X. Tang, et al, Sci. Rep. 2015. 5. 11958

Graphene wrapped ordered LiNi_{0. 5}Mn_{1. 5}O₄ nanorods as promising cathode material for lithium-ion batteries

Sci. Rep. 2015. 5. 11958

X. Tang, S. S. Jan, Y. Qian, H. Xia, J. Ni, S. V. Savilov, S. M. Aldoshin

LiNi_0.5Mn_1.5O₄ nanorodswrapped with graphene nanosheets have been prepared and investigated as high energy and high power cathodematerialforlithium-ion batteries. The structural characterization by X-ray diffraction, Raman spectroscopy, and Fourier transform infrared spectroscopy indicates the LiNi_0.5Mn_1.5O₄ nanorods prepared from beta-MnO₂ nanowires have ordered spinel structure with P4332 space group. The morphological characterization by scanning electron microscopy and transmission electron microscopy reveals that the LiNi_0.5Mn_1.5O₄ nanorods of 100-200 nm in diameter are well dispersed and wrapped in the graphene nanosheets for the composite. Benefiting from the highly conductive matrix provided by graphene nanosheets and one-dimensional nanostructure of the ordered spinel, the composite electrode exhibits superior rate capability and cycling stability. As a result, the LiNi_0.5Mn_1.5O₄-graphene composite electrode delivers reversible capacities of 127.6 and 80.8 mAh g(-1) at 0.1 and 10 degrees C, respectively, and shows 94% capacity retention after 200 cycles at 1 degrees C, greatly outperforming the bare LiNi0.5Mn1.5O4 nanorod cathode. The outstanding performance of the LiNi_0.5Mn_1.5O₄-graphene composite makes it promisingascathodematerialfor developing high energy and high power lithium-ion batteries.