摘要
为了提升汽车电池负极用储氢合金的电化学性能,对铸态Y_(0.2)La_(0.8)Ni_(3.2)Al_(0.2)Mn_(0.2)储氢合金进行了850~1050℃保温4 h的退火处理,并对比分析了铸态和退火态储氢合金的相结构、微观形貌和电化学性能(充放电曲线、压力-组成-温度曲线、循环曲线、极化曲线和倍率放电曲线)。结果表明:铸态和低温(850、900℃)退火态Y_(0.2)La_(0.8)Ni_(3.2)Al_(0.2)Mn_(0.2)储氢合金主要由CaCu_(5)型相、Ce_(2)Ni_(7)/Gd_(2)Co_(7)型相和Ce_(5)Co_(19)型相组成;950℃及以上温度退火态储氢合金由Ce_(2)Ni_(7)型相和Ce_(5)Co_(19)型相组成,Ce_(2)Ni_(7)型相丰度在退火温度为950℃时取得最大值。退火态储氢合金的最大放电容量(C_(max))均高于铸态储氢合金,且随着退火温度的升高,退火态储氢合金的C_(max)先增加后减小,在退火温度为950℃时取得最大值(372.6 mA·h/g)。随着退火温度的升高,Y_(0.2)La_(0.8)Ni_(3.2)Al_(0.2)Mn_(0.2)储氢合金的高倍率放电性能先升高后降低,在相同放电电流密度下,950℃退火态Y_(0.2)La_(0.8)Ni_(3.2)Al_(0.2)Mn_(0.2)储氢合金的高倍率放电性能最佳。Y_(0.2)La_(0.8)Ni_(3.2)Al_(0.2)Mn_(0.2)储氢合金的高倍率放电性能主要由氢扩散系数(D0)控制,通过调整退火温度可以获得电化学性能良好的Y_(0.2)La_(0.8)Ni_(3.2)Al_(0.2)Mn_(0.2)储氢合金,适宜的退火温度为950℃。
In order to improve the electrochemical performance of hydrogen storage alloys for automotive battery cathodes,as-cast Y_(0.2)La_(0.8)Ni_(3.2)Al_(0.2)Mn_(0.2)hydrogen storage alloys were annealed at 850~1050℃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 Y_(0.2)La_(0.8)Ni_(3.2)Al_(0.2)Mn_(0.2)hydrogen storage alloys were mainly composed of CaCu_(5)type phase,Ce_(2)Ni_(7)/Gd_(2)Co_(7)type phase,and Ce_(5)Co_(19)type phase,the hydrogen storage alloys annealed at 950℃and above were mainly composed of Ce_(2)Ni_(7)type phase and Ce_(5)Co_(19)type phase.The maximum abundance of Ce_(2)Ni_(7)type phase was obtained at 950℃.C_(max)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 Y_(0.2)La_(0.8)Ni_(3.2)Al_(0.2)Mn_(0.2)hydrogen storage alloy was firstly increased and then decreased,the C_(max)was achieved(372.6 mA·h/g)at 950℃.With the increase of annealing temperature,the high rate discharge performance of Y_(0.2)La_(0.8)Ni_(3.2)Al_(0.2)Mn_(0.2)hydrogen storage alloy was firstly increased and then decreased.At the same discharge current density,the high rate discharge performance of Y_(0.2)La_(0.8)Ni_(3.2)Al_(0.2)Mn_(0.2)hydrogen storage alloy annealed at 950℃was the highest.The high rate discharge performance of Y_(0.2)La_(0.8)Ni_(3.2)Al_(0.2)Mn_(0.2)hydrogen storage alloy was mainly controlled by the hydrogen diffusion coefficient D0,Y_(0.2)La_(0.8)Ni_(3.2)Al_(0.2)Mn_(0.2)hydrogen storage alloy with good electrochemical performance could be obtained by adjusting the annealing temperature,and the suitable annealing temperature was 950℃.
作者
胡文娟
申小中
王汝佳
路露
邹联力
HU Wenjuan;SHEN Xiaozhong;WANG Rujia;LU Lu;ZOU Lianli(Department of Intelligent Equipment and Automotive Engineering,Wuxi Vocational Institute of Commerce,Wuxi 214153,China;Jiangsu Province Engineering Research Center of Key Components for New Energy Vehicle,Wuxi 214153,China;School of automobile and traffic engineering,Jiangsu University of Technology,Changzhou 213001,China;Institute for Advanced Materials,School of Materials Science and Engineering,Jiangsu University,Zhenjiang 212013,China)
出处
《无机盐工业》
CAS
CSCD
北大核心
2024年第11期51-58,共8页
Inorganic Chemicals Industry
基金
江苏省高校自然科学基金面上项目(22KJD480002)。
