By: Joshua D. Rhodes, University of Texas at Austin

Science is messy, but it doesn’t have to be dirty.

On June 19, a group of respected energy researchers released a paper in the journal Proceedings of the National Academy of Sciences (PNAS) that critiqued a widely cited study on how to power the U.S. using only renewable energy sources. This new paper, authored by former NOAA researcher Christopher Clack and a small army of academics, said that the initial 2015 study had “errors, inappropriate methods and implausible assumptions,” about using only the sun, wind and water to fuel the U.S.

What followed was a storm of debate as energy wonks of all stripes weighed in on the merits of the PNAS analysis. Mark Z. Jacobson, a Stanford University professor who was the lead author of the 2015 study, shot back with detailed rebuttals, in one calling his fellow researchers “fossil fuel and nuclear supporters.”

Why the big kerfuffle? As an energy researcher who studies the technologies and policies for modernizing our energy system, I will try to explain.

In general, getting to a clean energy system – even if it’s 80 percent renewable – is a well agreed-upon goal and one that can be achieved; it’s that last 20 percent – and how to get there – that forms the main point of contention here.

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Researchers from Argonne National Laboratory and Oregon State University have developed new cathode architecture for lithium-sulfur batteries. The team, led by ECS member Khalil Amine, incorporated graphene and sulfide nanoparticles to improve electrical conductivity in the promising lithium-sulfur batteries.

Lithium-sulfur batteries hold major promise as researchers explore the range of energy storage technologies. With an extremely high theoretical energy density, these batteries have the potential to store up to five times as much energy as today’s best lithium-ion battery.

But there are barriers preventing that theoretical density from becoming an actual density. Namely, the discharge products of sulfur electrodes and cycling intermediates produced.

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Using energy stored in the batteries of electric vehicles to power large buildings not only provides electricity for the building, but also increases the lifespan of the vehicle batteries, new research shows.

Researchers have demonstrated that vehicle-to-grid (V2G) technology can take enough energy from idle electric vehicle (EV) batteries to be pumped into the grid and power buildings—without damaging the batteries.

This new research into the potentials of V2G shows that it could actually improve vehicle battery life by around ten percent over a year.

For two years, Kotub Uddin, a senior research fellow at the University of Warwick’s Warwick Manufacturing Group, and his team analyzed some of the world’s most advanced lithium ion batteries used in commercially available EVs—and created one of the most accurate battery degradation models existing in the public domain—to predict battery capacity and power fade over time, under various aging acceleration factors—including temperature, state of charge, current, and depth of discharge.

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A new development in electrolyte chemistry, led by ECS member Shirley Meng, is expanding lithium-ion battery performance, allowing devices to operate at temperatures as low as -60° Celsius.

Currently, lithium-ion batteries stop operating around -20° Celsius. By developing an electrolyte that allows the battery to operate at a high efficiency at a much colder temperature, researchers believe it could allow electric vehicles in cold climates to travel further on a single charge. Additionally, the technology could allow battery-powered devices, such as WiFi drones, to function in extreme cold conditions.

(MORE: Read ECS’s interview with Meng, “The Future of Batteries.”)

This from UC San Diego:

The new electrolytes also enable electrochemical capacitors to run as low as -80 degrees Celsius — their current low temperature limit is -40 degrees Celsius. While the technology enables extreme low temperature operation, high performance at room temperature is still maintained. The new electrolyte chemistry could also increase the energy density and improve the safety of lithium batteries and electrochemical capacitors.

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Researchers have developed a new kind of semiconductor alloy capable of capturing the near-infrared light located on the edge of the visible light spectrum.

Easier to manufacture and at least 25 percent less costly than previous formulations, it’s believed to be the world’s most cost-effective material that can capture near-infrared light—and is compatible with the gallium arsenide semiconductors often used in concentrator photovoltaics.

Concentrator photovoltaics gather and focus sunlight onto small, high-efficiency solar cells made of gallium arsenide or germanium semiconductors. They’re on track to achieve efficiency rates of over 50 percent, while conventional flat-panel silicon solar cells top out in the mid-20s.

“Flat-panel silicon is basically maxed out in terms of efficiency,” says Rachel Goldman, a professor of materials science and engineering, as well as physics at the University of Michigan, whose lab developed the alloy. “The cost of silicon isn’t going down and efficiency isn’t going up. Concentrator photovoltaics could power the next generation.”

Varieties of concentrator photovoltaics exist today. They are made of three different semiconductor alloys layered together. Sprayed onto a semiconductor wafer in a process called molecular-beam epitaxy—a bit like spray painting with individual elements—each layer is only a few microns thick. The layers capture different parts of the solar spectrum; light that gets through one layer is captured by the next.

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Scientists have found a way to wirelessly transmit electricity to a nearby moving object.

The method may have applications in transportation, medical devices, and more. If electric cars could recharge while driving down a highway, for example, it would virtually eliminate concerns about their range and lower their cost, perhaps making electricity the standard fuel for vehicles.

“In addition to advancing the wireless charging of vehicles and personal devices like cellphones, our new technology may untether robotics in manufacturing, which also are on the move,” says Shanhui Fan, a professor of electrical engineering at Stanford University and senior author of the study.

“We still need to significantly increase the amount of electricity being transferred to charge electric cars, but we may not need to push the distance too much more,” he says.

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Image: Open Water Power

Unpiloted underwater vehicles (UUVs) are used for a wide array of tasks, including exploring ship wreckage, mapping the ocean floor, and military applications. Now, a team from MIT has developed an aluminum-water power system that will allow UUVs to become safer, more durable, and have ten times more range compared to UUVs powered by lithium-ion batteries.

“Everything people want to do underwater should get a lot easier,” says Ian Salmon Mckay, co-inventor of the device. “We’re off to conquer the oceans.”

The aluminum-water power system is a direct response to lithium-ion batteries, which have a limited energy density causing service ships to chaperone UUVs while at sea, recharging the batteries when necessary. Additionally, UUV lithium-ion batteries have to be encased in expensive metal pressure vessels, making the battery both short-lived and pricey for use in UUVs.

This from MIT:

In contrast, [Open Water Power’s] power system is safer, cheaper, and longer-lasting. It consists of a alloyed aluminum, a cathode alloyed with a combination of elements (primarily nickel), and an alkaline electrolyte that’s positioned between the electrodes.

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A new study describes the mechanics behind an early key step in artificially activating carbon dioxide so that it can rearrange itself to become the liquid fuel ethanol.

Solving this chemical puzzle may one day lead to cleaner air and renewable fuel.

The scientists’ ultimate goal is to convert harmful carbon dioxide (CO2) in the atmosphere into beneficial liquid fuel. Currently, it is possible to make fuels out of CO2—plants do it all the time—but researchers are still trying to crack the problem of artificially producing the fuels at large enough scales to be useful.

Theorists at Caltech used quantum mechanics to predict what was happening at atomic scales, while experimentalists at the Department of Energy’s (DOE) Lawrence Berkeley National Lab (Berkeley Lab) used X-ray studies to analyze the steps of the chemical reaction.

“One of our tasks is to determine the exact sequence of steps for breaking apart water and CO2 into atoms and piecing them back together to form ethanol and oxygen,” says William Goddard professor of chemistry, materials science, and applied physics, who led the Caltech team. “With these new studies, we have better ideas about how to do that.”

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In an effort to increase security on airplanes, the U.S. government is considering expanding a ban on lithium-ion based devices from cabins of commercial flights, opting instead for passengers to transport laptops and other electronic devices in their checked luggage in the cargo department. However, statistics from the Federal Aviation Administration suggest that storing those devices in the cargo area could increase the risk of fires.

The FAA reports that batteries were responsible for nine airline fires in 2014. The number grew to 16 in 2015 and further to 31 in 2016. Most fires were able to be extinguished by passengers.
According to Homeland Security Secretary John Kelly, the U.S. government is considering expanding the ban to 71 additional airports.

(READ: “What’s Next for Batteries?” with Robert Kostecki.)

Mainstream concern regarding lithium-ion battery safety became widespread in 2016 when videos of hoverboards exploding began to emerge. Since then, news reports of smartphone and laptop batteries have emerged.

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Assuming that the deployment of carbon removal technology will outpace emissions and conquer global climate change is a poor substitute for taking action now, say researchers.

With the current pace of renewable energy deployment and emissions reductions efforts, the world is unlikely to achieve the Paris Climate Agreement’s goal of limiting global warming to 2 degrees Celsius above pre-industrial levels. This trend puts in doubt efforts to keep climate change damages from sea level rise, heat waves, drought, and flooding in check. Removing carbon dioxide from the atmosphere, also known as “negative emissions,” has been thought of as a potential method of fighting climate change.

In their new perspective published in the journal Science, however, researchers from Stanford University explain the risks of assuming carbon removal technologies can be deployed at a massive scale relatively quickly with low costs and limited side effects—with the future of the planet at stake.

“For any temperature limit, we’ve got a finite budget of how much heat-trapping gases we can put into the atmosphere. Relying on big future deployments of carbon removal technologies is like eating lots of dessert today, with great hopes for liposuction tomorrow,” says Chris Field, professor of biology and of earth system science and director of Stanford’s Woods Institute for the Environment.

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