Phase structure and electrochemical properties of non-stoichiometric La0.7Ce0.3(Ni3.65Cu0.75Mn0.35Al0.15(Fe0.43B0.57)0.10)x hydrogen storage alloys
来源期刊：JOURNAL OF RARE EARTHS2012年第12期
论文作者：范燕平 刘宝忠 张宝庆 吉力强 张志
文章页码：1249 - 1254
摘 要：Phase structure and electrochemical characteristics of Co-free La0.7Ce0.3（Ni3.65Cu0.75Mn0.35Al0.15（Fe0.43B0.57）0.10）x （0.90≤x≤1.10） al-loys were investigated. When x was 0.90, the alloy was composed of LaNi5, La3Ni13B2 and Ce2Ni7 phases. The Ce2Ni7 phase disappeared, and the abundant of La3Ni13B2 phase decreased when x increased to 0.95. When x was 1.00 or higher the alloys consisted of LaNi5 phase. The lat-tice parameter a and the cell volume V of the LaNi5 phase decreased, and the c/a ratio of the LaNi5 phase increased with x value increasing. Maximum discharge capacity of the alloy electrodes first increased and then decreased with x value increasing from 0.90 to 1.10, and the highest value was obtained when x was 1.00. High-rate dischargeability at the discharge current density of 1200 mA/g increased from 50.7% （x= 0.90） to 64.1% （x=1.10）. Both the charge-transfer reaction at the electrode/electrolyte interface and the hydrogen diffusion in the alloy were responsible for the high-rate dischargeability. Cycling capacity retention rate at 100th cycle （S100） gradually increased from 77.3% （x= 0.90） to 84.6% （x=1.10）, which resulted from the increase in Ni content and the c/a ratio of the LaNi5 phase with x value increasing.
范燕平1，刘宝忠2，张宝庆2，吉力强3，张志2
1. School of Physics and Chemistry,Henan Polytechnic University2. School of Materials Science&Engineering,Henan Polytechnic University3. Inner Mongolia Rare Earth Ovonic Metal Hydride Co.,Ltd
摘 要：Phase structure and electrochemical characteristics of Co-free La0.7Ce0.3（Ni3.65Cu0.75Mn0.35Al0.15（Fe0.43B0.57）0.10）x （0.90≤x≤1.10） al-loys were investigated. When x was 0.90, the alloy was composed of LaNi5, La3Ni13B2 and Ce2Ni7 phases. The Ce2Ni7 phase disappeared, and the abundant of La3Ni13B2 phase decreased when x increased to 0.95. When x was 1.00 or higher the alloys consisted of LaNi5 phase. The lat-tice parameter a and the cell volume V of the LaNi5 phase decreased, and the c/a ratio of the LaNi5 phase increased with x value increasing. Maximum discharge capacity of the alloy electrodes first increased and then decreased with x value increasing from 0.90 to 1.10, and the highest value was obtained when x was 1.00. High-rate dischargeability at the discharge current density of 1200 mA/g increased from 50.7% （x= 0.90） to 64.1% （x=1.10）. Both the charge-transfer reaction at the electrode/electrolyte interface and the hydrogen diffusion in the alloy were responsible for the high-rate dischargeability. Cycling capacity retention rate at 100th cycle （S100） gradually increased from 77.3% （x= 0.90） to 84.6% （x=1.10）, which resulted from the increase in Ni content and the c/a ratio of the LaNi5 phase with x value increasing.
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