无钴AB_5合金与纯钴的协同效应  

Synergy Effects of Co-free AB_5 Alloy and Pure Cobalt

作　　者：谢灵[1] 李佳佳[1] 杨猛[1] 姚磊[1] 王亚东[1] 马立群[1] 

机构地区：[1]南京工业大学材料科学与工程学院,江苏南京210009

出　　处：《热加工工艺》2017年第16期68-71,79,共5页Hot Working Technology

基　　金：国家自然科学基金资助项目(51201089);江苏省"六大人才高峰"项目(2012-XCL-034);江苏高校优势学科建设工程(PAPD)

摘　　要：采用电弧熔炼法制备出不含Co的AB_5型储氢合金,并将其与纯钴粉按不同质量比复合制成复合电极。采用XRD分析了AB_5合金的相结构,使用恒流充放电测试、循环伏安测试以及交流阻抗测试来研究复合电极的电化学性能。结果表明,当无钴的AB5储氢合金与纯钴粉按质量比为1∶5复合时,复合电极的性能最佳,其最大放电容量为534.7mAh/g,循环充放电50次之后的容量保持率为69.6%。复合电极AB_5∶Co=1∶5充放电时主要发生Co与Co(OH)_2之间的氧化还原反应,AB5的存在对Co的放电起着催化作用,促进了Co/Co(OH)_2反应,放电容量明显增加。Co-free AB5 hydrogen storage alloy was prepared by arc melting method. The composite electrodes were obtained by mixing Co-free AB5 and pure cobalt powder at different mass ratios. The phase structure of AB5 alloy was analyzed by XRD. The electrochemical properties of the composite electrodes were studied by galvanostatic charge and discharge tests, CV and AC impedance. The results indicate that when the mass ratio of Co-free AB5 and pure cobalt powder is 1∶5, the composite electrodes achieve the best performance. It possesses a maximum discharge capacity of 534.7 mAh/g and a capacity retention rate of 69.6% after 50 cycles for charge and discharge. The redox reactions between Co and Co（OH）2 are the main reaction of composite electrode AB5∶Co=1 ∶5 during charge and discharge. The existence of AB5 acts as a catalyst to promote the Co/Co（OH）2 reaction, which can increase the discharge capacity.

关 键 词：钴 AB5 电化学性能 

分 类 号：TG146[一般工业技术—材料科学与工程]