A solution-mediated reaction mechanism is proposed and confirmed for Li-S redox reactions through electrochemical and operando X-ray absorption spectroscopy characterization.
Significance and Impact
The solution-mediated reaction pathway bypasses traditional surface reactions in Li-S cells that cause passivation-induced premature failure and enables Li-S operation under lean-electrolyte conditions.
- A novel solution-mediated sulfur reduction pathway is demonstrated via a strategy retaining Li2S4 in solution.
- Operando X-ray absorption spectroscopy characterization confirms the solution reaction pathway.
- The new pathway decouples the sulfur reduction pathway from both electrolyte quantity and electroactive surface area.
- A practical Li-S cell is developed under the E/S ratio of 3 mLE gs-1 with a stable cycle life over 100 cycles.