Energy

Thermal Management Solutions for Directed Energy Applications

Directed Energy is an emerging technology that is being utilized in a variety of military and other applications. These high powered devices demand superior thermal management that operates effectively and reliably in ever decreasing foot print areas. Not only do these systems need to maintain a safe operating temperature, they often demand strict temperature uniformity across the system.

Posted in: On-Demand Webinars, Energy

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Survival of the Fittest - the Process Control Imperative

In tough times, manufacturers focus on reducing their operating costs, but may not be able to afford to spend their way out by buying more productive machinery. With that pathway closed, what are the opportunities for radically reducing costs without replacing existing machines? This paper explores Productive Process Pyramid™ and the four areas where substantial savings can be found if firms are prepared to change the way they control their machining processes.

Posted in: White Papers, Defense, Energy, Manufacturing & Prototyping

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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), 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, 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, 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, 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, Fire prevention, Risk assessments

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