Effect of transition metal composition on electrochemical performance of nickel-manganese-based lithium-rich layer-structured cathode materials in lithium-ion batteries

Figure shows the discharge curves of Li1.2NixMn0.8−xO2 (x=0.2 and 0.3) within potential range of 2.5−4.6 V (vs. Li/Li+) at 0.05 and 3 C. At low C-rate (0.05 C), the discharge capacity of high-nickel-content cathode (Li1.2Ni0.3Mn0.5O2) was less than that of low-nickel-content cathode (Li1.2Ni0.2Mn0.6O2); however, the discharge potential and capacity of Li1.2Ni0.3Mn0.5O2 was higher than those of Li1.2Ni0.2Mn0.6O2 at high C-rate (3 C). This means that the increase in Ni/Mn ratio was effective in improving rate-performance.155