Field effect (Electric, Magnetic) enhancement of catalytic performance refers to improving the efficiency and activity of catalytic reactions through the application of external fields. The field effect can introduce an electric field or magnetic field on the surface of the catalyst to regulate the energy barrier, electron transfer rate and catalytic activity of the catalytic reaction. This method can provide an effective ways to enhance the performance of the catalyst and promote the catalytic reaction. Metal-sulfur batteries(Li, Na) have been widely studied by researchers due to their high theoretical specific capacity (1675 mA h g^-1) and energy density (2600 Wh kg^-1). Due to the "shuttle effect" caused by the solubility of its intermediate product polysulfide, battery failure is caused. In this context, we extend the field effect to the field of metal-sulfur batteries to reduce the polysulfide redox reaction kinetics barrier to achieve high-performance in metal-sulfur batteries.

1. Through external heat-assisted electric polarization, the traditional α-phase PVDF binder without ferroelectric effect is converted into β-phase PVDF with ferroelectric enhancement to anchor polysulfide through electrostatic interaction force while enhancing the lithium ion diffusion resistance. The structure of the PVDF film before and after polarization was analyzed through XRD, Raman and FTIR, and it was found that as polarization increased, PVDF gradually transformed from the α phase to the β phase. The modified electrode can still maintain stable capacity after 1000 cycles at 1 C, and the decay rate of specific capacity is only 0.038%.[1]
2. Apply a constant magnetic field outside the battery and use CoS_x as the catalytic additive.[2] By exploring the impact of the magnetic field generated by the external magnet on the electrochemical performance of the battery, we found that the addition of the magnetic field can significantly improve the adsorption ability of polysulfides and the Li-S reaction kinetics. The CNF/CoS_x/S electrode exhibits excellent electrochemical performance. In the presence of a magnetic field, even at a high current density of 2 C, CNF/CoS_x/S dropped to 315 mA h g^-1 after 8150 cycles, with a decay rate of only 0.0084% per cycle.
3. CoFe₂O₄ catalyst under an external magnetic field assists sodium-sulfur battery to realize high electrochemical performance.[3] This work details the process of growing CoFe₂O₄, VO₂ and Co₃O₄ particles on the surface of CNF using a combination of electrospinning and hydrothermal processes. At the same time, this work systematically explores the process of the prepared cathode material catalyzing sodium polysulfides (SPSs) through ferromagnetic and paramagnetic catalysts under an external magnetic field. DFT calculations show that under a magnetic field, the adsorption energy of SPS on the ferromagnetic catalyst applying a magnetic field increases, and the kinetic barrier for SPS conversion decreases. Experimental results show that the spin-polarized Co ions in CoFe₂O₄ improve the ability to adsorb SPS and the electrocatalytic activity of SPS conversion. Experiments and theory have proven that the magnetic field can polarize the electrons of Co ions, thereby enhancing the adsorption of SPS and its catalytic conversion. The CNF/CoFe₂O₄/S cathode with spin polarization can last for 2700 cycles at 1 C, with a decay rate as low as 0.0039% per cycle. 

In summary, these works not only establish a new catalytic relationship and strategy for the field effect in the redox reaction kinetics of polysulfides, but also provide new ideas for applications in the field of efficient electrochemical energy storage.