Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “High voltage”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 325 records · Page 18
All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

Molecular Ionic Composites: A New Class of Polymer Electrolytes to Enable All-Solid-State and High-Voltage Lithium Batteries (Final Project Report for DOE EERE VTO grant EE0008860)

Based on a newly discovered class of solid PE materials, that is, molecular ionic composites (MICs), the major goal of this project is to develop solid-state lithium conductors targeted for use in transportation applications. MICs form a mechanically stiff, electrochemically stable, and thermally stable matrix. Specific objectives include the following: (1) development of robust MIC electrolyte thin films (~ 20 µm) to serve as simultaneous nonflammable separators and dendrite-blocking Li + conductors, (2) electrochemical quantification of key performance metrics including electrolyte stability, interfacial reactions, and suitability/compatibility with a range of electrode materials, and (3) comprehensive investigation of ion transport mechanisms and electrode-electrolyte interfacial reactivity under practical operating conditions using NMR and synchrotron X-ray analyses.

25 ENERGY STORAGE↗
DOE OSTI2021

Novel subnanosecond rise, flattop, 100 kV high voltage pulse generator (ASAP-LDRD-22-0122)

We looked to build a new type of 100 kV pulse generator that we hope will avoid many of the problems seen with other commercially available pulse generators. We looked to exploit recent improvements in both lasers and solid-state pulse charge units along with an alternative triggering layout to build something new. For the pulse charging unit, we collaborated with Texas Tech to leverage their knowledge and expertise in pulse transformers and solid-state switching. The final result of the LDRD looks promising. Texas Tech was able to build a pulse charge unit that meets our specifications regarding output, and we were able to integrate it with a switch and a laser to create a device that meets the goals of the LDRD. There is still much work to do to advance the design further and improve reliability, but the proto-type design satisfies the goals we set for this LDRD.

42 ENGINEERING↗
DOE OSTI2025

Megawatt-Class, High-Voltage SiC Power Electronics Converters for Advanced Manufacturing with Grid Support Services

DE-EE0009135 aimed to push the 10kV SiC MOSFET based power electronics to 3-phase 13.8kV 10MW to be used as a Megawatt Class Medium-Voltage Power Conditioning Systems – PCS – to enable “Resilient Distribution through Grid-dispatching and Uninterrupted Quality Power to Manufacturing Facilities” during transitory grid disturbances. As a stretch to those goals, Eaton added the load power peak shaving opportunity.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2022

ION PRODUCTION AND MITIGATION IN DC HIGH-VOLTAGE PHOTO-GUNS

One of the biggest obstacles to operating a GaAs polarized electron source with a long charge lifetime is the mitigation of ion back-bombardment. Several techniques exist to either clear ions from the accelerator or to mitigate ion damage of the photocathode. Predicting the effectiveness of these techniques requires sophisticated simulation models of electron impact ionization within the photo-gun. In this work, the effectiveness of applying a positive anode bias voltage to mitigate ion damage and increase the charge lifetime of the GaAs photocath?ode was studied over three run periods at the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab (JLab). The charge lifetime with the biased anode configuration was 1.80±0.51 times longer than the lifetime of the usual grounded anode configuration. Sim?ulations of ionization within the CEBAF photo-gun and adjacent beamline were made using General Particle Tracer (GPT) and a new C++ custom element to predict and explain the substantial improvement in charge lifetime. The experimental results and the development of the ionization custom element, with its use in simulations of ion back-bombardment with the biased anode, are described in detail.

Yoskowitz, Joshua↗
DOE OSTI2020

Electrodes with Electrodeposited Water-excluding Polymer Coating Enable High-Voltage Aqueous Supercapacitors

Aqueous supercapacitors are powerful energy sources, but they are limited by energy density that is much lower than lithium-ion batteries. Since raising the voltage beyond the thermodynamic potential for water splitting (1.23 V) can boost the energy density, there has been much effort on water-stabilizing salvation additives such as Li 2 SO 4 that can provide an aqueous electrolyte capable of withstanding ~1.8 V. Guided by the first-principles calculations that reveal water can promote hydrogen and oxygen evolution reactions, here, we pursue a new strategy of covering the electrode with a dense electroplated polymerized polyacrylic acid, which is an electron insulator but a proton conductor and proton reservoir. The combined effect of salvation and coating expands the electrochemical window throughout pH 3 to pH 10 to 2.4 V for both fast and slow proton-mediated redox reactions. This allows activated carbon to quadruple the energy density, a kilogram of nitrogen-doped graphene to provide 127 Watt-hour, and both to have improved endurance because of suppression of water-mediated corrosion. Therefore, aqueous supercapacitors can now achieve energy densities quite comparable to that of a lithium-ion battery, but at 100 times the charging/discharging speed and cycle durability.

Dong, Wujie↗
DOE OSTI2020

Broadband Communications Using High Voltage Transmission Lines - A Review

The possibilities afforded by using an existing transmission line infrastructure for the transport of broadband communications are many ranging from (conventional) A-to-B point-to-point links, to integration of Wi-Fi access points mounted at defined network (power and communications) locations, to operation as a fault-tolerant, rollover backup communications fabric (in conjunction with other transport media, such as optical fiber or terrestrial microwave). As stated by RCR Wireless reporter Jeff Kagan – regarding an ongoing in-field demonstration - “This is so much more cost effective for the company and so much easier for them to deliver an ultra-fast, gigabit speed, wireless internet connection anywhere there are power lines.” The same situation arises for a utility looking to augment or simply deploy a communications fabric in their region via treating the transmission line infrastructure as a communication fabric thereby reducing the cost and complexity of deployment. A circa 2020 review of broadband over powerlines (BPL) is presented here.

42 ENGINEERING↗
DOE OSTI2020

High voltage window electrolyte for supercapacitors

A supercapacitor according to the present invention includes a negative carbon-comprising electrode which does not intercalate sodium, and a positive carbon-comprising electrode. An electrolyte composition comprises sodium hexafluorophosphate and a non-aqueous solvent comprising at least one selected from the group consisting of ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, and tetraethylene glycol dimethyl ether. The supercapacitor has an electrochemical voltage window of from +0.0 V to 3.5 V (full cell voltage). The electrolyte has an electrochemical voltage window of from +0.05 V to 3.9 V vs. Na/Na+. A method of making and a method of operating a supercapacitor is also disclosed.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

High voltage window electrolyte for supercapacitors

A supercapacitor according to the present invention includes a negative carbon-comprising electrode which does not intercalate sodium, and a positive carbon-comprising electrode. An electrolyte composition comprises sodium hexafluorophosphate and a non-aqueous solvent comprising at least one selected from the group consisting of ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, and tetraethylene glycol dimethyl ether. The supercapacitor has an electrochemical voltage window of from +0.0 V to 3.5 V (full cell voltage). The electrolyte has an electrochemical voltage window of from +0.05 V to 3.9 V vs. Na/Na+. A method of making and a method of operating a supercapacitor is also disclosed.

25 ENERGY STORAGE↗
DOE OSTI2020

High voltage MOSFET devices and methods of making the devices

A SiC MOSFET device having low specific on resistance is described. The device has N+, P-well and JFET regions extended in one direction (Y-direction) and P+ and source contacts extended in an orthogonal direction (X-direction). The polysilicon gate of the device covers the JFET region and is terminated over the P-well region to minimize electric field at the polysilicon gate edge. In use, current flows vertically from the drain contact at the bottom of the structure into the JFET region and then laterally in the X direction through the accumulation region and through the MOSFET channels into the adjacent N+ region. The current flowing out of the channel then flows along the N+ region in the Y-direction and is collected by the source contacts and the final metal. Methods of making the device are also described.

42 ENGINEERING↗
DOE OSTI2020

Additives for high voltage lithium ion batteries

This invention relates to a method for preparing an electrochemical cell comprising the sequential steps of preparing a solution of a lithium salt in an non-aqueous solvent containing an additive compound, and maintaining the solution at a temperature in the range of about 20 to about 30° C. for about 5 to 10 days to form an aged electrolyte; assembling an electrochemical cell from an anode, a cathode, and the aged electrolyte; and electrochemically subjecting the electrochemical cell to formation cycling. The additive compound comprises one or more compounds selected from the group consisting of: (R3SiO)3B, (R3SiO)3XY, (R3SiO)3P, (R′O)3PO, (R3Si)3X′, R3SiOS(O)2R′; (R3Si)OC(═O)R′; wherein each R and R′ independently is a hydrocarbyl group; X is P or B; Y is O or S; X is Ti or Al. Electrochemical cells and batteries also are described.

Peebles, Cameron↗