Scientists have found a way to ensure fast charging and long service life of lithium-sulfur batteries

Two independent research groups have reported an advance in the development of lithium-sulfur batteries that will significantly speed up charging and extend battery life. One team focused on improving the cathode material, while the other developed an innovative solid electrolyte.

Image source: DGIST

According to TechSpot, the first work, led by Professor Jong-sung Yu from the Korea Institute of Science and Technology DGIST, focused on creating a nitrogen-doped porous carbon material that improves the charging speed of batteries. This material, produced using thermal reduction of magnesium, serves as the basis for retaining sulfur in the battery cathode. The final tests showed an impressive result – the battery reached a capacity of 705 mAh/g when fully charged in just 12 minutes.

Image source: DGIST

The unique carbon structure formed by the reaction of magnesium with nitrogen at high temperatures allowed for increased sulfur content and improved contact with the electrolyte. This resulted in a 1.6x increase in capacity compared to conventional batteries when quickly charged. In addition, nitrogen doping effectively suppressed the migration of lithium polysulfides, which helped retain 82% of the original capacity even after 1000 charge-discharge cycles.

The second study, carried out by Chinese and German scientists, concerned the development of a solid electrolyte that solves the problem of the slow chemical reaction between lithium ions and elemental sulfur. This glassy material is composed of boron, sulfur, lithium, phosphorus and iodine. The key feature here was the addition of iodine, which, due to its ability to quickly exchange electrons, accelerated the reactions in the electrode.

The results of the second group were no less interesting – the battery, which took just over a minute to charge, retained half of its capacity, while the battery with slower charging lost this capacity much faster. At an average charging speed, the battery retained more than 80% of its original capacity even after 25,000 cycles, which is significantly superior to its lithium-ion counterparts, which lose capacity after 1,000 cycles.

Together, both achievements bring closer the practical application of lithium-sulfur batteries and their commercialization. While research by Chinese and German scientists is focusing on the transformative potential of solid electrolytes in improving battery longevity and charging speeds, the DGIST team’s work has shown the promise of advanced cathode materials in fast charging scenarios.