Recent Advances in Anode-free Solid-state Batteries: A Review

Solid-state batteries (SSBs) have been intensively studied due to their high energy density and improved safety for next-generation energy storage systems. Anode-free SSBs (AFSSBs) maximize the energy density with zero- excess lithium and enable simplified manufacturing processes. However, the absence of lithium and interfacial irreversible reactions lead to fast capacity fading of AFSSBs. Therefore, examining the difficulties and challenges encountered by AFSSBs can pave the way for enhancing electrochemical stability with prolonged cycle life. In this review, the key issues affecting the electrochemical stability of AFSSBs are described, focusing on the stability of inorganic solid electrolytes (ISEs), kinetic limitations, and interfacial diffusion. Furthermore, we introduce recent strategies to improve the interfacial stability and electrochemical properties of AFSSBs. Finally, prospects and potential pathways for AFSSBs are stated, aiming to encourage the exploration of the emerging field.