Structurally stabilized lithium-metal anode via surface chemistry engineering

Abstract

Dendrite-free lithium (Li) has been the primary issue for the practical application of metallic Li anode. Repeated Li plating/stripping is known to inevitably lead to severe volume changes and gradual Li dendrite growth, eventually resulting in irreversible Li (called dead-Li) as an unexpected feature. In order to avoid the dead-Li, a lithiophilic surface is highly desirable and a nanoarchitectured host for metallic Li is also required. Herein, cobalt-embedded, mesoporous, nitrogen-doped graphite (N-doped graphite) is strategically proposed as a new innovative Li-metal storage host. After tuning the surface chemistry, the material shows high Li ion affinity as well as a highly lithiophilic surface, which is attributed to the low formation energy of N-doped graphite, strongly supported by density functional theory calculations. As a result, the desirable anode shows excellent electrochemical performance with high Li-metal reversible capacity and even stable long-term cyclability with no dead-Li formation. Our findings pave the way to optimize the Li-metal host up to the limit of the theoretical capacity.