Energy

Three-Dimensional Zinc Electrode Architectures for High-Performance Batteries

Zinc-based batteries offer a safe, inexpensive alternative to fire-prone lithium-based batteries, yet have been historically limited by poor rechargeability. A 3D zinc (Zn) “sponge” electrode architecture was developed comprising interpenetrating networks of Zn scaffolding and void space. The design characteristics yield superior electrochemical properties when cycled in alkaline electrolytes compared to conventional Zn powder-composite electrodes.

Posted in: Briefs, Energy, Architecture, Batteries, Battery cell chemistry, Architecture, Batteries, Battery cell chemistry, Zinc alloys
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Alpha-STREAM Convertor

Innovations offer a reliable and efficient way to generate power from any heat source.

Innovators at NASA’s Glenn Research Center have developed two novel technologies that make Stirling engines more efficient and less costly. First, Glenn’s thermoacoustic power converter uses sound to turn heat into electric power. Utilizing heat-driven pressures and volume oscillations from thermoacoustic sources to power piezoelectric alternators or other power-converter technologies, this device can generate electricity with unprecedented efficiencies. Unlike conventional Stirling-based devices, this thermoacoustic engine achieves high thermal-to-electrical efficiencies with no moving parts. Glenn’s second advancement for Stirling engines replaces the conventional linear alternator with a magnetostrictive alternator that converts the oscillating pressure wave into electric power (see figure). These innovations offer a reliable and efficient way to generate power from any heat source, benefiting applications such as combined heat and power (CHP) systems, distributed generation, solar power generation, and heating and cooling systems.

Posted in: Briefs, Energy, Alternators, Alternators, Electric power, Thermodynamics, Thermodynamics, Engine efficiency, Stirling engines
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Silicon Nanoparticles Enable Energy-Collecting Windows

Photovoltaic cells are hidden in the window frame, blending invisibly into the built environment.

Technology that embeds silicon nanoparticles into efficient luminescent solar concentrators (LSCs) has been developed. The LSCs are the key element of windows that can efficiently collect solar energy. When light shines through the surface, the useful frequencies of light are trapped inside and concentrated to the edges, where small solar cells can be put in place to capture the energy.

Posted in: Briefs, Energy, Windows and windshields, Solar energy, Nanomaterials
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Bacteria-Powered Battery is Printed on a Single Sheet of Paper

This battery enables self-sustained, paper-based, point-of-care devices.

A bacteria-powered battery that can power disposable electronics has been created on a single sheet of paper. The manufacturing technique reduces fabrication time and cost, and the design could revolutionize the use of bio-batteries as a power source in remote, dangerous, and resource-limited areas.

Posted in: Briefs, Energy, Batteries, Batteries, Bacteria, Medical equipment and supplies, Fabrication, Biomaterials
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Internal Short Circuit (ISC) Device Helps Improve Lithium-Ion Battery Design

This tool helps manufacturers ensure the safety and reliability of electric vehicle batteries.

Battery safety is key to the acceptance and penetration of electric vehicles into the marketplace. When battery internal shorts occur, they tend to surface without warning, and usually after the cell has been in use for several months. While some failures simply result in the cell getting very hot, in extreme cases, cells go into thermal runaway, igniting the device in which they are installed. The most publicized failures involved burning laptop and cellphone batteries, and resulted in millions of recalls.

Posted in: Briefs, Energy, Lithium-ion batteries, Switches, Lithium-ion batteries, Switches, Thermodynamics, Thermodynamics, Reliability, Reliability, Fire, Electric vehicles
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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), Heating, ventilation, and air conditioning systems (HVAC), Polymers
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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, Energy storage systems, Lithium-ion batteries, Ultracapacitors and supercapacitors, Electric vehicles, Hybrid electric vehicles
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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, Voltage regulators, Electric power, Fuel cells
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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, Battery cell chemistry, Lithium-ion batteries, Electrolytes, Electric vehicles
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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, Battery cell chemistry, Lithium-ion batteries, Fire prevention, Risk assessments
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