Improving the electrochemical performance of lithium-rich cathode materials Li_1.2Mn_0.54Ni_0.13Co_0.13O₂ by a method of tungsten doping

In order to alleviate the capacity and voltage attenuation of the Li-rich materials, a series of tungsten-doped Li_1.2Mn_0.54-xNi_0.13Co_0.13W_xO₂ (0 ≤ x ≤ 0.04) were produced through a sol-gel method. The XRD patterns exhibit a representative structure of hexagonal α-NaFeO₂ and a well-layered structure. XPS index that the valence of W is 6+. From the results of charge-discharge cycling, appropriate W doping for Li-rich layered oxides can prominently raise its performance. After 100 cycles, the 0.02W-doped sample obtain a capacity retention ratio of 82.6% (154.7 mAh g⁻¹) at 1 C, but the ratio for the pure sample only is 77.5% (121.7 mAh g⁻¹) at the same conditions. Meanwhile, the 0.02W-doped sample can obtain the best properties at different rates. The results reveal that the modification method of W-doping can stabilize the structure of the Li-rich materials and enhance the properties. [Figure not available: see fulltext.].