Recent advances in the mitigation of dendrites in lithium-metal batteries

Utilizing lithium (Li) metal as the anode can enable lithium metal battery (LMB) systems to achieve energy densities of up to 1150 Wh Kg(-1), approaching that of gasoline. However, the use of Li metal is plagued with a whole host of problems, the most serious of which is the issue of nucleation of Li metal dendrites. These dendrites grow inexorably on charge-discharge cycling, piercing through the battery separator membrane and eventually electrically shorting the battery. This can result in thermal runaway leading to an unacceptable fire hazard. In this review article, we focus on recent advances in mitigating, suppressing, and healing Li metal dendrites in LMBs with liquid electrolytes. We discuss a whole host of exciting approaches including electrolyte engineering, interface engineering, the use of stable Li hosts, homogenizing Li-ion flux, and the physical healing of dendrites using temperature fields. We discuss the pros and cons of these approaches and provide our perspectives for future research directions. In particular, it is important to consider dendrite mitigation in a full-cell setting and with a realistic form factor such as prismatic or cylindrical cells. Given the multifaceted nature of the dendrite challenge, it is unlikely that there is a single magic solution, making it necessary to explore a combination of strategies to work in synergy to make Li metal anodes viable in commercial systems.