Inorganic Chemicals Industry ›› 2024, Vol. 56 ›› Issue (11): 51-58.doi: 10.19964/j.issn.1006-4990.2024-0003

• New energy battery materials • Previous Articles     Next Articles

Effect of annealing temperature on phase structure and electrochemical performance of hydrogen storage alloys for automotive batteries

HU Wenjuan1,2(), SHEN Xiaozhong1,2, WANG Rujia3, LU Lu1,2, ZOU Lianli4   

  1. 1.Department of Intelligent Equipment and Automotive Engineering,Wuxi Vocational Institute of Commerce,Wuxi 214153,China
    2.Jiangsu Province Engineering Research Center of Key Components for New Energy Vehicle,Wuxi 214153,China
    3.School of automobile and traffic engineering,Jiangsu University of Technology,Changzhou 213001,China
    4.Institute for Advanced Materials,School of Materials Science and Engineering,Jiangsu University,Zhenjiang 212013,China
  • Received:2024-01-03 Online:2024-11-10 Published:2024-11-27

Abstract:

In order to improve the electrochemical performance of hydrogen storage alloys for automotive battery cathodes,as-cast Y0.2La0.8Ni3.2Al0.2Mn0.2 hydrogen storage alloys were annealed at 850~1 050 ℃ holding for 4 h,the phase composition,microstructure and electrochemical properties(charge discharge curve,pressure composition temperature curve,cycle curve,polarization curve,and rate discharge curve) of as-cast and annealed hydrogen storage alloys at different temperatures were compared and analyzed.The results showed that the as-cast and low-temperature(850,900 ℃) annealed Y0.2La0.8Ni3.2Al0.2Mn0.2 hydrogen storage alloys were mainly composed of CaCu5 type phase,Ce2Ni7/Gd2Co7 type phase,and Ce5Co19 type phase,the hydrogen storage alloys annealed at 950 ℃ and above were mainly composed of Ce2Ni7 type phase and Ce5Co19 type phase.The maximum abundance of Ce2Ni7 type phase was obtained at 950 ℃.Cmax of annealed hydrogen storage alloys was higher than that of cast hydrogen storage alloys,and with the increase of annealing temperature,the maximum discharge capacity of annealed Y0.2La0.8Ni3.2Al0.2Mn0.2 hydrogen storage alloy was firstly increased and then decreased,the Cmax was achieved(372.6 mA·h/g) at 950 ℃.With the increase of annealing temperature,the high rate discharge performance of Y0.2La0.8Ni3.2Al0.2Mn0.2 hydrogen storage alloy was firstly increased and then decreased.At the same discharge current density,the high rate discharge performance of Y0.2La0.8Ni3.2Al0.2Mn0.2 hydrogen storage alloy annealed at 950 ℃ was the highest.The high rate discharge performance of Y0.2La0.8Ni3.2Al0.2Mn0.2 hydrogen storage alloy was mainly controlled by the hydrogen diffusion coefficient D0,Y0.2La0.8Ni3.2Al0.2Mn0.2 hydrogen storage alloy with good electrochemical performance could be obtained by adjusting the annealing temperature,and the suitable annealing temperature was 950 ℃.

Key words: Y0.2La0.8Ni3.2Al0.2Mn0.2 hydrogen storage alloy, annealing temperature, phase structure, microscopic morphology, electrochemical performance

CLC Number: