Science Daily April 19, 2024 An internal team of researchers (Japan, Taiwan) proposed a floating four-phase interleaved chargepump bidirectional dc-dc converter (F4P-ICPBDC) with wide Buck/Boost voltage ratio. The interleaved structure was used to mitigate the current ripple across the low-voltage side capacitor and inductors, while the floating configuration facilitated the high Buck/Boost voltage conversion ratio. To ensure a balanced average inductor current throughout the entire range of duty cycle, an asymmetric duty limit control strategy was implemented. Bidirectional synchronous rectification operations were seamlessly carried out without the need for additional hardware, which enhanced the overall converter efficiency. They developed a […]
Category Archives: Energy
Discovery of organic catalyst could lead to cheaper fuel cells
Phys.org April 15, 2024 Researchers at the University of Virginia have developed an iminium-based organoelectrocatalyst (im+) for oxygen reduction reaction with trifluoroacetic acid as a proton source in acetonitrile solution under both electrochemical and spectrochemical conditions using decamethylferrocene as a chemical reductant. Under spectrochemical conditions, H2O2 was the primary reaction product. They attributed this difference in selectivity to the interception of the free superoxide intermediate under electrochemical conditions by the reduced catalyst… read more. Open Access TECHNICAL ARTICLE
Magnetic fields boost clean energy
Nanowerk April 7, 2024 Magnetic field effects on electrocatalysis have recently gained attention due to the substantial enhancement of the oxygen evolution reaction (OER) on ferromagnetic catalysts. An international team of researchers (Switzerland, Argentina) used a specifically designed magneto-electrochemical system and non-magnetic electrodes to quantify magnetic field effects. They found marginal enhancement in reactions with high reactant availability, such as the OER, whereas substantial boosts exceeding 50% were observed in diffusion limited reactions, exemplified by the oxygen reduction reaction (ORR). According to the researchers their results advanced the fundamental understanding of magnetic fields in electrocatalysis and unveil new prospects for […]
New device gathers, stores electricity in remote settings
Science Daily April 9, 2024 Researchers at the University of Utah investigated a pyro electrochemical cell (PEC) as a novel device concept for direct conversion of thermal energy to stored electrochemical energy. The PEC integrated a porous, pyroelectric separator within a supercapacitor. The pyroelectric separator induced an electric field within the PEC when exposed to a temperature change with time. The electric field drove ions into electrode double layers to charge the cell. Experimental results were coupled with simulations to explore PEC response when thermally cycled, with predicted pyroelectric orientation effects observed in two tests. The pyroelectric separator showed a […]
A simple way to harvest more ‘blue energy’ from waves
Science Daily April 3, 2024 Due to the advantages of simple structure and flexibility for energy harvesting, the tube liquid–solid triboelectric nanogenerator (TLS-TENG) has attracted much attention. However, it is limited by low output power due to its low surface charge density and transfer efficiency. Researchers in China proposed and constructed TLS-TENG (SVE-TLS-TENG) with enhanced output performance. Through the space volume effect, the open-circuit voltage (Uoc), short-circuit current (Isc), and transfer charge (Qtc) of SVE-TLS-TENG they improved energy harvesting by 3.5 times, 2.3 times, and 2 times, respectively. The SVE-TLS-TENG has high output performance for harvesting low-frequency and high-entropy motion […]
Tests show high-temperature superconducting magnets are ready for fusion
MIT News March 4, 2024 The SPARC Toroidal Field Model Coil (TFMC) Program was a three-year effort between 2018 and 2021 that developed novel rare earth barium copper oxide (REBCO) superconductor technologies and then successfully utilized these technologies to design, build, and test a first-in-class, high-field (∼20 T), representative-scale (∼3 m) superconducting toroidal field (TF) coil. The program was executed jointly by the MIT Plasma Science and Fusion Center (PSFC) and Commonwealth Fusion Systems (CFS) as a technology enabler of the superconducting high-field pathway to fusion energy, and as a risk retirement program for the no insulation (NI) TF magnet […]
Breakthrough synthesis method improves solar cell stability
Science Daily October 26, 2023 2D multilayered halide perovskites have emerged as a platform for understanding organic–inorganic interactions, tuning quantum confinement effects and realizing efficient and durable optoelectronic devices. However, reproducibly synthesizing 2D perovskite crystals with a perovskite-layer thickness using existing crystal growth methods is challenging. An international team of researchers (Rice University, Houston, Northwestern University, University of Pennsylvania, France) demonstrated a kinetically controlled space confinement for the growth of phase-pure Ruddlesden–Popper and Dion–Jacobson 2D perovskites. Phase-pure growth was achieved by progressively increasing the temperature for a fixed time or the crystallization time at a fixed temperature, which allowed for […]
Scientists design novel nonlinear circuit to harvest clean power using graphene
Phys.org August 18, 2023 An international team of researchers (USA – University of Arkansas, UC Berkeley, Spain) theoretically considered a graphene ripple as a Brownian particle coupled to an energy storage circuit. When circuit and particle are at the same temperature, the second law forbids harvesting energy from the thermal motion of the Brownian particle, even if the circuit contains a rectifying diode. However, when the circuit contains a junction followed by two diodes wired in opposition, the approach to equilibrium may become ultraslow. Detailed balance is temporarily broken as current flows between the two diodes and charges storage capacitors. […]
MIT engineers create an energy-storing supercapacitor from ancient materials
MIT News July 31, 2023 A team of researchers in the US (MIT, Harvard University) investigated using cement, water, and carbon black as chemical precursors for energy storage. Texture analysis revealed that the hydration reactions of cement in the presence of carbon generates a fractal-like electron-conducting carbon network that permeates the load-bearing cement-based matrix. The energy storage capacity of this space-filling carbon black network of the high specific surface area accessible to charge storage was shown to be an intensive quantity, whereas the high-rate capability of the carbon-cement electrodes exhibited self-similarity due to the hydration porosity available for charge transport. […]
Team creates simple superconducting device that could dramatically cut energy use in computing
Phys.org July 28, 2023 Accomplishing unequal supercurrents in the forward and backward directions in superconductors would enable unprecedented functionalities. This nonreciprocity of critical supercurrents is called the superconducting (SC) diode effect. An international team of researchers (USA – MIT, US Army DEVCOM, High School (Alabama, Washington). Switzerland, Spain) demonstrated the strong SC diode effect in conventional SC thin films, such as niobium and vanadium, employing external small magnetic fields. Interfacing the SC layer with a ferromagnetic semiconductor EuS, they further accomplished the nonvolatile SC diode effect reaching an efficiency of 65%. By careful control experiments and theoretical modeling, they demonstrated […]