杂多酸处理对La-Y-Ni系A_(2)B_(7)型储氢合金电化学性能的影响  

Effect of heteropolyacid treatment on the electrochemical properties of La-Y-Ni system A_(2)B_(7)-type hydrogen storage alloy performance

作　　者：王成均 雷鸣 沈秉金 张乾坤 罗永春[1,2] WANG Cheng-jun;LEI Ming;SHEN Bing-jin;ZHANG Qian-kun;LUO Yong-chun(School of Materials Science and Engineering,Lanzhou University of Technology,Lanzhou 730050,China;State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals,Lanzhou University of Technology,Lanzhou 730050,China;Lanzhou Jinchuan Technology Park Co.Ltd.,Lanzhou 730100,China)

机构地区：[1]兰州理工大学材料科学与工程学院,甘肃兰州730050 [2]兰州理工大学省部共建有色金属先进加工与再利用国家重点实验室,甘肃兰州730050 [3]兰州金川科技园有限公司,甘肃兰州730100

出　　处：《兰州理工大学学报》2025年第1期25-33,共9页Journal of Lanzhou University of Technology

基　　金：国家自然科学基金(51761026)。

摘　　要：制备了退火态A_(2)B_(7)型La_(0.33)Y_(0.67)Ni_(3.23)Mn_(0.17)Al_(0.1)储氢合金,采用磷钨酸(H_(3)PW_(12)O_(40)),(phosphotungstic acid,TPA)水溶液对该退火合金进行浸渍处理,研究了TPA处理对合金组织结构、表面形貌、组成以及合金电化学性能的影响.结果表明:经TPA处理后的合金表面形成了腐蚀性凹坑或微孔,同时在合金表面形成了含有高氧化价态钨酸根离子的富Ni层.TPA处理可明显改善合金电极的电化学性能,当TPA质量浓度为0.1 mol/L时,合金电极的交换电流密度I_(0)最大,此时合金电极具有最大的1 C放电容量(364 mAh/g),其容量保持率S_(100)和大电流放电性能HRD_(900)分别为93.23%和81.92%,明显优于未处理合金电极的S_(100)(88.12%)和HRD 900(76.05%).TPA处理前后电极表面与电解质溶液界面处的电子转移阻抗是影响电极高倍率放电动力学性能的控制步骤.The annealed state A_(2)B_(7)type La_(0.33)Y_(0.67)Ni_(3.23)Mn_(0.17)Al_(0.1)hydrogen storage alloy was prepared,and the annealed alloy was impregnated with phosphotungstic acid(H_(3)PW_(12)O_(40)),(phosphotungstic acid(TPA))aqueous solution.The effects of TPA treatment on the organization,surface morphology,composition,and the electrochemical properties of the alloy were investigated.The results showed that corrosive pits or micropores are formed on the surface of the TPA-treated alloy,and a Ni-rich layer containing tungstate ions with high oxidation valence is formed on the surface of the alloy.The TPA treatment can significantly improve the electrochemical performance of the alloy electrode.The exchange current density I_(0)of the alloy electrode is the largest when the concentration of TPA is 0.1 mol/L.At this time,the alloy electrode has the largest 1C discharge capacity(364 mAh/g),and its capacity retention rate S_(100)and high-current discharge performance HRD_(900)are 93.23%and 81.92%,respectively,which are significantly better than those of the untreated alloy electrode with S 100(88.12%)and HRD 900(76.05%).The electron transfer impedance at the interface between the electrode surface and the electrolyte solution before and after the TPA treatment is a controlling step affecting the electrode’s high-magnification discharge electrodynamic performance.

关 键 词：La-Y-Ni系A_(2)B_(7)型储氢合金 杂多酸 表面处理 

分 类 号：TG139.7[一般工业技术—材料科学与工程]