Cellulose fiber-enabled mitigation of polysulfide shuttling and dendritic lithium growth in lithium–sulfur batteries

Decarbonization demands more batteries. Lithium-sulfur (Li–S) batteries are considered one of the most promising next-generation “post-Li-ion” batteries, whose practical viability is still hindered by two major challenges, polysulfide shuttling and dendritic lithium growth. Coating cellulose fibers onto separators has been proven to be an effective route for solving the two challenges simultaneously. Studying the working mechanism of the cellulose fiber is important yet difficult when the battery is in operation. Here, density functional theory and molecular dynamic simulations unveiled atomistically how cellulose fiber impedes polysulfides and lithium ions passing through the fiber, mitigating polysulfide shuttling and retarding dendritic lithium growth. This cost-effective modification paves the way towards more viable, sustainable Li–S batteries.