Stable Lithium Deposition Enabled by an Acid-Treated g-C<sub>3</sub>N<sub>4</sub> Interface Layer for a Lithium Metal Anode
Xiaoyu Luan, Chenggang Wang, Chunsheng Wang, Xin Gu, Jian Yang, Yitai Qian
Abstract
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-C3N4 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-C3N4-coated Li electrodes are greatly improved in symmetric cells, which show cycling stability over 400 h at 1 mA cm–2 in ester-based electrolytes and over 2100 h in ether-based electrolytes. As for the Li//LiFePO4 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–1 after 400 cycles at 1 C.