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

Abstract

Abstract 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.

Keywords

• 1,2,4,5‐benzenetetramine tetrahydrochloride
• electrolyte additive
• lithium metal anode
• solvent sheath