Dependence of structure and temperature for lithium-rich layered-spinel microspheres cathode material of lithium ion batteries

作者：Wang, Di; Yu, Ruizhi; Wang, Xianyou^*; Ge, Long; Yang, Xiukang

来源：Scientific Reports, 2015, 5(1): 8403.

DOI：10.1038/srep08403

Homogeneous lithium-rich layered-spinel 0.5Li(2)Mn(O)3 center dot 0.5LiMn(1/3)Ni(1/3)Co(1/3)O(2) microspheres (similar to 1 mu m) are successfully prepared by a solvothermal method and subsequent high-temperature calcinations process. The effects of temperature on the structure and performance of the as-prepared cathode material are systemically studied by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), galvanostatical charge/discharge and electrochemical impedance spectra. The results show that a spinel Li4Mn5O12 component can be controllably introduced into the lithium-rich layered material at 750 degrees C. Besides, it has been found that the obtained layered-spinel cathode material represents excellent electrochemical characteristics. For example, it can deliver a high initial discharge capacity of 289.6 mAh g(-1) between 2.0 V and 4.6 V at a rate of 0.1 C at room temperature, and a discharge capacity of 144.9 mAhg(-1) at 5 C and 122.8 mAhg(-1) even at 10 C. In addition, the retention of the capacity is still as high as 88% after 200 cycles, while only 79.9% for the single-phase layered material. The excellent electrochemical performance of the as-prepared cathode material can probably be attributed to the hybrid structures combining a fast Li-ion diffusion rate of 3D spinel Li4Mn5O12 phase and a high capacity of the layered Li-Mn-Ni-Co-O component.

• 出版日期2015-2-12
• 单位湘潭大学