Ni-rich LiNixMnyCo1âˆ’xâˆ’yO2 (x â‰¥ 0.8) cathode is widely applied in high-end vehicle for its relatively high speciï¬c capacity and operating potential, which receives extensive attention in academia and industry. However, poor cycling performance and high cost hinder its further applications in lithium-ion batteries. In this work, 2-Methylenesuccinic anhydride is utilized as a functional cathode additive. Through the interaction between low valence Ni ions and anhydride, the facile approach allows functional 2-Methylenesuccinic anhydride more precisely work at the interface. As the operation potential rises, 2-Methylenesuccinic anhydride is oxidized prior to the electrolyte and a robust CEI layer rich in carbon oxygen double bond is built in the surface of cathode particles upon cycling, which has been analyzed by TEM and XPS. Besides, 2-Methylenesuccinic anhydride can absorb the trace of water in the cathode and electrolyte. As a result, the 0.5wt% 2-Methylenesuccinic anhydride modified NCM sample retains 91.6 % of initial capacity after charge-discharge 400 cycles at 2C. The novel modification strategy by adding a cathode additive is of important significance for mitigating deleterious side reactions in the interface for Ni-rich NCM materials.
Keywords high energy density cathode, energy storage, lithium ion batteries, organic anhydride, energy systems, Ni-rich cathode materials