(1. 重慶師范大學 功能材料實驗室，重慶 400047；
2. 重慶大學 材料科學與工程學院，重慶 400044)
摘 要: 采用自蔓延高溫合成法制備V3TiNi0.56Al0.2Crx(x=0~0.3) 貯氫合金，經(jīng)XRD和電化學測試等研究Cr添加量對合金微結(jié)構(gòu)及電化學性能的影響。結(jié)果表明： 當x為0、0.1和0.2時，V3TiNi0.56Al0.2Crx合金均由V基固溶體主相和TiNi相組成；當x=0.3時，合金由V基固溶體主相和具有六方結(jié)構(gòu)的C14型Laves相組成；隨著Cr含量的增加，合金主相的晶胞常數(shù)和晶胞逐漸減小；添加Cr以后，合金電極的最大放電容量降低，對活化性能基本沒有影響；此外，添加Cr可使合金循環(huán)性能得到明顯改善，V3TiNi0.56Al0.2Cr0.3合金經(jīng)過10次充放電循環(huán)后，容量保持率為99%，大電流放電性能最好；隨著Cr含量的增加，合金中氫的擴散系數(shù)逐漸增大。
關(guān)鍵字: 貯氫合金；V3TiNi0.56Al0.2Crx合金；自蔓延高溫合成；組織結(jié)構(gòu)；電化學性能
（1. Functional Material Laboratory, Chongqing Normal University, Chongqing 400047, China;
2. College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China）
Abstract:The V3TiNi0.56Al0.2Crx(x=0−0.3) hydrogen storage materials were prepared by self-propagating high-temperature synthesis. The influences of Cr content on the microstructure and electrochemical properties of these alloys were studied by X-ray diffraction and electrochemical measurement. The results show that when x are 0, 0.1 and 0.2, the alloys are composed of V-based solid solution as main phase and TiNi phase. When x=0.3, the alloys are composed of V-based solid solution as main phase and laves phase of C14 with hexagonal structure. The unit cell constant and the quantity of unit cell both reduce gradually with increasing Cr addition. The maximum discharge capacity of the alloy electrode is decreased by introduction of Cr, whereas the activation behavior is almost not affected. The cycling capability of the alloys are improved obviously, the capacity of V3TiNi0.56Al0.2Cr0.3 alloy keeps 99% after ten times of charge, and discharge, and good discharge properties can be got under heavy current. The diffusion coefficient of hydrogen in the alloys increases with increasing Cr addition.
Key words: hydrogen storage materials; V3TiNi0.56Al0.2Crx alloy; self-propagating high-temperature synthesis; constitution microstructure; electrochemical properties
