Engines & Power Electronics : Energy storage & regeneration


Electrodes with Low-Cost Replaceable Tips

UW–Madison researchers have developed a new electrode design incorporating disposable tips. The tips can have a snapping mechanism or embedded magnet that attaches to the main shaft of the electrode. An insulating material seals the connection against any liquid. The tips may be modified with other entities such as nanoparticles, enzymes and antibodies.

Reducing Overpotential Needed to Create Hydrogen by Water Electrolysis

UW–Madison researchers have developed an electrolyzer used to produce gas by electrolysis with a lower overpotential requirement than conventional electrolyzers. The electrolyzer includes a housing, an electrical power source and an electrode comprising a conducting support and a nanoporous oxide coating material.

The researchers also developed a method of using the electrolyzer to produce a gas such as hydrogen by contacting an aqueous solution such as water with the electrode and applying a voltage from an electrical power source. By appreciably reducing the amount of voltage required to convert water to hydrogen and oxygen, this technology enables on-demand hydrogen production for point of use or storage.

Optimized Lithium Anode/Carbon Monofluoride Batteries Operable at High Temperatures

UW-Madison researchers have developed a Li/CFx battery that operates at temperatures in excess of 100 ºC. In this battery, alkyl carbonates are replaced with organosilicon-based electrolytes. The organosilicon electrolytes and CFx cathode are contained within a stainless steel coin cell, which also contains the lithium anode, a polypropylene separator and a salt. The electrolytes have low vapor pressure and low flammability, enhancing the safety and maximizing the operating temperature of the battery. In addition to operating at elevated temperatures, the battery possesses the optimal performance characteristics expected from CFx-type batteries.

Nanoporous Insulating Oxide Electrolyte Membrane Ultracapacitor and Button Cell

UW-Madison researchers have developed methods of using nano-scale nanoporous insulating oxides to construct capacitors and ultracapacitors. Combining an insulating oxide composite layer (Al2O3, TiO2, MgAl2O4, etc.) member with a conductive member results in an electrode that is useful in the construction of ultracapacitors. The composite layer is made from a stable sol-gel suspension containing particles of the insulating oxide.

These ultracapacitors provide energy storage equal to or better than conventional ultracapacitors, making them potentially useful in innumerable industries, especially the automotive industry. The ultracapacitor is preferably configured in a stacked, coiled or button cell.

Metal-Coated Vertically Aligned Carbon Nanofibers

UW-Madison researchers have developed a method for decorating carbon nanostructures with uniform metal coatings to provide electrodes with high structural stability and surface area. The process uses arrays of vertically aligned carbon nanofibers separated by interstices. The nanofibers are functionalized by covalently binding a layer of organic linker molecules to their surface. Electroless deposition is then used to deposit a continuous metal coating onto the functionalized surfaces. The resulting metal-coated nanofibers form highly stable and reproducible electrodes with high surface areas. These electrodes can be used in devices such as supercapacitors and fuel cells.

Solid Polysiloxane Electrolyte for Use in Lithium Batteries

UW-Madison researchers have now developed a solid, polysiloxane-containing polymer composition for lithium batteries. In addition to polysiloxanes, the polymer mixture contains a cross-linking molecule, a catalyst and an inhibitor. The mixture exists initially as a liquid that can be poured into batteries. When heated to 50 to 75°C, the polymer gradually solidifies into a soft, flexible gel.

Direct Charge Radioisotope Activation and Power Generation for Microelectromechanical Systems

UW-Madison researchers have developed an electrical power generator that has several advantages over conventional power sources for microsystems. Specifically, the energy carried by particles emitted by radioactive decay is captured and converted to mechanical potential energy that is stored in an elastically deformable element. The energy can be used to activate other mechanical parts directly or can be converted to electrical energy.