Lithium-sulfur batteries have a high specific capacity (1675 mA h g-1) and energy density (2600 Wh kg-1). However, the poor conductivity of the Li polysulfides (Li2Sn, 4 ≤ n ≤ 8) formed seriously restricts practical applications. ZHANG Junping’s group has now reported laponite as a clay mineral super-electrolyte lithium battery separator. It has a unique lamellar structure and a large specific surface. In lithium-sulfur batteries, laponite inhibits a polysulfide shuttle and increases Li+ conductivity and Li+ transfer. The resulting battery is excellent in cycle stability, performance, and inhibition of self-discharge. The formation of polysulfides is effectively inhibited by forming a Li-S bond and a Li···O bond between the polysulfide and the O active site of the clay mineral. The clay separator can be prepared by a simple coating method and exhibits excellent performance in both LiFePO4 and lithium sulfur batteries.
CAS news release, September 10, 2018