Mn、Mg共掺杂Ni(OH)2的电化学性能

采用缓冲溶液法制备复合掺杂Mn、Mg的正极材料Ni0.82Mn0.18-xMgx(OH)2(x=0.06、0.09、0.12)。采用XRD、XPS和SEM等测试表征材料的晶体结构、锰价态和形貌,采用循环伏安和恒流充放电测试研究Mn、Mg不同掺杂比例对氢氧化镍电化学性能的影响。结果表明,Mn、Mg掺杂样品均为β相,晶粒细化;Ni0.82Mn0.09Mg0.09(OH)2样品具有优异的电极反应可逆性和充放电性能,100 mA·g^-1电流密度下的放电比容量(290.6 mAh·g^-1)优于商用β-Ni(OH)2(281.1 mAh·g^-1);且500 mA·g^-1电流密度下循环30圈后,Ni0.82Mn0.09Mg0.09(OH)2的放电比容量未见衰减,其循环稳定性优于商用β-Ni(OH)2。

Electrochemical Performance of Mn and Mg Co-doped Ni(OH)2

To reduce costs and improve performance of the positive electrode materials,the buffer solution method was used to prepare manganese and magnesium doped nickel hydroxide,labeled as Ni0.82Mn0.18-xMgx(OH)2(x=0.06,0.09,0.12).XRD,XPS and SEM tests were used to characterize the crystal structure,manganese valence state and morphology of the samples.Cyclic voltammetry and constant current charge-discharge tests were used to study the influence of Mn and Mg doping ratio on the electrochemical performance of Ni(OH)2.The results showed that the samples doped Mn and Mg were allβ-phase and the crystal particles were smaller;Ni0.82Mn0.09Mg0.09(OH)2 showed excellent electrode reaction reversibility and charge-discharge performance.Specific discharge capacity(290.6 mAh·g^-1)of Ni0.82Mn0.09Mg0.09(OH)2 was better than that of the commercialβ-Ni(OH)2(281.1 mAh·g^-1)at 100 mA·g^-1;moreover,after cycling for 30 cycles at a current density of 500 mA·g^-1,the specific discharge capacity of Ni0.82Mn0.09Mg0.09(OH)2 was no decay,indicating its cycle stability is better than that of the commercialβ-Ni(OH)2.