The Graphite Gold Rush

Much like the gold rush in North America in the 1800s, people are going out in droves searching for a different kind of precious metal, graphite. The thing your third grade pencils were made of is now one of the hottest commodities on the market. This graphite is not being mined by your run-of-the-mill, old-timey soot covered prospectors anymore. Big mining companies are all looking for this important resource integral to the production of lithium ion batteries due to the rise in popularity of electric cars. These players include Graphite Energy Corp., Teck Resources Limited, Nemaska LithiumLithium Americas Corp., and Cruz Cobalt Corp..

These companies looking to manufacturer their graphite-based products, have seen steady positive growth over the past year. Their development of cutting-edge new products seems to be paying off. But in order to continue innovating, these companies need the graphite to do it. One junior miner looking to capitalize on the growing demand for this commodity is Graphite Energy Corp. Graphite Energy is a mining company, that is focused on developing graphite resources. Graphite Energy‘s mining technology is friendly to the environment and has indicate graphite carbon (Cg) in the range of 2.2 percent to 22.30 percent with average 10.50 percent Cg from their Lac Aux Bouleaux Graphite Property in Southern Quebec.

Graphite is one of the most in demand technology metals that is required for a green and sustainable world. Demand is only set to increase as the need for lithium ion batteries grows, fueled by the popularity of electric vehicles. However, not all graphite is created equal. The price of natural graphite has more than doubled since 2013 as companies look to maintain environmental standards which the use of synthetic graphite cannot provide due to its pollutant manufacturing process. Synthetic graphite is also very expensive to produce, deriving from petroleum and costing up to ten times as much as natural graphite. Therefore manufacturers are interested in increasing the proportion of natural graphite in their products in order to lower their costs.

High-grade large flake graphite is the solution to the environmental issues these companies are facing. But there is only so much supply to go around. Recent news by Graphite Energy Corp. on February 26th showed promising exploratory results. The announcement of the commencement of drilling is a positive step forward to meeting this increased demand.

Everything from batteries to solar panels need to be made with this natural high-grade flake graphite because what is the point of powering your home with the sun or charging your car if the products themselves do more harm than good to the environment when produced. However, supply consistency remains an issue since mines have different raw material impurities which vary from mine to mine. Certain types of battery technology already require graphite to be almost 100 percent pure. It is very possible that the purity requirements will increase in the future.


SuperPowerful Tiny Device Converts Light Into Electricity

In today’s increasingly powerful electronics, tiny materials are a must as manufacturers seek to increase performance without adding bulk. Smaller also is better for optoelectronic devices — like camera sensors or solar cells —which collect light and convert it to electrical energy. Think, for example, about reducing the size and weight of a series of solar panels, producing a higher-quality photo in low lighting conditions, or even transmitting data more quickly.

However, two major challenges have stood in the way: First, shrinking the size of conventionally used “amorphousthin-film materials also reduces their quality. And second, when ultrathin materials become too thin, they are almost transparent — and actually lose some ability to gather or absorb light.

Now, in a nanoscale photodetector that combines both a unique fabrication method and light-trapping structures, a team of engineers from the University at Buffalo (UB) and the University of Wisconsin-Madison (UW-Madison) has overcome both of those obstacles. The researchers — electrical engineers Qiaoqiang Gan at UB, and Zhenqiang (Jack) Ma and Zongfu Yu at UW-Madison — described their device, a single-crystalline germanium nanomembrane photodetector on a nanocavity substrate, in the July 7, 2017, issue of the journal Science Advances.

This image shows the different layers of the nanoscale photodetector, including germanium (red) in between layers of gold or aluminum (yellow) and aluminum oxide (purple). The bottom layer is a silver substrate

We’ve created an exceptionally small and extraordinarily powerful device that converts light into energy,” says Gan, associate professor of electrical engineering in UB’s School of Engineering and Applied Sciences, and one of the paper’s lead authors. “The potential applications are exciting because it could be used to produce everything from more efficient solar panels to more powerful optical fibers.”

The idea, basically, is you want to use a very thin material to realize the same function of devices in which you need to use a very thick material,” says Ma, the Lynn H. Matthias Professor and Vilas Distinguished Achievement Professor in electrical and computer engineering at UW-Madison, also a lead author. Nanocavities are made up of an orderly series of tiny, interconnected molecules that essentially reflect, or circulate, light.

The new device is an advancement of Gan’s work developing nanocavities that increase the amount of light that thin semiconducting materials like germanium can absorb. It consists of nanocavities sandwiched between a top layer of ultrathin single-crystal germanium and a bottom, reflecting layer of silver.


Sion, The Solar-Powered Car

What has room for 6 passengers, an all-electric range of up to 155 miles (250 kilometers), and a body covered in solar panels that can add as many as 18 miles (30 kilometers) of driving a day from sunlight? That would be the Sono Motors Sion, an innovative solar-powered car from a team of German entrepreneurs that is scheduled to have its world debut on July 27 (2017).

The Sion project was able to move forward thanks to an Indiegogo crowdfunding campaign last year that raised over a half million dollars. More than 1,000 people have participated so far.

The car will have two versions. The Urban comes with a 14.4 kilowatt-hour battery pack. It has a range of about 75 miles (121 kilometers) and will cost $13,200. The Extender version has a 30 kilowatt-hour battery and a range of 155 miles (250 kilometers). Its target price is $17,600. Neither price includes the battery. Like the Renault Zoe, customers will either buy the battery separately or lease it. The leasing option gives owners the flexibility to upgrade the battery later as improvements in battery technology become available.

The hood, roof, and rear hatch of the Sion are covered with monocrystalline silicon cells that are 21% efficient. On a sunny day, they can generate enough electricity to add 18 miles of range. The solar cells are 8 millimeters thick and embedded in a polycarbonate layer that is shatterproof, weather resistant, and light in weight. The Sion can also be 80% charged using an AC outlet in about 30 minutes, according to company claims. No DC charging option is available. The car also comes with an outlet that can power electronic devices.

Inside, all the seats of the 5 door hatchback fold flat, offering multiple configurations for carrying passengers and cargo. There is a 10 inch center display and smartphone connectivity via WiFi or Bluetooth. The ventilation system is called breSono and incorporates a dollop of moss, which is said to act as a natural filter when an electrical charge is applied.

The company will offer an online maintenance and repair system it calls reSono. It allows owners to order parts online and comes with a video that shows them how to install the parts when they arrive.  Or they can take the car and the parts to any local auto repair shop facility to get them installed.


Printable solar cells

A University of Toronto (U of T) Engineering innovation could make building printing cells as easy and inexpensive as printing a newspaper. Dr. Hairen Tan and his team have cleared a critical manufacturing hurdle in the development of a relatively new class of solar devices called perovskite solar cells. This alternative solar technology could lead to low-cost, printable solar panels capable of turning nearly any surface into a power generator.

Printable Perovskite SolarCell

Economies of scale have greatly reduced the cost of silicon manufacturing,” says University Professor Ted Sargent (ECE), an expert in emerging solar technologies and the Canada Research Chair in Nanotechnology and senior author on the paper. “Perovskite solar cells can enable us to use techniques already established in the printing industry to produce solar cells at very low cost. Potentially, perovskites and silicon cells can be married to improve efficiency further, but only with advances in low-temperature processes.”

Today, virtually all commercial solar cells are made from thin slices of crystalline silicon which must be processed to a very high purity. It’s an energy-intensive process, requiring temperatures higher than 1,000 degrees Celsius and large amounts of hazardous solvents.

In contrast, perovskite solar cells depend on a layer of tiny crystals — each about 1,000 times smaller than the width of a human hair — made of low-cost, light-sensitive materials. Because the perovskite raw materials can be mixed into a liquid to form a kind of ‘solar ink’, they could be printed onto glass, plastic or other materials using a simple inkjet process.


Electronics: How To Dissipate Heat in A Nanocomputer

Controlling the flow of heat through semiconductor materials is an important challenge in developing smaller and faster computer chips, high-performance solar panels, and better lasers and biomedical devices. For the first time, an international team of scientists led by a researcher at the University of California, Riverside has modified the energy spectrum of acoustic phononselemental excitations, also referred to as quasi-particles, that spread heat through crystalline materials like a wave—by confining them to nanometer-scale semiconductor structures. The results have important implications in the thermal management of electronic devices. Led by Alexander Balandin, Professor of Electrical and Computing Engineering and UC Presidential Chair Professor in UCR’s Bourns College of Engineering, the research is described in a paper published in the journal Nature Communications.


The team used semiconductor nanowires from Gallium Arsenide (GaAs), synthesized by researchers in Finland, and an imaging technique called Brillouin-Mandelstam light scattering spectroscopy (BMS) to study the movement of phonons through the crystalline nanostructures. By changing the size and the shape of the GaAs nanostructures, the researchers were able to alter the energy spectrum, or dispersion, of acoustic phonons. The BMS instrument used for this study was built at UCR’s Phonon Optimized Engineered Materials (POEM) Center, which is directed by Balandin.

Controlling phonon dispersion is crucial for improving heat removal from nanoscale electronic devices, which has become the major roadblock in allowing engineers to continue to reduce their size. It can also be used to improve the efficiency of thermoelectric energy generation, Balandin said. In that case, decreasing thermal conductivity by phonons is beneficial for thermoelectric devices that generate energy by applying a temperature gradient to semiconductors.

For years, the only envisioned method of changing the thermal conductivity of nanostructures was via acoustic phonon scattering with nanostructure boundaries and interfaces. We demonstrated experimentally that by spatially confining acoustic phonons in nanowires one can change their velocity, and the way they interact with electrons, magnons, and how they carry heat. Our work creates new opportunities for tuning thermal and electronic properties of semiconductor materials,” Balandin said.


Solar Powered House: Tiles Instead Of Panels

Tesla founder and CEO Elon Musk wasn’t kidding when he said that the new Tesla solar roof product was better looking than an ordinary roof: the roofing replacement with solar energy gathering powers does indeed look great. It’s a far cry from the obvious and somewhat weird aftermarket panels you see applied to roofs after the fact today.


The solar roofing comes in four distinct styles that Tesla presented at the event, including “Textured Glass Tile,” “Slate Glass Tile,” “Tuscan Glass Tile, and “Smooth Glass Tile.” Each of these achieves a different aesthetic look, but all resembled fairly closely a current roofing material style. Each is also transparent to solar, but appears opaque when viewed from an angle.

The current versions of the tiles actually have a two percent loss on efficiency, so 98 percent of what you’d normally get from a traditional solar panel, according to Elon Musk. But the company is working with 3M on improved coatings that have the potential to possibly go above normal efficiency, since it could trap the light within, leading to it bouncing around and resulting in less energy loss overall before it’s fully diffused.

Of course, there’s the matter of price: Tesla’s roof cost less than the full cost of a roof and electricity will be competitive or better than the cost of a traditional roof combined with the cost of electricity from the grid, Musk said. Tesla declined to provide specific pricing at the moment, since it will depend on a number of factor including installation specifics on a per home basis.

Standard roofing materials do not provide fiscal benefit back to the homeowner post-installation, besides improving the cost of the home. Tesla’s product does that, by generating enough energy to fully power a household, with the power designed to be stored in the new Powerwall 2.0 battery units so that homeowners can keep a reserve in case of excess need.

The solar roof product should start to see installations by summer next year, and Tesla plans to start with one or two of its four tile options, then gradually expand the options over time. As they’re made from quartz glass, they should last way longer than an asphalt tile — at least two or three times the longevity, though Musk later said “they should last longer than the house”.


Solar-powered Wireless Charging Station For Electric Bikes

Members of the Delft University of Technology (TU Delft) in Netherlands have presented the first solar-powered wireless charging station for electric bikes.


This is a major step forward in terms of sustainable transport and accelerating the energy transition because the combination of solar energy, wireless charging and electric bikes is unique. In this charging station, we charge the DC battery in the bike with the solar energy from the eight solar panels via the DC supply. The charging station can also store 10 kWh of solar energy in the batteries, enabling it to function independently“, sayd  Pavol Bauer, who leads the Direct Current (DC) Systems, Energy Conversion & Storage group at the University.

The charging station is ready for immediate use: it can accommodate four electric bikesan electric scooter and a research bike that are charged wirelessly. The charging station also serves as a living lab, a testbed for further research. In the last two years, ten students have graduated on the strength of their work on the project. For example, a student of Electrical Engineering, Mathematics and Computer Science designed a DC system and created a system to enable the bike to be charged wirelessly, another calculated and determined the output and position of the solar panels, and an Industrial Design Engineering student was responsible for designing the charging station.

The electric research bike is equipped with a dual stand and a small coil. At the charging station, the bike can be parked on the stand on a magnetic tile. The bike is charged directly via the coil. The user can monitor the charging status on a built-in screen on the charging station or on his or her mobile phone. Wireless charging takes around the same time as the ‘conventional‘ charging of electric bikes.

It is anticipated that the eight panels will generate sufficient energy to power the electric bikes and the scooter in winter. In summer, any excess power will be fed to the electricity grid. Pavol Bauer’s group now plans to work on the further development of wireless charging for various bikes and scooters. The ultimate aim is for the charging station to consist solely of several tiles used as a solar panel, which can be cycled on, known as solar roads. Integrating solar cells and the wireless charging system makes an expensive system unnecessary.


Solar Cells : How To Boost Efficiency Up To 30%

Researchers from the University of Houston have reported the first explanation for how a class of materials changes during production to more efficiently absorb light, a critical step toward the large-scale manufacture of better and less-expensive solar panels. The work, published this month as the cover story for Nanoscale, offers a mechanism study of how a perovskite thin film changes its microscopic structure upon gentle heating, said Yan Yao, assistant professor of electrical and computer engineering and lead author on the paper. This information is crucial for designing a manufacturing process that can consistently produce high-efficiency solar panels.

Perovskite cheap

Last year Yao and other researchers identified the crystal structure of the non-stoichiometric intermediate phase as the key element for high-efficiency perovskite solar cells. But what happened during the later thermal annealing step remained unclear. The work is fundamental science, Yao said, but critical for processing more efficient solar cells.

Otherwise, it’s like a black box,” he said. “We know certain processing conditions are important, but we don’t know why.”

The work also yielded a surprise: the materials showed a peak efficiency – the rate at which the material converted light to electricity – before the intermediate phase transformation was complete, suggesting a new way to produce the films to ensure maximum efficiency. Yao said researchers would have expected the highest efficiency to come after the material had been converted to 100 percent perovskite film. Instead, they discovered the best-performing solar devices were those for which conversion was stopped at 18 percent of the intermediate phase, before full conversion.

We found that the phase composition and morphology of solvent engineered perovskite films are strongly dependent on the processing conditions and can significantly influence photovoltaic performance,” the researchers wrote. “The strong dependence on processing conditions is attributed to the molecular exchange kinetics between organic halide molecules and DMSO (dimethyl sulfoxide) coordinated in the intermediate phase.

Perovskite compounds commonly are comprised of a hybrid organic-inorganic lead or tin halide-based material and have been pursued as potential materials for solar cells for several years. Yao said their advantages include the fact that the materials can work as very thin films – about 300 nanometers, compared with between 200 and 300 micrometers for silicon wafers, the most commonly used material for solar cells. Perovskite solar cells also can be produced by solution processing at temperatures below 150 degrees Centigrade (about 300 degrees Fahrenheit) making them relatively inexpensive to produce.

At their best, perovskite solar cells have an efficiency rate of about 22 percent, slightly lower than that of silicon (25 percent). But the cost of silicon solar cells is also dropping dramatically, and perovskite cells are unstable in air, quickly losing efficiency. They also usually contain lead, a toxin.

Still, Yao said, the materials hold great promise for the solar industry, even if they are unlikely to replace silicon entirely. Instead, he said, they could be used in conjunction with silicon, boosting efficiency to 30 percent or so.


Smart Threads For Clothing And Robots

Fabrics containing flexible electronics are appearing in many novel products, such as clothes with in-built screens and solar panels. More impressively, these fabrics can act as electronic skins that can sense their surroundings and could have applications in robotics and prosthetic medicine. King Abdullah University of Science and Technology (KAUST – Saudi Arabia) researchers have now developed smart threads that detect the strength and location of pressures exerted on them1. Most flexible sensors function by detecting changes in the electrical properties of materials in response to pressure, temperature, humidity or the presence of gases. Electronic skins are built up as arrays of several individual sensors. These arrays currently need complex wiring and data analysis, which makes them too heavy, large or expensive for large-scale production.

Yanlong Tai and Gilles Lubineau from the University’s Division of Physical Science and Engineering have found a different approach. They built their smart threads from cotton threads coated with layers of one of the miracle materials of nanotechnology: single-walled carbon nanotubes (SWCNTs).

smart threadsThe twisted smart threads developed by KAUST researchers can be woven into pressure-sensitive electronic skin fabrics for use in novel clothing, robots or medical prosthetics

Cotton threads are a classic material for fabrics, so they seemed a logical choice,” said Lubineau. “Networks of nanotubes are also known to have piezoresistive properties, meaning their electrical resistance depends on the applied pressure.”

The researchers showed their threads had decreased resistance when subjected to stronger mechanical strains, and crucially the amplitude of the resistance change also depended on the thickness of the SWCNT coating.

These findings led the researchers to their biggest breakthrough: they developed threads of graded thickness with a thick SWCNT layer at one end tapering to a thin layer at the other end. Then, by combining threads in pairs—one with graded thickness and one of uniform thickness—the researchers could not only detect the strength of an applied pressure load, but also the position of the load along the threads.

Our system is not the first technology to sense both the strength and position of applied pressures, but our graded structure avoids the need for complicated electrode wirings, heavy data recording and analysis,” said Tai.

The researchers have used their smart threads to build two- and three-dimensional arrays that accurately detect pressures similar to those that real people and robots might be exposed to.
We hope that electronic skins made from our smart threads could benefit any robot or medical prosthetic in which pressure sensing is important, such as artificial hands,” said Lubineau.

Perovskite Solar Cells Surpass 20% Efficiency

Researchers from the Ecole Polytechnique Fédérale de Lausanne (EPFL) in Switzerland are pushing the limits of perovskite solar cell performance by exploring the best way to grow these crystals.
Michael Graetzel and his team found that, by briefly reducing the pressure while fabricating perovskite crystals, they were able to achieve the highest performance ever measured for larger-size perovskite solar cells, reaching over 20% efficiency and matching the performance of conventional thin-film solar cells of similar sizes. This is promising news for perovskite technology that is already low cost and under industrial development. However, high performance in pervoskites does not necessarily herald the doom of silicon-based solar technology. Safety issues still need to be addressed regarding the lead content of current perovskite solar-cell prototypes in addition to determining the stability of actual devices.

peroskite solar cell

Layering perovskites on top of silicon to make hybrid solar panels may actually boost the silicon solar-cell industry. Efficiency could exceed 30%, with the theoretical limit being around 44%. The improved performance would come from harnessing more solar energy: the higher energy light would be absorbed by the perovskite top layer, while lower energy sunlight passing through the perovskite would be absorbed by the silicon layer. Graetzel is known for his transparent dye-sensitized solar cells. It turns out that the first perovskite solar cells were dye-sensitized cells where the dye was replaced by small perovskite particles. His lab’s latest perovskite prototype, roughly the size of an SD card, looks like a piece of glass that is darkened on one side by a thin film of perovskite. Unlike the transparent dye-sensitized cells, the perovskite solar cell is opaque.

The results are published in Science.


Bubble-Pen To Build Nanocomputer, Sensor, Solar Panel…

Researchers in the Cockrell School of Engineering at The University of Texas at Austin have solved a problem in micro- and nanofabrication — how to quickly, gently and precisely handle tiny particles — that will allow researchers to more easily build tiny machines, biomedical sensors, optical computers, solar panels and other devices. They have developed a device and technique, called bubble-pen lithography, that can efficiently handle nanoparticles — the tiny pieces of gold, silicon and other materials used in nanomanufacturing. The new method relies on microbubbles to inscribe, or write, nanoparticles onto a surface.

A research team led by Texas Engineering assistant professor Yuebing Zheng has invented a way to handle these small particles and lock them into position without damaging them. Using microbubbles to gently transport the particles, the bubble-pen lithography technique can quickly arrange particles in various shapes, sizes, compositions and distances between nanostructures.

bubble-pen litho

The ability to control a single nanoparticle and fix it to a substrate without damaging it could open up great opportunities for the creation of new materials and devices,” Zheng said. “The capability of arranging the particles will help to advance a class of new materials, known as metamaterials, with properties and functions that do not exist in current natural materials.

The team, which includes Cockrell School associate professor Deji Akinwande and professor Andrew Dunn, describe their patented device and technique in a paper published in Nano Letters.


Omnidirectional Solar Cells Boost Efficiency

In recent years, a complicated discussion over which direction solar cells should facesouth or west — has likely left customers uncertain about the best way to orient their panels. Now researchers from 3 different universities in Taiwan  are attempting to resolve this issue by developing solar cells that can harvest light from almost any angle, and the panels self-clean to boot.

solar farm

Commercial solar panels work best when sunlight hits them at a certain angle. Initially, experts had suggested that solar panels face south to collect the most energy from the sun. But an influential 2013 report by Pecan Street, an energy-research organization, advised that systems tilt westward to maximize efficiency. Further analysis has found that determining the ideal angle is more complicated — in essence, it depends on where you live. And even if customers get the positioning correct, they’re still losing out on prime sunlight because most residential systems can’t move or adjust to the sun’s track across the sky. Jr-Hau He, Kun-Yu Lai fron the National Taiwan University and colleagues wanted to address this shortcoming. The researchers developed a glass coating that incorporates ultrathin nanorods and honeycomb nanowalls that can help underlying solar cells harvest sunlight from multiple angles. The cell efficiency can be boosted by 5.2 to 27.7 percent, depending on the angle of the light, and the efficiency enhancement can be up to 46 percent during long-term use. 

The material also repelled dust and pollution that would otherwise block some rays from getting absorbed and converted to electricity. The new glass coating kept panels working outdoors at optimum levels for six weeks while the efficiency of panels with an unmodified coating dropped over the same period.