动力电池用铝代氢氧化镍结构及电化学性能

Structural and electrochemical performance of aluminum substituted nickel hydroxide used in power battery

利用控制结晶工艺制备出了Al取代的氢氧化镍 ,对样品进行了晶体结构及电化学行为的研究。XRD分析表明 ,Al代氢氧化镍具有与α Ni(OH) 2 相似的晶体结构 ,具有较大的层间距 ,有利于质子的迁移。电化学测试表明 ,这种材料在电化学循环过程中具有多电子转移的能力 ,其单原子的电子转移数可达 1.4～ 1.5个 ,在 0 .2C充电时的充电效率将近10 0 %。在 10C充、放电时的效率均高达 90 %以上 ,具有优良的平台特性和大电流充放电性能 。

Aluminum substituted nickel hydroxide was prepared by using a technique called 'controlled crystallization process'. The crystal structure and electrochemical performance of the sample were analyzed.The results of XRD analysis show that the structure of the Al substituted nickel hydroxide is similar with that of the α nickel hydroxide, and it has a large interslab distance that is helpful for the diffusion of proton. The results of the electrochemical tests show that the material has the capability to transfer more than one electron. The NEE(number of exchanged electron) that one nickel atom can transfer during the electrochemical cycles may reach 1.4～1.5, the charge efficiency of the material is near 100% when it is charged at 0.2 C rate, and its charge/discharge efficiency are more than 90% when it is charged/discharged at 10 C rate. The excellent plateau characteristic and the performance at large current make it the favorite choice of the cathode materials for the power battery used in electric vehicles.