Constructing LiCl-Rich Solid Electrolyte Interphase by High Amine-Containing 1,2,4,5-Benzenetetramine Tetrahydrochloride Additive

Strategies that aim to achieve highly stable lithium metal batteries (LMBs) are extensively explored. To date, the controlled formation of high-quality inorganic SEI is still quite challenging, which requires a deep understanding and hence the fine-tuning of solvation chemistry by using functional additives in the electrolyte. In this work, a high amine-containing 1,2,4,5-benzenetetramine tetrahydrochloride (BHCL) is developed as a dual-function electrolyte additive for LMBs. The amine group with a high donor number increases the lithium affinity, while the phenyl group with a strong inductive effect prevents the decomposition of solvents, and the free chloride ions replace anions mediating the formation of the rigid inorganic LiCl-rich SEI layer. The experimental results corroborate the theoretical findings. The modified Li||Li symmetric battery is stably cycled for over 2500 h at 1 mA cm−2 current density with an overpotential of ≈45 mV. The performances of the Li||Cu and Li||LFP cells are also significantly enhanced. Therefore, this work provides a promising design principle of multifunctional electrolyte additive. ; Li symmetric battery is stably cycled for over 2500 h at 1 mA cm−2 current density with an overpotential of ≈45 mV. The performances of the Li ; Cu and Li ; LFP cells are also significantly enhanced. Therefore, this work provides a promising design principle of multifunctional electrolyte additive.