Prussian blue analogues wrapped by reduced graphene oxide as an efficient electrocatalyst for lithium-sulfur batteries

Abstract

In this work, three-dimensional microspheres composed of FeMn prussian blue analogue (FeMn PBA) and reduced graphene oxide (rGO) were realized through spray drying technology. The FeMn PBA@rGO composite shows distinctive microsphere structure with wrinkled surface, in which FeMn PBA polyhedron closely coated by rGO. This unique structure with well rGO coated shell could enhance the structural stability and provide effective charge transfer channels at the cathode/electrolyte interface. Moreover, the polar FeMn PBA could provide abundant adsorptions to capture soluble lithium polysulfides (LiPSs) and catalytic sites to effectively accelerate LiPSs conversion reaction. Benefiting from this rational design, the Li-S cells with FeMn PBA@rGO host material exhibit an initial reversible capacity of 1145 mAh g-1 at 0.2 C and good cycling stability. Those findings point an effective direction for the development on functional catalysts with distinctive structure and chemical composition for advanced Li-S batteries.