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.