Organosilicon Electrolyte and Carbon Nanotubes Make More Power Supercapacitors

Wisconsin Alumni Research Foundation (Madison, WI) reveals a more powerful electrochemical double-layer capacitor using organosilicon electrolytes and carbon nanotubes in U.S. Patent 7,612,985. University of Wisconsin inventors Viacheslav V. Dementiev, Robert C. West, Robert J. Hamers and Kiu-Yuen Tse say the electrolytes can provide improved supercapacitors, and improved electrodes and separators for use in capacitors and batteries. They could be used in electric and hybrid-electric vehicles, satellites, wind generators, photovoltaics, copy machines, high power electronic household appliances, electric tools, electric power generation, and electric distribution systems.

Lingzhi Zhang, Robert West and Viacheslav Dementiev have also developed lithium batteries using pure polysiloxane electrolytes. When compared to the carbonate electrolyte, the polysiloxane electrolyte proved to be superior in every way. In a test to simulate the batteries' life spans, the two batteries are charged and discharged repeatedly. The battery using the carbonate electrolyte failed after 500 cycles, which is equivalent to approximately two years of use. Results from this same test show a projected lifetime of over twelve years for the battery using the polysiloxane electrolyte. This increase is a direct result of polysiloxane's superior electrochemical stability. Furthermore, silicone electrolytes are nonflammable, environmentally benign and nontoxic, all of which are necessary for the battery to be implantable in the human body.

Quallion already uses the electrolytes developed at UW-Madison in new lithium batteries that power an implant device called the Bion. This device is a neurostimulator capable of alleviating many of the debilitating symptoms of epilepsy, strokes, Parkinson's disease and spinal cord injuries. The Bion is only 18 millimeters long and three millimeters in diameter. It is implanted using a hypodermic needle near the point where a nerve connection has been broken. The neurostimulator relays electrical signals from one side of the severed nerve to the other, effectively bridging the gap.