Simultaneously Preventing Oxygen Evolution, Structure Degradation, and Thermal Release in Lithium‐Rich Layered Oxides via In Situ Surface Anchoring Negative Thermal Expansion Material

ABSTRACT Lithium‐rich layered oxides (LRLOs) are promising cathode materials for high‐energy–density batteries, but face challenges like irreversible oxygen evolution, structural degradation, and poor thermal stability. Herein, quadruple synergistic effects have been proposed to simultaneously boost structural integrity, cyclability, and electrochemical performance of Li _1.2 Ni _0.2 Mn _0.6 O ₂ (LR) by surface in situ anchoring a negative thermal expansion (NTE) material ZrW ₂ O ₈ via calcination. The 3D rigid framework of ZrW ₂ O ₈ dynamically compensates for lattice strain via its isotropic contraction behavior caused by heat as well as inhibits side reactions, while strong affinity between Zr/W and oxygen elevates the energy barrier for oxygen evolution. The oxygen evolution amount of LR is reduced by 34.9%, while the Li ⁺ diffusion coefficient and capacity retention of LR after 500 cycles at 25°C are increased by approximately 144.94% and 113.08%, respectively. Simultaneously, the strain of LR after cycling at 60°C and the released heat are decreased by 44.84% and 28.03%, respectively. The results of density functional theory (DFT) calculations further validate that the anchored ZrW ₂ O ₈ increases the oxygen vacancy formation energy by up to 0.92 eV. Both in situ and ex situ techniques have been adopted to explore the enhancement mechanism. It offers a novel approach to develop energy materials with excellent performance.