New Developments June 2017

Graphene electrodes offer new functionalities in molecular electronic nanodevices The field of nanoscale molecular electronics aims to exploit individual molecules as the building blocks for electronic devices, to improve functionality and enable developers to achieve an unprecedented level of device miniaturization and control. The main obstacle hindering progress in this field is the absence of stable contacts between the molecules and metals used that can both operate at room temperature and provide reproducible results. Graphene possesses not only excellent mechanical stability, but also exceptionally high electronic and thermal conductive properties, making the emerging 2D material very attractive for a range of possible applications in molecular electronics. "We find that by carefully designing the chemical contact of molecules to graphene-based materials, we can tune their functionality," said Dr Rungger. "Our single-molecule diodes showed that the rectification direction of electric current can be indeed switched by changing the nature of chemical contact of each molecule," added Dr Rudnev. The findings will also help researchers working in electro-catalysis and energy conversion research design graphene/molecule interfaces in their experimental systems to improve the efficiency of the catalyst or device.

Economists find improved electricity storage leads to innovation, efficiency Lazkano notes that the findings indicate that improved energy storage, while addressing a basic problem of renewable energy, does not necessarily spur the replacement of fossil fuels by renewable sources, as many had thought. Lazkano says that fossil fuel plants, particularly coal-fired plants, must pay a significant cost when ramping up production to meet peak demands. By storing energy, those plants can dampen the swings in production and mitigate the ramping costs. "This means that the mere existence of storage technology, which benefits both renewable and fossil fuel power generation, doesn't necessarily lead to lower carbon emissions from electricity generation." The authors say policy measures are needed to increase the use of renewable energy and prevent increased use of "dirtier" fuels such as coal. However, they note that storage offers electricity system operators better ways to combine conventional and renewable electricity.

Saving Lives and Money: The Potential of Solar to Replace Coal By swapping solar photovoltaics for coal, the US could prevent 51,999 premature deaths a year, potentially making as much as $2.5 million for each life saved. A team has calculated US deaths per kilowatt hour per year for coal related to air pollution-related diseases associated with burning coal. Tens of thousands of Americans die prematurely each year from air pollution-related diseases associated with burning coal. By transitioning to solar photovoltaics (PV) in the US, up to 51,999 American lives would be saved at $1.1 million invested per life. To fully replace all the coal production in the US with solar PV, it would take 755 gigawatts -- a significant increase compared to the 22.7 gigawatts of solar installed in the US currently. The total cost of installing that much solar power totals $1.5 trillion, but that investment is figured into Pearce and Prehoda's calculations, and is a profitable investment.

IVYS Simple Fuel Station Offers Homemade Hydrogen For $250,000 IVYS President and CEO Darryl Pollica told InsideEVs at the MovinOn sustainable mobility conference in Montreal today that the Simple Fuel station is better for fleet use than a commercial retailer. That’s because the biggest capacity station can only make – through electrolysis – 10 kilograms of 700-bar H2 a day. That’s enough for a lot of hydrogen forklifts, but only around two hydrogen-powered passenger cars. The Honda Clarity, for example, needs 5.46 kg for a full tank. The hydrogen production options are either 5 or 10 kilograms a day, and eitehr 350 or 700 bar pressure. The dispense rate is about 10 minutes per kilogram, but it will vary depending on the kind of vehicle sucking down the fuel.

High-performance tin anode for Li-ion batteries The structured electrode delivers a capacity of 795 mAh gSn−1 (Sn basis) and 1812 mAh cmel-3 (electrode basis). The long-term cycling shows only 0.04% capacity decay per cycle. The route we developed in this work could also be applied to other high capacity materials (such as Si, Sb, MnO, Co3O4, SnO2, etc), which need extra space and good electron conducting pathway.

'Instantly rechargeable' battery could change the future of electric and hybrid automobiles "The biggest challenge for industry is to extend the life of a battery's charge and the infrastructure needed to actually charge the vehicle. The greatest hurdle for drivers is the time commitment to keeping their cars fully charged." "Ifbattery is developing an energy storage system that would enable drivers to fill up their electric or hybrid vehicles with fluid electrolytes to re-energize spent battery fluids much like refueling their gas tanks." The spent battery fluids or electrolyte could be collected and taken to a solar farm, wind turbine installation or hydroelectric plant for re-charging. "Instead of refining petroleum, the refiners would reprocess spent electrolytes and instead of dispensing gas, the fueling stations would dispense a water and ethanol or methanol solution as fluid electrolytes to power vehicles," Cushman said. "Users would be able to drop off the spent electrolytes at gas stations, which would then be sent in bulk to solar farms, wind turbine installations or hydroelectric plants for reconstitution or re-charging into the viable electrolyte and reused many times. It is believed that our technology could be nearly 'drop-in' ready for most of the underground piping system, rail and truck delivery system, gas stations and refineries." "Other flow batteries exist, but we are the first to remove membranes which reduces costs and extends battery life," Mueterthies said. "Membrane fouling can limit the number of recharge cycles and is a known contributor to many battery fires," Cushman said. "Ifbattery's components are safe enough to be stored in a family home, are stable enough to meet major production and distribution requirements and are cost effective."

Switching beans for beef could get the US 75% of the way to emissions reduction targets Replacing beef with beans could achieve up to 75 percent of the emissions reduction that the United States needs to reach by 2020, claims a group of American researchers. Practically speaking, this huge leap could be accomplished simply by replacing daily beef portions with 188 grams of beans. The LCA showed that one kilogram of beef produces an estimated 40.2 kilograms of carbon dioxide equivalent (or CO2e, which describes what the climate impact of a greenhouse gas would be if it were CO2). That was compared to just 0.8 kilograms of CO2e for each kilo of beans. Switching beans for beef would save between 209 and 334 million tonnes of CO2e by 2020 in the United States. That’s between 47 percent and 75 percent of the total greenhouse gas reduction needed to reach the country’s 2020 emissions target. It would also free up 42 percent of US cropland that’s used to farm crops for cattle feed.

High Cost of Cobalt Pushes Up Prices of Lithium Batteries for IT Devices by More Than 15% Between First and Second Quarter Compared against the average of the January to March period, prices of lithium batteries for IT devices have already risen by more than 15%. “Despite having physical size limitations, cylindrical cells are very in-demand for mid-power applications, which include products such as electric bicycles and gaming notebooks. Furthermore, cylindrical cells are still the best choice for situations that require C-rate (>1C). As battery suppliers allocate more their production capacity to meet the growing demand for batteries powering xEVs (plug-in vehicles), the IT battery market has actually experienced a shortage of cylindrical cells.” Prismatic cells were initially positioned to supplant polymer cells in the IT battery market. However, branded device vendors have been hesitant to use prismatic cells because of the weight consideration. The penetration rate of prismatic cells in the IT battery market therefore is not expected to rise significantly in the short term. Polymer cells will likely hold on to their mainstream status in the IT battery market in the next five years, enjoying steady growth in both demand and supply.

Low cost, scalable water splitting fuels the future hydrogen economy The current industrial method of producing hydrogen -- steam reforming of methane -- results in the release of CO2 into the atmosphere. Other methods utilize waste heat, such as from advanced nuclear power plants, or concentrated solar power, both of which face technical challenges to becoming commercially feasible. Another industrial process uses platinum as the catalyst to drive the water-splitting process. Although platinum is a near-perfect catalyst, it is also expensive. A cheaper catalyst could make hydrogen a reasonable alternative to fossil fuels in transportation, and power fuel cells for energy storage applications. "Molybdenum disulfide (MoS2) has been predicted as a possible replacement for platinum, because the Gibbs free energy for hydrogen absorption is close to zero.”  The lower the Gibbs free energy, the less external energy has to be applied to produce a chemical reaction. In its stable phase, MoS2 is a semiconductor, which limits its ability to conduct electrons. To get around that problem, the team added reduced graphene oxide, a highly conducting form of carbon. Then, to further decrease the free energy, they alloyed the MoS2 with tungsten to create a thin film with alternating graphene and tungsten-molybdenum disulfide layers. The addition of tungsten lowers the electrical voltage required to split water by half, from 200 millivolts with pure MoS2, to 96 millivolts with the tungsten-molybdenum alloy. "What happens in these alloys is an exquisite overlap of orbitals which makes the reaction more efficient. This is not observed in the pure components. It is an example where the hybrid is better than the pure components."

What's powering your devices? A study in the journal Energy Policy that shows many Americans would prefer to power their homes with wind, solar and other forms of renewable energy if given the option. "Our work shows that U.S. consumers, regardless of political standing, age, or gender, want to use more renewable energy and less fossil fuels." They surveyed 234 U.S. consumers online to determine their interest in two hypothetical apps that would help them either to lower their monthly power bills or to use more electricity generated by renewables. Overall, respondents were equally interested in reducing their carbon emissions and saving money, the researchers found. If consumers knew that during the day their energy mix was 30 percent renewables, and at night it was 100 percent coal, then they might well run their dishwasher in the morning when the sun is up instead of when they go to bed. We'd eventually like to link our app with smart home devices so that people can program their appliances to automatically run when there are more renewables in use on the grid.

New ultrathin material for splitting water could make hydrogen production cheaper Chemists have invented a new, cheap catalyst for splitting water with an electrical current to efficiently produce clean hydrogen fuel. Splitting water usually requires two different catalysts, but this catalyst can drive both of the reactions required to separate water into oxygen and hydrogen. The technology is based on the creation of ultrathin slices of porous metal-organic complex materials coated onto a foam electrode. The catalysts developed at UNSW are made of abundant, non-precious metals like nickel, iron and copper. They belong to a family of versatile porous materials called metal organic frameworks, which have a wide variety of other potential applications. Until now, metal-organic frameworks were considered poor conductors and not very useful for electrochemical reactions. Conventionally, they are made in the form of bulk powders, with their catalytic sites deeply embedded inside the pores of the material, where it is difficult for the water to reach. By creating nanometre-thick arrays of metal-organic frameworks, Zhao's team was able to expose the pores and increase the surface area for electrical contact with the water.

Molecular system for artificial photosynthesis A molecular system for artificial photosynthesis is designed to mimic key functions of the photosynthetic center in green plants -- light absorption, charge separation, and catalysis -- to convert solar energy into chemical energy stored by hydrogen fuel. Photosynthesis in green plants converts solar energy to stored chemical energy by transforming atmospheric carbon dioxide and water into sugar molecules that fuel plant growth. Scientists have been trying to artificially replicate this energy conversion process, with the objective of producing environmentally friendly and sustainable fuels, such as hydrogen and methanol. Now, chemists from the U.S. Department of Energy's (DOE) Brookhaven National Laboratory and Virginia Tech have designed two photocatalysts (materials that accelerate chemical reactions upon absorbing light) that incorporate individual components specialized for light absorption, charge separation, or catalysis into a single "supramolecule." In both molecular systems, multiple light-harvesting centers made of ruthenium (Ru) metal ions are connected to a single catalytic center made of rhodium (Rh) metal ions through a bridging molecule that promotes electron transfer from the Ru centers to the Rh catalyst, where hydrogen is produced.

Batteries from scrap metal Chinese scientists have made good use of waste while finding an innovative solution to a technical problem by transforming rusty stainless steel mesh into electrodes with outstanding electrochemical properties that make them ideal for potassium-ion batteries. Lithium ion batteries are based on the displacement of lithium ions. While charging, the ions move toward the graphite electrode, where they are stored between the layers of carbon. When discharging, they are released. However, lithium is expensive and reserves are limited. Sodium ion batteries have been explored as an alternative. "Potassium ions are just as inexpensive and readily available as sodium, and potassium ion batteries would be superior from the electric aspect," reports Xin-Bo Zhang. "However, the significantly larger radius of the potassium ions has posed a problem. Repeated storage and release of these ions destabilizes the materials currently used in electrodes." The metal from stainless steel mesh from filters and sieves can be reclaimed in a furnace, but this process requires a great deal of money, time, and energy, as well as producing emissions. Says Zhang: "Conversion into electrodes could develop into a more ecologically and economically sensible form of recycling." The corroded mesh is dipped into a solution of potassium ferrocyanide (yellow prussiate of potash, known as a fining agent for wine). This dissolves iron, chromium, and nickel ions out of the rust layer. These combine with ferricyanide ions into the complex salt known as Prussian blue, a dark blue pigment that is deposited onto the surface of the mesh as scaffold-like nanocubes. Potassium ions can easily and rapidly be stored in and released from these structures. The researchers then use a dip-coating process to deposit a layer of graphene oxide (oxidized graphite layers). This layer nestles tightly onto the nanocubes. Subsequent reduction converts the graphene oxide to reduced graphene oxide (RGO), which consists of layers of graphite with isolated oxygen atoms. Zhang explains, "the RGO coating inhibits clumping and detachment of the active material. At the same time, it significantly increases the conductivity and opens ultrafast electron-transport pathways."

Scientists unveil first printable, stable perovskite solar cell good for 10K hours They designed a hybrid 2D/3D perovskite solar cell. The 2D perovskite serves as a protective window to guard against moisture, so the 3D perovskite can generate electricity. The team built 10 by 10 centimeters squared solar panels, with what the university described as a fully printable industrial-scale process. The hybrid 2D/3D perovskite solar cells are resistant to oxygen and water, while still able to transport electrical charges. They absorb light from the whole visible spectrum. The efficiency isn’t great yet – just 11.2 percent. But the university noted that efficiency was constant for over 10,000 hours, with zero loss in performance.

Losing sleep over climate change Researchers show that unusually warm nights can harm human sleep and that the poor and elderly are most affected. Rising temperatures will make sleep loss more severe. According to their findings, if climate change is not addressed, temperatures in 2050 could cost people in the United States millions of additional nights of insufficient sleep per year. By 2099, the figure could rise by several hundred million more nights of lost sleep annually. "Sleep has been well-established by other researchers as a critical component of human health. Too little sleep can make a person more susceptible to disease and chronic illness, and it can harm psychological well-being and cognitive functioning," Obradovich said. "What our study shows is not only that ambient temperature can play a role in disrupting sleep but also that climate change might make the situation worse by driving up rates of sleep loss." The main finding is that anomalous increases in nighttime temperature by 1 degree Celsius translate to three nights of insufficient sleep per 100 individuals per month. The effect is also not spread evenly across all demographic groups. Those whose income is below $50,000 and those who are aged 65 and older are affected most severely. For older people, the effect is twice that of younger adults. And for the lower-income group, it is three times worse than for people who are better off financially. Warmer temperatures could cause six additional nights of insufficient sleep per 100 individuals by 2050 and approximately 14 extra nights per 100 by 2099.

Could renewable 'power-by-wire' help fix China’s air pollution problems? We found that transmitting a hybrid of 60 per cent renewable power and 40 per cent coal -- known as hybrid-by-wire -- reduces 20 per cent more national air-pollution-associated deaths, and decreases three times more carbon emissions, than transmitting only coal-based electricity. The study also found that, although transmitting coal power was slightly more effective at reducing air pollution impacts than simply replacing old coal power plants with newer, cleaner ones in the east, both coal scenarios had approximately the same carbon emissions. Relocating coal power generation to arid western regions could exacerbate water scarcity. Alternatively, extensive development of hydropower may have major impacts on local ecosystems. It is extremely important, therefore, that grid planners consider the overall impact of long-distance electricity transmission on the environment at regional, national and global scales.

Wireless charging of moving electric vehicles overcomes major hurdle If electric cars could recharge while driving down a highway, it would virtually eliminate concerns about their range and lower their cost, perhaps making electricity the standard fuel for vehicles. Now Stanford University scientists have overcome a major hurdle to such a future by wirelessly transmitting electricity to a nearby moving object. "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," said Shanhui Fan, a professor of electrical engineering 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." The hope is that you'll be able to charge your electric car while you're driving down the highway. A coil in the bottom of the vehicle could receive electricity from a series of coils connected to an electric current embedded in the road. Some transportation experts envision an automated highway system where driverless electric vehicles are wirelessly charged by solar power or other renewable energy sources. The goal would be to reduce accidents and dramatically improve the flow of traffic while lowering greenhouse gas emissions.

Future trucks fueled by hydrogen created with solar power: Exhaust? Pure water vapor "In Japan, 150,000 fuel cells have been installed households to generate power and heat," Møller-Holst says. "In the US, more than 10,000 hydrogen-powered forklifts are operating in warehouses and distribution centres." "In Germany, the first fuel cell train is already undergoing trials, and Norway is one of many European countries that is now considering hydrogen-powered trains based on the conclusions of a study carried out by SINTEF for the Norwegian Railroad Administration," says Møller-Holst. But why is Japan investing so heavily in hydrogen? The rationale is that more than 90 per cent of the country's energy demand is currently covered by imported fossil energy sources. Hence, the Japanese are not just interested in hydrogen as a fuel for transport, but also for stationary power generation. In order to reduce greenhouse gas emissions, Japan has already entered into an agreement with Australia to import of hydrogen from 2020. "The German industrial giant Siemens has concluded that hydrogen is the best storage option for energy capacities greater than 10 GWh. More than 30 per cent of the power generation in Germany is covered by wind and solar sources, and pilot testing of hydrogen as a storage medium is well underway, "says Møller-Holst. No other technology can compete with hydrogen when it comes to emission-free long-haul transport. That's why ASKO, Norway's largest food wholesaler, is aiming to have its first hydrogen-powered delivery trucks on the roads in 2018. There is no doubt that electrical drive trains will replace conventional mechanical fossil-based propulsion in the future and that batteries will become very important in all transport segments. However, hydrogen becomes an increasingly good option if vehicles are heavier and have a longer distance to go. "Prior to 2020 biodiesel should replace fossil diesel fuel as an interim solution. Then, in the early 2020s, investments in battery-powered trains will be the most attractive option," he said. "From the mid 2020s, hydrogen is the solution that best fulfils the various requirements that apply for freight trains on the future railroad network." Four regions in Germany are currently taking the lead internationally. They have commissioned 100 hydrogen-powered passenger trains. The first is already undergoing trials and the technology is expected to be ready for freight trains before 2025. Tommy Mokkelbost is a Senior Research Scientist working at SINTEF's Svalbard office. He envisages that hydrogen could be produced from wind farms located in Norway's northernmost county, Finnmark, where the wind never stops blowing, but where today's power grid capacity is very limited. Hydrogen could then be transported to Svalbard in liquid form using hydrogen tankers.

Inexpensive organic material gives safe batteries a longer life Modern batteries power everything from cars to cell phones, but they are far from perfect -- they catch fire, they perform poorly in cold weather and they have relatively short lifecycles, among other issues. UH researchers have discovered a new material that has proven an effective anode for acid and alkaline batteries, including emerging aqueous metal-ion batteries, offering the promise of safe, long-lasting batteries that work across a range of temperatures. They use quinones -- an inexpensive, earth-abundant and easily recyclable material -- to create stable anode composites for any aqueous rechargeable battery. The material also can be used to create a "drop-in replacement" for current battery anodes, allowing the new material to be used without changing existing battery manufacturing lines, he said. In addition to slowing the deterioration of batteries for vehicles and stationary electricity storage batteries, it also would make battery disposal easier because the material does not contain heavy metals.

Corn better used as food than biofuel, study finds To compare the energy efficiency and environmental impacts of corn production and processing for food and for biofuel, the researchers inventoried the resources required for corn production and processing, then determined the economic and environmental impact of using these resources -- all defined in terms of energy available and expended, and normalized to cost in U.S. dollars. "There are a lot of abstract concepts to contend with when discussing human-induced effects in the critical zone in agricultural areas," Richardson said. "We want to present it in a way that will show the equivalent dollar value of the human energy expended in agricultural production and how much we gain when corn is used as food versus biofuel." In monetary terms, their results show that the net social and economic worth of food corn production in the U.S. is $1,492 per hectare, versus a $10 per hectare loss for biofuel corn production. "One of the key factors lies in the soil," Richardson said. The assessment considered both short-term and long-term effects, such as nutrients and carbon storage in the soil.

Sustainable ethanol from carbon dioxide? A possible path Most cars and trucks in the United States run on a blend of 90 percent gasoline and 10 percent ethanol, a renewable fuel made primarily from fermented corn. But to produce the 14 billion gallons of ethanol consumed annually by American drivers requires millions of acres of farmland. A recent discovery by Stanford University scientists could lead to a new, more sustainable way to make ethanol without corn or other crops. This promising technology has three basic components: water, carbon dioxide and electricity delivered through a copper catalyst. To compare electrocatalytic performance, the researchers placed the three large electrodes in water, exposed them to carbon dioxide gas and applied a potential to generate an electric current. The results were clear. When a specific voltage was applied, the electrodes made of copper (751) were far more selective to liquid products, such as ethanol and propanol, than those made of copper (100) or (111). The explanation may lie in the different ways that copper atoms are aligned on the three surfaces. "We plan to use this method on nickel and other metals to further understand the chemistry at the surface. We think this study is an important piece of the puzzle and will open up whole new avenues of research for the community."

Clean energy stored in electric vehicles to power buildings This new research into the potentials of vehicle-to-grid (V2G) shows that it could actually improve vehicle battery life by around ten percent over a year. For two years, Dr Uddin's team analysed 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. Given that battery degradation is dependent on calendar age, capacity throughput, temperature, state of charge, current and depth of discharge, V2G is an effective tool that can be used to optimise a battery's conditions such that degradation is minimised. Hence, taking excess energy from an idle EV to power the grid actually keeps the battery healthier for longer.

Solar material for producing clean hydrogen fuel A new material has been created based on gold and black phosphorus to produce clean hydrogen fuel using the full spectrum of sunlight. Now, a team in Osaka University has developed a material to harvest a broader spectrum of sunlight. The three-part composites of this material maximize both absorbing light and its efficiency for water splitting. The core is a traditional semiconductor, lanthanum titanium oxide (LTO). The LTO surface is partly coated with tiny specks of gold, known as nanoparticles. Finally, the gold-covered LTO is mixed with ultrathin sheets of the element black phosphorus (BP), which acts as a light absorber. "BP is a wonderful material for solar applications, because we can tune the frequency of light just by varying its thickness, from ultrathin to bulk," the team leader Tetsuro Majima says. "This allows our new material to absorb visible and even near infrared light, which we could never achieve with LTO alone." By absorbing this broad sweep of energy, BP is stimulated to release electrons, which are then conducted to the gold nanoparticles coating the LTO. Gold nanoparticles also absorb visible light, causing some of its own electrons to be jolted out. The free electrons in both BP and gold nanoparticles are then transferred into the LTO semiconductor, where they act as an electric current for water splitting. As a result, the material is 60 times more active than pure LTO.

New technology will enable properties to share solar energy IN the UK alone, some 1.5 million homes are equipped with solar panels, and it has been estimated that by 2020 the figure could soar to 10 million, with the prospect of lower energy bills for consumers and massive reductions in CO2 emissions. Now, a University of Huddersfield researcher is developing new technologies that could enable clusters of houses to share their solar energy, rather than simply exporting surplus electricity to the national grid. Also, new systems for fault detection will enable householders to monitor and maintain the efficiency of their panels.

This paint converts humidity to hydrogen fuel The ink can “be coated on any substrate, leading to efficient and low-cost hydrogen production from humid environments,” say researchers at the Royal Melbourne Institute of Technology in Australia who developed the formulation. That means houses painted with it could harvest solar energy and produce hydrogen fuel to power electric cars. The Australian researchers made their solar paint with a material called amorphous molybdenum sulfide. The material is good at absorbing moisture and is an excellent catalyst that enables water molecules to split. It’s not the best at absorbing sunlight, however. So the researchers mixed it with titanium oxide, a material used as white pigment in wall paints. They made a water-based suspension of a mixture containing 90 percent molybdenum sulfide and 10 percent titanium oxide. Then they coated this ink on a substrate that they exposed to moisture and sunlight. The titanium oxide absorbs sunlight and produces charge-carrying electrons. The molybdenum sulfide catalysts use the electrons’ energy to split water molecules they have absorbed from the surrounding air. The hydrogen would have to be captured for use. They now plan to integrate the material with a gas separation membrane that would help to collect the hydrogen for storage and use.