Electrochemical characterization of Li2MnO3–Li[Ni1/3Co1/3Mn1/3]O2–LiNiO2 cathode synthesized via co-precipitation for lithium secondary batteries

Various compositions of the xLi2MnO3–yLi[Ni1/3Co1/3Mn1/3]O2–zLiNiO2 electrode system were synthesized using metal oxide precursor by adopting co-precipitation method. XRD revealed that the prepared cathode materials possess α-NaFeO2 structure with R3¯m space group. Scanning electron micrographs demonstrated the morphology of all the synthesized samples, wherein spherical agglomerates with size of 5–10 μm have been acknowledged. Among the tested samples, Li[Li0.18Ni0.220Co0.120Mn0.480]O2 shows the excellent capacity retention (95.6%) in the voltage range of 2.0–4.6 V and the better rate capability than the other samples. But, on the other hand, Li[Li0.20Ni0.133Co0.133Mn0.534]O2 (x = 0.6, y = 0.4 and z = 0.0) shows the highest discharge capacity. However, the capacity retention of the material at 50 mA g−1 is lower than that of Li[Li0.18Ni0.220Co0.120Mn0.480]O2. Furthermore, the capacity retention at 1250 mA g−1 is only 42.6% of the capacity obtained at 20 mA g−1.