Building better solid‐state batteries with silicon‐based anodes

Silicon (Si)‐based solid‐state batteries (Si‐SSBs) are attracting tremendous attention because of their high energy density and unprecedented safety, making them become promising candidates for next‐generation energy storage systems. Nevertheless, the commercialization of Si‐SSBs is significantly impeded by enormous challenges including large volume variation, severe interfacial problems, elusive fundamental mechanisms, and unsatisfied electrochemical performance. Besides, some unknown electrochemical processes in Si‐based anode, solid‐state electrolytes (SSEs), and Si‐based anode/SSE interfaces are still needed to be explored, while an in‐depth understanding of solid–solid interfacial chemistry is insufficient in Si‐SSBs. This review aims to summarize the current scientific and technological advances and insights into tackling challenges to promote the deployment of Si‐SSBs. First, the differences between various conventional liquid electrolyte‐dominated Si‐based lithium‐ion batteries (LIBs) with Si‐SSBs are discussed. Subsequently, the interfacial mechanical contact model, chemical reaction properties, and charge transfer kinetics (mechanical–chemical kinetics) between Si‐based anode and three different SSEs (inorganic (oxides) SSEs, organic–inorganic composite SSEs, and inorganic (sulfides) SSEs) are systemically reviewed, respectively. Moreover, the progress for promising inorganic (sulfides) SSE‐based Si‐SSBs on the aspects of electrode constitution, three‐dimensional structured electrodes, and external stack pressure is highlighted, respectively. Finally, future research directions and prospects in the development of Si‐SSBs are proposed. This review provides a systematic overview of silicon‐based solid‐state batteries (Si‐SSBs), focusing on the different interfacial configuration characteristics and mechanisms between various types of solid‐state electrolytes and Si‐based anodes as well as the correlations between these interfacial characteristics and electrochemical performance. We envision that this review can point navigation for benefiting the future advancement of Si‐SSBs.