The Weakened Super‐Exchange Interaction Realizes the Direct Regeneration of Spent Lithium‐lon Battery Cathodes

The direct regeneration of cathodes is an effective technique to address resource waste and environmental pollution caused by spent lithium-ion batteries (LIBs). However, Li⁺ migration within the rock-salt phase of degraded LiNi_0.5Co_0.2Mn_0.3O₂ cathodes follows an energetically unfavorable 2-transition metal (2-TM) transport pathway (tetrahedral sites between face-sharing octahedra), creating a kinetic barrier that fundamentally limits direct regeneration. A Na-based molten salt pretreatment is applied to introduce Na atoms into the unoccupied tetrahedral sites of the rock-salt phase, which alters the electronic state distribution of bridged oxygen anions and reduces super-exchange interactions between TM atoms in adjacent layers, thereby triggering a phase transformation from rock-salt to targeted layered structure. Consequently, the Li⁺ migration pathway shifts from a high-energy 2-TM route to a more favorable low-barrier 1-TM route, enabling efficient lithiation and complete restoration of the cathode. The regenerated materials exhibit high structural uniformity and excellent electrochemical performance, achieving 78% capacity retention after 500 cycles. This study provides an insightful perspective on direct LIB recycling by regulating super-exchange interactions within the degraded cathode structures.