Tech Briefs Q&A: Photocatalyst Device Turns Pollution into Power

Researchers from the University of Antwerp and KU Leuven have built a proof-of-concept device that performs two noble functions simultaneously: purifying polluted air and generating power. Read the Tech Briefs Q&A with Professor Sammy Verbruggen.

Posted in: News, Energy, Energy Harvesting, Energy Storage, Renewable Energy, Solar Power

High-Efficiency Power Converter for the Internet of Things

Researchers from MIT’s Microsystems Technologies Laboratories (MTL) have designed a new power converter that maintains its efficiency at currents ranging from 100 picoamps to 1 milliamp.

Internet of Things sensors will have to operate at very low powers to extend battery life for months, or make do with energy harvested from the environment. But that means that they’ll need to draw a wide range of electrical currents. Researchers from MIT developed a new step-down power converter that features a variable clock that can run switch controllers at a wide range of rates.

Posted in: News, Energy Storage, Renewable Energy

Self-Charging Battery Could Make Chargers Obsolete

New technology developed by Hydro-Québec and McGill University is capable of harvesting and storing energy using light – a self-charging battery. To create the light-charged batteries, a standard cathode from a lithium-ion battery can be “sensitized” to light by incorporating photo-harvesting dye molecules.

Posted in: News, Energy Harvesting, Energy Storage

New Device Harnesses Heat to Power Computers

The thermal diode may allow computers to use heat as an alternate energy source. (Karl Vogel/Engineering)

One of the biggest problems with computers is keeping them cool so they don’t overheat. University of Nebraska–Lincoln engineers developed an alternative energy source that would allow computing at ultra-high temperatures. The nano-thermal-mechanical device, or thermal diode, could be used in space exploration, for exploring the core of the earth, for oil drilling, or in applications requiring calculations and data processing in real time in places where computers have not been able to function.

Posted in: News, Energy Harvesting, Thermoelectrics

Hybrid Tractor-Trailers Take the Road

A prize-winning hybrid technology puts a Toyota Prius-like spin on the tractor trailer.

Posted in: Homepage, News, Automotive, Energy, Energy Efficiency, Energy Harvesting, Energy Storage, Renewable Energy

PTC Heater Brings Greater Control for Hand-held Medical Devices and Disposables

Point of Care diagnostics devices, whether handheld or single-use, often require a brief application of tightly controlled heat. The disposable nature of these devices requires a low-cost component capable of delivering that heat reliably and safely. Heatron's new PTC heater solution uses a polymer-based heater technology that controls heat to within ±2°C of the target temperature, and reduces unit cost by eliminating sensors and applied controls.

Posted in: White Papers, Briefs, TSP, Electronics & Computers, Thermoelectrics, Medical, Medical equipment and supplies, Heating, ventilation, and air conditioning systems (HVAC), Polymers

High-Voltage Supercapacitors for Improved Energy Density Hybrid Power Sources

Both the aerospace and automotive industries depend increasingly on electrochemical energy storage. Reduction in mass, increase in energy, and increase in power can benefit both of these areas dramatically. Supercapacitors are currently under consideration for use in both hybrid electric vehicles (HEV) and electric vehicles (EV) to improve delivery of power (due to their high rate capability), improve the life of the lithium-ion batteries (due to their ability to buffer the detrimental effects of high current pulses or alternating currents on the battery), and implement more efficient capture of regenerative breaking energy (due to their excellent charge acceptance at high rates).

Posted in: Briefs, Energy, Energy storage systems, Lithium-ion batteries, Ultracapacitors and supercapacitors, Electric vehicles, Hybrid electric vehicles

Fuel Cell Power Management

This technique produces multiple voltages simultaneously from a single fuel cell stack, without the need for converters.

An innovation from NASA Glenn Research Center increases the efficiency and versatility of fuel cell stacks for power generation. To meet the requirements of a fuel cell system, engineers have typically added direct-current-to-direct-current (DC-to-DC) converters that reduce the voltage produced at the ends of the fuel cell stack. This smaller voltage is then used to operate the valves, pumps, heaters, and electronics that make up the fuel cell system. However, adding DC-to-DC converters increases cost, reduces efficiency, adds to the system part count (which reduces reliability), and increases both the mass and volume of the fuel cell system. NASA's innovative technique features multiple power points that connect different numbers of cells in an electrical series, allowing the fuel cell stack to produce electrical power at multiple DC voltages simultaneously. This capability eliminates DC-to-DC converter electronics, thereby reducing cost and simplifying the system.

Posted in: Briefs, Energy, Voltage regulators, Electric power, Fuel cells

Solid-State Lithium Sulfur Battery

Applications include electric vehicles, consumer electronics, UAVs, and wind and solar energy storage.

Sulfur is a promising cathode for lithium batteries due to its high theoretical specific capacity (1673 mAh/g), low cost, and environmental friendliness. With a high specific energy density of 2500 Wh/kg, which is a five times greater energy density than a conventional Li-ion battery, Li-S batteries hold great potential for next-generation high-energy storage systems. However, wide-scale commercial use has been limited because some key challenges, such as the dissolution of the intermediate discharge product (Li2Sx, 2<X<8) in conventional liquid electrolytes, remain unsolved. On the other hand, all-solid-state batteries (SSBs) are considered to be the ultimate power supply for pure electric vehicles (EVs). SSB systems demonstrate a new approach for novel Li-S batteries. Replacing the organic electrolyte with solid-state electrolytes (SSEs) will intrinsically eliminate the dissolution of polysulfide. However, all of the solidstate Li-S batteries incorporating current state-of-the-art SSEs suffer from high interfacial impedance due to their low surface area.

Posted in: Briefs, Energy, Battery cell chemistry, Lithium-ion batteries, Electrolytes, Electric vehicles

Standardized Heating Method to Trigger and Prevent Thermal Runaway Propagation in Lithium-Ion Batteries

Lithium-ion (Li-ion) cells are increasingly used in high-voltage and high-capacity modules. The Li-ion chemistry has the highest energy density of all rechargeable battery chemistries, but associated with that energy is the issue of catastrophic thermal runaway with a fire. With recent incidents in the commercial aerospace and electronics sectors, methods are required to prevent cell-to-cell thermal runaway propagation. The goal of this work was to achieve a common method for triggering a single cell in a Li-ion battery module into thermal runaway, determine if one can consistently obtain this thermal runaway event, and design mitigation measures to address propagation of the thermal runaway to other cells in the module.

Posted in: Briefs, Energy, Battery cell chemistry, Lithium-ion batteries, Fire prevention, Risk assessments

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