Co Single‐Atom Catalysis for High‐Efficiency LiCl/Cl ₂ Conversion in Rechargeable Lithium‐Chlorine Batteries

Abstract

Abstract Lithium‐chlorine (Li‐Cl 2 ) secondary batteries are emerging as promising candidates for high‐energy‐density power sources and an extensive operational temperature range. However, conventional electrode materials suffer from weak adsorption for chlorine gas (Cl 2 ) and low conversion efficiency of lithium chloride (LiCl), leading to significant loss of chlorine‐based active materials. This issue hampers the cyclability of Li‐Cl 2 batteries. In this work, it is demonstrated that synergistic Cl 2 adsorption on the electrode surface and the energy barrier for LiCl reactions are crucial for enhancing Cl 2 /LiCl conversion efficiency. Consequently, a cobalt (Co) single‐atom site catalyst with a Co‐N 4 coordination environment has been developed, which significantly diminishes the transformation barrier of solid LiCl particles into Cl 2 and concurrently enhances the chemical adsorption of Cl 2 , facilitating uniform nucleation of LiCl. As a result, the Li‐Cl 2 @Co‐NC battery developed has achieved a 0.6 V reduction in polarization voltage under high current densities, effectively addressing the issue of low conversion efficiency between Cl 2 and LiCl. At room temperature, the Li‐Cl 2 @Co‐NC battery achieves over 600 cycles at 1500 mA g −1 ; At −40 °C, it reaches 650 cycles at 500 mA g −1 . The research overcomes the cycle stability barrier in high‐current Li‐Cl 2 batteries and offers a strategy for batteries with a wide temperature range and long cycle life.