Prussian Blue Analogue Framework Hosts for Li–S Batteries

Lithium–sulfur (Li–S) batteries hold promise for next-generation energy storage due to their high theoretical energy density (∼2600 Wh kg–1). However, practical use is hindered by capacity loss from the polysulfide shuttle effect and poor energy efficiency due to slow kinetics. To overcome these challenges, we developed a novel sulfur host material featuring highly porous concave nanocubes derived from a Prussian blue analogue. By controlling the annealing conditions, we achieved a high surface area (up to 248 m2 g–1), which enhances polysulfide adsorption, thereby reducing sulfur dissolution and minimizing the loss of cathode capacity during cycling. Operando Raman spectroscopy revealed that this material also provides a synergistic catalytic effect, lowering polarization/overpotentials within Li–S cells. The optimized material enables an extended battery life with high sulfur loading, a low E/S ratio, and excellent capacity retention over long-term cycles, demonstrating its potential to improve Li–S battery performance.