Significant improvement in performances of LiNi0.5Mn1.5O4 through surface modification with high ordered Al-doped ZnO electro-conductive layer

• DOI: 10.1016/j.apsusc.2015.01.120
• Publication Date: 2015-01-24T02:07:42Z
• Authors: Hongdan Sun; Bingbo Xia; Weiwei Liu; Guoqing Fang; Jingjing Wu; Haibo Wang; Ruixue Zhang; Shingo Kaneko; Junwei Zheng; Hongyu Wang; Decheng Li
• Keywords: Surface Modification

Abstract Al-doped ZnO (AZO)-coated LiNi 0.5 Mn 1.5 O 4 (LNMO) was prepared by sol–gel method. Transmission electron microscopy (TEM) analysis indicates that AZO layer grown on the surface of LNMO is high ordered. The results of electrochemical performance measurements reveal that the AZO-coated LNMO electrode displays the best rate capability compared with the bare LNMO and ZnO-coated LNMO, even at a high rate of 10 C. The discharge capacity of the AZO-coated LNMO electrode can still reach 114.3 mAh g −1 , about 89% of its discharge capacity at 0.1 C. Moreover, AZO-coated LNMO electrode shows a remarkable improvement in the cyclic performance at a high rate at elevated temperature due to the protective effect of AZO coating layer. The electrode delivers a capacity of 120.3 mAh g −1 with the capacity retention of 95% at 5 C in 50 cycles at 50 °C. The analysis of electrochemical impedance spectra (EIS) indicates that AZO-coated LNMO possesses the lowest charge transfer resistance compared to the bare LNMO and ZnO-coated LNMO, which may be responsible for improved rate capability.