Boosting Li-S batteries through the synergistic effect of recycled ferrites and external magnetic induction

Despite being considered one of the most promising energy storage technologies, lithium-sulfur batteries (LSBs) are limited in terms of commercialization by the shuttle effect and slow reaction kinetics. In this work, we demonstrate for the first time that the use of recycled ferrite in conjunction with an external magnetic field generated by a permanent magnet can enhance the reaction kinetics and the adsorption of polysulfides (LiPSs), and hence the electrochemical stability. An in-depth kinetic study shows that under the effect of an external magnetic field, the electrode has lower polarization, a higher Li+ diffusion coefficient and a lower activation energy between electrochemical stages. The electrode also has a capacity retention up to 40 % higher and half the capacity loss per cycle at a high rate of 1C. At an ultra-high rate of 10C, the electrode has a capacity of 507 mAh g−1 after 150 cycles and an areal capacity of up to 3 mAh cm−2 at an ultra-high loading of 13 mg cm−2. In addition to the promising results observed in electrochemical terms, our approach is also more sustainable due to the use of a recycled electronic material obtained via dry milling, thereby avoiding the use of fossil carbons.