Researchers at the Massachusetts Institute of Technology, led by Associate Professor Yang Shao-Horn, in collaboration with Professor Paula Hammond, have found that using carbon nanotubes for one of the battery’s electrodes produced up to a tenfold increase in the amount of power that a lithiun-ion battery could deliver from a given weight of material.

In the new battery electrode, carbon nanotubes are "electrostatically self-assembled" into a tightly bound structure that is porous at the nanometer scale. The carbon nanotubes have many oxygen groups on their surfaces, which can store a large number of lithium ions. This enables carbon nanotubes to serve as the positive electrode in lithium batteries.

Carbon nanotubes are a form of pure carbon in which sheets of carbon atoms are rolled up into tiny tubes. Normally, carbon nanotubes on a surface tend to clump together in bundles, leaving few exposed surfaces to undergo reactions. The "electrostatic self-assembly" process incorporates organic molecules on the nanotubes and they assemble in a way that has a many exposed surfaces.

The new batteries have some of the advantages of both capacitors and conventional lithium batteries. Like capacitors, they can produce very high power outputs in short bursts - but the energy output for a given weight of the new electrode material is five times greater than for conventional capacitors. Like conventional batteries, they can provide lower power steadily for long periods - but the total power delivery rate with the new batteries is10  times that of lithium-ion batteries

In addition to their high power output, the carbon nanotube electrodes showed very good stability over time. After 1,000 cycles of charging and discharging a test battery, there was no detectable change in the material’s performance.

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Physicists at Boston College have developed a nano-scale solar cell, inspired by the coaxial cable, which offers greater efficiency than any previously designed nanotech thin film solar cell

A limiting factor in making highly efficient thin film sollar cells is the need for the cells to be thick enough to collect a sufficient amount of light, yet thin enough to extract current. The Boston College researchers have found a way to resolve this challenge using a coaxial design for cells constructed with amorphous, rather than crystalline, silicon

The researchers say that the nanocoax cells yield power conversion efficiency in excess of 8 percent, which is higher than any nanostructured thin film solar cell to date.

"Many groups around the world are working on nanowire-type solar cells, most using crystalline semiconductors," said Michael Naughton, a professor of physics at Boston College. "This nanocoax cell architecture, on the other hand, does not require crystalline materials, and therefore offers promise for lower-cost solar power with ultrathin absorbers. With continued optimization, efficiencies beyond anything achieved in conventional planar architectures may be possible, while using smaller quantities of less costly material."

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A team of MIT Biological Material Group researchers has developed a way of using a modified virus as a kind of biological scaffold that can assemble the nanoscale components needed to split a water molecule into hydrogen and oxygen atoms.

During photosynthesis in plant cells, natural pigments absorb sunlight, while catalysts then promote the use of that energy to split water into its component hydrogen and oxygen molecules.

The MIT team, led by Professor Angela Belcher, engineered a common, harmless bacterial virus called M13 so that it would attract and bind with molecules of  a biological pigment (in this case zinc porphyrins) and a catalyst (iridium oxide). The virus acts as a kind of scaffolding, causing the pigments and catalysts to line up with the right spacing to trigger the water-splitting reaction.

Using the virus to make the system assemble itself improves the efficiency of the oxygen production fourfold.
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Chih-hung Chang, an associate professor of chemical engineering at Oregon State University, is developing a new approach to solar energy which he believes may dramatically lower their cost while reducing waste and environmental impacts.

Currently, thin-film solar cells are made using methods such as sputtering, evaporation and electrodeposition. Those processes can be time-consuming, or require expensive vacuum systems or exotic chemicals that raise production costs.

An alternative approch is to use chemical bath deposition. This is a low-cost deposition technique that was developed more than a century ago. The problem is that changes in the growth solution over time make it difficult to control thickness. The depletion of reactants also limits the achievable thickness.

The technology developed at Oregon State University to deposit "nanostructure films" on various surfaces in a continuous flow microreactor makes the use of this process more commercially practical.

"We’ve now demonstrated that this system can produce thin-film solar absorbers on a glass substrate in a short time, and that’s quite significant," said Chih-hung Chang. "That’s the first time this has been done with this new technique."

Thin-film solar cells produced by applications such as this could ultimately be used in the creation of solar energy roofing systems. "If we could produce roofing products that cost-effectively produced solar energy at the same time, that would be a game changer," Chang said. "Thin film solar cells are one way that might work. All solar applications are ultimately a function of efficiency, cost and environmental safety, and these products might offer all of that."

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Researchers at the Fraunhofer Institute in Bremen have developed a paint which they say improves the efficiency of ships, aircraft and wind turbines by reducing their flow resistance.

They have achieved this by modelling the paint’s structure on the scales of fast-swimnming sharks which evolved in a manner that significantly diminishes drag.

Carribean Reef Sharl (Image by Albert Kok via Wikimedia)

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Researchers led by Jongyoon Han at the Massachusetts Institute of Technology have developed a nanotechnology device able to extract salt from seawater, paving the way for small-scale desalination for drought regions and disaster zones.

Conventional desalination works by forcing water through a membrane to remove molecules of salt. This process requires a lot of energy and maintenance of the membrane. As a result, conventional desalination plants are big and expensive.

The new nanotechnology device works by a process called "ion concentration polarisation". A current of charged ions is passed through an ion-selective membrane. This creates a force which moves charged ions and particles in the water away from the membrane. Salt ions and any impurities get pushed to the side. This saltier water is then drawn off, leaving only de-salinated water.

The energy efficiency of the process is comparable to a large-scale desalination plant but small to medium scale, and even battery-power, desalination devices are feasible.

The costs of scaling up the process have not yet been determined but overheads should be lower than in conventional plants because gravity, rather than pumps, can be used to feed the water and because there is less of a problem with membrane fouling.

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Scientists at the University of East Anglia, led by Professor Thomas Nann, have reported a breakthrough in the production of hydrogen from water using the energy of sunlight.

Hydrogen is obtained from water by electrolysis. But, because the efficiency of the process is typically only between 20 and 40%, using a solar photovoltaic process to generate the necessary electricity uses more energy than is stored in the hydrogen which is produced.

The East Anglia team have found a way to increase the efficiency of the process to 60% or more, which could make it cost-effective.

They achieved this by using gold electrodes coated with nanoclusters of indium phosphide, which are up to 400 times more likely to absorb incoming photons than current electrodes. The nanoparticle-coated  electrodes are also much more durable than alternatives.

The scientists are now investigating the possibility of using alternative, cheaper materials than gold for the electrodes.

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Engineers at Princeton University, led by Professor Michael McAlpine, have developed a power-generating rubber film which could harness natural body movements such as breathing and walking, to power pacemakers, mobile phones and other electronic devices. For example, shoes made of the material could harvest the pounding of walking and running to power mobile electrical devices.

The material is composed of ceramic nanoribbons embedded into silicone rubber sheets. The nanoribbons are made of lead zirconate titanate, a ceramic material that generates an electrical voltage when pressure is applied to it  The silicone sheets, with embedded nanoribbons,  generate electricity when flexed and are highly efficient at converting mechanical energy to electrical energy.

Because the silicone is biocompatible (it is already used for cosmetic implants and medical devices), it can be implanted in the body to power medical devices. Placed against the lungs, sheets of the material could use breathing motions to power pacemakers, obviating the current need for surgical replacement of the batteries to power the devices.

As well as generating electricity when it is flexed, the material flexes when electrical current is applied to it. This opens the door to other kinds of applications, such as use for microsurgical devices.

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Scientists at the US Department of Energy’s Pacific Northwest National Laboratory have developed a new method for capturing significantly more heat from low-temperature geothermal resources. A technical and economic analysis conducted by the Massachusetts Institute of Technology has estimated that enhanced geothermal systems could provide 10 percent of the United States’ overall electrical generating capacity by 2050.

Their technique uses the rapid expansion and contraction capabilities of a new liquid, called a biphasic fluid, developed by the research team. To improve efficiency, the scientists have added nanostructured metal-organic heat carriers, which boost the power generation capacity to near that of a conventional steam cycle.

The researchers expect to have a functioning prototype generating electricity by the end of the year.

Ironically, development of the technique came out of research aimed at finding nanomaterials for capturing carbon dioxide from buring fossil fuels.

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KLD Energy Technologies, an electric engine company based in Texas, has developed an new electric motor which it believes will overcome the disappointing performance and high price of electric scooters produced to date.

The company has built an engine using nano-crystalline composite materials, which it says is ten times more efficient than traditional iron core motors. The cost of magnets made from the material has dropped from $4 to $5 ten years ago to around 20 cents today.

KLD has contracted with Sufat Co Ltd, Vietnam’s largest scooter manufacturer, to produce scooters using its motor.  Sufat is planning to build 50,000 of the scooters next year.

The companies say that the scooters will have a top speed of 125 kilometres per hour and will accelerate to 80 kilometres per hour in less than 10 seconds. They will be able to take a variety of bateries and their range will depend on the batery chosen.

Scooters with comparable performance currently cost around $US11,000. KLD expects its new scooters to sell for about $US1,500.

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