Three-Dimensional Carbon Foam Modified with Mg<sub>3</sub>N<sub>2</sub> for Ultralong Cyclability of a Dendrite-Free Li Metal Anode
Wenxu Song, Shiqiang Cui, Jiangjiang Zhang, Shangze Fan, Lanli Chen, Hanming Zhang, Yatong Zhang, Xiaomin Meng
Abstract
Uncontrolled growth of lithium dendrites and huge volume change during the lithium plating/stripping process as well as poor mechanical properties of the solid electrolyte interphase (SEI) are key obstacles to the development of a stable Li metal anode. Here, an ultralight Mg 3 N 2 -modified carbon foam (CF-Mg 3 N 2 ) was fabricated as a collector to address these issues. The calculated results show that the CF-Mg 3 N 2 composite is relatively stable in terms of energy. Based on the synergistic effect of the three-dimensional skeleton and the lithiophilic nature of Mg 3 N 2, homogeneous lithium deposition/stripping was realized around the foam carbon skeleton with an extremely low nucleation overpotential (∼9.3 mV) and high retention of Coulombic efficiency (99.3%) as well as long cyclability (700 cycles and 3000 h in half and symmetrical cells, respectively). Meanwhile, Mg 3 N 2 -CF@Li//LiFePO 4 full cells also showed better rate capability and more stable cycling capability than CF@Li//LiFePO 4 and Li//LiFePO 4 cells, exhibiting extreme practicality. Accordingly, the design concept mentioned in this work provides a far-reaching influence on the development of a stable Li metal anode.