Ultrahigh‐Power Pseudocapacitors Based on Ordered Porous Heterostructures of Electron‐Correlated Oxides

Nanostructured transition‐metal oxides can store high‐density energy in fast surface redox reactions, but their poor conductivity causes remarkable reductions in the energy storage of most pseudocapacitors at high power delivery (fast charge/discharge rates). Here it is shown that electron‐correlated oxide hybrid electrodes made of nanocrystalline vanadium sesquioxide and manganese dioxide with 3D and bicontinuous nanoporous architecture (NP V2O3/MnO2) have enhanced conductivity because of metallization of electron‐correlated V2O3 skeleton via insulator‐to‐metal transition. The conductive V2O3 skeleton at ambient temperature enables fast electron and ion transports in the entire electrode and facilitates charge transfer at abundant V2O3/MnO2 interface. These merits significantly improve the pseudocapacitive behavior and rate capability of the constituent MnO2. Symmetric pseudocapacitors assembled with binder‐free NP V2O3/MnO2 electrodes deliver ultrahigh electrical powers (up to ≈422 W cm23) while maintaining the high volumetric energy of thin‐film lithium battery with excellent stability. 3D electron‐correlated oxide‐hybrid electrodes comprising nanocrystalline V2O3 and MnO2 exhibit exceptionally high conductivity, as a result of metallization of V2O3 skeleton via insulator‐to‐metal transition. This enables heterostructured V2O3/MnO2 pseudocapacitors to deliver ultrahigh electrical power, while maintaining the high volumetric energy of thin‐film lithium batteries.