High-nickel and cobalt-free layered LiNi0.90Mn0.06Al0.04O2 cathode for lithium-ion batteries

In order to obtain superior cathode materials for lithium-ion batteries with lower cost and higher energy density, the research of nickel-based cathode materials trend towards high Ni, low Co or no Co composition. To demonstrate the feasibility of this compositional transformation, we introduce a Co-free LiNi0.90Mn0.06Al0.04O2 (NMA) cathode material with a Ni content of 90 mol%, ranging from LiNi0.90Co0.1O2 (NC) to low Co LiNi0.90Mn0.06Co0.04O2 (NMC) composition transformation. All samples were synthesized by an organic amine coprecipitation method. The results show that the NMA cathode can provide the first discharge specific capacity of 223.1 mAh g−1 at 0.1 C and 2.5–4.3 V, although is lower than that of NC and NMC, it has a higher average discharge voltage of 47 and 17 mV, respectively. At a high voltage window ranging from 2.5 to 4.5 V, the first discharge specific capacity up to 232.1 mAh g−1, and the capacity retention rate of 100 cycles at 0.5 C is as high as 93.3%, which is much higher than the 66.9% of the NC. The dQ dV−1 and discharge curves show that the NMA phase transition is gentler and the polarization is smaller during the high-voltage charge-discharge process, which also indicates that the destructive effect of Co on the layered structure is further enhanced at high potential. In conclusion, this work provides favorable support for NMA as a next-generation candidate for high-nickel and Co-free cathode materials.