Unlike LIBs, the reaction pathway in LSBs results in an accumulation of solid lithium sulfide (Li2S6) and liquid lithium polysulfide (LiPS), causing a loss of active material from the sulfur cathode (positively charged electrode) and corrosion of the lithium anode (negatively charged electrode). to enhance battery life, scientists are trying to find catalysts which will make this degradation efficiently reversible during use.
In a new study published in ChemSusChem, scientists from Gwangju Institute of Technology (GIST), Korea, report their breakthrough during this endeavor. “While trying to find a replacement electrocatalyst for the LSBs, we recalled a previous study we had performed with cobalt oxalate (CoC2O4) during which we had found that charged ions can easily adsorb on this material’s surface during electrolysis. This motivated us to hypothesize that CoC2O4 would exhibit an identical behavior with sulfur in LSBs also ,” explains Prof. Jaeyoung Lee from GIST, who led the study.
To test their hypothesis, the scientists constructed an LSB by adding a layer of CoC2O4 on the sulfur cathode.
Sure enough, observations and analyses revealed that CoC2O4’s ability to adsorb sulfur allowed the reduction and dissociation of Li2S6 and LiPS.
Further, it suppressed the diffusion of LiPS into the electrolyte by adsorbing LiPS on its surface, preventing it from reaching the lithium anode and triggering a self-discharge reaction.
These actions together improved sulfur utilization and reduced anode degradation, thereby enhancing the longevity, performance, and energy storage capacity of the battery.
Charged by these findings, Prof. Lee envisions an electronic future governed by LSBs, which LIBs cannot realize. “LSBs can enable efficient electric transportation like in unmanned aircrafts, electric buses, trucks and locomotives, additionally to large-scale energy storage devices,” he observes. “We hope that our findings can get LSBs one step closer to commercialization for these purposes.”
Perhaps, it’s only a matter of time before lithium-sulfur batteries power the planet .