Zhao Xiaoyu, Xia Shuixin, Zhang Xun, Pang Yuepeng, Xu Fen, Yang Junhe, Sun Lixian, Zheng Shiyou
School of Materials Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China.
School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China.
ACS Appl Mater Interfaces. 2021 May 5;13(17):20240-20250. doi: 10.1021/acsami.1c04735. Epub 2021 Apr 20.
Lithium (Li) metal is regarded as one of the most prospective electrodes for next-generation rechargeable batteries. However, its widespread usage has been fettered by low coulombic efficiency (CE), poor cycling stability, and serious safety concerns, mainly arising from huge volumetric variation, inhomogeneous Li deposition, and dendrite growth during repeated Li plating/stripping cycles. Herein, we propose a facile one-pot electrospinning-derived highly lithiophilic nanocopper-reinforced three-dimensional-structured carbon nanofiber (Cu-CNF) as functional scaffold to stabilize the Li metal. The Cu-CNF scaffolded Li metal demonstrates homogeneous nanoplate-like Li deposition, enhanced CE, and ultrastable long lifespan cycling. As coupled with LiNiCoMnO (NCM811), the cell possesses a remarkably stable high capacity retention of 93% over 300 cycles at 0.2 C. Furthermore, the cells paired with a thick LiFePO (LFP) electrode (∼12 mg cm) still can deliver a superior cycling performance even under the harsh conditions of an extremely low negative/positive electrode capacity (N/P) ratio (∼1.5) and lean electrolyte. Density functional theory calculations are performed to disclose the mechanism of the enhanced electrochemical performance of Cu-CNF scaffolded Li. This work provides a handy and cost-effective method to design superior performance Li metal anodes for practical applications.
锂(Li)金属被认为是下一代可充电电池最具前景的电极材料之一。然而,其广泛应用受到低库仑效率(CE)、较差的循环稳定性以及严重的安全问题的制约,这些问题主要源于在反复的锂电镀/剥离循环过程中巨大的体积变化、不均匀的锂沉积以及枝晶生长。在此,我们提出一种简便的一锅法静电纺丝衍生的高度亲锂的纳米铜增强三维结构碳纳米纤维(Cu-CNF)作为功能支架来稳定锂金属。由Cu-CNF支架支撑的锂金属表现出均匀的纳米片状锂沉积、增强的CE以及超稳定的长寿命循环。与LiNiCoMnO(NCM811)耦合时,该电池在0.2 C下300次循环中具有93%的显著稳定高容量保持率。此外,即使在极低的负/正极容量(N/P)比(约1.5)和贫电解质的苛刻条件下,与厚锂铁磷酸盐(LFP)电极(约12 mg cm)配对的电池仍能提供优异的循环性能。进行密度泛函理论计算以揭示Cu-CNF支架支撑的锂电化学性能增强的机制。这项工作提供了一种简便且经济高效的方法来设计用于实际应用的高性能锂金属负极。