New lithium-ion battery design that’s 2,000 times more powerful, recharges 1,000 times faster

Researchers at the University of Illinois at Urbana-Champaign have developed a new lithium-ion battery technology that is 2,000 times more powerful than comparable batteries. According to the researchers, this is not simply an evolutionary step in battery tech, “It’s a new enabling technology… it breaks the normal paradigms of energy sources. It’s allowing us to do different, new things.”

Currently, energy storage is all about trade-offs. You can have lots of power (watts), or lots of energy (watt-hours), but you can’t generally have both. Supercapacitors can release a massive amount of power, but only for a few seconds; fuel cells can store a vast amount of energy, but are limited in their peak power output. This a problem because most modern applications of bleeding-edge tech — smartphones, wearable computers, electric vehicles — require large amounts of power and energy. Lithium-ion batteries are currently the best solution for high-power-and-energy applications, but even the best li-ion battery designs demand that industrial designers and electronic engineers make serious trade-offs when creating a new device.

Which brings us neatly onto the University of Illinois’ battery, which has a higher power density than a supercapacitor, and yet comparable energy density to current nickel-zinc and lithium-ion batteries. According to the university’s press release, this new battery could allow for wireless devices to transmit their signals 30 times farther — or, perhaps more usefully, be equipped with a battery that’s 30 times smaller. If that wasn’t enough, this new battery is rechargeable – and can be charged 1,000 times faster than conventional li-ion batteries. In short, this is a dream battery. (See: DoE calls for a chemical battery with 5x capacity, within 5 years – can it be done?)

These huge advances stem from a brand new cathode and anode structure, pioneered by the University of Illinois researchers. In essence, a standard li-ion battery normally has a solid, two-dimensional anode made of graphite and a cathode made of a lithium salt. The new Illinois battery, on the other hand, has a porous, three-dimensional anode and cathode. To create this new electrode structure, the researchers build up a structure of polystyrene (Styrofoam) on a glass substrate, electrodeposit nickel onto the polystyrene, and then electrodeposit nickel-tin onto the anode and manganese dioxide onto the cathode. The diagram above does a good job of explaining the process.

The end result is that these porous electrodes have a massive surface area, allowing for more chemical reactions to take place in a given space, ultimately providing a massive boost to discharge speed (power output) and charging. So far, the researchers have used this tech to create a button-sized microbattery, and you can see in the graph below how well their battery compares to a conventional Sony CR1620 button cell. The energy density is slightly lower, but the power density is 2,000 times greater. On the opposite end of the bleeding-edge spectrum — increased energy density, but lower power density — thenIBM’s lithium-air battery currently leads the pack.

Energy density vs. power density for a variety of battery technologies, including University of Illinois’ new microstructured anode/cathode li-ion battery

In real-world use, this tech will probably be used to equip consumer devices with batteries that are much smaller and lighter — imagine a smartphone with a battery the thickness of a credit card, which can be recharged in a few seconds. There will also be plenty of applications outside the consumer space, in high-powered settings such as lasers and medical devices, and other areas that normally use supercapacitors, such as Formula 1 cars and fast-recharge power tools. For this to occur, though, the University of Illinois will first have to prove that their technology scales to larger battery sizes, and that the production process isn’t prohibitively expensive for commercial production. Here’s hoping.

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Single-Layer Tin Could Go Beyond Graphene, Conducting Electricity with 100% Efficiency

2D Tin Could Be Next Super Material, Say Theorists

A single layer of tin atoms could be the world’s first material to conduct electricity with 100% efficiency at the temperatures that computer chips operate, according to a team of theoretical physicists led by researchers from the U.S. department of energy’s (DOE) SLAC national accelerator naboratory and Stanford University. Researchers call the new material “stanene”, combining the Latin name for tin (stannum) with the suffix used in graphene, another innovative single-layer material.

"Stanene could increase the speed and lower the power needs of future generations of computer chips, if our prediction is confirmed by experiments that are underway in several laboratories around the world," said the team leader, Shoucheng Zhang, a physics professor at Stanford and the Stanford Institute for Materials and Energy Sciences (SIMES), a joint institute with SLAC.

The Path to Stanene

For the past decade, Shoucheng Zhang and colleagues have been calculating and predicting the electronic properties of a special class of materials known as topological insulators, which conduct electricity only on their outside edges or surfaces and not through their interiors. When topological insulators are just one atom thick, their edges conduct electricity with 100% efficiency. These unusual properties result from complex interactions between the electrons and nuclei of heavy atoms in the materials.

“The magic of topological insulators is that by their very nature, they force electrons to move in defined lanes without any speed limit, like the German autobahn. As long as they’re on the freeway – the edges or surfaces – the electrons will travel without resistance,” said Mr. Zhang.

In 2006 and 2009, Mr. Zhang’s group predicted that mercury telluride and several combinations of bismuth, antimony, selenium and tellurium should be topological insulators, and they were soon proven right in experiments performed by others. But none of those materials is a perfect conductor of electricity at room temperature, limiting their potential for commercial applications.

Earlier this year, visiting scientist Yong Xu, who is now at Tsinghua University in Beijing, collaborated with Zhang’s group to consider the properties of a single layer of pure tin.

“We knew we should be looking at elements in the lower-right portion of the periodic table. All previous topological insulators have involved the heavy and electron-rich elements located there,” said Mr. Xu.

^{Adding fluorine atoms (yellow) to a single layer of tin atoms (grey) should allow a predicted new material, stanene, to conduct electricity perfectly along its edges (blue and red arrows) at temperatures up to 100°C (212°Fahrenheit).}

Their calculations indicated that a single layer of tin would be a topological insulator at and above room temperature, and that adding fluorine atoms to the tin would extend its operating range to at least 100°C (212°Fahrenheit).

Ultimately a Substitute for Silicon?

Mr. Zhang said the first application for this stanene-fluorine combination could be in wiring that connects the many sections of a microprocessor, allowing electrons to flow as freely as cars on a highway. Traffic congestion would still occur at on- and off-ramps made of conventional conductors, he said. But stanene wiring should significantly reduce the power consumption and heat production of microprocessors.

Manufacturing challenges include ensuring that only a single layer of tin is deposited and keeping that single layer intact during high-temperature chip-making processes.

“Eventually, we can imagine stanene being used for many more circuit structures, including replacing silicon in the hearts of transistors. Someday we might even call this area Tin Valley rather than Silicon Valley,” said Mr. Zhang.

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Qualcomm Unleashes High-End Mobile Application Processor with 4K Video Support.

Qualcomm Introduces Snapdragon 805 System-on-Chip 

Four Cores, New Graphics, Quad-Channel Memory, New Technologies

Qualcomm, the world’s largest developer of mobile application processors, a new Snapdragon 800-series system-on-chip that features vastly improved performance and capabilities. The new processor is among the world’s first SoCs to support video in ultra-high-definition (UHD) resolutions and formats. Qualcomm Snapdragon 805 application processor promises to become the world’s fastest mobile chip to date.

Qualcomm Snapdragon 805 features four ARM Krait 450 cores designed to work at 2.50GHz; Adreno 420 graphics processing engine that supports hardware tessellation and geometry shaders as well as provides 40% higher performance than the predecessor; quad-channel LPDDR3 memory controller with up to 25.6GB/s bandwidth; and a number of other innovations, such as new special-purpose multimedia accelerators, enhanced dual camera image signal processors (ISPs) and so on. The chip does not feature baseband capabilities, but supports WiFi 802.11n/ac (2.4 and 5GHz) and Bluetooth 4.0.

Qualcomm Snapdragon 805 can be paired with Qualcomm Gobi MDM9x25 or the Gobi MDM9x35 modem, powering superior seamless connected mobile experiences. The Gobi MDM9x25 chipset announced in February 2013 has seen significant adoption as the first embedded, mobile computing solution to support 4G/LTE carrier aggregation and LTE Category 4 with superior peak data rates of up to 150Mb/s. Additionally, Qualcomm’s most advanced Wi-Fi for mobile, 2-stream dual-band Qualcomm VIVE 802.11ac, enables wireless 4K video streaming and other media-intensive applications. With a low-power PCIe interface to the QCA6174, tablets and high-end smartphones can take advantage of faster mobile Wi-Fi performance (over 600Mb/s), extended operating range and concurrent Bluetooth connections, with minimal impact on battery life.

“Using a smartphone or tablet powered by Snapdragon 805 processor is like having an UltraHD home theater in your pocket, with 4K video, imaging and graphics, all built for mobile. We are delivering the mobile industry’s first truly end-to-end Ultra HD solution, and coupled with our industry leading Gobi LTE modems and RF transceivers, streaming and watching content at 4K resolution will finally be possible,” said Murthy Renduchintala, executive vice president, Qualcomm Technologies.

The Snapdragon 805 processor is sampling now and expected to be available in commercial devices by the first half of 2014.

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Synaptic Transistor Learns While It Computes

Our brains have upwards of 86 billion neurons, connected by synapses that not only complete myriad logic circuits; they continuously adapt to stimuli, strengthening some connections while weakening others. We call that process learning, and it enables the kind of rapid, highly efficient computational processes that put Siri and Blue Gene to shame.
Materials scientists at the Harvard School of Engineering and Applied Sciences (SEAS) have now created a new type of transistor that mimics the behavior of a synapse. The novel device simultaneously modulates the flow of information in a circuit and physically adapts to changing signals.

Exploiting unusual properties in modern materials, the synaptic transistor could mark the beginning of a new kind of artificial intelligence: one embedded not in smart algorithms but in the very architecture of a computer. The findings appear in Nature Communications.

"There's extraordinary interest in building energy-efficient electronics these days," says principal investigator Shriram Ramanathan, associate professor of materials science at Harvard SEAS. "Historically, people have been focused on speed, but with speed comes the penalty of power dissipation. With electronics becoming more and more powerful and ubiquitous, you could have a huge impact by cutting down the amount of energy they consume."

The human mind, for all its phenomenal computing power, runs on roughly 20 Watts of energy (less than a household light bulb), so it offers a natural model for engineers.
"The transistor we've demonstrated is really an analog to the synapse in our brains," says co-lead author Jian Shi, a postdoctoral fellow at SEAS. "Each time a neuron initiates an action and another neuron reacts, the synapse between them increases the strength of its connection. And the faster the neurons spike each time, the stronger the synaptic connection. Essentially, it memorizes the action between the neurons."

In principle, a system integrating millions of tiny synaptic transistors and neuron terminals could take parallel computing into a new era of ultra-efficient high performance.
While calcium ions and receptors effect a change in a biological synapse, the artificial version achieves the same plasticity with oxygen ions. When a voltage is applied, these ions slip in and out of the crystal lattice of a very thin (80-nanometer) film of samarium nickelate, which acts as the synapse channel between two platinum "axon" and "dendrite" terminals. The varying concentration of ions in the nickelate raises or lowers its conductance — that is, its ability to carry information on an electrical current — and, just as in a natural synapse, the strength of the connection depends on the time delay in the electrical signal.

Structurally, the device consists of the nickelate semiconductor sandwiched between two platinum electrodes and adjacent to a small pocket of ionic liquid. An external circuit multiplexer converts the time delay into a magnitude of voltage which it applies to the ionic liquid, creating an electric field that either drives ions into the nickelate or removes them. The entire device, just a few hundred microns long, is embedded in a silicon chip.
The synaptic transistor offers several immediate advantages over traditional silicon transistors. For a start, it is not restricted to the binary system of ones and zeros.

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