Wayne
State University researchers have developed a novel method for the preparation
of unique 3-D composites of conductive graphene and high capacitance
MnO2 as electrode materials, to fabricate asymmetric aqueous
supercapacitors for energy-storage applications.
Currently MnO2 is commonly coated onto
current collectors to form very thin films with a thickness of ten to
one-thousand nanometers in order to minimize the limitation of poor
conductivity. Therefore, the
relative amount of MnO2 on current collector is always low and does not provide
sufficient energy and power density.
In this invention, the novel composites are constructed using 2-D
graphene sheets with atomic thickness and 1-D MnO2 nanowires of a controlled
size for applications in high-energy, high-power and low-cost aqueous
supercapacitors for electrochemical energy storage. The use of aqueous electrolytes over
organic electrolytes offers better ionic conductivity and lower production
costs, which makes them well suited for use in next-generation large scale
supercapacitors. Furthermore, the
use of aqueous electrolytes overcomes the toxicity, high costs, and
environmental hazards associated with the use of organic electrolytes in current
supercapacitor technology.
Such next-generation supercapacitors could compete with rechargeable
batteries in the market of mobile electronics devices, electric vehicles,
industrial equipment, military devices and energy grids.
Technology
Advantages:
·
Improves
the energy density of supercapacitors
·
Improves
cycle life of MnO2 based supercapacitors,
·
Use
of aqueous electrolyte reduces the dangers and environmental hazard typically
associated with organic electrolytes
·
Use
of low cost aqueous electrolyte reduce overall costs of large scale
applications
Commercial
Applications:
·
Mobile
electronic devices
·
Electric
vehicles
·
Industrial
equipment
·
Military
devices
·
Energy
grids
Patent
Status:
Provisional
patent on file