Zhang Xue-Liang, Ruan Zhi-Qin, He Qiao-Tong, Hong Xu-Jia, Song Xin, Zheng Qi-Feng, Nie Jia-Hui, Cai Yue-Peng, Wang Hongxia
School of Chemistry, South China Normal University, Guangzhou 510006, P. R. China.
School of Chemistry and Physics, Queensland University of Technology (QUT), Brisbane, QLD 4001, Australia.
ACS Appl Mater Interfaces. 2021 Jan 20;13(2):3078-3088. doi: 10.1021/acsami.0c21747. Epub 2021 Jan 5.
The practical applications of Li metal batteries (LMBs) have long been limited by the obstacles of low Coulombic efficiency (CE) and formation of dendrites on Li metal electrode. Herein, we demonstrated the synthesis of a novel three-dimensional (3D) nanostructured skeleton substrate composed of nitrogen-doped hollow carbon fiber/carbon nanosheets/ZnO (NHCF/CN/ZnO) using 2-methylimidazole (2-MIZ)-coated 3D cloth as a scaffold. The mechanism of formation of this novel hierarchical structure was investigated. The multilayered hierarchical structure and abundant lithiophilic nucleation sites of the substrate provide a stable environment for the deposition and stripping of lithium metal, thus preventing the generation of lithium dendrites. Consequently, the lithium anode based on the NHCF/CN/ZnO current collector demonstrated an excellent Coulombic efficiency of 96.47% after 400 cycles at 0.5 mA cm. The prepared NHCF/CN/ZnO/Li electrode also showed outstanding cycling performance of over 800 h and an ultralow voltage hysteresis of less than 30 mV in a symmetric cell at 5 mA cm and 5 mAh cm. Even at a high loading of the cathode with 10.4 mg cm, the full cell of NHCF/CN/ZnO/Li anode with LiFePO can also work very well. Our work offers a path toward the facial preparation of 3D hierarchical structure for high-performance lithium metal batteries.
锂金属电池（LMBs）的实际应用长期以来一直受到低库仑效率（CE）以及锂金属电极上枝晶形成等障碍的限制。在此，我们展示了一种新型三维（3D）纳米结构骨架基底的合成，该基底由氮掺杂中空碳纤维/碳纳米片/ZnO（NHCF/CN/ZnO）组成，使用涂覆有2 - 甲基咪唑（2 - MIZ）的3D布作为支架。研究了这种新型分级结构的形成机制。该基底的多层分级结构和丰富的亲锂成核位点为锂金属的沉积和脱嵌提供了稳定的环境，从而防止锂枝晶的产生。因此，基于NHCF/CN/ZnO集流体的锂阳极在0.5 mA cm下循环400次后表现出96.47%的优异库仑效率。制备的NHCF/CN/ZnO/Li电极在5 mA cm和5 mAh cm的对称电池中还表现出超过800 h的出色循环性能和小于30 mV的超低电压滞后。即使在阴极高负载为10.4 mg cm时，NHCF/CN/ZnO/Li阳极与LiFePO的全电池也能很好地工作。我们的工作为高性能锂金属电池的3D分级结构的简便制备提供了一条途径。
