摘要
采用高能球磨方法制备了Mg-Ni非晶,并用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、差热分析仪(DTA)、电池综合性能测试仪等分析了该非晶的热稳定性、活化性能、电化学稳定性以及容量衰减机理等.结果表明:Mg-Ni非晶在室温下首次活化即可达到最大容量440 mAh.g-1,具有较好的充放电活化特性,但是其容量衰减较快,其主要原因有:非晶相在充放电过程中逐渐晶化形成Mg2NiH4,Ni相;Mg被电解液腐蚀生成Mg(OH)2;非晶颗粒经多次循环后产生粉化.在Mg-Ni中添加适量的镧可提高其热稳定性、电化学稳定性且不影响其活化性能.
The amorphous Mg-Ni based alloys were prepared by high energy ball milling. The thermal stability, activation properties, electrochemical characteristics and mechanism of the discharge capacity loss of the amorphous electrodes were investigated by using X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), Differential Thermal Analyzer (DTA) and battery test apparatus. The results showed that the amorphous Mg-Ni alloys could reach their maximum electrochemical discharge capacities (about 440 mAh(.)g(-1)) at the first charge/discharge test but the capacities decreased rapidly with the increase in cyclic number. The amorphous Mg-Ni specimens would decompose to crystalline Mg(2)NiH(4) and Ni phases and form Mg(OH)(2) phase on the surface of the particles during the charge/discharge cycling, and the particle of the alloys would decrease as the increase in cycle numbers. Partially substituting Mg with appropriate La could lead to improvement of the thermal and cyclic stabilities and did not affect the activation characteristics.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2005年第4期661-664,共4页
Rare Metal Materials and Engineering
基金
国家自然科学基金资助(50171024)
广西壮族自治区自然科学基金资助(0135053)
关键词
高能球磨
贮氢合金
电化学性能
Mg-Ni非晶
机理
high energy ball milling
hydrogen storage alloy
electrochemical properties
amorphous Mg-Ni based alloys
mechanism
