Luan Xiaoyu, Wang Chenggang, Wang Chunsheng, Gu Xin, Yang Jian, Qian Yitai
Key Laboratory of Colloid and Interface Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, P. R. China.
Institute of New Energy, College of New Energy, State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao 266580, P. R. China.
ACS Appl Mater Interfaces. 2020 Mar 4;12(9):11265-11272. doi: 10.1021/acsami.9b23520. Epub 2020 Feb 21.
Li metal has been regarded as one of the most promising anode candidates for high-energy rechargeable lithium batteries. Nevertheless, the practical applications of the Li anode have been hampered because of its low Coulombic efficiency and safety hazards. Here, acid-treated g-CN with O- and N-containing groups are coated on Li foil through a facile physical pressing method. The O- and N-containing groups cooperate to rearrange the concentration of Li ions and enhance the Li ion transfer. Hence, the cycle and rate performances of acid-treated g-CN-coated Li electrodes are greatly improved in symmetric cells, which show cycling stability over 400 h at 1 mA cm in ester-based electrolytes and over 2100 h in ether-based electrolytes. As for the Li//LiFePO full cells, there is a high capacity retention of 80% over 400 cycles at 1 C. The full cells of Li//S in ether-based electrolytes also exhibit a capacity of 520 mA h g after 400 cycles at 1 C.
锂金属被视为高能可充电锂电池最有前景的负极候选材料之一。然而，锂负极的实际应用因库仑效率低和安全隐患而受到阻碍。在此，通过简便的物理压制方法将含有O和N基团的酸处理g-CN涂覆在锂箔上。含O和N的基团协同作用，重新排列锂离子浓度并增强锂离子转移。因此，在对称电池中，酸处理g-CN涂覆的锂电极的循环和倍率性能得到极大改善，在酯基电解质中，1 mA cm² 下显示出超过400小时的循环稳定性，在醚基电解质中超过2100小时。对于Li//LiFePO₄全电池，在1 C下400次循环后容量保持率高达80%。在醚基电解质中Li//S全电池在1 C下400次循环后也表现出520 mA h g⁻¹ 的容量。
