電化學(xué)貯氫性能的影響
(1. 鋼鐵研究總院 功能材料研究所，北京 100081; 2. 內(nèi)蒙古科技大學(xué) 材料與冶金學(xué)院，包頭 014010;
3.包頭稀土研究院 科技處，包頭 014010)
摘 要: 為了改善Mg2Ni型貯氫合金的電化學(xué)貯氫性能，以Co部分替代合金中的Ni，用快淬工藝制備Mg2Ni型Mg2Ni1−xCox (x = 0, 0.1, 0.2, 0.3, 0.4)合金, 獲得長度連續(xù)、厚度約為30 μm、寬度約為25 mm的快淬合金薄帶。并用XRD、SEM、HRTEM分析快淬態(tài)合金薄帶的微觀結(jié)構(gòu)；用DSC研究快淬薄帶的熱穩(wěn)定性；用程控電池測試儀測定合金薄帶的電化學(xué)貯氫性能；探索Co替代Ni對快淬Mg2Ni型合金結(jié)構(gòu)及電化學(xué)貯氫性能的影響。結(jié)果表明：在快淬無Co合金中沒有發(fā)現(xiàn)非晶相，但快淬含Co合金中存在明顯的非晶結(jié)構(gòu)，證明Co替代Ni提高了Mg2Ni型合金的非晶形成能力。Co替代Ni使快淬態(tài)合金的熱穩(wěn)定性略有提高，顯著地改善了合金的電化學(xué)貯氫性能，包括放電容量、電化學(xué)循環(huán)穩(wěn)定性以及高倍率放電性能，這主要歸因于Co替代Ni導(dǎo)致結(jié)構(gòu)的變化以及非晶形成能力的提高。
關(guān)鍵字: Mg2Ni型合金；快淬；Co替代Ni；電化學(xué)貯氫
ZHANG Yin2, GUO Shi-hai1, WANG Xin-lin1
（1. Department of Functional Materials Research, Central Iron and Steel Research Institute, Beijing 100081, China;
2. School of Materials and Metallurgy, Inner Mongolia University of Science and Technology, Baotou 014010, China;
3. Department of Science and Technology, Baotou Research Institute of Rare Earths, Baotou 014010, China）
Abstract:In order to improve the electrochemical hydrogen storage characteristics of the Mg2Ni-type alloy, Ni in the alloy was partially substituted by element Co. The Mg2Ni-type Mg2Ni1−xCox (x = 0, 0.1, 0.2, 0.3, 0.4) alloys were prepared by melt-spinning technology. The spun ribbons with a continuous length, a thickness of about 30 μm and a width of about 25 mm were obtained. The microstructures of the spun alloy ribbons were analyzed by XRD, SEM and HRTEM. The thermal stability of the as-spun alloys was investigated by DSC. The electrochemical hydrogen storage performances of the spun alloy ribbons were tested by an automatic galvanostatic system. The influences of substituting Ni with Co on the structure and electrochemical hydrogen storage characteristics of melt spun Mg2Ni-type alloy were investigated. The results show that no amorphous phase is detected in the as-spun Co-free alloy, but the as-spun alloys containing Co display an evident percent of amorphous phase, suggesting that the substitution of Co for Ni significantly heightens the glass forming ability of the Mg2Ni-type alloy. The substitution of Co for Ni causes a slight increase in the thermal stability of the as-spun alloy, and significantly improves the electrochemical hydrogen storage performances of the alloys, involving the discharge capacity and the cycle stability as well as the high rate discharge (HRD) capability, for which the increased glass forming ability by Co substitution is mainly responsible.
Key words: Mg2Ni-type alloy; melt-spinning; substituting Ni with Co; electrochemical hydrogen storage
