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 Na 2 S 2 O 8 surface treatment to obtain micro-sized particles in the Li-rich Li 1.172 Ni 0.135 Co 0.135 Mn 0.539 O 2 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/cm 3 ) 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.