AlN-Fe纳米复合薄膜:一种新型锂离子电池负极材料

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

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。

AIN-Fe nanocomposite thin films with different AIN-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 AIN-Fe nanocomposite films with an AIN/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 AIN-Fe nanocomposite thin films with lithium reveals that AIN decomposes during the discharge process to form the LiAI alloy and Li3N. During recharge, a part of Li3N reacts with Fe to form Fe3N, and the rest reacts with AI to form AIN. In subsequent cycles, all of Fe3N, AIN, and AI react with Li reversibly, contributing to the reversible charge-discharge processes and to the superior electrochemical performance ofAIN-Fe nanocomposite thin films. Thus, this study provides a new perspective to design advanced electrode materials for lithium-ion batteries.