Jiang Huiyu, Lin Xiaohang, Wei Chuanliang, Zhang Yuchan, Feng Jinkui, Tian Xuelei
Key Laboratory for Liquid-Solid Structural Evolution & Processing of Materials (Ministry of Education), School of Materials Science and Engineering, Shandong University, Jinan, 250061, P. R. China.
Small. 2022 Apr;18(17):e2107637. doi: 10.1002/smll.202107637. Epub 2022 Mar 22.
The advantages of sodium metal, such as abundant resources, low cost, high capacity, and high working potential, make it a promising metal anode. Unfortunately, the hazardous dendrite growth of sodium metal is one of the major hindrances for the practical application of sodium metal batteries (SMBs). By applying multifunctional Mg(II)@Ti C MXene as the protective layer for commercial Cu foil, the wettability of the electrolyte on the current collector is dramatically improved with the suppression of sodium dendrites. Moreover, the first-principles calculations prove that the surface of Mg(0001) is able to establish a connection with Na(111) growth, with Mg acting as the nucleation seed for sodium. The experimental results indicate that even when a high areal capacity of sodium (2 mAh cm ) is deposited, no sodium dendrite is observed. Electrochemical tests, including symmetric cells, Na||Cu asymmetric cells, and full cells, prove the sodiophilic character of Mg -decorated Ti C MXene. The results may also create a new pathway for developing other dendrite-free metal anodes, such as Li/K/Zn/Ca/Mg.
钠金属具有资源丰富、成本低、容量高和工作电位高等优点，使其成为一种很有前景的金属负极。不幸的是，钠金属危险的枝晶生长是钠金属电池（SMBs）实际应用的主要障碍之一。通过将多功能Mg(II)@Ti C MXene用作商业铜箔的保护层，电解质在集流体上的润湿性得到显著改善，同时抑制了钠枝晶的生长。此外，第一性原理计算证明，Mg(0001)表面能够与Na(111)生长建立连接，Mg作为钠的成核种子。实验结果表明，即使沉积高面积容量的钠（2 mAh cm ），也未观察到钠枝晶。包括对称电池、Na||Cu非对称电池和全电池在内的电化学测试证明了Mg修饰的Ti C MXene的亲钠特性。这些结果也可能为开发其他无枝晶金属负极（如Li/K/Zn/Ca/Mg）创造一条新途径。
