Single-crystalline Ni-rich cathodes with high capacity have drawn much attention for mitigating cycling and safety crisis of their polycrystalline analogues. However, planar gliding and intragranular cracking tend to occur in single crystals with cycling, which undermine cathode integrity and therefore cause capacity degradation. Herein, we intensively investigate the origin and evolution of the gliding phenomenon in single-crystalline Ni-rich cathodes. Discrete or continuous gliding forms are revealed with new surface exposure including the gliding plane (003) and reconstructed (−108) under surface energy drive. It is also demonstrated that the gliding process is the in-plane migration of transition metal ions, and reducing oxygen vacancies will increase the migration energy barrier by which gliding and microcracking can be restrained. The designed cathode with less oxygen deficiency exhibits outstanding cycling performance with an 80.8% capacity retention after 1000 cycles in pouch cells. Our findings provide an insight into the relationship between defect control and chemomechanical properties of single-crystalline Ni-rich cathodes.

Lithium‐ion batteries (LIBs) are in great demand for their impressive successes in serving people's daily life. Concomitantly, recycling the retired LIBs has also aroused the enthusiasm of widespread studies due to its great significance in the sustainable development of LIBs. Among the spent LIBs, LiFePO4 (LFP) is the main force because of its widespread use in electric vehicles and grids due to its stability and favorable price. However, considering the low cost of LFP manufacture as well as the abundance of Fe and P, traditional metallurgy processes are not economically feasible for recycling LFP because of high energy consumption and tedious steps. Here, this work proposes a green recycling method to directly regenerate the degraded LFP electrode via an in situ electrochemical process with a functionalized prelithiation separator. Compared with the existing recycling strategies for LFP batteries, the proposed method takes full advantage of the degraded cathode scraps without destroying the original structure, greatly reducing the cost of the remanufacture of the cathode electrodes simply via a prelithiation technique.