Improvement of electrochemical properties of lithium-rich manganese-based cathode materials by Ta2O5

As one of the most promising cathodes for next-generation lithium-ion batteries, lithium-rich materials have been widely studied because of their excellent electrochemical performance. However, due to their unstable microstructure and electrolyte/material interface, the practical application of lithium-rich cathodes has been greatly hindered. Building a stable interface structure is an ideal choice for high-voltage lithium-rich cathode materials in lithium-ion batteries. A Ta2O5 layer can resist HF acid corrosion and plays an important role in controlling the electrochemical properties of lithium-rich oxides. Here, a series of lithium-rich manganese-based cathode materials of Li1.2Ni0.1Co0.1Mn0.6O2 (LNCM) were prepared by the rapid co-precipitation and high-temperature solid-phase methods. Ta2O5-coating was coated on the surface of the cathode material by simple solid-state mixed sintering. Compared with the original Li1.2Ni0.1Co0.1Mn0.6O2 the 5% Ta2O5-coating cathode showed better electrochemical properties in rate performance and cycle stability. The specific capacity of the first cycle discharge reached 292.9 mAhg(-1) at 0.1 C, and the coulombic efficiency was 80.16%. The capacity was 92 mAhg(-1) at 10 C and 85.35% after 100 cycles at 2 C. The results showed that the Ta2O5 coating can effectively suppress the voltage decay, reduce the electrode polarization, improve the rate performance of the material and improve the structural stability of the cathode material.