Advances in high-coulombic-efficiency lithium metal anodes under practical conditions in liquid electrolytes

Abstract

Lithium (Li) metal batteries are regarded as the forefront of high-energy-density battery technology, surpassing the performance of traditional Li-ion batteries. However, their cycle life is notably impeded by the suboptimal coulombic efficiency (CE) of Li metal anodes. CE serves as a pivotal metric for the reversibility of Li plating and stripping processes. The low CE stems from the generation of inactive Li, a phenomenon exacerbated by practical operational conditions. Improving CE is paramount for the practical applications of Li metal batteries. It is crucial to comprehend the genesis of inactive Li and to devise effective strategies aimed at achieving high CE. This review delves into the core principles of CE, its significance across various battery configurations, methodologies for calculation, the pivotal factors influencing CE, and the underlying mechanisms for its enhancement. Subsequently, the review summarizes the advancements in achieving high-CE Li metal anodes under practical conditions, examining both composite Li anodes and electrolyte engineering strategies. Finally, the discussion turns to the challenges and prospective research avenues for enhancing the CE of Li metal anodes under practical conditions in liquid electrolytes, with the ultimate goal of realizing viable Li metal batteries.