Realizing excellent cycle stability over a wide temperature range for Li1.2Mn0.6Ni0.2O2 cathode by Li4Mn5O12 coating

The Li-rich cathode Li 1.2 Mn 0.6 Ni 0.2 O 2 (PLR) has garnered much attention as an attractive candidate for lithium-ion batteries due to its low cost, environmental friendliness, and wide voltage window. However, challenges such as rapid capacity degradation and voltage decay resulting from the release of lattice oxygen remain unresolved. Herein, a spinel phase Li 4 Mn 5 O 12 coating was generated on the surface of Li 1.2 Mn 0.6 Ni 0.2 O 2 cathode (SLR) through KMnO 4 surface modification, aiming to enhance the structure stability and conductivity of PLR. The results demonstrate that the Li 4 Mn 5 O 12 coating effectively inhibits the release of lattice oxygen and accelerates the speed of lithiation and delithiation processes of Li 1.2 Mn 0.6 Ni 0.2 O 2 cathode, thereby significantly enhancing cycling stability over a wide temperature range. Particularly notable is SLR cathode, which shows superior capacity retention of 92.5 % at 1.0 C after 200 cycles at room temperature. Meanwhile, the SLR material retains excellent electrochemical properties even at high temperatures (60°C) with a capacity of 192.9 mAh/g after 100 cycles. This study not only elucidates the mechanism of Li 4 Mn 5 O 12 modification on Li 1.2 Mn 0.6 Ni 0.2 O 2 cathode, but also provides an effective strategy to improve the performance of Li-rich cathode materials .