Regulating of Lithium‐Ion Dynamic Trajectory by Ferromagnetic CoF₂ to Achieve Ultra‐Stable Deep Lithium Deposition Over 10000 h

Abstract Currently, the realization of controllable Li electrodeposits to further extend the cycling life of Li metal anode remains challenging. Herein, it is reported that carbon nanosheet array‐loaded ferromagnetic CoF 2 nanoparticles on carbon cloth (CC@CoF 2 /C) as an internal micro‐magnetic field source to manipulate the dynamic trajectory of Li + deposition via the magnetohydrodynamic effect. This approach ensures uniform lithium‐ion distribution and improves deep plating capacity, achieving a prolonged cycle life of the dendrite‐free Li anode. Finite element simulations, in situ characterizations, and electrochemical tests confirm that magnetic CoF 2 not only guides Li + migration through Lorentz force to prevent dendritic growth but also improves uniform Li deposition due to the in situ conversion of LiF‐rich solid electrolyte interphase during electroplating. Meanwhile, a CC@CoF 2 /C‐based half‐cell operates stably over 10 000 h at 1 mA cm −2 with a low 7.8 mV overpotential. When matched with a commercial LiFePO 4 cathode, the full cell reveals a high capacity of 122.96 mAh g −1 at a 2 C rate after 1000 cycles, retaining 91.95% capacity. The proposed strategy can be effectively expanded and adapted to investigate the deposition behavior of a wide range of metal anodes, offering a versatile and robust analytical framework for addressing diverse metal‐based electrochemical systems.