(內(nèi)蒙古科技大學(xué) 內(nèi)蒙古自治區(qū)白云鄂博礦多金屬資源綜合利用重點(diǎn)實(shí)驗(yàn)室，包頭 014010)
摘 要: 研究了La2Mg(Ni1-xZnx)9 (x=0.1, 0.15, 0.2)合金的組織結(jié)構(gòu)、儲(chǔ)氫性能及失效行為特征。Zn傾向于在AB5型相中固溶，顯著促進(jìn)了AB5和AB2型相含量的提高。雖然Zn降低了合金的電化學(xué)放電容量和高倍率性能，但適量的Zn能夠顯著提高合金的電化學(xué)循環(huán)穩(wěn)定性。100次充放電循環(huán)后La2Mg(Ni0.9Zn0.1)9合金的容量保持率可達(dá)94%。原因在于Zn有利于合金結(jié)構(gòu)穩(wěn)定性的保持和抗粉化能力，特別是Zn能在合金表面形成致密鈍化膜，顯著提高了合金的耐腐蝕性。通過(guò)上述研究結(jié)果，提出含Zn合金性能改進(jìn)的關(guān)鍵在于降低合金吸放氫平臺(tái)壓并抑制AB2型相的含量。
關(guān)鍵字: La-Mg-Ni系儲(chǔ)氫合金；Zn；電化學(xué)性能；失效行為
（Key Laboratory of Integrated Exploitation of Bayan Obo Multi-Metal Resources, Inner Mongolia University of Science and Technology, Baotou 014010, China）
Abstract:Effect of Zn substitution on the microstructure, hydrogen storage properties and degradation characters of AB3 type La-Mg-Ni alloys was studied in the present work. Zn prefers to dissolve in AB5-type phase, leading to disappearance of AB3-type phase, elevation of abundance of AB5 and AB2-type phase. While the content of A2B7-type phase first increases and then decreases with the increasing of Zn. Although the discharge capacity and high rate dischargeability are weakened, the cycling stability can be dramatically improved by proper Zn substitution. The capacity retention of the La2Mg(Ni0.9Zn0.1)9 alloy after 100 charge/discharge cycles reaches to 94%, which can be ascribed to improvement of the structural stability, anti-pulverization and corrosion resistant caused by Zn addition. Based on these results, reducing the hydrogen absorption/desorption plateau and abundance of the AB2-type phase is considered to be the key issue to further improvement of the Zn-contained La-Mg-Ni alloys.
Key words: La-Mg-Ni-based hydrogen storage electrode alloys; Zn; electrochemical performances; degradation characters
