Hybrid energy storage devices (hybrid of supercapacitor and battery) can be charged and discharged within seconds like a conventional capacitor and also have a high energy density like a battery.
These are two electrode electrochemical cells which should have good electrical conductivity and capability to store huge amount of charges with long term stability. Electrode material along with the electrolyte determines the charge storage characteristics of a hybrid energy storage device.
Nano-Interconnection Team is working on developing novel nano-heterostructured electrode materials to be used in the next generation hybrid energy storage systems. Different substrates (metallic and carbon based) were investigated to fabricate the electrode due to their good conductivity and unique structure.
Three dimensional hierarchical NiO nanostructures with combined microstructure of nanoflakes and nanoflowers, Coaxial NiO/Ni nanowire, Co3O4 nanowire, α-CoMoO4 nanoflakes, NiO-In2O3 heterostructure and Ni3(PO4)2.8H2O, Co3(PO4)2·8H2O nano/microflakes have been developed. The Co3(PO4)2·8H2O electrode exhibits a high specific capacitance of 1578 F g-1 (6.3 F cm-2) at 5 mA cm-2 , and the Co3(PO4)2·8H2O //activated carbon hybrid device delivered a good energy density of 29.29 Wh kg-1 (1.17 mWh cm-3). The NiO-In2O3/NF based symmetric supercapacitor exhibits a remarkable cycle stability of 79% after 50,000 cycles. Furthermore, the team is aspire to increase the energy density beyond 100 Wh kg-1 and enhance the cycling stability towards 100,000 cycles for these hybrid energy storage devices.
The flexible substrate-supported nanomaterials based packaged hybrid energy storage device was assembled in our lab. We also design different packages for various electrode materials and electrolytes to develop complete energy storage device.