Reduced Expansion and Strain to Boost Performance and Safety of LiNi0.8Co0.1Mn0.1O₂ by Cubic ZrMo₂O₈ Nanorods with Isotropic Negative Thermal Expansion

Nickel-rich cathode materials are attractive for high-energy batteries but have disadvantages like thermal runaway and poor cyclability. To accelerate the applications, cubic ZrMo2O8 nanorods with isotropic negative thermal expansion (NTE) property are synthesized and utilized to modify LiNi0.8Co0.1Mn0.1O2 (NCM811). The NCM811 modified with 3 wt % ZrMo2O8 (ZM3) exhibits the best electrochemical performance, and its capacity retention ratios after 100 cycles are 15.9 and 30.4% higher than those of the pristine NCM811 at 25 and 60 °C. Compared with NCM811, ZrMo2O8 reduces the value of RSPI + Rct at 25 °C by 43.7% and the potential differences between Ni2+/Ni3+ redox peaks, while it shifts the exothermic peak from 206.1 to 220.8 °C along with 31.3% lower released heat. Simultaneously, ZrMo2O8 decreases 69.9% of the strain as well as suppresses the side reactions, microcracks, and cation mixing. The improving mechanism of the modified material is discussed. It paves a strategy to update energy materials.