Spatially Coupled Cl ₂ Confinement and Activation at Curved Ni Single‐Atom Sites for Highly Reversible Li–Cl ₂ Batteries

ABSTRACT Leveraging the high‐potential Cl 2 /LiCl redox couple (∼3.6 V), rechargeable Li‐Cl 2 batteries hold compelling promise for next‐generation energy storage. However, their practical viability is severely impeded by poor Cl 2 retention and sluggish conversion kinetics, particularly under deep‐cycling and high‐rate regimes. Here, we present a spatially coupled Cl 2 ‐management cathode that integrates Cl 2 confinement and short‐range transport within a micropore‐rich matrix with spontaneous activation at dense pore wall‐anchored, curved Ni single‐atom sites. Via this closed‐loop pathway from Cl 2 storage to LiCl deposition, the Li‐Cl 2 battery achieves a remarkable 1.21 V polarization reduction at 1500 mAh g −1 cut‐off capacity at 2000 mA g −1 . Consequently, an ultrahigh cumulative capacity exceeding 1.0 million mAh g −1 , which doubles the lifespan of state‐of‐the‐art Li‐Cl 2 systems, is achieved through the integrated approach incorporating this pathway, the robust, partially graphitized support, and an optimized discharge‐cutoff protocol. Furthermore, the exceptional all‐climate robustness (–40°C to +70°C), coupled with a high reversible areal capacity of 7.65 mAh cm −2 in pouch cells, establishes a new paradigm for practical, high‐energy storage systems.