Scientists report a systematic study involving theoretical and experimental approaches to evaluate the Li-ion storage capability in 2D atomic sheets of nonlayered MoO2. They describe a new process - polymer-assisted reduction - to make atomically flat 2D sheets of MoO2. Since MoO2 is not a 2D material, this process opens a new pathway to make 2D nanostructures from non-layered materials. By successfully making 2D atomic sheets of MoO2, the researchers fabricated a battery electrode in which the Li ion diffusion and electron transport are exceptionally fast.
Inspired by the designs printed on T-shirts, researchers recently reported a new class of wearable power sources. To explore the feasibility of power sources directly printed on cotton T-shirts, which look like letters or symbols, they chose electric double layer supercapacitors based on activated carbon materials as a model electrochemical system. These T-shirts look and behave like a normal T-shirt but feature printed supercapacitors in the shape of letters and symbols.
Motived by the large number of non-layered materials, e.g. transition metal oxides, which hold great promise in battery applications, scientists aim to extend the concept of nanofluidic channels into intrinsically non-layered materials and improve their electrochemical properties. In a new study, researchers have developed a Co3O4-based two-dimensional nano-architecture possessing nanofluidic channels with specially designed interlayer characteristics for fast lithium ion transport, leading to exceptional performance in lithium ion batteries ever reported for this material.
So far, most of the developed self-powered piezoelectric devices are rigid or have limited lateral stretchability and could not be used to harvest energy from lateral strain, which greatly limits their applications on large strain deformation. In new work, researchers have successfully fabricated a piezoelectric nanocomposite device with good transparency, high stretchability, and self-powered sensing characteristics. Attached to the human body, it can harvest biomechanical energy and monitor physiological signals.
The wearable power sources required for wearable and implantable electronic devices are limited by the size of the gadgets they power. Microsupercapacitors are newly emerging miniaturized high-power microelectrochemical energy-storage devices that can deliver high power density, fast charge and discharge, and a superior cycling lifetime. A new study shows that electrode fractal design is a viable strategy for improving the performance of integrated microsupercapacitors that use thin-film electrodes at no extra processing or fabrication cost.
Self-powered nanotechnology based on one type of nanogenerators - piezoelectric nanogenerators - aims at powering nanodevices and nanosystems using the energy harvested from the environment in which these systems are suppose to operate. This offers a completely new approach for harvesting mechanical energy using organic and inorganic materials. Researchers have now reported a novel bio-piezoelectric nanogenerator using naturally abundant, self-aligned cellulose fibrous untreated onion skin as efficient piezoelectric material.
Efficient electrocatalysts lie at the heart of a series of significant energy conversion and storage technologies, and atomically precise understanding of the influences of component dopants is crucial for looking into the reaction mechanism and controlled synthesis of the desired electrocatalysts. Graphitic carbon nitride is a promising electrocatalytic material owing to its intrinsically high N content and abundant edge sites. This material has been researched towards some of the most significant electrocatalytic reactions including oxygen reduction/evolution reaction and hydro evolution reaction. New work has comprehensively explored the influences of component elements within graphitic carbon nitride motiety for electrocatalytic reactions.
Chemical engineering researchers have reported the usage of activated carbon prepared from tea leaves, improving the mass transport phenomenon (33 % performance improvement) in an operating direct methanol fuel cell, owing to its pore structure characteristics. The cell performance underwent drastic changes in the mass transport region of the fuel cell polarization curve, comparable to the standard membrane electrode assembly. This is attributed to the pore structure of this framework aiding in enhanced water removal, as a result more air molecules react with the platinum catalyst sites finally improving the fuel cell performance.