Improving Cycle Stability of Anode-Free All-Solid-State Lithium-Ion Batteries by Pore Engineering of the Carbon Protective Layer

Anode-free all-solid-state lithium-ion batteries (ASSBs) have gained much attention due to their high energy density and superior safety. However, unwanted side reactions between electrodeposited Li metal and solid-state electrolyte should be suppressed to improve cycle stability of the ASSBs. Although there have been some studies with respect to composition and microstructure of carbon-based protective layers, such as silver-carbon composite layer, correlation between the microstructure of the protective layer and the cycle performance of the anode-free ASSBs has not been revealed yet. Herein, we demonstrate that the full cell applying the carbon protective layer with the smallest pore volume achieved the highest capacity retention of the initial capacity up to 78.8% after 300 cycles, probably due to the largest volume fraction of lithiated carbon nanoparticles after charging since lithiated carbon could serve as Li ion conducting media and allow uniform Li deposition. Detailed characterizations and electrochemical analysis of different types of carbon protective layers will be further discussed in this presentation.