添加Si对La-Mg-Ni系A_2B_7型电极合金循环稳定性的影响  

Impact of adding Si on the cycle stability of the La-Mg-Ni-based A_2 B_7-type electrode alloy

作　　者：张羊换[1,2] 任慧平[1] 杨泰[1,2] 尚宏伟[1,2] 翟亭亭[2] 赵栋梁[2] 

机构地区：[1]内蒙古科技大学内蒙古自治区白云鄂博矿多金属资源综合利用重点实验室,内蒙古包头014010 [2]钢铁研究总院功能材料研究所,北京100081

出　　处：《功能材料》2013年第19期2778-2782,共5页Journal of Functional Materials

基　　金：国家自然科学基金资助项目(50961009)

摘　　要：为了改善La-Mg-Ni系A2B7型电极合金的电化学循环稳定性，在合金中添加少量Six采用真空感应熔炼制备了La0.8Mg0.2Ni3.3Co0.2Six（x=0～0．2）电极合金，并将部分合金在真空条件下，温度为900、950、1000和1050℃下进行了退火处理。用XRD、SEM分析了铸态及退火态舍金的微观结构，测试了铸态及快淬态合金的电化学循环稳定性。结果表明，铸态及快淬态合金均具有多相结构，包括两个主相（La，Mg）2Ni7和LaNi5及一个残余相LaNi3。添加Si使LaNi5相增加而（La，Mg）2Ni7相减少。合金的电化学循环稳定性随Si含量的增加而增加，当Si含量x从0增加到0．2时，铸态合金100次充放循环后的容量保持率（S100）从64．2％增加到73．1％，而950℃退火态合金的S100值从80．3％增加到93．7％。In order to improve the cycle stability of the La-Mg-Ni-based A2BT-type electrode alloy, a small amount of Si has been added to the alloy. The compositions of La0.8Mg0.2Ni3.3Co0.2Six（x=0～0.2） alloys were prepared by using a vacuum induction furnace, and a part of the alloys was annealed at 900, 950, 1000 and 1050℃ in vacuum. The microstructure of the as-cast and annealed alloys were examined by XRD and SEM, what＇s more, the electrochemical cycle stability of the as-cast and quenched alloys has been checked out. The results indicated that the as-cast and quenched alloys had a multiphase structure, including two major phases of （La, Mg）2Ni7 and LaNi5 as well as a residual phase of LaNi3. The additive Si leaded to a increase in LaNi5 phase and a decrease in （La, Mg）2Ni7 phase. Additionally, with the increase of Si content from 0 to 0.2, the capacity retention rate （S100） of as-cast alloys enhanced from 64.2% to 73.1%, meanwhile, the capacity remaining rate （S100） of the alloys quenched at 950℃ grew from 80.3% to 93.7%.

关 键 词：A2B7型电极合金 添加Si 退火 微观结 构 循环稳定性 

分 类 号：TG139.7[一般工业技术—材料科学与工程]