Reveal the capacity loss of lithium metal batteries through analytical techniques

Abstract High energy density and stable long cycle are the basic requirements for an ideal battery. At present, lithium (Li) metal anode is regarded as one of the most promising anode materials, but it still faces major problems in terms of capacity fading and safe and stable long‐term cycle. The reason for the continuous fading of Li anode capacity is mainly due to the loss of active Li source, and the loss of Li source is mainly due to the continuous generation of dead Li. At the same time, the unstable interface and dendrite growth of Li anodes during the Li plating/delithiation process eventually lead to battery safety issues. In fact, recent studies have shown that the disordered expansion of dendrites is the main reason for the infinite generation of dead Li. Therefore, here we take different detection techniques as clues, review the exploration process of qualitative and quantitative research on the source and mechanism of Li capacity loss, and summarize the strategies to reduce dead Li generation and capacity fading by inhibiting dendrite formation. In particular, we give suggestions on the development of advanced testing methods on how to further study the problem of dead Li, and also give relevant strategy suggestions on how to completely solve the problem of capacity loss in the future, with the main goal of suppressing dendrites.