High dielectric 3D scaffold to suppress Li-dendrites and increase the reversibility of anode-less Li-metal anodes

Abstract

The lithium metal anode is intensively investigated because it considerably increases Li-battery energy density. However, the formation of dendritic/mossy Li-metal microstructures amplifies electrolyte decomposition and Li deactivation. Here we investigate the impact of a high-dielectric porous scaffold, aiming to eliminate the fundamental driver for dendritic/mossy Li-metal growth, the large electrical field gradients at inhomogeneities at the anode surface. In an anode-less (Li-metal free) high-dielectric porous scaffold, this promotes dense plating as observed by operando solid-state NMR. Even in a simple carbonate electrolyte, 1M LiPF6 in EC/DMC, the high-dielectric scaffold improves the plating/stripping efficiency up to 99.82%, extending the cycle life, indicating that electrolyte decomposition is minimized by the induced compact Li-metal plating. The large porosity of the scaffolds, non-optimized and easy to prepare, enables a specific capacity beyond 2000 mA h g-1, presenting a facile approach to promote compact Li-metal plating to improve Li-metal anode efficiency and safety.