacity (3590 mAh g–1), and recently its use in solid-state batteries (SSBs) has been proposed. Although SSBs utilizing silicon anodes show broad and attractive application prospects, current results are still in an infant state in terms of electrochemical performance, analytical characterization and mechanistic understanding. This paper aims to summarize current achievements and remaining challenges for the use of silicon anodes in SSBs and to provide a perspective for SSB cells with high energy density. Three types of cells with their specific type of silicon anode (i.e., thin-film cells, powder-pressed pellet-type cells, and sheet-type pouch cells) are reviewed, from their electro-chemo-mechanical behavior to microstructure optimization. Future directions for research of silicon anodes in SSBs are outlined, such as quantifying the partial ionic/electronic conductivity of silicon anodes, clarifying their interfacial stability, and investigating their chemo-mechanical stability.