Synthesis and electrochemical performance of micro-sized Li-rich layered cathode material for Lithium-ion batteries

Li-rich layered oxides with micro-sized primary particles usually exhibit higher pellet density and better cycling performance. However, it is often at the expense of high reversible capacity. Here, we reported a simple strategy through a new chemical lithiation with micro-sized spinel-precursors and Na2S2O8 surface treatment to obtain micro-sized particles in the Li-rich Li1.172Ni0.135Co0.135Mn0.539O2 oxide without compromising its discharge capacity (260 mAh/g at 0.1C). Benefited from its larger particles and lower specific surface area, the obtained micron Li-rich layered material manifests its higher pellet density (3.18 g/cm3) and better cycling performance in comparison with the nano-sized Li-rich layered material. After 100 cycles at 0.1 C, it can still deliver a capacity of 192 mAh/g with retention of 74%, much higher than 167 mAh/g with retention of 67% of the nano-sized sample. Moreover, the micron Li-rich layered material also exhibits good rate performance with a capacity of 174 mAh/g at 2C benefited from the 3D Li+ insertion/extraction channel of its surface spinel content. These results may provide a new insight on improving pellet density of high-performance Li-rich layered cathode materials.