Using unique design and building methods, researchers have created a prototype for an ultra-thin, curving concrete roof that will also generate solar power.

The self-supporting, doubly curved shell roof has multiple layers: the heating and cooling coils and the insulation are installed over the inner concrete layer. A second, exterior layer of the concrete sandwich structure encloses the roof, onto which builders install thin-film photovoltaic cells.

Philippe Block, a professor of architecture and structures at ETH Zurich, and Arno Schlüter, a professor of architecture and building systems, led the team. They want to put the new lightweight construction to the test and combine it with intelligent and adaptive building systems.

(more…)

A new kind of lithium sulfur battery could be more efficient, less expensive, and safer than currently available lithium batteries.

“We demonstrated this method in a coin battery,” says Donghai Wang, associate professor of mechanical engineering at Penn State. “But, I think it could eventually become big enough for cell phones, drones, and even bigger for electric vehicles.”

Lithium sulfur batteries should be a promising candidate for the next generation of rechargeable batteries, but they are not without problems. For lithium, the efficiency in which charge transfers is low, and, lithium batteries tend to grow dendrites—thin branching crystals—when charging that do not disappear when discharged.

The researchers examined a self-formed, flexible hybrid solid-electrolyte interphase layer that is deposited by both organosulfides and organopolysulfides with inorganic lithium salts. The researchers report that the organic sulfur compounds act as plasticizers in the interphase layer and improve the mechanical flexibility and toughness of the layer. The interphase layer allows the lithium to deposit without growing dendrites. The Coulombic efficiency is about 99 percent over 400 recharging discharging cycles.

(more…)

A new sodium-based battery can store the same amount of energy as a state-of-the-art lithium ion at a substantially lower cost.

As a warming world moves from fossil fuels toward renewable solar and wind energy, industrial forecasts predict an insatiable need for battery farms to store power and provide electricity.

Chemical engineer Zhenan Bao and materials scientists Yi Cui and William Chueh of Stanford University aren’t the first researchers to design a sodium ion battery. But they believe their approach has the price and performance characteristics to create a sodium ion battery that costs less than 80 percent of a lithium ion battery with the same storage capacity.

$150 a ton

“Nothing may ever surpass lithium in performance,” Bao says. “But lithium is so rare and costly that we need to develop high-performance but low-cost batteries based on abundant elements like sodium.”

With materials constituting about one-quarter of a battery’s price, the cost of lithium—about $15,000 a ton to mine and refine—looms large. Researchers say that’s why they are basing the new battery on widely available sodium-based electrode material that costs just $150 a ton.

(more…)

A closer look at catalysts is giving researchers a better sense of how these atom-thick materials produce hydrogen.

Their findings could accelerate the development of 2D materials for energy applications, such as fuel cells.

The researchers’ technique allows them to probe through tiny “windows” created by an electron beam and measure the catalytic activity of molybdenum disulfide, a two-dimensional material that shows promise for applications that use electrocatalysis to extract hydrogen from water.

Initial tests on two variations of the material proved that most production is coming from the thin sheets’ edges.

Researchers already knew the edges of 2D materials are where the catalytic action is, so any information that helps maximize it is valuable, says Jun Lou, a professor of materials science and nanoengineering at Rice University whose lab developed the technique with colleagues at Los Alamos National Laboratory.

(more…)

Engineers working to make solar cells more cost effective ended up finding a method for making sonar-like collision avoidance systems in self-driving cars.

The twin discoveries started, the researchers say, when they began looking for a solution to a well-known problem in the world of solar cells.

Solar cells capture photons from sunlight in order to convert them into electricity. The thicker the layer of silicon in the cell, the more light it can absorb, and the more electricity it can ultimately produce. But the sheer expense of silicon has become a barrier to solar cost-effectiveness.

So the engineers figured out how to create a very thin layer of silicon that could absorb as many photons as a much thicker layer of the costly material. Specifically, rather than laying the silicon flat, they nanotextured the surface of the silicon in a way that created more opportunities for light particles to be absorbed.

Their technique increased photon absorption rates for the nanotextured solar cells compared to traditional thin silicon cells, making more cost-effective use of the material.

(more…)

Just a few months ago, business magnate Elon Musk announced that he would spearhead an effort to build the world’s largest lithium-ion battery in an effort to deliver a grid-scale battery to expand South Australia’s renewable energy supply. Now, reports state that Musk is delivering on his promise, stating that the battery is already half complete.

The battery is set to sustain 100 megawatts of power and store that energy for 129 megawatt hours. That roughly translates to enough energy to power 30,000 homes. On top of this large technological order, Musk stated that if his team could not develop the battery in 100 days or less, it would be free for the Australian transmission company.

“This serves as a great example to the rest of the world of what can be done,” Musk told an audience in Australia, as reported by ABC news. “To have that [construction] done in two months; you can’t remodel your kitchen in that period of time.”

The battery is expected to cost $39 million (USD). The operational deadline, as decided by the Australian government, is December 1, 2017.

Lithium batteries made with asphalt could charge 10 to 20 times faster than the commercial lithium-ion batteries currently available.

The researchers developed anodes comprising porous carbon made from asphalt that show exceptional stability after more than 500 charge-discharge cycles.

A high-current density of 20 milliamps per square centimeter demonstrates the material’s promise for use in rapid charge and discharge devices that require high-power density.

“The capacity of these batteries is enormous, but what is equally remarkable is that we can bring them from zero charge to full charge in five minutes, rather than the typical two hours or more needed with other batteries,” says James Tour, the chair in chemistry and a professor of computer science and of materials science and nanoengineering at Rice University.

The Tour lab previously used a derivative of asphalt—specifically, untreated gilsonite, the same type used for the battery—to capture greenhouse gases from natural gas. This time, the researchers mixed asphalt with conductive graphene nanoribbons and coated the composite with lithium metal through electrochemical deposition.

(more…)

Image: CC0 Public Domain

Researchers have created a way to look inside fuel cells to see the chemical processes that lead them to breakdown.

Fuel cells could someday generate electricity for nearly any device that’s battery-powered, including automobiles, laptops, and cellphones. Typically using hydrogen as fuel and air as an oxidant, fuel cells are cleaner than internal combustion engines because they produce power via electrochemical reactions. Since water is their primary product, they considerably reduce pollution.

The oxidation, or breakdown, of a fuel cell’s central electrolyte membrane can shorten their lifespan. The process leads to formation of holes in the membrane and can ultimately cause a chemical short circuit. Engineers created the new technique to examine the rate at which this oxidation occurs with hopes of finding out how to make fuel cells last longer.

Using fluorescence spectroscopy inside the fuel cell, they are able to probe the formation of the chemicals responsible for the oxidation, namely free radicals, during operation. The technique could be a game changer when it comes to understanding how the cells break down, and designing mitigation strategies that would extend the fuel cell’s lifetime.

“If you buy a device—a car, a cell phone—you want it to last as long as possible,” says Vijay Ramani, professor of environment & energy at the School of Engineering & Applied Science at Washington University in St. Louis.

(more…)

A novel compound called 3Q conducts electricity and retains energy better than other organic materials currently used in batteries, researchers report.

“Our study provides evidence that 3Q, and organic molecules of similar structures, in combination with graphene, are promising candidates for the development of eco-friendly, high capacity rechargeable batteries with long life cycles,” says Loh Kian Ping, professor in the chemistry department at NUS Faculty of Science.

Rechargeable batteries are the key energy storage component in many large-scale battery systems like electric vehicles and smart renewable energy grids. With the growing demand of these battery systems, researchers are turning to more sustainable, environmentally friendly methods of producing them. One option is to use organic materials as an electrode in the rechargeable battery.

Organic electrodes leave lower environment footprints during production and disposal which offers a more eco-friendly alternative to inorganic metal oxide electrodes commonly used in rechargeable batteries.

The structures of organic electrodes can also be engineered to support high energy storage capabilities. The challenge, however, is the poor electrical conductivity and stability of organic compounds when used in batteries. Organic materials currently used as electrodes in rechargeable batteries—such as conductive polymers and organosulfer compounds—also face rapid loss in energy after multiple charges.

(more…)

By: Joshua M. Pearce, Michigan Technology University

As the U.S. military increases its use of drones in surveillance and combat overseas, the danger posed by a threat back at home grows. Many drone flights are piloted by soldiers located in the U.S., even when the drones are flying over Yemen or Iraq or Syria. Those pilots and their control systems depend on the American electricity grid – large, complex, interconnected and very vulnerable to attack.

Without electricity from civilian power plants, the most advanced military in world history could be crippled. The U.S. Department of Energy has begged for new authority to defend against weaknesses in the grid in a nearly 500-page comprehensive study issued in January 2017 warning that it’s only a matter of time before the grid fails, due to disaster or attack. A new study by a team I led reveals the three ways American military bases’ electrical power sources are threatened, and shows how the U.S. military could take advantage of solar power to significantly improve national security.

A triple threat

The first threat to the electricity grid comes from nature. Severe weather disasters resulting in power outages cause between US$25 billion and $70 billion in the U.S. each year – and that’s average years, not those including increasingly frequent major storms, like Hurricanes Harvey and Irma.

The second type of threat is from traditional acts of crime or terrorism, such as bombing or sabotage. For example, a 2013 sniper attack on a Pacific Gas and Electric substation in California disabled 17 transformers supplying power to Silicon Valley. In what the head of the Federal Energy Regulatory Commission called “the most significant incident of domestic terrorism involving the grid that has ever occurred,” the attacker – who may have been an insider – fired about 100 rounds of .30-caliber rifle ammunition into the radiators of 17 electricity transformers over the course of 19 minutes. The electronics overheated and shut down. Fortunately, power company engineers managed to keep the lights on in Silicon Valley by routing power from other sources.

(more…)