(1. 四川大学 高分子研究所，成都 610065； 2. 四川大学 化学工程学院，成都 610065； 3. 伍伦贡大学 超导与电子材料研究所，伍伦贡 2522； 4. 成都理工大学 材料与化学化工学院，成都 610059)
摘 要: 采用原位诱导法制备得到了一系列xLiM2O4？(1-x)LiNi1/3Co1/3Mn1/3O2(M=Ni, Co, Mn; x=0, 0.1, 0.2, 0.3, 0.4, 0.5)尖晶石/层状异质结构复合材料。借助X射线衍射、扫描电镜、差示扫描量热仪、恒电流间歇滴定技术和恒电流充放电测试表征手段对材料的晶体结构、微观形貌和电化学性能进行了研究。电化学性能结果表明：x=0.2材料的倍率性能和循环性能最佳，在2.7~4.3 V、1C下循环100次后，放电比容量为137 mA？h/g，容量保持率为93%；10C时的放电比容量为112 mA？h/g，相比于原始LiNi1/3Co1/3Mn1/3O2材料在10C的放电比容量(95 mA？h/g)有较大提高。此外，快充慢放能力测试也证实了该材料的结构稳定，其在5C充、1C放的充放电机制下，循环100次后的放电比容量还能高达120 mA？h/g，容量保持率为87%。恒电流间歇滴定技术(GITT)的结果表明。x=0.2材料的DLi+值比原始LiNi1/3Co1/3Mn1/3O2材料的要高出一个数量级，说明尖晶石相的引入从根本上改善了材料的电化学性能。
关键字: 异质尖晶石/层状结构；LiNi1/3Co1/3Mn1/3O2；锂离子电池；电化学性能
（1. Polymer Research Institute, Sichuan University, Chengdu 610065, China; 2. School of Chemical Engineering, Sichuan University, Chengdu 610065, China; 3. Institute for Superconducting and Electronic Materials, University of Wollongong, Wollongong NSW 2522, Australia; 4. College of Materials and Chemistry and Chemical Engineering, Chengdu University of Technology, Chengdu 610059, China）
Abstract:A series of heterostructured spinel/layered xLiM2O4？(1-x)LiNi1/3Co1/3Mn1/3O2 (M=Ni, Co, Mn; x=0, 0.1, 0.2, 0.3, 0.4, 0.5) cathodes were prepared by in-situ induced coating method. Powder X-ray diffractometry (XRD), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), galvanostetic intermittent titration technique (GITT) and galvanostatic charge-discharge tests were employed to analyze the crystal structure, micromorphology and electrochemical properties of the as prepared materials. Electrochemical results indicate that the x=0.2 sample has the best rate performance and long-term cycling stability. It delivers a discharge capacity of 137 mA？h/g at 2.7-4.3 V and 1C after 100 cycles, with the outstanding capacity retention being 93%. At 10C, the specific capacity of the material is 112 mA？h/g, which is improved greatly when compared with the pristine LiNi1/3Co1/3Mn1/3O2 (95 mA？h/g at 10C). Additionally, the fast-charging test results are indicative of the fact that this cathode has sufficiently stable structure, because it can still deliver a discharge capacity higher than 120 mA？h/g after 100 cycles with capacity retention of 87% at 5C charge and 1C discharge. Galvanostatic intermittent titration technique (GITT) results show that DLi+ of x=0.2 sample is higher by one order of magnitude than the pristine LiNi1/3Co1/3Mn1/3O2, indicating that the introduced spinel phase could fundamentally enhance the electrochemical performance for cathodes.
Key words: heterostructured spinel/layered; LiNi1/3Co1/3Mn1/3O2; lithium-ion battery; electrochemical performance
