Twisted carbon nanotubes could achieve significantly better energy storage than advanced lithium-ion batteries

Phys.org  July 26, 2024 Single-walled carbon nanotubes (SWCNTs), which typically exhibit great toughness, have emerged as promising candidates for innovative energy storage solutions. An international team of researchers (Japan, USA – University of Maryland Baltimore County, Michigan State University, South Africa) produced SWCNT ropes wrapped in thermoplastic polyurethane elastomers, and demonstrated experimentally that a twisted rope composed of these SWCNTs possesses the remarkable ability to reversibly store nanomechanical energy. The gravimetric energy density of the twisted ropes reaches up to 2.1 MJ kg−1, exceeded the energy storage capacity of mechanical steel springs by over four orders of magnitude and surpassed advanced lithium-ion […]

Rubber-like stretchable energy storage device fabricated with laser precision

Science Daily  April 24, 2024 Researchers in South Korea fabricated deformable micro supercapacitors (MSCs) based on eutectic gallium-indium liquid metal (EGaIn) current collectors with integrated graphene using laser ablation because of strong laser absorption of graphene and EGaIn. By controlling the gap size between neighboring interdigitated electrodes and mass loading of graphene, they were able to get a high areal capacitance with reliable rate performance. Because of the intrinsic liquid characteristics of EGaIn current collector, the areal capacitance of fabricated MSC retained 90% of original value even after repetitive folding and 20% stretching up to 1000 cycles. They successfully integrated […]

Bendable energy storage materials by cool science

Science Daily  March 19, 2024 Mesoporous metal oxides exhibit excellent physicochemical properties and are widely used in various fields, including energy storage/conversion, catalysis, and sensors. Although several soft-template approaches are reported, high-temperature calcination for both metal oxide formation and template removal is necessary, which limits direct synthesis on a plastic substrate for flexible devices. Researchers in South Korea developed a universal synthetic approach that combines thermal activation and oxygen plasma to synthesize diverse mesoporous metal oxides (V2O5, V6O13, TiO2, Nb2O5, WO3, and MoO3) at low temperatures (150–200 °C), which could be applied to a flexible polymeric substrate. To demonstrate their […]

Energy storage in molecules

Science Daily  August 30, 2023 Photoswitches are molecular systems that are chemically transformed after interaction with light and they find potential application in many new technologies. The design and discovery of photoswitch candidates require intricate molecular engineering of a range of properties to optimize a candidate to a specific application. An international team of researchers (Denmark, Spain) performed a large-scale screening of approximately half a million bicyclic diene photoswitches in the context of molecular solar thermal energy storage using ab initio quantum chemical methods. They devised an efficient strategy for scoring the systems based on their predicted solar energy conversion […]

Iron for energy storage

Max-Plank Society  December 2, 2022 The combustion of iron powders seems very promising for stable and high-density energy storage technology. To better understand their in-process morphological and microstructural evolution an international team of researchers (Germany, the Netherlands) investigated two iron powder combustion pathways, one in air and one with the assistance of a propane pilot flame. Both processes resulted in spherical hollow particles composed of a complex microstructure of wüstite, magnetite and/or hematite. They observed nanoparticles on the micro-sized combustion products which indicated partial evaporation. According to the researchers the associated gas production inside the liquid droplet could be the […]

Energy storage materials built from nano-sized molecular blocks

Phys.org  September 20, 2022 Researchers in Sweden have developed a method for producing solid materials from aqueous solutions containing nano-sized niobium molecules, called polyoxoniobates which are water-soluble. They act as molecular building blocks to make a wide range of materials, including supercapacitors that facilitate lithium-ion storage. The nanometer sized molecules can be dissolved in water and spin coated to deposit thin films of niobium pentoxide. When the films are heated to temperatures ranging from 200 to 1200°C, surfaces with varying corrosion resistance and electrochemical properties are obtained. This approach facilitates deposition of alkali-free, metal oxide thin films with varying crystallinity, […]

How ultrathin polymer films can be used for storage technology

Phys. org  July 18, 2022 Researchers in Germany showed that precisely applied mechanical pressure can improve the electronic properties of a widely used ferroelectric semi-crystalline polymer material polyvinylidene fluoride (PVDF). However, PVDF’s structure, unlike crystals, is not completely ordered. They discovered that atomic force microscopy can be used to establish a certain electric order in the material. They scanned the material sample with a tip only a few nanometers in size. Using a laser they measured, evaluated the vibrations that were produced, and analyzed the material’s surface structure at the nano level. They discovered that this also changed the electrical […]

Unexpected energy storage capability where water meets metal surfaces

Science Daily  January 19, 2022 Strong interaction of metal with water molecules leads to water chemisorption and accumulation of ions in the Helmholtz layer beyond expectation, resulting in a higher interface charge storage ability. An international team of researchers (Germany, Israel, France) extracted new physico-chemical information on the capacitance and structure of the electrical double-layer of platinum and gold nanoparticles at the molecular level, employing single nanoparticle electrochemistry. The charge storage ability of the solid/liquid interface is larger by one order-of-magnitude than predicted by the traditional mean-field models of the double-layer. Using molecular dynamics simulations, they investigated the possible relationship […]

Stretching the capacity of flexible energy storage (w/video)

Nanowerk  September 8, 2021 In spite of the excellent electrical and electrochemical properties, two-dimensional transition metal carbide (MXene) is often limited by the high stiffness for the direct implementation in next-generation stretchable and wearable energy storage devices. After screening for the thickness, researchers in China identified the crumpled MXene film of ∼3 μm in thickness as the optimal choice to mitigate the crack formations under large and repetitive mechanical strains. The as-prepared symmetric supercapacitor demonstrated a high specific capacitance of ∼470 mF cm–2, ultrahigh stretchability up to 800% area strain, and >90% retention of the initial capacitance after 1000 stretch–relaxation […]

Powering up stretchy technology

Nanowerk  December 30,2020 Implantable devices need electronics that can be integrated with soft tissue and accommodate the motion of the body. A team of researchers in the US (Michigan State University, Duke University, Oak Ridge National Laboratory) is working on “plant wearables,” which are sensors for crops that can stretch and bend as the plants grow and move. To power these devices they used 4D printing to create supercapacitors that can stretch to new limits without compromising their electrochemical performance. The team used an aerosol jet printer to directly deposit a specially formulated ink onto a stretchable polymer substrate. The […]