This technology is a nanocomposite for lithium-sulfur batteries in which sulfur nanoparticles are grown directly on exfoliated 2D metal oxide nanosheets, such as lepidocrocite-structured titanium oxide. The nanosheets serve as both a host for sulfur and an adsorbent for lithium polysulfides.
In lithium-sulfur batteries, the shuttle effect—where lithium polysulfides generated during discharge dissolve into the electrolyte and migrate between the cathode and anode—leads to continuous loss of active material. This results in low coulombic efficiency, rapid capacity degradation, and worsened performance as sulfur content increases.
This technology utilizes titanate nanosheets with Lewis acidity derived from under-coordinated Ti species to strongly bind polysulfides by converting them into thiosulfate/polythionate complexes. Because the sulfur is grown directly on the nanosheet surface, the contact is intimate, and cycle stability is maintained even when sulfur content exceeds 80 parts by weight per 100 parts of the composite. Applicable to lightweight batteries for drones and Urban Air Mobility (UAM), high-energy-density lithium-sulfur pouch cells, and wearable power sources, it chemically prevents polysulfide dissolution in high-sulfur electrodes, thereby enhancing both gravimetric energy density and capacity retention.
This invention was developed with support from the Research Center for Hybrid Interface Materials of the Ministry of Science and ICT.
US11145859B2, WO2019-083274A2
