Wang Yunfei, Wang Yuanhao, Sun Xiang, Yang Wenhua, Xu Jie, Cao Derang, Li Shandong, Wang Xia
College of Physics, University-Industry Joint Center for Ocean Observation and Broadband Communication, Qingdao University, Qingdao, 266071, P. R. China.
College of Electronics and Information, Qingdao University, Qingdao, 266071, P. R. China.
ChemSusChem. 2025 Jan 14;18(2):e202400675. doi: 10.1002/cssc.202400675. Epub 2024 Sep 24.
The application of sodium metal battery is hampered by the large volume change and uncontrollable top growth of Na metal. Herein, a dual strategy including constructing a three-dimensional gradient ZnO/FeCo (ZFC) framework of decreasing sodiophilic capability from bottom to top, and imposing magnetic fields based on magnetohydrodynamic (MHD) effect, is proposed to regulate the sodium deposition/stripping behavior and realize the bottom-up deposition of Na. Therefore, the ZFC framework under a magnetic field of 200 mT exhibits high electrochemical reversibility with a Coulombic efficiency of 99.77 % at 1 mA cm and 1 mAh cm. Meanwhile, the ZFC composite anode (ZFC@Na) with the magnetic field of 200 mT delivers a small polarization voltage of approximately10 mV and long cycle life of more than 2500 h at 5 mA cm and 5 mAh cm in symmetric cells, along with good cycle stability in ZFC@Na||NaV(PO) full cells (200 cycles at 1 C with a high capacity retention of 98 %). Accordingly, the novel strategy of combining magnetic fields and sodiophilic gradient frameworks provides a perspective to solve the issues of sodium dendrite growth.
钠金属电池的应用受到钠金属体积变化大以及顶部生长不可控的阻碍。在此，提出了一种双重策略，包括构建一种三维梯度ZnO/FeCo（ZFC）框架，其亲钠能力从底部到顶部逐渐降低，以及基于磁流体动力学（MHD）效应施加磁场，以调节钠的沉积/剥离行为并实现钠的自下而上沉积。因此，在200 mT磁场下的ZFC框架表现出高电化学可逆性，在1 mA cm和1 mAh cm时库仑效率为99.77 %。同时，在200 mT磁场下的ZFC复合阳极（ZFC@Na）在对称电池中，于5 mA cm和5 mAh cm时提供约10 mV的小极化电压和超过2500 h的长循环寿命，并且在ZFC@Na||NaV(PO)全电池中具有良好的循环稳定性（在1 C下循环200次，高容量保持率为98 %）。因此，结合磁场和亲钠梯度框架的新策略为解决钠枝晶生长问题提供了一个视角。
