AlN-Fe纳米复合薄膜:一种新型锂离子电池负极材料

采用脉冲激光沉积技术(PLD)制备了不同比例的Al N-Fe纳米复合薄膜(Al N和Fe摩尔比为3:1;2:1;1:1;1:2),首次研究了其作为锂离子电池负极材料的电化学行为。发现当Al N和Fe的比例为2:1时,复合薄膜具有最佳的电化学性能。在500 m A·g~(-1)电流密度下,Al N-Fe(2:1)经过100次循环充放电后容量仍能保持510 m Ah·g~(-1)。对其电化学反应机理研究发现,在放电过程中,Al N-Fe纳米复合薄膜中的Al N发生分解,Al N-Fe生成Li Al合金和Li_3N。纳米Fe颗粒的引入有效提高Al N的电化学活性;在充电过程中,部分Li_3N与Fe纳米颗粒反应生成了Fe_3N,其余部分Li_3N重新生成Al N。随后的充放电过程由Fe_3N、Al N和Al三者与Li的可逆反应共同参与,保证了Al N-Fe纳米复合薄膜优异的电化学性能。该研究为设计开发新型锂离子电池电极材料提供了一种新的思路。

AlN-Fe Nanocomposite Thin Film:A New Anode Material for Lithium-Ion Batteries

AlN-Fe nanocomposite thin films with different AlN-Fe ratio were prepared by pulsed laser deposition (PLD).They were investigated as new anode materials for lithium ion batteries for the first time.The AlN-Fe nanocomposite films with an AlN/Fe ratio of 2:1 show the best electrochemical performance.They exhibit a specific capacity of 510 mA·g^-1 after 100 cycles at a rate of 500 mA·g^-1.Further, the study of the electrochemical reaction mechanism of the AlN-Fe nanocomposite thin films with lithium reveals that AlN decomposes during the discharge process to form the LiAl alloy and Li₃N.During recharge, a part of Li₃N reacts with Fe to form Fe₃N, and the rest reacts with Al to form AlN.In subsequent cycles, all of Fe₃N, AlN, and Al react with Li reversibly, contributing to the reversible charge-discharge processes and to the superior electrochemical performance of AlN-Fe nanocomposite thin films.Thus, this study provides a new perspective to design advanced electrode materials for lithium-ion batteries.