Defect-rich CeO ₂ in a hollow carbon matrix engineered from a microporous organic platform: a hydroxide-assisted high performance pseudocapacitive material

A microporous organic polymer (MOP) was utilized for the engineering of nanoparticulate CeO₂ in a hollow carbon matrix (H-C/CeO₂). After CeO₂ nanoparticles were incorporated into a hollow MOP platform (H-MOP) through the decomposition of cerium acetate, successive carbonization produced H-C/CeO₂. The redox feature of defective CeO₂ in a conductive carbon matrix induced promising pseudocapacitive behavior. In particular, the H-C/CeO₂ showed excellent electrochemical performance in an alkaline electrolyte (KOH), due to the hydroxide ion-assisted redox behavior of defective CeO₂. H-C/CeO₂-3 with an optimized amount of CeO₂ showed specific capacitances of up to 527 (@0.5 A g^-1) and 493 F g^-1 (@1 A g^-1). Even at high current densities of 10 and 20 A g^-1, the H-C/CeO₂-3 maintained high capacitances of 458 and 440 F g^-1, respectively. After 10 000 cycling tests, the H-C/CeO₂-3 retained the 94-95% capacitance of the first cycle.