温度对LaNi_(3.8)Co_(0.6)Mn_(0.3)M_(0.3)储氢合金结构和电极性能的影响（英文）  

Effect of Temperature on Structure and Electrode Properties of La Ni_(3.8)Co_(0.6)Mn_(0.3)M_(0.3) Hydrogen Storage Alloys

作　　者：李斯[1] 周怀营[1] 刘文平[1] 张怀刚[1] 邓健秋[1] 王仲民[1] 

机构地区：[1]桂林电子科技大学广西信息科学实验中心,广西桂林541004

出　　处：《稀有金属材料与工程》2015年第7期1591-1596,共6页Rare Metal Materials and Engineering

基　　金：National Natural Science Foundation of China(51261003);National Key Basic Research Development Program of China("973"Program)(2010CB631303);Natural Science Foundation of Guangxi(2012 GXNSFGA060002,2011GXNSFD018004)

摘　　要：对La Ni3.8Co0.6Mn0.3M0.3(M=Ni,Al,Cu)储氢合金在238,273,303和323 K温度下的结构和电化学性能进行了一系列的实验研究。A,B,C分别代表La Ni4.1Co0.6Mn0.3(Ni替代),La Ni3.8Co0.6Mn0.3Al0.3(Al替代)和La Ni3.8Co0.6Mn0.3Cu0.3(Cu替代)3种储氢合金,通过X射线衍射仪分别对样品A,B,C的结构进行了研究,对样品A,B,C合金粉末制成的电极进行了模拟电池测试。结果证实,制备的合金均由具有Ca Cu5型六方晶格结构的La Ni5相构成。3种合金中,Cu替代的合金电极低温性能得到改善,Al替代的合金电极高温放电能力得到提高。交流阻抗图谱分析表明,B合金电极样品的高温放电能力提高是由于合金电极表面形成的致密氧化膜层减缓了合金腐蚀所致,样品B,C的高倍率性能衰退是由于电极表面的充放转移反应和氢原子扩散速率下降造成的,而样品C的优良低温性能则是合金电极表面高的充放电转移反应速率所致。A series of experiments have been performed to investigate the temperature effects on the structure and the electrochemical properties of LaNi3.8Co0.6Mn0.3M0.3（M=Ni, Al, Cu） hydrogen storage alloys at different temperatures of 238, 273, 303 and 323 K.Samples A, B and C were used to represent LaNi4.1Co0.6Mn0.3（Ni substituted alloy）, LaNi3.8Co0.6Mn0.3Al0.3（Al substituted alloy） and LaNi3.8Co0.6Mn0.3Cu0.3（Cu substituted alloy）, respectively.The structures and the electrochemical properties of A, B and C hydrogen storage alloys were investigated by XRD and simulated battery test, respectively.The results reveal that all of the alloys are composed of the homogeneous LaNi5 phase with a Ca Cu5-type hexagonal structure.The low-temperature properties of the Cu substituted alloy are improved, and the high-temperature discharge capacity of the Al substituted alloy is enhanced.Electrochemical impedance spectroscopy（EIS） analysis shows that the improvement of high-temperature discharge capacity of alloy electrode B is attributed to the formation of dense oxide film to protect the active material from corrosion, which is not favorable to charge-transfer reaction at the interface of electrode-electrolyte.The deterioration in the high-rate dischargeability（HRD） of alloy electrodes B and C are attributed to the degradation of electrochemical kinetics, including both charge-transfer reactions on the electrode surface and hydrogen diffusion in the bulk.Furthermore, the good low-temperature performance of alloy electrode C is due to the improvement of charge-transfer reaction.

关 键 词：储氢合金 LaNi3.8Co0.6Mn0.3M0.3 电极性能 高倍率放电能力 宽温 

分 类 号：TG139.7[一般工业技术—材料科学与工程]