Pushing Lithium-Sulfur Batteries towards Practical Working Conditions through a Cathode-Electrolyte Synergy

The commercialization of lithium-sulfur (Li-S) batteries is still hindered by the unsatisfactory cell performance under practical working conditions, which is mainly caused by the sluggish cathode redox kinetics, severe polysulfide shuttling, and poor Li stripping/plating reversibility. Herein, we report an effective strategy by combining Se-doped S hosted in an ordered macroporous framework with a highly fluorinated ether (HFE)-based electrolyte to simultaneously address the aforementioned issues in both cathode and anode. A reversible and stable high areal capacity of > 5.4 mAhcm(-2) with high Coulombic efficiency > 99.2 % can be achieved under high areal Se/S loading (5.8 mg cm(-2)), while the underlying mechanism was further revealed through synchrotron X-ray probes and Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS). The practical application potential was further evaluated at low (0 degrees C) and high (55 degrees C) temperatures under high areal Se/S loading (>5.0 mg cm(-2)) and thin Li metal (40 mu m).