Improving the Cycling Performance of the Layered Ni Rich Oxide Cathode by Introducing Low Content Li2MnO3
Abstract The layered Ni rich oxide LiNi 0.8 Co 0.1 Mn 0.1 O 2 cathode has been significantly attractive due to its large reversible capacity ~200 mAh g 1 However, the inherent poor cycling stability of the Ni based cathode materials is always a serious issue for restricting its commercialization. In this paper, we introduced Li 2 MnO 3 as an electrochemical inactive component in Ni rich oxide LiNi 0.8 Co 0.1 Mn 0.1 O 2 to stabilize its structure. The modified LiNi 0.8 Co 0.1 Mn 0.1 O 2 composites with low content Li 2 MnO 3 were prepared by a solid state reaction process. The results from XRD structure refinement and SAED confirm that Li 2 MnO 3 phase exists homogeneously in the composites. The modified LiNi 0.8 Co 0.1 Mn 0.1 O 2 composites with inactive Li 2 MnO 3 show much better cycling stability and stable average discharge voltage compared with the pristine one when charged to 4.5 V. Especially, the modified LiNi 0.8 Co 0.1 Mn 0.1 O 2 composite with 10% Li 2 MnO 3 (LNCMO 1090) delivers a reversible capacity of 207 mAh g 1 and keeps 155 mAh g 1 after 100 cycles at 20 mA g 1 (0.1C) corresponding to a capacity retention of 75% while LiNi 0.8 Co 0.1 Mn 0.1 O 2 could only maintain a capacity of 128 mAh g 1 with a capacity retention of 59% after 100 cycles. The improved cycling performance of the Li 2 MnO 3 containing electrode could be attributed to the stabilized effect of Li 2 MnO 3 on the electrode surface structure, as evidenced by the lower charge transfer resistance.