Lithium metal anode is a promising anode for next-generation lithium-based batteries. However, the lithium dendrite growth due to uneven Li-ion deposition could cause safety problem, and the unceasing formation of solid electrolyte interphase layer leads to capacity fading of anode. Here, we report a mechanism of Li electrodeposition under a magnetic field with the direction perpendicular or parallel to electric field in the cell systematically. We for the first time observe that at the initial nuclei stage the deposited Li metal is needlelike; for the later growth stage, a very compact deposits with dendrite-free structure can be obtained. Compared with perpendicular magnetic field, the parallel one can facilitate more uniform and dense lithium growth. The Lorentz force and the electric field force during Li platting are calculated and compared. It also indicates that the magnetic field can contribute to a smooth Li deposits after cycling at various current densities and deposited capacities. The polarization of the Li symmetrical cells is reduced in the magnetic field resulting in more stable cycling performance. In addition, improved electrochemical performance of the Li|LiCoO₂ half cells can be achieved by applying a magnetic field. The study demonstrates that the electromagnetic environment is critical to stabilizing Li-metal anode in high-energy-rechargeable batteries.

锂金属阳极是下一代锂基电池的有希望的阳极。然而，由于不均匀的锂离子沉积导致的锂枝晶生长可能引起安全问题，并且固体电解质中间层的不断形成导致阳极的容量衰减。在这里，我们系统地报告了在垂直或平行于电场方向上的磁场下锂电沉积的机理。我们第一次观察到在成核初期，沉积的锂金属是针状的。在随后的生长阶段，可以获得非常紧凑的无枝晶结构的沉积物。与垂直磁场相比，平行磁场可以促进更均匀和致密的锂生长。计算并比较了镀锂过程中的洛伦兹力和电场力。这也表明，磁场在各种电流密度和沉积容量下循环后，可有助于平滑的Li沉积。Li对称电池的极化在磁场中减小，从而导致更稳定的循环性能。此外，改善了Li | LiCoO的电化学性能通过施加磁场可以实现_2个半电池。研究表明，电磁环境对于稳定高能可充电电池中的锂金属阳极至关重要。