P,Fe co-doped LiMn2O4, a multifunctional material to boost fast charging of lithium-ion batteries assisted by magnetic field

Abstract

Fast-charging lithium-ion batteries (LIBs) are essential for enhancing the competitiveness of electric vehicles (EVs) and the rapid charging of consumer electronics. The magnetohydrodynamic (MHD) effect, induced by the Lorentz force acting on moving ions in the electrolyte, has been effectively used to explain the impact of magnetic fields on electrochemical systems. Previous works have shown that when a ferromagnetic electrode in an LIB is exposed to a magnetic field, it is possible to achieve 30% and 50% capacity enhancement and improve its capacity retention. However, generic materials used in the anode or cathode of current batteries exhibit low MHD effects due to their paramagnetic behaviour. This leads to the need to apply large external magnetic fields to witness significant effects, which therefore limits the potential of this technology. To bridge this gap, it is crucial to alter the magnetic behaviour of generic materials used in batteries and systematically study their impact. This research introduces a novel P and Fe co-doped LiMn₂O₄ (LMO) material that exhibits ferromagnetism. The developed feature enables the use of low-intensity magnetic fields (33 mT) to control its electrochemical behaviour in an LIB and gain around 25% of capacity. By potentiometric charge/discharge measurements, electrochemical impedance spectroscopy, Atomic Force Microscopy, and COMSOL Multiphysics simulation, it is uncovered the impact of the low-intensity magnetic field on the charge transfer resistance of the cathode and the mitigation of dendrite formation on the anode. This shows the potential of this material in boosting fast charging capabilities and mitigating common degradation issues in LIBs. The study demonstrates how this new material can be a game-changer in the development of more efficient and durable LIBs.