Journal of Materials Science & Technology ( IF 11.2 ) Pub Date : 2022-04-29 , DOI: 10.1016/j.jmst.2022.04.011 Lei Hu 1, 2 , Lin Li 1 , Yuyang Zhang 1 , Xiaohong Tan 3 , Hao Yang 4 , Xiaoming Lin 3 , Yexiang Tong 2
Designing novel electrode materials with unique structures is of great significance for improving the performance of lithium ion batteries (LIBs). Herein, copper-doped Co1-xTe@nitrogen-doped carbon hollow nanoboxes (Cu-Co1-xTe@NC HNBs) have been fabricated by chemical etching of CuCo-ZIF nanoboxes, followed by a successive high-temperature tellurization process. The as-synthesized Cu-Co1-xTe@NC HNBs composite demonstrated faster ionic and electronic diffusion kinetics than the pristine CoTe@NC HNBs electrode. The existence of Co-vacancy promotes the reduction of Gibbs free energy change (∆GH*) and effectively improves the Li+diffusion coefficient. XPS and theoretical calculations show that performance improvement is ascribed to the electronic interactions between Cu-Co1-xTe and nitrogen-doped carbon (NC) that trigger the shift of the p-band towards facilitation of interfacial charge transfer, which in turn helps boost up the lithium storage property. Besides, the proposed Cu-doping-induced Co-vacancy strategy can also be extended to other conversion-type cobalt-based material (CoSe2) in addition to as-obtained Cu-Co1-xSe2@NC HNBs anodes for long-life and high-capacity LIBs. More importantly, the fabricated LiCoO2//Cu-Co1-xTe@NC HNBs full cell exhibits a high energy density of 403 Wh kg−1 and a power density of 6000 W kg−1. We show that the energy/power density reported herein is higher than that of previously studied cobalt-based anodes, indicating the potential application of Cu-Co1-xTe@NC HNBs as a superior electrode material for LIBs.
中文翻译:
在碲化钴中构建钴空位以诱导锂离子半/全电池的快速离子/电子扩散动力学
设计具有独特结构的新型电极材料对于提高锂离子电池(LIBs)的性能具有重要意义。在此,通过对 CuCo-ZIF 纳米盒进行化学蚀刻,然后进行连续的高温碲化工艺,制备了铜掺杂的 Co 1- x Te@氮掺杂碳中空纳米盒 (Cu-Co 1- x Te@NC HNB) . 与原始 CoTe@NC HNBs 电极相比,合成后的 Cu-Co 1- x Te@NC HNBs 复合材料表现出更快的离子和电子扩散动力学。Co-vacancy 的存在促进了 Gibbs 自由能变化(Δ G H*)的降低,有效地提高了 Li +扩散系数。XPS 和理论计算表明,性能改进归因于 Cu-Co 1- x Te 和氮掺杂碳 (NC) 之间的电子相互作用,它触发了 p 带向促进界面电荷转移的转变,这反过来又有助于提高储锂性能。此外,除了长期获得的 Cu-Co 1- x Se 2 @NC HNBs 阳极之外,所提出的 Cu 掺杂诱导的 Co 空位策略还可以扩展到其他转换型钴基材料 (CoSe 2 ) -寿命和高容量LIB。更重要的是,制备的 LiCoO 2 //Cu-Co 1- xTe@NC HNBs 全电池具有 403 Wh kg -1的高能量密度和 6000 W kg -1的功率密度。我们表明,本文报道的能量/功率密度高于先前研究的钴基负极,表明 Cu-Co 1 - x Te@NC HNBs 作为 LIBs 的优良电极材料的潜在应用。