A thyristor will stay conducting until the current through the device is zero (“current zero”) or perhaps slightly negative. LLNL’s approach is to use the opticondistor (“OTV”) to force this current zero in order to force the device into an “off” state. By combining a light-activated thyristor with an OTV, a noise-immune, high efficiency, high-power switching device can be constructed. The…
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![OALV design with High-k Photoconductor and High-k Optical Window](/sites/default/files/styles/scale_exact_400x400_/public/2024-01/OALV%20design.png?itok=xMV74hXb)
LLNL researchers has developed designs to augment WBG/UWBG-based OALVs to improve their power handling capability under CW operational environments. These designs include:
![LLNL energy grid protection device](/sites/default/files/styles/scale_exact_400x400_/public/2023-10/LLNL%20energy%20grid%20protection%20device_0.png?itok=vpqzRY_R)
The approach is to leverage the fact that a momentary “load” equal to the power transmission line impedance, (Z0), during the transient can suppress its propagation. Z(0) is typically a fixed impedance of several hundred ohms based on the geometry of most single wire transmission lines.
So, an isolated self-powered opticondistor (OTV) system may provide an ultrafast method of…
![JFET Device Structure](/sites/default/files/styles/scale_exact_400x400_/public/2023-10/JFET%20device%20structure.png?itok=NRzXbnhk)
LLNL’s novel approach is to use diamond substrates with the desired donor (nitrogen) and acceptor (boron) impurities. In order to optically activate these deep impurities, the invention requires at least one externally or internally integrated light source. The initial exposure to light can set up the desired conduction current, after which the light source could be turned off. Even with…
![Tunneling Diode between two DSRDs](/sites/default/files/styles/scale_exact_400x400_/public/2023-10/TunnelingDiode.png?itok=DfeB26vp)
Instead of producing individual DSRDs and bonding them, Tunnel DSRD's entire stack structure is grown epitaxially on a n- or p-type silicon wafer, resulting in a novel, “monolithic” stacked DSRD. A tunnel diode is essentially a diode with very highly doped p and n regions such that the reverse breakdown voltage is 200 meV or lower.
![Boss Circuit Breaker](/sites/default/files/styles/scale_exact_400x400_/public/2023-09/Boss%20Circuit%20Breaker.png?itok=7XJ44vZ0)
LLNL’s novel approach to enable MVDC power systems to operate safely is to develop a wideband gap bulk optical semiconductor switch (WBG BOSS) circuit breaker. For higher power, efficiency and temperature operation, vanadium-doped silicon carbide (V-doped SiC) appears to be the most promising basis for WBG BOSS circuit breaker (other dopants like aluminum, boron and nitrogen may further…
![Sub-device integrated with Main device of the flow battery (A) and a cross-section of the sub-device (B)](/sites/default/files/styles/scale_exact_400x400_/public/2023-09/Sub-device%20for%20flow%20battery.png?itok=72VMgGtP)
LLNL researchers has developed an approach to mitigate HER on the ‘plating’ electrode, which uses a sub-device as a rebalancing cell to restore electrolyte properties, including pH, conductivity, and capacity across the main device of the flow battery. This sub-device, which may need to be powered externally, has three major physical components: (1) a cathode electrode, (2) an anode electrode…
![Electrical grid](/sites/default/files/styles/scale_exact_400x400_/public/2022-06/electricaGrid875x500px.jpg?itok=vKB8x1kB)
LLNL has developed a novel methodology for using commercially available automated sensors and actuators which can be deployed at scale in large appliances and plug-in EVs to provide as needed electric grid stabilization capabilities. The approach comprises of a population of voltage relays with a range of setpoints that would gradually reduce load as voltage falls. More severe voltage…
![Electrodeposition of Zn onto 3D printed copper nanowire (CuNW)](/sites/default/files/styles/scale_exact_400x400_/public/2023-07/ElectrodepositionofZnon3dprintedCuNW.jpg?itok=2G2D1kt9)
Improving the active material of the Zn anode is critical to improving the practicality of Zn-MnO2 battery technology. LLNL researchers have developed a new category of 3D structured Zn anode using a direct-ink writing (DIW) printing process to create innovative hierarchical architectures. The DIW ink, which is a gel-based mixture composed of zinc metal powder and organic binders, is extruded…
![Compared with conventional slurry-based film electrode manufacturing methods, dry laser powder bed fusion is promising in generating structured electrodes for high power, low cost lithium ion batteries](/sites/default/files/styles/scale_exact_400x400_/public/2023-06/conventional%20vs%20laser%20PBF%20for%20electrodes.jpg?itok=4KG4KLlE)
To address many of the aforementioned challenges of manufacturing LIBs and SSBs, LLNL researchers have developed a number of inventions that offer proposed solutions for their components:
![Segments of transmission line lengths can be switched to open circuit (as shown) or shorted to the ground (not shown)](/sites/default/files/styles/scale_exact_400x400_/public/2023-05/Segments%20of%20tranmission%20line%20lengths.png?itok=FF0qaBGw)
Design and construction of a photoconductive switch requires a diamond photoconductor illuminated by light of a certain excitation wavelength. The diamond material is specifically doped with substitutional nitrogen, which act as a source of electrons. The device architecture allows maximum light entering the aperture. The top and bottom electrodes are made of ultra wide band gap (UWBG)…
![Annular illumination on photo conductor by Conical Total Internal Reflection “CTIR” endcap](/sites/default/files/styles/scale_exact_400x400_/public/2023-05/CONIFR.png?itok=L4wSanXF)
The approach is to use a custom-designed frustrum and attach it to the optical fiber that connects to the PCSS. Light from the fiber enters the frustrum, spreads out, and enters the PCSS. Any unabsorbed light re-enters the frustrum and, because of its geometry, reflects back into the PCSS itself with only a negligible fraction escaping from the fiber. The shape of the novel frustrum is…
![Electromechanical battery](/sites/default/files/styles/scale_exact_400x400_/public/2022-06/Electromechanical%20battery.jpg?itok=vgNlfBIu)
The design calculations that have been performed in exploring the potentialities of LLNL's new approaches to flywheel energy storage have been built on existing and past LLNL flywheel programs, including a program aimed at flywheel systems for the bulk storage of electricity at utility scale. To achieve the requirements of such systems, as mentioned above, LLNL has developed some key new…
![OTV Image](/sites/default/files/styles/scale_exact_400x400_/public/2022-02/OTV%20Image.png?itok=KEAmHqpM)
The Optical Transconductance Varistor (OTV, formerly Opticondistor) overcomes depletion region voltage limitations by optically exciting wide bandgap materials in a compact package. A 100μm thick crystal could have the capability approaching 40kV and would replace numerous equivalent junction devices. Thus, unlike present junction transistors or diodes, this wide bandgap device can be stacked…