Fluorinated Carbamate-Based Electrolyte Enables Anion-Dominated Solid Electrolyte Interphase for Highly Reversible Li Metal Anode
Wenhui Hou, Pan Zhou, Honghui Gu, Yu Ou, Yingchun Xia, Xuan Song, Yang Lu, Shuaishuai Yan, Qingbin Cao, Hao Liu, Fengxiang Liu, Kai Liu
Abstract
Li metal is regarded as the most promising battery anode to boost energy density. However, being faced with the hostile compatibility between the Li anode and traditional carbonate electrolyte, its large-scale industrialization has been in a distressing circumstance due to severe dendrite growth caused by unsatisfying solid electrolyte interphase (SEI). With this regard, accurate control over the composition of the SEI is urgently desired to tackle the electrochemical and mechanical instability at the electrolyte/anode interface. Herein, we report a rationally designed fluorinated carbamate-based electrolyte employing LiNO 3 as one of the main salts to induce the preferable anion decomposition to achieve a homogeneous and inorganic (LiF, Li 3 N, Li 2 O)-rich SEI. Thus, this electrolyte achieves a high Coulombic efficiency of 99% of the Li metal anode, a stable cycling over 1000 h for Li|Li symmetric cells, more than 100 cycles in 40-μm-thin Li|high-loading-NCM811 full batteries, and >50 cycles in Cu|LiFePO 4 pouch cells, which is a promising electrolyte for highly reversible Li metal batteries.