超声波对α-Ni(OH)2电极结构及电化学性能的影响

摘要

Al/Co co-doped α-Ni(OH)2 samples were prepared by either ultrasonic co-precipitation method (Sample B) or co-precipitation method (Sample A).The crystal structure and particle size distribution of the prepared samples were examined by X-ray diffraction (XRD) and laser particle size analyzer,respectively.The results show that Sample B has more crystalline defects and smaller average diameter than Sample A.The cyclic voltammetry and electrochemical impedance spectroscopy measurements indicate that Sample B has better electrochemical performance than Sample A,such as better reaction reversibility,lower charge-transfer resistance and better cyclic stability.Proton diffusion coefficient of Sample B is 1.96× 10-10cm2/s,which is two times as large as that (9.78× 10-11 cm2/s) of Sample A.The charge-discharge tests show that the discharge capacity (308 mA.h/g) of Sample B is 25 mA·h/g higher than that of Sample A (283 mA·h/g).%分别采用共沉淀法和超声波共沉淀法制备Al/Co复合掺杂α-Ni(OH)2样品A和B,用XRD和激光粒度仪表征样品的晶相结构和粒度分布.结果表明,样品B比样品A具有较多的晶格缺陷和较小的平均粒径.循环伏安特性及电化学阻抗谱测试显示,样晶B比样品A具有更好的电化学性能:较好的反应可逆性、较低的电荷转移电阻和较高的循环寿命等.样品B的质子扩散系数为1.96×10-10cm2/s,约为样品A(9.78×10-11cm2/s)的2倍.充放电测试显示,样品B的放电比容量达到308 mA·h/g,比样品A的放电比容量高25 mA·h/g.