Microbatteries and Microsupercapacitors
Related research topics in our group:
Stretchable and Healable Electronics
In the content of environmental degradation, renewable energy technologies are in urgent demand. Our group focuses on developing materials synthesis methods for energy storage devices that are facile and scalable, often achieving several processing requirements in a single step.
For microbatteries, the simultaneous realization of confined growth and doping of transition metals is capable of delivering unique bifunctional catalytic activity but is a challenge. We have devised synthesis strategies that concurrently realizes geometric confined growth and doping of various transition metals into a graphene host. The result is a nanosheet material that can simultaneously catalyze for both the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR). Subsequent combination with planar electrodes and a hydrogel polymer electrolyte further demonstrate the application of the nanosheets as an air-cathode bifunctional electrocatalyst for solid-state rechargeable micro-Zn-air batteries (SR-MZABs).
Microsupercapacitors (MSCs) with excellent flexibility and electrochemical capacitance are promising energy storage devices for wearable electronics. We have investigated a 3D porous poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS)/graphene composite sponge (PGCS) fabricated via a facile self-assembly process for highly stretchable, high areal capacitance MSCs. The proposed self-assembly process enables simultaneously the following in one-step: (1) separation of PSS and PEDOT from PEDOT:PSS, (2) reduction of graphene oxide (GO) into reduced graphene oxide (rGO), and (3) integration of PEDOT and rGO into a hybrid 3D composite. By tuning the mass ratio of PEDOT:PSS and GO, PGCSs with different porosity, mechanical properties, conductivity, and capacitance can be obtained. This facile approach provides a general strategy in synergistic self-assembly of composite sponges and the design of stretchable 3D MSCs, suitable for energy storage devices with high stretchability and high energy density.
T. Jiang, H. Hu*, F. Lei, J. Hu, M. Wu, and D Ho*, "Concurrently realizing geometric confined growth and doping of transition-metals within graphene hosts for biofunctional electrocatalyst toward solid-state rechargeable micro-Zn-air batteries," ACS Applied Materials and Interfaces, accepted.
W R Yan, J H Li, G P Zhang, L Wang*, and D Ho*, "Synergistic self-assembled 3D PEDOT:PSS/graphene composite sponge for stretchable microsupercapacitors," Journal of Materials Chemistry A (JMCA), 8, 2, 2020.
W Abbas, D Ho*, and A Pramanick, "High energy-storage efficiency and thermal stability of A-side deficient and 110 textured BaTiO3-BiScO3 thin films," Journal of the American Ceramic Society, accepted.
H Li, J Li, C Hou*, D Ho*, Q Zhang, Y Li, and H Wang*, "Solution-Processed Porous Tungsten Molybdenum Oxide Electrodes for Energy Storage Smart Windows," Advanced Materials Technologies, 1700047, 2017.