LaNi_(2.5)Co_(0.5)储氢合金在充放电循环过程中的电化学性能研究
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摘要
以感应熔炼法制备的LaNi_(2.5)Co_(0.5)合金为研究对象,对该合金及其氢化物的相结构进行了分析,并对合金电极的放电容量保持率、高倍率放电性能、氢扩散系数及极化电流密度等电化学性能进行了研究.结果表明:吸氢后的合金会产生明显的非晶化现象,造成合金吸放氢能力和氢化物稳定性下降.随着循环次数的增加,合金的放电容量和高倍率放电性能均表现出先快速下降到逐渐缓慢降低的趋势,而合金的氢扩散系数和极化电流密度却呈现出不同的变化趋势.高倍率放电性能的下降主要与合金表面反应活性相关,说明表面劣化现象是造成合金电化学性能衰退的主要因素.
The phase structures of LaNi_(2.5)Co_(0.5) alloy and its hydride which was prepared by induction melting methodwere analyzed,and the electrochemical properties such as discharge capacity retention,high rate discharge performance,hydrogen diffusion coefficient and polarization current of the alloy electrode were also investigated.The results showed that the amorphous phenomena occurred after charging for the alloy,which resulted in the decrease of hydrogen concentration and hydride stability.The discharge capacity and high rate of dischargeability of the alloy decreased first fast and then slowly by increasing cycles,but the hydrogen diffusion coefficient and polarization current density of the alloys showed different variation trend.The high rate dischargeability was mainly controlled by the surface reactivity,which indicated that the surface degradation was the main factor on electrochemical performances of the alloy electrode.
The phase structures of LaNi_(2.5)Co_(0.5) alloy and its hydride which was prepared by induction melting methodwere analyzed,and the electrochemical properties such as discharge capacity retention,high rate discharge performance,hydrogen diffusion coefficient and polarization current of the alloy electrode were also investigated.The results showed that the amorphous phenomena occurred after charging for the alloy,which resulted in the decrease of hydrogen concentration and hydride stability.The discharge capacity and high rate of dischargeability of the alloy decreased first fast and then slowly by increasing cycles,but the hydrogen diffusion coefficient and polarization current density of the alloys showed different variation trend.The high rate dischargeability was mainly controlled by the surface reactivity,which indicated that the surface degradation was the main factor on electrochemical performances of the alloy electrode.
引文
[1]CHEN Jun,KURIYAMA N,TAKESHITA H T,et al.Hydrogen storage alloys with PuNi3-type structure as metal hydride electrodes[J].Electrochem Solid-State Letters,2000,3(6):249-252.
[2]LUSHNIKOV S A,VERBETSKY V N,GLAZKOV V P,et al.Structure,chemical bonds and anisotropy in hydrides IMC with CeNi3and PuNi3structure[J].Journal of Alloys and Compounds,2007,446(11):28-33.
[3]张翰威,李一鸣,任慧平,等.La0.88Mg0.12Ni3.45与商用AB5型储氢合金失效行为的对比研究[J].稀土,2016,37(2):21-30.ZHANGHanwei,LI Yiming,REN Huiping,et al.Degradation behavior of hydrogen storage alloy La0.88Mg0.12Ni3.45[J].Chinese Rare Earths,2016,37(2):21-30.
[4]钟成林,晁栋梁,陈云贵,等.制备工艺对AB5型高容量贮氢合金电化学性能的影响[J].稀有金属材料与工程,2013,42(7):1522-1525.ZHONGChenglin,CHAO Dongliang,CHEN Yungui,et al.Effect of preparation process on electrochemical performances of AB5-type high capacity hydrogen storage alloys[J].Rare Metal Materials and Engineering,2013,42(7):1522-1525.
[5]刘宝忠,李安铭,范燕平,等.La0.7Ce0.3Ni3.75Mn0.35Al0.15Cu0.75-xFex合金的相结构和电化学储氢性能[J].中国有色金属学报(英文版),2012,22(11):2730-2735.LIUBaozhong,LI Anming,FAN Yanping,et al.Phase structure and electrochemical properties of La0.7Ce0.3Ni3.75Mn0.35Al0.15Cu0.75-xFex hydrogen storage alloys[J].Transactions of Nonferrous Metals Society of China,2012,22(11):2730-2735.
[6]师彦春,张羊换,赵小龙,等.La-Mg-Ni系(AB3~3.5型)贮氢合金循环寿命改善途径[J].金属功能材料,2007,14(6):33-37.SHIYanchun,ZHANG Yanghuan,ZHAO Xiaolong,et al.Approaches to enhance the cycle life of La-Mg-Ni(AB3~3.5type)system hydrogen storage alloys[J].Metallic Functional Materials,2007,14(6):33-37.
[7]张永健.新型复合镍氢电池用负极合金的结构和性能研究[D].厦门:厦门大学,2013.ZHANG Yongjian.The structure and properties of the novel composite MH-Ni battery anode alloys[D].Xiamen:Xiamen University,2013.
[8]梅兴志,罗永春,张国庆,等.稀土系A2B7型La1-xScxNi2.6Co0.3Mn0.5Al0.1(x=0~0.5)储氢合金相结构和电化学性能研究[J].无机材料学报,2015,30(10):1049-1055.MEIXingzhi,LUO Yongchun,ZHANG Guoqing,et al.Structural and electrochemical properties of A2B7 type La1-xScxNi2.6Co0.3Mn0.5Al0.1(x=0~0.5)hydrogen storage alloys[J].Journal of Inorganic Materials,2015,30(10):1049-1055.
[9]王大辉.La-Mg-Ni系La2MgNi7.5Co1.5贮氢合金的结构和电化学性能研究[D].兰州:兰州理工大学,2007.WANG Dahui.Study on structure and electrochemical properties of La-Mg-Ni system La2MgNi7.5Co1.5 hydrogen storage alloy[D].Lanzhou:Lanzhou University of Technology,2007.
[10]廖彬.La-Mg-Ni系AB3型贮氢合金的相结构与电化学性能[D].杭州:浙江大学,2004.LIAO Bin.Phase structure and electrochemical properties of La-Mg-Ni system AB3-type hydrogen storage electrode alloys[D].Hangzhou:Zhejiang University,2004.
[11]DONG Zhenwei,MA Liqun,SHEN Xiaodong,et al.Cooperative effect of Co and Al on the microstructure and electrochemical properties of AB3-type hydrogen storage electrode alloys for advanced MH/Ni secondary battery[J].International Journal of Hydrogen Energy,2011,36(1):893-900.
[12]IWAKURA C,OURA T,HIROSHI I,et al.Effects of substitution with foreign metals on the crystallographic,thermodynamic and electrochemical properties of AB5-type Hydrogen storage alloys[J].Electrochimica Acta,1996,41(1):117-121.
[2]LUSHNIKOV S A,VERBETSKY V N,GLAZKOV V P,et al.Structure,chemical bonds and anisotropy in hydrides IMC with CeNi3and PuNi3structure[J].Journal of Alloys and Compounds,2007,446(11):28-33.
[3]张翰威,李一鸣,任慧平,等.La0.88Mg0.12Ni3.45与商用AB5型储氢合金失效行为的对比研究[J].稀土,2016,37(2):21-30.ZHANGHanwei,LI Yiming,REN Huiping,et al.Degradation behavior of hydrogen storage alloy La0.88Mg0.12Ni3.45[J].Chinese Rare Earths,2016,37(2):21-30.
[4]钟成林,晁栋梁,陈云贵,等.制备工艺对AB5型高容量贮氢合金电化学性能的影响[J].稀有金属材料与工程,2013,42(7):1522-1525.ZHONGChenglin,CHAO Dongliang,CHEN Yungui,et al.Effect of preparation process on electrochemical performances of AB5-type high capacity hydrogen storage alloys[J].Rare Metal Materials and Engineering,2013,42(7):1522-1525.
[5]刘宝忠,李安铭,范燕平,等.La0.7Ce0.3Ni3.75Mn0.35Al0.15Cu0.75-xFex合金的相结构和电化学储氢性能[J].中国有色金属学报(英文版),2012,22(11):2730-2735.LIUBaozhong,LI Anming,FAN Yanping,et al.Phase structure and electrochemical properties of La0.7Ce0.3Ni3.75Mn0.35Al0.15Cu0.75-xFex hydrogen storage alloys[J].Transactions of Nonferrous Metals Society of China,2012,22(11):2730-2735.
[6]师彦春,张羊换,赵小龙,等.La-Mg-Ni系(AB3~3.5型)贮氢合金循环寿命改善途径[J].金属功能材料,2007,14(6):33-37.SHIYanchun,ZHANG Yanghuan,ZHAO Xiaolong,et al.Approaches to enhance the cycle life of La-Mg-Ni(AB3~3.5type)system hydrogen storage alloys[J].Metallic Functional Materials,2007,14(6):33-37.
[7]张永健.新型复合镍氢电池用负极合金的结构和性能研究[D].厦门:厦门大学,2013.ZHANG Yongjian.The structure and properties of the novel composite MH-Ni battery anode alloys[D].Xiamen:Xiamen University,2013.
[8]梅兴志,罗永春,张国庆,等.稀土系A2B7型La1-xScxNi2.6Co0.3Mn0.5Al0.1(x=0~0.5)储氢合金相结构和电化学性能研究[J].无机材料学报,2015,30(10):1049-1055.MEIXingzhi,LUO Yongchun,ZHANG Guoqing,et al.Structural and electrochemical properties of A2B7 type La1-xScxNi2.6Co0.3Mn0.5Al0.1(x=0~0.5)hydrogen storage alloys[J].Journal of Inorganic Materials,2015,30(10):1049-1055.
[9]王大辉.La-Mg-Ni系La2MgNi7.5Co1.5贮氢合金的结构和电化学性能研究[D].兰州:兰州理工大学,2007.WANG Dahui.Study on structure and electrochemical properties of La-Mg-Ni system La2MgNi7.5Co1.5 hydrogen storage alloy[D].Lanzhou:Lanzhou University of Technology,2007.
[10]廖彬.La-Mg-Ni系AB3型贮氢合金的相结构与电化学性能[D].杭州:浙江大学,2004.LIAO Bin.Phase structure and electrochemical properties of La-Mg-Ni system AB3-type hydrogen storage electrode alloys[D].Hangzhou:Zhejiang University,2004.
[11]DONG Zhenwei,MA Liqun,SHEN Xiaodong,et al.Cooperative effect of Co and Al on the microstructure and electrochemical properties of AB3-type hydrogen storage electrode alloys for advanced MH/Ni secondary battery[J].International Journal of Hydrogen Energy,2011,36(1):893-900.
[12]IWAKURA C,OURA T,HIROSHI I,et al.Effects of substitution with foreign metals on the crystallographic,thermodynamic and electrochemical properties of AB5-type Hydrogen storage alloys[J].Electrochimica Acta,1996,41(1):117-121.