无机盐工业
主管:中海油天津化工研究设计院有限公司
主办:中海油天津化工研究设计院有限公司
   中海油炼油化工科学研究院(北京)有限公司
   中国化工学会无机酸碱盐专业委员会
ISSN 1006-4990 CN 12-1069/TQ

无机盐工业 ›› 2024, Vol. 56 ›› Issue (11): 65-71.doi: 10.19964/j.issn.1006-4990.2023-0625

• 新能源电池材料 • 上一篇    下一篇

Co替代Ni对汽车电池用La0.8Mg0.2Ni3.8-x Co x 储氢合金电化学性能的影响

彭卫锋1(), 施卫2   

  1. 1.常州工程职业技术学院,江苏 常州 213164
    2.江苏理工学院,江苏 常州 213001
  • 收稿日期:2023-12-30 出版日期:2024-11-10 发布日期:2024-11-27
  • 作者简介:彭卫锋(1978— ),男,实验师,研究方向为汽车材料等;E-mail:weifeng78@sina.com
  • 基金资助:
    江苏省“333工程”科研项目项目(BRA2020315)

Effect of Co replacing Ni on electrochemical performance of La0.8Mg0.2Ni3.8-x Co x hydrogen storage alloy for automotive batteries

PENG Weifeng1(), SHI Wei2   

  1. 1.Changzhou Technical College of Engineering,Changzhou 213164,China
    2.Jiangsu University of Technology,Changzhou 213001,China
  • Received:2023-12-30 Published:2024-11-10 Online:2024-11-27

摘要:

采用磁悬浮熔炼炉制备了铸态La0.8Mg0.2Ni3.8-x Co x 储氢合金,研究了Co含量对La0.8Mg0.2Ni3.8-x Co x 储氢合金相结构和电化学性能的影响。结果表明,不同Co含量的La0.8Mg0.2Ni3.8-x Co x 储氢合金主要由LaNi5相、Ce5Co19相、Pr5Co19相和CeNi2相组成,La0.8Mg0.2Ni3.8-x Co x 储氢合金中x值增大(Co含量增加)会促使Ce5Co19相向Pr5Co19相转变,且当x=1.05时储氢合金中LaNi5相含量最小。随着x值增大,储氢合金的放氢平台先减小后增大、最大储氢量先增大后减小、第100次充放电后的容量保持率(S100)先增大后减小,当x=0.15时储氢合金的最大放电容量和S100取得最大值,分别为352.39 mA·h/g和81.29%。随着La0.8Mg0.2Ni3.8-x Co x 储氢合金中x值从0.65增加至2.25,储氢合金电极的交流阻抗逐渐增大,交换电流密度逐渐减小,氢扩散系数先增大后减小并在x=1.05时取得最大值,电流密度为300、600、900 mA/g时的高倍率放电性能均逐渐减小。结果表明,交换电流密度是决定La0.8Mg0.2Ni3.8-x Co x 储氢合金电极高倍率放电性能的关键因素。

关键词: Co含量, La0.8Mg0.2Ni3.8-x Co x 储氢合金, 相结构, 微观形貌, 电化学性能

Abstract:

As-cast La0.8Mg0.2Ni3.8-x Co xhydrogen storage alloy was prepared by magnetic levitation melting furnace,the effect of Co content(x=0.65~2.25) on the phase structure and electrochemical performance of hydrogen storage alloy were studied.The results showed that the phases of hydrogen storage alloys with different Co contents were mainly LaNi5,Ce5Co19,Pr5Co19 and CeNi2 phase.The increase of x value(Co content) in La0.8Mg0.2Ni3.8-x Co x hydrogen storage alloy promoted the transformation of Ce5Co19 phase to Pr5Co19 phase,and the LaNi5 phase content in the hydrogen storage alloy was the smallest when x=1.05.As the value of x increased,the hydrogen release platform of the hydrogen storage alloy was firstly decreased and then increased,and the maximum hydrogen storage capacity was firstly increased and then decreased.The capacity retention rate (S100) after the 100th charge and discharge was firstly increased and then decreased.When x=0.15,the hydrogen storage alloy obtained the maximum values of Cmax and S100,which were 352.39 mA·h/g and 81.29% respectively.With the increase of x value from 0.65 to 2.25,the AC impedance of hydrogen storage alloy electrodes was gradually increased,and the exchange current density was gradually decreased.The hydrogen diffusion coefficient was firstly increased and then decreased,and reached its maximum value at x=1.05.The high rate discharge performance was gradually decreased at current densities of 300,600,and 900 mA/g.The results indicated that the exchange current density was the key factor determining the high rate discharge performance of La0.8Mg0.2Ni3.8-x Co x hydrogen storage alloy electrodes.

Key words: Co content, hydrogen storage alloy, phase structure, micro morphology, electrochemical performance

中图分类号: