Construction of Co-Mn Prussian Blue Analog Hollow Spheres for Efficient Aqueous Zn-ion Batteries.

Prussian blue analogs (PBAs) are considered as reliable and promising cathode materials for aqueous Zn-ion batteries (AZIBs), but they suffer from low capacity and poor cycling stability due to insufficient active sites and structural damage caused by the ion insertion/extraction processes. Herein, a template-engaged ion exchange approach has been developed for the synthesis of Co-substituted Mn-rich PBA hollow spheres (CoMn-PBA HSs) as cathode materials for AZIBs. Benefiting from the multiple advantageous features including hollow structure, abundant active sites, shortened diffusion path of electrons/Zn 2+ ions, and partial Co substitution, the CoMn-PBA HSs electrode shows efficient zinc ion storage properties in terms of high capacity, decent rate capability and prolonged cycle life.