Interlayer chemical confinement enables highly reversible and durable lithium-chlorine batteries

Abstract

Rechargeable lithium-chlorine (Li-Cl2 ) batteries represent a promising high-energy-density technology for use in large-scale applications. However, conventional cathodes suffer from weak interactions with Cl 2 and uneven LiCl deposition, resulting in poor Cl2 /LiCl conversion kinetics and limited cycle life. In this study, an interlayer chemical confinement strategy is proposed to enable highly reversible Cl 2 /LiCl conversion in Ti3C2Sx MXenes. Specifically, the confined space in MXene interlayer effectively suppresses Cl2 escape while the sulfur surface terminations form covalent interactions with Cl to further immobilize Cl2 and lower the LiCl nucleation barrier to achieve uniform deposition. In situ characterization combined with theoretical calculations reveals the reversible Cl2/LiCl redox reaction with a low energy barrier occurs within the confined interlayer space. This confinement strategy imparts the Li-Cl2 battery with a high specific capacity of up to 2200 mAh g-1 , in conjunction with long cycle lives of 1300 and 1200 cycles when operating at 25 and -60 ℃, respectively. This study provides new insights into the nanoconfinement effect and opens a promising avenue for the development of high-performance metal-Cl2 batteries.