摘要
采用高频感应悬浮炉制备Mm_(0.75)Mg_(0.25)Ni_(3.5)Co_(0.2)Al_(0.3)(Mm表示富镧混合稀土)铸态合金并进行不同温度的退火处理。XRD分析表明:合金相主要由LaNi_(5)和La_(2)Ni_(7)相组成,退火处理后的合金相LaNi_(5)和La_(2)Ni_(7)衍射峰加强。当退火温度为800℃时,La_(2)Ni_(7)晶胞体积达到最大值0.5497nm^(3),说明合金经该温度退火处理,Co、Al合金元素能更好地溶入主相内。电化学测试分析表明:合金经800℃退火处理,其最大放电容量高达351.5mA·h/g,通过130个充放电循环后容量保持率仍有82.3%,并具备优异的高倍率放电性能。
Mm_(0.75)Mg_(0.25)Ni_(3.5)Co_(0.2)Al_(0.3)(Mm represents lanthanum-rich mixed rare earth)as-cast alloy was prepared in a high-frequency induction levitation furnace and then annealed at different temperatures.XRD analysis shows that the alloy is mainly composed of LaNi_(5) phase and La_(2)Ni_(7) phase.The diffraction peaks of LaNi_(5) and La_(2)Ni_(7) alloy phases are strengthened after annealing treatment.At the annealing temperature of 800℃,the unit cell volume of La_(2)Ni_(7) reaches the maximum value of 0.5497nm^(3),indicating that Co and Al alloying elements can be better dissolved in the main phases after annealing treatment at 800℃.Elec-trochemical test analysis shows that the annealed alloy at 800℃ has a maximum discharge capacity of up to 351.5 mA·h/g,a capacity retention rate of 82.3%after 130charge-discharge cycles,and excellent high-rate discharge performance.
作者
韦宁燕
韦洪浪
卢照
WEI Ning-yan;WEI Hong-lang;LU Zhao(Bowen College of Management,Guilin University of Technology,Guilin 541006,China;Guilin University of Technology at Nanning,Nanning 530001,China;Guangxi Key Laboratory of Information Materials,Guilin University of Electronic Technology,Guilin 541004,China)
出处
《稀有金属与硬质合金》
CAS
CSCD
北大核心
2022年第3期82-86,92,共6页
Rare Metals and Cemented Carbides
基金
国家自然科学地区基金(52061007)
广西自然科学基金面上项目(2018GXNSFAA294069,2019GXNSFAA245003)
广西基地人才专项(19110078)
广西信息材料重点实验室项目(191012-Z)。
关键词
镍氢电池
储氢合金
退火
物相
循环稳定性
高倍率放电
Ni-MH battery
hydrogen storage alloy
annealing
phase
cycle stability
high rate discharge
