(西安交通大學(xué) 金屬材料強(qiáng)度國家重點(diǎn)實(shí)驗(yàn)室， 西安 710049)
摘 要: 研究了儲氫合金 (MlMg)Ni4-xCo0.7Znx(0≤x≤0.3) 的氣相儲氫特性和電化學(xué)性能。 結(jié)果表明， 隨著Zn含量的增加， 合金吸、 放氫 (室溫下) 的平臺壓力降低， 最大儲氫量減少， 分別從1.58% (x=0) 減少到1.44%(x=0.2)、 1.19% (x=0.3)；合金的放電容量減少， 分別從380mAh/g (x=0) 減少到366mAh/g (x=0.1)、 345mAh/g (x=0.2)、 271mAh/g (x=0.3)， 但循環(huán)穩(wěn)定性得到提高，經(jīng)100次充放電循環(huán)后的容量衰減率從16% (x=0) 降低到4% (x=0.3)；適當(dāng)控制Zn含量， 既對合金的放電容量無大的影響， 又可提高合金放電的穩(wěn)定性，尤其是在大電流下放電的穩(wěn)定性。
關(guān)鍵字: 儲氫合金； P-C-T曲線； 放電容量； 循環(huán)穩(wěn)定性
（State Key Laboratory for Mechanical Behavior of Materials,
Xi′an Jiaotong University, Xi′an 710049, China）
Abstract:The gas hydrogen storage characteristics and electrochemical properties of (MlMg)Ni4-xCo0.7Znx (0≤x≤0.3) were studied. The results indicate that the absorption/desorption plateau pressures of the alloys lower and the highest hydrogen contents decrease from 1.58% (x=0) to 1.44% (x=0.2) and 1.19% (x=0.3) respectively with the increase of Zn in the alloys. The discharge capacities of the alloys decrease to a certain extent from 380mAh/g (x=0) to 366mAh/g (x=0.1), 345mAh/g (x=0.2) and 271mAh/g (x=0.3) respectively with the increase of Zn in the alloys, but their cycle stabilities are improved. The attenuation rate of capacity decreases from 16%(x=0) to 4%(x=0.3) after 100 charge/discharge cycles. The proper content of Zn influences the discharge capacity of the alloys a little， but promotes the discharge stability, especially at high current density.
Key words: hydrogen storage alloy; P-C-T curve; discharge capacity;cycle stability
