Dual Hybrid Energy Storage Device with a Battery–Electrochemical Capacitor Hybrid Cathode and a Battery-Type Anode

The design of appropriate material architectures and a judicious combination of storage modes are expected to deliver electrical energy storage devices of larger specific energy (E S) and specific power (P S). Herein, a battery–electrochemical capacitor hybrid material as a cathode [i.e., porous carbon filled with three-dimensional MnCo2O4 nanoflowers (3DMCNF), 3DMCNF-AC] and a corresponding battery component (3DMCNF) as an anode are used in a dual hybrid device using a 1 M LiPF6 electrolyte. The cathodic and the anodic properties of the electrodes are separately studied in the half-cell configuration with respect to the Li/Li+ electrode. The 3DMCNF-AC hybrid cathode showed larger specific capacitance (∼165 F·g–1) in the potential range (∼2 to 4.5 V vs Li/Li+) than that of a pure porous carbon cathode (∼115 F·g–1, ∼2 to 4 V vs Li/Li+) at 100 mA·g–1 cycling. The half-cell 3DMCNF anode showed a discharge capacity of ∼1020 mA·h·g–1 in the potential range of ∼0.01–3.0 V versus Li/Li+ at a similar cycling condition to that of the cathode. The dual hybrid full device delivered ∼3.5 V with an E S of up to ∼153 W·h·kg–1 and a P S of up to ∼3500 W·kg–1.