Hollow microspherical layered xLi2MnO3·(1-x)LiNiO2 (x=0.3–0.7) as cathode material for lithium–ion batteries

Abstract

Li-rich layered Li2MnO3 is of great attraction for high energy lithium ion batteries. However, its cycling is still needed for improvements. Here we report a hollow microsphere-structured xLi2MnO3·(1-x)LiNiO2 (x = 0.3–0.7) that is synthesized by using in-situ template-sacrificial strategy. Powder X-ray diffraction (XRD) and scanning electron microscope (SEM) characterizations prove that the xLi2MnO3·(1-x)LiNiO2 (x = 0.3–0.7) are based on monoclinic Li2MnO3 with α-NaFeO2 layered structure in which Li+ ions are orderly arranged in the transition metal layers, and the hollow-microspheres have diameters of ∼3 μm. Electrochemical results show that the optimal ratio of Li2MnO3/LiNiO2 is 0.6/0.4. As a consequence, the stabilized discharge capacity of 0.6Li2MnO3·0.4LiNiO2 (0.6LLMNO) is ∼210 mAh g−1 after the first few cycles. This shows that appropriate amount Ni substitution for Mn in Li2MnO3 helps to improve the specific capacity and cycling stability.