Phys.org April 19, 2024 The light-induced ultrafast switching between molecular isomers norbornadiene and quadricyclane can reversibly store and release a substantial amount of chemical energy. Prior work observed signatures of ultrafast molecular dynamics in both isomers upon ultraviolet excitation but could not follow the electronic relaxation all the way back to the ground state experimentally. An international team of researchers (USA – Kansas State University, University of Nebraska–Lincoln, SLAC National Accelerator Laboratory, Brown University, UK, Germany, Italy, Sweden, Australia) identified two competing pathways by which electronically excited quadricyclane molecules relaxed to the electronic ground state. The fast pathway (<100 femtoseconds) was […]
Tag Archives: Energy storage
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 […]
Newly developed hydrogel nanocomposite for the mass production of hydrogen
Phys.org April 27, 2023 Despite recent progress in designing highly active photocatalysts, inefficient solar energy and mass transfer, the instability of catalysts and reverse reactions impede their practical large-scale applications. Storing solar energy in chemical bonds aided by heterogeneous photocatalysis is desirable for sustainable energy conversion. Researchers in South Korea designed a floatable photocatalytic platform constructed from porous elastomer–hydrogel nanocomposites. The nanocomposites at the air–water interface featured efficient light delivery, facile supply of water and instantaneous gas separation. Consequently, a high hydrogen evolution rate of 163 mmol h–1 m–2 was achieved using Pt/TiO2 cryoaerogel, even without forced convection. When fabricated in an area […]
New sodium, aluminum battery aims to integrate renewables for grid resiliency
Science Daily February 7, 2023 Recent explorations pairing a sodium anode and aluminum cathode have demonstrated reversible, energy dense Na-Al cells with excellent rate capability using the electrochemical reaction between a molten Na anode and a NaAlCl4/Al cathode. A team of researchers in the US (Pacific Northwest National Laboratory, industry) investigated the fundamental aspects of the NaAlCl4-NaAl2Cl7 reaction chemistry, and Na-metal/chloroaluminate batteries with excellent reversibility and areal capacity. Increasing the voltage window of the chloroaluminate Na-Al battery higher voltage was contributed by the acidic chloroaluminate cathode reaction, unlocking an additional specific energy of ∼119 Wh kg−1 by utilizing the conversion […]
Breathing supercapacitor
Nanowerk January 13, 2023 Currently commercialized supercapacitors still suffer from limited energy densities. Taking inspiration from anolis lizard, an international team of researchers (UK, China) has developed a supercapacitor with a “breathing” electrode. To breathe underwater the lizard brings along an air bubble that is attached to a layer of scales on their head. Under water, it repeatedly breathes this bubble in and out. The researchers used chlorine gas which iteratively reinspires in porous carbon materials, that improves the energy density by orders of magnitude. They showed that porous carbon with pore size around 3 nm delivers the best chlorine […]
New battery technology has potential to significantly reduce energy storage costs
Science Daily December 7, 2022 The issues arising from the low S mass loading and poor cycling stability caused by the shuttle effect of polysulfides seriously limit the operating capacity and cycling capability of room-temperature sodium–sulfur (RT-Na/S) batteries. An international team of researchers (China, Australia) synthesized sulfur-doped graphene frameworks supporting atomically dispersed 2H-MoS2 and Mo1 (S@MoS2-Mo1/SGF) with a record high sulfur mass loading of 80.9 wt.% as an integrated dual active sites cathode for RT-Na/S batteries. They displayed unprecedented cyclic stability with a high initial capacity and a low-capacity fading rate of 0.05% per cycle over 1000 cycles. Experimental and […]
Dual membrane offers hope for long-term energy storage
Science Daily May 3, 2022 Polysulfide-air redox flow batteries demonstrated great potential for long-duration energy storage technologies that can be deployed at grid scale. However, the crossover of polysulfide is one significant challenge. Researchers in the UK have developed a stable and cost-effective alkaline-based hybrid polysulfide-air redox flow battery where a dual-membrane-structured flow cell design mitigates the sulfur crossover issue. Moreover, combining manganese/carbon catalyzed air electrodes with sulfidated Ni foam polysulfide electrodes, the redox flow battery achieves a maximum power density of 5.8 mW cm−2 at 50% state of charge and 55 °C. Compared with the best results obtained to date […]
‘Freeze-thaw battery’ is adept at preserving its energy
Science Daily April 5, 2022 Grid-level storage of seasonal excess can be an important asset to renewable electricity. As a proof-of-concept researchers at Pacific Northwest National Laboratory applied the freeze-thaw thermal cycling strategy to Al-Ni molten salt batteries and demonstrated effective capacity recovery over 90% after a period of 1–8 weeks. They explored three activation methods of the nickel cathode in a molten-salt battery: (1) heat treating the cathode granules under H2/N2, (2) incorporating a partially charged NiCl2/Ni cathode, and (3) doping the molten salt electrolyte with sulfur. Sulfur doping, a cost-efficient method suitable for large-scale applications, was not only […]
Study shows that zwitterions can raise the dielectric constant of soft materials
Phys.org December 17, 2021 To create efficient energy storage solutions and actuators, engineers need materials with high dielectric constant. The current method of incorporating polar additives with a high dielectric constant has not yielded high enough dielectric constant for many applications. Researchers at Penn State University have demonstrated a new method for raising the dielectric constant by adding zwitterions, small molecules with one positive electrical charge and one negative electrical charge separated by covalent bonds. Zwitterions are non-volatile molecules that are highly polar. In their recent experiments, the team added the zwitterions to polymeric single-ion conductors. Zwitterions raised dielectric constant […]
Making clean hydrogen is hard, but researchers just solved a major hurdle
Phys.org July 19, 2021 To create electrically conductive paths through a thick silicon dioxide researchers at UT Austin used a technique first deployed in the manufacturing of semiconductor electronic chips. By coating the silicon dioxide layer with a thin film of aluminum and heating the entire structure, arrays of nanoscale “spikes” of aluminum that completely bridge the silicon dioxide layer were created. These can be replaced by nickel or other materials that help catalyze the water-splitting reactions. When illuminated by sunlight, the devices efficiently oxidized water to form oxygen molecules while also generating hydrogen at a separate electrode and exhibited […]