Hydrofluoric Acid‐Removable Additive Optimizing Electrode Electrolyte Interphases with Li<sup>+</sup> Conductive Moieties for 4.5 V Lithium Metal Batteries
Gaoxue Jiang, Jiandong Liu, Jian He, Huaping Wang, Shihan Qi, Junda Huang, Daxiong Wu, Jianmin Ma
Abstract
Abstract High‐voltage lithium metal batteries (LMBs) are capable to achieve the increasing energy density. However, their cycling life is seriously affected by unstable electrolyte/electrode interfaces and capacity instability at high voltage. Herein, a hydrofluoric acid (HF)‐removable additive is proposed to optimize electrode electrolyte interphases for addressing the above issues. N, N‐dimethyl‐4‐(4,4,5,5‐tetramethyl‐1,3,2‐dioxaborolan‐2‐yl) aniline (DMPATMB) is used as the electrolyte additive to induce PF 6 − decomposition to form a dense and robust LiF‐rich solid electrolyte interphase (SEI) for suppressing Li dendrite growth. Moreover, DMPATMB can help to form highly Li + conductive Li 3 N and LiBO 2 , which can boost the Li + transport across SEI and cathode electrolyte interphase (CEI). In addition, DMPATMB can scavenge traced HF in the electrolyte to protect both SEI and CEI from the corrosion. As expected, 4.5 V Li|| LiNi 0.6 Co 0.2 Mn 0.2 O 2 batteries with such electrolyte deliver 145 mAh g −1 after 140 cycles at 200 mA g −1 . This work provides a novel insight into high‐voltage electrolyte additives for LMBs.