Instead of batteries, a new cell phone harvests the few microwatts of power it needs from a different source: ambient radio signals or light.

Researchers were also able to make Skype calls using the battery-free phone, demonstrating that the prototype—made of commercial, off-the-shelf components—can receive and transmit speech and communicate with a base station.

“We’ve built what we believe is the first functioning cell phone that consumes almost zero power,” says Shyam Gollakota, an associate professor of computer science & engineering at the University of Washington and coauthor of the paper.

“To achieve the really, really low power consumption that you need to run a phone by harvesting energy from the environment, we had to fundamentally rethink how these devices are designed.”

Researchers eliminated a power-hungry step in most modern cellular transmissions—converting analog signals that convey sound into digital data that a phone can understand. This process consumes so much energy that it’s been impossible to design a phone that can rely on ambient power sources.

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In an effort to develop a more affordable, plentiful alternative to lithium-ion batteries, researchers from Purdue University are pursuing rechargeable potassium based batteries, demonstrating a way to derive carbon for battery electrodes from old tires.

“With the growth of rechargeable batteries for electronic devices, electric vehicles and power grid applications, there has been growing concern about the sustainability and cost of lithium,” says Vilas G. Pol, an associate professor in the Davidson School of Chemical Engineering at Purdue University and former member of ECS. “In the last decade, there has been rapid progress in the investigation of metal-ion batteries beyond lithium, such as sodium and potassium.”

Researchers in the field believe that potassium based batteries show potential for large-scale grid storage due to their low cost and the abundance of the element itself.

“The intermittent energy generated from solar and wind requires new energy storage systems for the grid,” Pol says. “However, the limited global availability of lithium resources and high cost of extraction hinder the application of lithium-ion batteries for such large-scale energy storage. This demands alternative energy storage devices that are based on earth-abundant elements.”

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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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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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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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In 2016, Solar Impulse 2 was the first solar-powered electrified aircraft to make a trip around the world. But that aircraft wasn’t the first to partake in electric flight, nor will it be the last.

Since the development of the battery-powered Militky MB-E1 in the early 1970s, there has been excitement surrounding the promise of an electric aircraft. However, many of the concepts being floated around by aerospace companies assume huge improvements in current battery technology.

The problem? According to a recently published article in Wired, current battery technology does not offer the power-to-weight ratio needed to make battery-powered planes feasible.

But battery technology has taken leaps over the past few years. Energy storage devices are become more efficient and lighter simultaneously. But how long will it take to be able to pack enough energy into a device while remaining light enough to glide through the sky?

“There’s already been a lot of progress,” Venkat Srinivasan, battery expert with Argonne National Lab, told Wired. “It’s not the same ballpark as Moore’s law progress because it’s chemistry, not electronics, but it’s still very good.”

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The electric vehicle market continues to build momentum every year, with consumers around the world growing more interested. But in order for EVs to pave the way for the future of transportation, more efficient, longer-lasting batteries will need to be developed.

That’s where ECS member Jeff Dahn, leader of Tesla’s researcher partnership through his Dalhousie University research group, comes in. Recently, Dahn and his team unveiled new chemistry that could increase battery lifecycle at high voltages without significant degradation.

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The consumer demand for seamless, integrated technology is on the rise, and with it grows the Internet of Things, which is expected to grow to a multitrillion-dollar market by 2020. But in order to develop a fully integrated electronic network, flexible, lightweight, rechargeable power sources will be required.

A team of researchers from Ulsan National Institute of Science and Technology is looking to address that issue, developing inkjet-printed batteries that can be modified to fit devices of any shape and size. The team reports that the newly developed inks can be printed onto paper to create a new class of printed supercapacitors.

(READ: Rise of Cyber Attacks: Security in the Digital Age)

This from Ulsan National Institute of Science and Technology:

The process involves using a conventional inkjet printer to print a preparatory coating—a ‘wood cellulose-based nanomat’—onto a normal piece of A4 paper. Next, an ink of activated carbon and single-walled nanotubes is printed onto the nanomat, followed by an ink made of silver nanowires in water. These two inks form the electrodes. Finally, an electrolyte ink—formed of an ionic liquid mixed with a polymer that changes its properties when exposed to ultraviolet light—is printed on top of the electrodes. The inks are exposed at various stages to ultraviolet irradiation and finally the whole assembly is sealed onto the piece of paper with an adhesive film.

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Lithium-ion batteries power a vast majority of the world’s portable electronics, but the magnification of recent safety incidents have some looking for new ways to keep battery-related hazards at bay. The U.S. Navy is one of those groups, with chemists in the U.S. Naval Research Laboratory (NRL) unveiling a new battery, which they say is both safe and rechargeable for applications such as electric vehicles and ships.

“We keep having too many catastrophic news stories of lithium-ion batteries smoking, catching fire, exploding,” says Debra Rolison, head of NRL’s advanced electrochemical materials section and co-author of the recently published paper. “There’ve been military platforms that have suffered severe damage because of lithium-ion battery fires.”

Once example of such damage came in 2008, when an explosion and fire caused by a lithium-ion battery damaged the Advanced SEAL Delivery Vehicle 1 at its base in Pearl Harbor.

While generally safe when manufactured properly, lithium-ion batteries host an organic liquid which is flammable if the battery or device gets too hot.

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Like all things, batteries have a finite lifespan. As batteries get older and efficiency decreases, they enter what researchers call “capacity fade,” which occurs when the amount of charge your battery could once hold begins to decrease with repeated use.

But what if researchers could reduce this capacity fade?

That’s what researchers from Argonne National Laboratory are aiming to do, as demonstrated in their open access paper, “Transition Metal Dissolution, Ion Migration, Electrocatalytic Reduction and Capacity Loss in Lithium-Ion Full Cells,” which was recently published in the Journal of The Electrochemical Society.

The capacity of a lithium-ion battery directly correlates to the amount of lithium ions that can be shuttled back and forth as the device is charged and discharged. Transition metal ions make this shuttling possible, but as the battery is cycled, some of those ions get stripped out of the cathode material and end up at the battery’s anode.

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