Jin Qianzheng, Lu Hongfei, Zhang Zili, Xu Jing, Sun Bin, Jin Yang, Jiang Kai
School of Electrical Engineering, Zhengzhou University, Zhengzhou, 450001, P. R. China.
State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China.
Adv Sci (Weinh). 2022 Mar;9(7):e2103845. doi: 10.1002/advs.202103845. Epub 2022 Jan 9.
The propensity of sodium anode to form uniform electrodeposit is bound up with the nature of electrode surface and regulation of Na-ion flux, as well as distribution of electronic field, which is quite crucial for high-areal-capacity sodium metal batteries (SMBs). Herein, a novel metallic sodium/sodium-tin alloy foil anode (Na/NaSn) with 3D interpenetrated network and porous structure is prepared through facile alloy reaction. The strong sodiophilic properties of sodium-tin alloy can lower the nucleation energy, resulting in smaller depositing potential and strong adsorption of Na , while synergistic effect of porous skeleton and additional potential difference (≈0.1 V) between Na and Na-Sn alloy (Na Sn ) can alleviate volume expansion, redistribute the Na-ion flux and regulate electronic field, which favors and improves homogeneous Na deposition. The as-fabricated Na/NaSn electrode can endow excellent plating/stripping reversibility at high areal capacity (over 1600 h for 4 mAh cm at 1 mA cm and 2 mAh cm at 2 mA cm ), fast electrochemical kinetics (500 h under 4 mAh cm at 4 mA cm ) and superior rate performances. A novel strategy in the design of high-performance Na anodes for large-scale energy storage is provided.
钠阳极形成均匀电沉积物的倾向与电极表面性质、钠离子通量的调控以及电场分布密切相关，这对于高面积容量钠金属电池（SMBs）至关重要。在此，通过简便的合金反应制备了一种具有三维互穿网络和多孔结构的新型金属钠/钠锡合金箔阳极（Na/NaSn）。钠锡合金的强亲钠性质可降低成核能，导致更小的沉积电位和对Na⁺的强吸附，而多孔骨架的协同效应以及Na与Na-Sn合金（NaₓSn₁₋ₓ）之间的附加电位差（≈0.1 V）可减轻体积膨胀，重新分布钠离子通量并调节电场，这有利于并改善均匀的钠沉积。所制备的Na/NaSn电极在高面积容量下（在1 mA cm⁻²时4 mAh cm⁻²超过1600小时，在2 mA cm⁻²时2 mAh cm⁻²）可赋予优异的电镀/脱镀可逆性、快速的电化学动力学（在4 mA cm⁻²时4 mAh cm⁻²下500小时）和优异的倍率性能。为大规模储能的高性能钠阳极设计提供了一种新策略。
