Lithium-sulfur batteries have been a hot topic in battery research because of their ability to produce up to 10 times more energy than conventional batteries, which means they hold great promise for applications in energy-demanding electric vehicles. However, there have been fundamental road blocks to commercializing these sulfur batteries.
Dislocations in oxides such as cerium dioxide, a solid electrolyte for fuel cells, turn out to have a property that is the opposite of what researchers had expected, according to a new analysis. Researchers had thought that a certain kind of strain would speed the transport of oxygen ions through the material, potentially leading to the much faster diffusion that is necessary in high-performance solid-oxide fuel cells.
A research partnership is reporting advances on how to make solar cells stronger, lighter, more flexible and less expensive when compared with the current silicon or germanium technology on the market. The researchers discovered how a blend of conjugated polymers resulted in structural and electronic changes that increased efficiency three-fold, by incorporating graphene in the active layer of the carbon-based materials.
Graphene nanoribbons formed into a 3-D aerogel and enhanced with boron and nitrogen are excellent catalysts for fuel cells, even in comparison to platinum, according to Rice Univ. researchers. A team led by materials scientist Pulickel Ajayan and chemist James Tour made metal-free aerogels from graphene nanoribbons and various levels of boron and nitrogen to test their electrochemical properties.
On the search for high-performance materials for applications such as gas storage, thermal insulators or dynamic nanosystems it’s essential to understand the thermal behavior of matter down to the molecular level. Classical thermodynamics average over time and over a large number of molecules. Within a 3-D space single molecules can adopt an almost infinite number of states, making the assessment of individual species nearly impossible.
Lithium-ion batteries unleash electricity as electrochemical reactions spread through active materials. Manipulating this complex process and driving the reactions into the energy-rich heart of each part of these active materials is crucial to optimizing the power output and ultimate energy capacity of these batteries. Now, scientists have mapped these atomic-scale reaction pathways and linked them to the battery’s rate of discharge.
In science, it’s commonly known that materials can change in a number of ways when subjected to different temperatures, pressures or other environmental forces. A material might melt or snap in half. And for engineers, knowing when and why that might happen is crucial information. Now, a Florida State Univ. researcher has laid out an overarching theory that explains why certain materials act the way they do.
Wake up in the morning and stretch; your midsection narrows. Pull on a piece of plastic at separate ends; it becomes thinner. So does a rubber band. One might assume that when a force is applied along an axis, materials will always stretch and become thinner. Wrong.
The blue-rayed limpet is a tiny mollusk that lives in kelp beds along the coasts of Norway, Iceland, the U.K., Portugal and the Canary Islands. These diminutive organisms might escape notice entirely, if not for a very conspicuous feature: bright blue dotted lines that run in parallel along the length of their translucent shells. Depending on the angle at which light hits, a limpet’s shell can flash brilliantly even in murky water.
Designing or exploring new materials is all about controlling their properties. In a new study, Cornell Univ. scientists offer insight on how different “knobs” can change material properties in ways that were previously unexplored or misunderstood.
To power a car so it can travel hundreds of miles at a time, lithium-ion batteries of the future are going to have to hold more energy without growing too big in size. That's one of the dilemmas confronting efforts to power cars through rechargeable battery technologies. In order to hold enough energy to enable a car trip of 300 to 500 miles before recharging, current lithium-ion batteries become too big or too expensive.
Univ. of Manchester scientists have used graphene to target and neutralize cancer stem cells while not harming other cells. This new development opens up the possibility of preventing or treating a broad range of cancers, using a non-toxic material.
Superconductor materials are prized for their ability to carry an electric current without resistance, but this valuable trait can be crippled or lost when electrons swirl into tiny tornado-like formations called vortices. These disruptive mini-twisters often form in the presence of magnetic fields, such as those produced by electric motors.
Scientists have known how to draw thin fibers from bulk materials for decades. But a new approach to that old method, developed by researchers at Massachusetts Institute of Technology, could lead to a whole new way of making high-quality fiber-based electronic devices. The idea grew out of a long-term research effort to develop multifunctional fibers that incorporate different materials into a single long functional strand.
Graphene is often touted as a replacement for silicon in electronic devices due to its extremely high conductivity and unbeatable thinness. But graphene isn’t the only 2-D material that could play such a role. Univ. of Pennsylvania researchers have made an advance in manufacturing one such material, molybdenum disulphide.
Researchers succeeded in creating an electrocatalyst that is needed for storing electric energy made of carbon and iron. A challenge that comes with the increased use of renewable energy is how to store electric energy. Platinum has traditionally been used as the electrocatalyst in electrolyzers that store electric energy as chemical compounds.
Researchers at the Univ. of California, Riverside have developed a novel paper-like material for lithium-ion batteries. It has the potential to boost by several times the specific energy, or amount of energy that can be delivered per unit weight of the battery. This paper-like material is composed of sponge-like silicon nanofibers more than 100 times thinner than human hair.
Researchers at the Univ. of Illinois at Urbana-Champaign have developed a unique single-step process to achieve 3-D texturing of graphene and graphite. Using a commercially available thermally activated shape-memory polymer substrate, this 3-D texturing, or "crumpling," allows for increased surface area and opens the doors to expanded capabilities for electronics and biomaterials.
A team of researchers from the Univ. of Michigan and Western Michigan Univ. is exploring new materials that could yield higher computational speeds and lower power consumption, even in harsh environments. Most modern electronic circuitry relies on controlling electronic charge within a circuit, but this control can easily be disrupted in the presence of radiation, interrupting information processing.
Compact, sensitive and fast nanodetectors are considered to be somewhat of a "Holy Grail" sought by many researchers around the world. And now a team of scientists in Italy and France has been inspired by nanomaterials and has created a novel solid-state technology platform that opens the door to the use of terahertz photonics in a wide range of applications.
The future of electronics could lie in a material from its past, as researchers from The Ohio State Univ. work to turn germanium, the material of 1940s transistors, into a potential replacement for silicon. At the American Association for the Advancement of Science meeting, Asst. Prof. of Chemistry Joshua Goldberger reported progress in developing a form of germanium called germanane.
A research team led by North Carolina State Univ. has identified and synthesized a material that can be used to create efficient plasmonic devices that respond to light in the mid-infrared (IR) range. This is the first time anyone has demonstrated a material that performs efficiently in response to this light range, and it has applications in fields ranging from high-speed computers, to solar energy to biomedical devices.
Researchers at the Univ. of Surrey’s Advanced Technology Institute manipulated zinc oxide, producing nanowires from this readily available material to create an ultraviolet (UV) light detector that is 10,000 times more sensitive to UV light than a traditional zinc oxide detector. Currently, photoelectric smoke sensors detect larger smoke particles found in dense smoke, but are not as sensitive to small particles of smoke.
Although most materials slightly expand when heated, there is a new class of rubber-like material that not only self-stretches upon cooling; it reverts back to its original shape when heated, all without physical manipulation. The material is like a shape-memory polymer because it can be switched between two different shapes.
As you heat up a piece of iron, the arrangement of the iron atoms changes several times before melting. This unusual behavior is one reason why steel, in which iron plays a starring role, is so sturdy and ubiquitous in everything from teapots to skyscrapers. But the details of just how and why iron takes on so many different forms have remained a mystery.