摘要
以正硅酸乙酯为原料,采用溶胶-凝胶法制备多孔SiO2凝胶,将LaNi4.25Al0.75合金粉与凝胶混合在500℃进行真空烧结。将真空烧结所得样品在吸氢系统中进行吸、放氢性能测试,用恒流电池测试仪研究其电化学性能。研究结果表明:所得样品的抗氧化性能明显比纯LaNi4.25Al0.75合金粉的抗氧化性能强,在常温下吸氢后暴露在空气中没有出现自燃现象;所得样品在吸、放氢测试中表现出良好的稳定性能,当以1C放电到0.9 V时,经30次充、放电循环后,纯LaNi4.25Al0.75合金的初始容量为270 mA.h/g,容量衰减27.8%;包覆多孔SiO2凝胶后其初始放电容量为260 mA.h/g,容量仅衰减7.5%。
The SiO2 gel was prepared through hydrolysis and condensation polymerization of tetraethyl orthosilicate and H20. The gel and LaNi4.25Al0.75 powders were mixed completely and heated at 500 ℃ for 2 h to obtain samples. The absorption hydrogen property of sample was tested at 0.5 MPa in H2. The constant current batteries tester was used to characterize the electrochemical properties of obtained samples. The results show that the sample after absorbing H2 does not self-ignite in atmosphere at normal temperature and has excellent combustion resistance property. The obtained samples have stable absorption/desorption hydrogen properties, and the initial discharge capacities of pure LaNi4.25A10.75 and obtained sample are 270 mA.h/g and 260 mA.h/g, and then decrease by 27.8% and 7.5% after 30 charge/discharge cycles to 0.9 V at 1 C, respectively.
出处
《中南大学学报(自然科学版)》
EI
CAS
CSCD
北大核心
2007年第2期190-194,共5页
Journal of Central South University:Science and Technology
基金
国家高技术研究计划资助项目(2003AA305820)
中南大学博士后基金资助项目(2006)
关键词
AB5贮氢合金
表面处理
电化学性能
改性
AB5 hydrogen storage alloy
surface treatment
electrochemical properties
modification