18 May 2017
Battery stores energy in nontoxic, noncorrosive aqueous solutions
Researchers from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) have developed a new flow battery that stores energy in organic molecules dissolved in neutral pH water.
This new chemistry allows for a non-toxic, non-corrosive battery with an exceptionally long lifetime and offers the potential to significantly decrease the costs of production.
The research, published in ACS Energy Letters, was led by Michael Aziz, the Gene and Tracy Sykes Professor of Materials and Energy Technologies and Roy Gordon, the Thomas Dudley Cabot Professor of Chemistry and Professor of Materials Science.
Flow batteries store energy in liquid solutions in external tanks — the bigger the tanks, the more energy they store.
A new company Tenka Energy, LLC ™ has been formed to exploit and commercialize the Next Generation Super-Capacitors and Batteries. The opportunity is based on Nanoporous-Nickel Flexible Thin-Form, Scalable Super Capacitors and Si-Nanowire Battery Technologies with Exclusive IP Licensing Rights from Rice University.
… Problem 1: Current capacitors and batteries being supplied to the relevant markets lack the sustainable power density, discharge and recharge cycle and warranty life. Combined with a weight/ size challenge and the lack of a ‘flexible form factor’, existing solutions lack the ability to scale and manufacture at Low Cost, to satisfy the identified industries’ need for solutions that provide commercial viability & performance.
Solution: For Marine & Drone Batteries – Medical Devices
- High Energy Density = 2X More Time on the Water; 2X Flight Time for Drones
- Simplified Manufacturing = Lower Costs
- Simple Electrode Architecture = Flex Form Factor (10X Energy Density Factor)
- Flexible Form = Dramatically Less Weight and Better Weight Distribution
- Easy to Scale Technology
To Read the Full Article Click on the Link Below:
28 Feb 2017
Technology I: University of Central Florida
Leaving your phone plugged in for hours could become a thing of the past, thanks to a new type of battery technology that charges in seconds and lasts for over a week.
Watch the Video
While it probably won’t be commercially available for a years, the researchers said it has the potential to be used in phones, wearables and electric vehicles.
“If they were to replace the batteries with these supercapacitors, you could charge your mobile phone in a few seconds and you wouldn’t need to charge it again for over a week,” said Nitin Choudhary, a UCF postdoctoral associate, who conducted much of the research, published in the academic journal ACS Nano.
How does it work?
Unlike conventional batteries, supercapacitors store electricity statically on their surface which means they can charge and deliver energy rapidly. But supercapacitors have a major shortcoming: they need large surface areas in order to hold lots of energy.
To overcome the problem, the researchers developed supercapacitors built with millions of nano-wires and shells made from two-dimensional materials only a few atoms thick, which allows for super-fast charging. Their prototype is only about the size of a fingernail.
“For small electronic devices, our materials are surpassing the conventional ones worldwide in terms of energy density, power density and cyclic stability,” Choudhary said.
Cyclic stability refers to how many times a battery can be charged, drained and recharged before it starts to degrade. For lithium-ion batteries, this is typically fewer than 1,500 times.
Supercapacitors with two-dimensional materials can be recharged a few thousand times. But the researchers say their prototype still works like new even after being recharged 30,000 times.
Those that use the new materials could be used in phones, tablets and other electronic devices, as well as electric vehicles. And because they’re flexible, it could mean a significant development for wearables.
Technology II: Rice University
Identified Key Markets and Commercial Applications
- Medical Devices and Wearable Electronics
- Drone/Marine Batteries and Power Banks
- Powered Smart Cards and Motor Cycle/ EV Batteries
- Sensors & Power Units for the iOT (Internet of Things) [Flexible Form, Energy Dense]
The Coming Power Needs of the iOT
- The IoT is populated with billions of tiny devices.
- They’re smart.
- They’re cheap.
- They’re mobile.
- They need to communicate.
- Their numbers growing at 20%-30%/Year.
The iOT is Hungry for POWER! All this demands supercapacitors that can pack a lot of affordable power in very small volumes …Ten times more than today’s best supercapacitors can provide.
Highly Scalable – Energy Dense – Flexible Form – Rapid Charge
Problem 1: Current capacitors and batteries being supplied to the relevant markets lack the sustainable power density, discharge and recharge cycle, warranty life combined with a ‘flexible form factor’ to scale and satisfy the identified industry need for commercial viability & performance.
Solution I: (Minimal Value Product) Tenka is currently providing full, functional Super Capacitor prototypes to an initial customer in the Digital Powered Smart Card industry and has received two (2) phased Contingent Purchase Orders during the First Year Operating Cycle for 120,000 Units and 1,200,000 Units respectively.
Solution II: For Drone/ Marine Batteries – Power Banks & Medical Devices
- Double the current ‘Time Aloft’ (1 hour+)
- Reduces operating costs
- Marine batteries – Less weight, longer life, flex form
- Provides Fast Recharging, Extended Life Warranty.
- Full -battery prototypes being developed
Small batteries will be produced first for Powered Digital Smart Cards (In addition to the MVP Super Caps) solving packaging before scaling up drone battery operations. Technical risks are mainly associated with packaging and scaling.
The Operational Plan is to take full advantage of the gained ‘know how’ (Trade Secrets and Processes) of scaling and packaging solutions developed for the Powered Digital Smart Card and the iOT, to facilitate the roll-out of these additional Application Opportunities. Leveraging gained knowledge from operations is projected to significantly increase margins and profitability. We will begin where the Economies of Scale and Entry Point make sense (cents)!
“We are building and Energy Storage Company starting Small & Growing Big!”
Watch the YouTube Video
Fuel cell electric vehicles have a long way to go before they can compete with their battery EV cousins, and energy storage is a key sticking point when the fuel is hydrogen. Hydrogen is light, plentiful, and fabulously energy dense, but energy storage in a personal mobility unit racing down a crowded highway is a different kind of chicken. Safety, cost, and performance are critical sticking points, and a research team at Lawrence Berkeley Laboratory is on to a solution for at least one of those.
Energy Storage Challenges For Hydrogen Fuel Cell EVs
The US Energy Department’s 2015 annual report provides a birds-eye view of the array of energy storage solutions that are emerging for hydrogen fuel cells, including advancements in hydrogen tank technology as well as solids-based storage.
Despite the progress, according to the Energy Department, challenges still remain for stationary and portable fuel cells in terms of raising the energy storage density, and there are “significant challenges” for fuel cell EVs. The problem is this:
Hydrogen has the highest energy per mass of any fuel; however, its low ambient temperature density results in a low energy per unit volume, therefore requiring the development of advanced storage methods that have potential for higher energy density.
The Energy Department has set a goal of 2020 for achieving verifiable hydrogen storage systems for light duty fuel cell EVs that meet the driving public’s thirst for range, comfort, refueling convenience, and performance. Here are the targets:
1.8 kWh/kg system (5.5 wt.% hydrogen)
1.3 kWh/L system (0.040 kg hydrogen/L)
$10/kWh ($333/kg stored hydrogen capacity)
However, the Energy Department is already looking beyond the current state of on-road technology to meet its 2020 goal. According to the agency, the 300-mile range is being met by using compressed gas, high pressure energy storage technology, and the problem is that competing technology on the market today — primarily gasmobiles and hybrids — already exceeds that range.
To compete for consumers on the open market, the agency is pursuing a near-term goal of improving compressed gas storage, primarily by deploying fiber reinforced composites that enable 700 bar pressure.
The long term goal consists of two pathways. One is to improve “cold” compressed gas energy storage technology, and the other is to go a different route altogether and store hydrogen within materials such as sorbents, chemical hydrogen storage materials, and metal hydrides.
The Berkeley Lab Energy Storage Solution
Where were we? Oh right, Berkeley Lab. Berkeley Lab has been tackling the metal hydride pathway.
Metal hydrides are compounds that consist of a transition metal bonded to hydrogen. They are believed to be the most “technologically relevant” class of materials for storing hydrogen, partly due to the broad range of applications.
That’s the theory. The problem is that when it comes to real world performance, metal hydrides are highly sensitive to contamination and they degrade somewhat rapidly unless properly shielded.
The Berkeley Lab energy storage solution consists of a graphene “filter” encasing nanocrystals of magnesium. With the addition of the graphene layer, the magnesium crystals act as a sort of sponge for absorbing hydrogen, providing both safety and compactness without causing performance issues:
The graphene shields the nanocrystals from oxygen and moisture and contaminants, while tiny, natural holes allow the smaller hydrogen molecules to pass through. This filtering process overcomes common problems degrading the performance of metal hydrides for hydrogen storage.
Berkeley Lab has provided this photo to show off how stable the crystals are when exposed to air (for scale, the bottle cap is about the size of a thumbnail):
At one atom thick (yes, one atom), graphene is known to be an incredibly finicky material to work with. It is extremely difficult to synthesize it without defects, but that’s not a problem for this energy storage solution. The defects are actually desirable in this case. The tiny gaps enable molecules of hydrogen gas to wriggle through, but oxygen, water, and other contaminants are too large to penetrate the shield.
The new energy formula also solves another key challenge for metal hydrides. They tend to take in and dispense hydrogen at a relatively slow pace, but the Berkeley Lab solution has sped up the intake-outflow cycle significantly. That effect is attributed to the nanoscale size of the graphene-shielded crystals, which provide a greater surface area.
Energy Department Gets The Last Word?
We’ve been having a lively debate about fuel cell electric EVs over here at CleanTechnica, so let’s hear from the Berkeley Lab team:
A potential advantage for hydrogen-fuel-cell vehicles, in addition to their reduced environmental impact over standard-fuel vehicles, is the high specific energy of hydrogen, which means that hydrogen fuel cells can potentially take up less weight than other battery systems and fuel sources while yielding more electrical energy.
However, the team also makes it clear that:
More R&D is needed to realize higher-capacity hydrogen storage for long-range vehicle applications that exceed the performance of existing electric-vehicle batteries…
Among other issues, the next step for a sustainable fuel cell EV future is to develop sustainable and renewable sources for hydrogen fuel. Currently the main source of hydrogen is natural gas, which puts fuel cell EVs in the same boat as battery EVs that draw electricity from a coal or natural gas-fired grid.
California is committed to 33 percent energy from renewable resources by 2020. With that deadline fast approaching, researchers across the state are busy exploring options.
Solar energy is attractive but for widespread adoption, it requires transformation into a storable form. This week in ACS Central Science, researchers report that nanowires made from multiple metal oxides could put solar ahead in this race.
One way to harness solar power for broader use is through photoelectrochemical (PEC) water splitting that provides hydrogen for fuel cells. Many materials that can perform the reaction exist, but most of these candidates suffer from issues, ranging from efficiency to stability and cost.
Peidong Yang and colleagues designed a system where nanowires from one of the most commonly used materials (TiO2) acts as a “host” for “guest” nanoparticles from another oxide called BiVO4. BiVO4 is a newly introduced material that is among the best ones for absorbing light and performing the water splitting reaction, but does not carry charge well while TiO2 is stable, cheap and an efficient charge carrier but does not absorb light well.
Together with a unique studded nanowire architecture, the new system works better than either material alone.
The authors state their approach can be used to improve the efficiencies of other photoconversion materials.
We report the use of Ta:TiO2|BiVO4 as a photoanode for use in solar water splitting cells. This host−guest system makes use of the favorable band alignment between the two semiconductors. The nanowire architecture allows for simultaneously high light absorption and carrier collection for efficient solar water oxidation.
Metal oxides that absorb visible light are attractive for use as photoanodes in photoelectrosynthetic cells. However, their performance is often limited by poor charge carrier transport. We show that this problem can be addressed by using separate materials for light absorption and carrier transport. Here, we report a Ta:TiO2|BiVO4 nanowire photoanode, in which BiVO4 acts as a visible light-absorber and Ta:TiO2 acts as a high surface area electron conductor. Electrochemical and spectroscopic measurements provide experimental evidence for the type II band alignment necessary for favorable electron transfer from BiVO4 to TiO2. The host–guest nanowire architecture presented here allows for simultaneously high light absorption and carrier collection efficiency, with an onset of anodic photocurrent near 0.2 V vs RHE, and a photocurrent density of 2.1 mA/cm2 at 1.23 V vs RHE.
Article adapted from a American Chemical Society news release. To Read the FULL release, please click on the link provided below.
Publication: TiO2/BiVO4 Nanowire Heterostructure Photoanodes Based on Type II Band Alignment. Resasco, J et al. ACS Central Science (3 February, 2016): Click here to view.
Genesis Nanotechnology – “Great Things from Small Things”
21 Oct 2015
The opportunity is electricity storage, which until now has been limited by technology to a relatively modest scale. That’s about to change. And it means that Canada – and specifically Ontario – can become an ideal seedbed for storage technology, because there are ready markets for both large- and small-scale storage systems.
First, the large scale. Ontario has a fleet of nuclear generators that operate around the clock, and come close to filling the demand for power at off-peak hours. In addition, Ontario has developed a large renewable energy sector of wind and solar generation (in addition to its traditional hydro stations.) Problems sometimes arise when the natural weather cycles that drive wind and solar production are out of synch with the market cycle. On a sunny, breezy Saturday afternoon in May, with the nuclear plants running flat out, the hydro stations churning out power with the spring runoff and solar and wind systems near peak production, Ontario may have more electricity than it needs.
Our electricity system operators have a solution, of course: Sell the excess electricity to our neighbours. But since our neighbours are often in the same boat, Ontario must cut the price close to zero – or in extreme situations, even pay neighbouring states or provinces to absorb our overproduction.
Wouldn’t it make far more sense to store that excess energy, knowing that it will be needed in a matter of days, or even hours? What’s been lacking is the technology to do the job.
That’s changing however, as Ontario’s current program to procure 50 megawatts of storage capacity demonstrates. Companies with a variety of approaches are working hard to bring their solutions to market – many of them clustered at the MaRS centre in Toronto. Some, such as Hydrogenics Corp., convert electricity into hydrogen, which can be used to supplement natural gas.
My own company, NRStor, has partnered with Temporal Power and is operating a flywheel storage system in Minto, Ont., that helps the market operator to maintain consistent voltage on the grid.
Of course, businesses around the globe are looking at the same opportunities as we are, and here lies the opportunity for Canada to rebrand its energy economy.
A recent report by Deutsche Bank calls battery storage the “holy grail of solar penetration,” and believes that with the current rate of progress in improving efficiency, mass adoption of lithium ion batteries at a commercial/utility scale could occur before 2020.
Analysis by Prof. Andrew Ford of Washington State University calculates that a 1,000-megawatt air storage system from U.S.-based General Compression Inc. could deliver $6- to $8-billion of value to Ontario – in the form of lower energy costs to local utilities – over a 20-year period. All this is of interest to large-scale electricity system operators, big utilities and their customers.
But there is another reason for us to pay attention to energy storage – a reason grounded on a much more human scale. There are still large rural areas around the globe where there is no reliable electrical grid – including Northern Canada.
There is great potential for these communities, including remote First Nations communities, to improve their standard of living by installing microscale renewable generation in combination with storage, and relying less on carbon-spewing diesel generators, powered by fuel that must be transported long distances at great expense.
Storage is the key to making renewable energy a fully competitive component of any electrical grid. It can make our grid cleaner and more efficient, for the benefit of all consumers – large and small, urban and rural. We have the chance, in Canada, to become world leaders in developing this technology. Let’s seize it.
Annette Verschuren is the chairwoman and CEO of NRStor and on the board of MaRS Discovery District.
Annette Verschuren is speaking at the Cleantech Canadian Innovation Exchange (CIX Cleantech) conference in Toronto on Oct. 15.
By Michael Berger – Nanowerk. During 2002 and 2003, Nobel laureate Richard E. Smalley developed a list of the Top Ten Problems Facing Humanity over the next 50 years. The Richard E. Smalley Institute for Nanoscale Science and Technology at Rice University (which in May 2015 has been merged with the Rice Quantum Institute into a new entity: the Smalley-Curl Institute) has identified 5 of these problems as society’s Grand Challenges – and energy tops the list.
Since then, researchers around the world have demonstrated the potential for nanotechnology to be a key technology on the path to a sustainable energy future. Against the double-whammy backdrop of an energy challenge – the world’s appetite for energy keeps growing1 – plus a climate challenge – climate goals (2°C target) require substantial reduction in greenhouse gases (see: Climate change: Action, trends and implications for business. pdf) – it is the role of innovative energy technologies to provide socially acceptable solutions through energy savings; efficiency gains; and decarbonization.
Why is nanotechnology relevant here? Many effects important for energy happen at the nanoscale: In solar cells, for instance, photons can free electrons from a material, which can then flow as an electric current; the chemical reactions inside a battery or fuel cell release electrons which then move through an external circuit; or the role of catalysts in a plethora of chemical reactions. These are just a few examples where nanoscale engineering can significantly improve the efficiency of the underlying processes.
The working principle of a solar cell. (Image: University of Massachusetts Amherst)
Nanotechnologies are not tied exclusively to renewable energy technologies. While researchers are exploring ways in which nanotechnology could help us to develop energy sources, they also develop techniques to access and use fossil fuels much more efficiently. Corrosion resistant nanocoatings, nanostructured catalysts, and nanomembranes have been used in the extraction and processing of fossil fuels and in nuclear power. There is no silver bullet – nanotechnology applications for energy are extremely varied, reflecting the complexity of the energy sector, with a number of different markets along its value chain, including energy generation, transformation, distribution, storage, and usage. Nanotechnology has the potential to have a positive impact on all of these – albeit with varying effects.
Nanomaterials could lead to energy savings through weight reduction or through optimized function:
- In the future, novel, nano-technologically optimized materials, for example plastics or metals with carbon nanotubes (CNTs), will make airplanes and vehicles lighter and therefore help reduce fuel consumption;
- Novel lighting materials (OLED: organic light-emitting diodes) with nanoscale layers of plastic and organic pigments are being developed; their conversion rate from energy to light can apparently reach 50 % (compared with traditional light bulbs = 5%);
- Nanoscale carbon black has been added to modern automobile tires for some time now to reinforce the material and reduce rolling resistance, which leads to fuel savings of up to 10%;
- Self-cleaning or “easy-to-clean”-coatings, for example on glass, can help save energy and water in facility cleaning because such surfaces are easier to clean or need not be cleaned so often;
- Nanotribological wear protection products as fuel or motor oil additives could reduce fuel consumption of vehicles and extend engine life;
- Nanoparticles as flow agents allow plastics to be melted and cast at lower temperatures;
- Nanoporous insulating materials in the construction business can help reduce the energy needed to heat and cool buildings.
Nanomaterials could improve energy generation and energy efficiencies:
- Various nanomaterials can improve the efficiency of photovoltaic facilities;
- Dye solar cells (‘Grätzel cells’) with nanoscale semiconductor materials mimic natural photosynthesis in green plants;
- Plastics with carbon nanotubes as coatings on the rotor blades of wind turbines make these lighter and increase the energy yield;
- Nano optimized lithium-ion batteries have an improved storage capacity as well as an increased lifespan and find use in electric vehicles for example;
- Fuel cells with nanoscale ceramic materials for energy production require less energy and resources during manufacturing;
- The effectiveness of catalytic converters in vehicles can be increased by applying catalytically active precious metals in the nanoscale size range.
We have compiled an overview of Nanotechnology in Energy that shows how nanotechnology innovations could impact each part of the value-added chain in the energy sector – energy sources; energy conversion; energy distribution; energy storage; and energy usage.
The European GENNESYS project identified a range of nanomaterial application and requirements for future energy applications3. (click on image to enlarge) In the short term, energy nanotechnology is likely to have the greatest impact in the areas of efficiency of photovoltaics (among renewables, solar has by far the biggest global energy potential) and energy storage where it can help overcome current performance barriers and substantially improve the collection and conversion of solar energy. Nanotechnology for Solar Energy Collection and Conversion is one of the five Signature Initiatives funded by the U.S. National Nanotechnology Initiative. The goals are to enhance understanding of conversion and storage phenomena at the nanoscale, improve nanoscale characterization of electronic properties, and help enable economical nanomanufacturing of robust devices. The initiative has three major thrust areas:
- – improve photovoltaic solar electricity generation;
- – improve solar thermal energy generation and conversion; and
- – improve solar-to-fuel conversions.
The thermodynamic limit of 80% efficiency is well beyond the capabilities of current photovoltaic technologies, whose laboratory performance currently approaches only 43% 2. Nanomaterials even make it possible to raise light yield of traditional crystalline silicon solar cells. By using cheaper, nanoscale materials than the current dominant technology (single-crystal silicon, which uses a large amount of fossil fuels for production), the cost of solar cells could be brought down. Numerous research labs are working on nanotechnology-enabled batteries to increase their efficiencies for electric vehicles, home, or grid storage systems. Improving the efficiency/storage capacity of batteries and supercapacitors with nanomaterials will have a substantial economical impact.
Graphene has already been demonstrated to have many promising applications in energy-related areas. (read more: “Graphene materials for energy storage applications“). Nanotechnology also has the potential to deliver the next generation lithium-ion batteries with improved performance, durability and safety at an acceptable cost (“The promise of nanotechnology for the next generation of lithium-ion batteries“).
A major push on basic research for energy technologies is coming from the U.S. Department of Energy, which since 2009 has invested nearly $800m as part of the Energy Frontier Research Center (EFRC) program. For example, the Joint Center for Artificial Photosynthesis (JCAP) has developed a nanowire-based design that incorporates two semiconductors to enhance absorption of light; or the Nanostructures for Electrical Energy Storage (NEES) EFRC Center has demonstrated that precise nanostructures can be constructed to test the limits of 3-D nanobatteries by designing billions of tiny batteries inside nanopores.
Against the double-whammy backdrop of an energy challenge and a climate challenge it is the role of innovative energy technologies to provide socially acceptable solutions through energy savings; efficiency gains; and decarbonization.
So where does that leave ‘nanotechnology’? It may not be the silver bullet, but nanomaterials and nanoscale applications will have an important role to play.
Notes 1) Energy demand grows by 37% to 2040 on planned policies, an average rate of growth of 1.1%. World electricity demand increases by almost 80% over the period 2012-2040. 1.6bn people still without access to electricity, thereof 950 million in sub-Saharan Africa. (Source: IEA World Energy Outlook 2014) 2) Source: NSI Solar White Paper (pdf) 3) Source: GENNESYS White paper
22 Jul 2015
Tesla Motors CTO JB Straubel was the headliner at Intersolar North America last week. He talked about the transition to lithium-ion batteries and how that opened the floodgates for electric cars and stationary storage (eventually); the synergy between EVs, solar, and grid storage; the growth of solar power and grid storage; blah blah blah.
I know, I actually love all that stuff as much as the rest of you — it’s what I read, edit, & write about every day(!) — but it’s basically all general history and trends we know all about. But then JB dropped the awesome-bomb:
“I think we’re at the beginning of a new cost-decline curve, and, you know, this is something where there’s a lot of similarities to what happened with photovoltaics. Almost no one [would have predicted] that photovoltaic prices would have dropped as fast as they have, and storage is right at the cliff, heading down that price curve. It’s soon going to be cheaper to drive a car on electricity — a pure EV on electricity — than it is to drive a gasoline car. And as soon as we see that kind of shift in the actual cost of operation in a car that you can actually use for your daily driver, you know, from all manufacturers I believe we’re going to see electric vehicles come to dominate the whole transportation fleet.
“Also, that same battery cost decrease is going to drive batteries in the grid. There’s going to be much faster growth of grid energy storage than I think most people expected. You suddenly get to have energy that’s 100% firm and buffered from photovoltaics that’s cheaper than fossil energy. And we’re within sort of grasping distance of that goal, which is very, very exciting.
“Because once we get to that, and there really is no going back, it will make sense to do this economically without any environmental consideration whatsoever. So that’s the amazing tipping point that’s going to happen within I’m quite certain the next 10 years.”
The next 10 years!
(Though, he didn’t actually drop the mic.)
You can watch the highlights via Intersolar on YouTube — video below:
Another great quote, however, was this gem: “It’s not going to be many years before Tesla will have a million cars, or 70 gigawatt-hours of storage.” (That quote wasn’t in the highlight video above for some reason!)
| Solar energy is the world’s most plentiful and ubiquitous energy source, and researchers around the world are pursuing ways to convert sunlight into a useful form.
Most people are aware of solar photovoltaics that generate electricity and solar panels that produce hot water. But there is another thrust of solar research: turning sunlight into liquid fuels.
|Research in solar-derived liquid fuels, or solar fuels, aims to make a range of products that are compatible with our energy infrastructure today, such as gasoline, jet fuel and hydrogen. The goal is to store sunlight in liquid form, conveniently overcoming the transient nature of sunlight. I am among the growing number of researchers focused on this field.|
|How can this be done? And what scientific challenges remain before one can fill up a car on solar-generated fuel?|
|Packing heat: concentrating sunlight into a reactor to split H2O and CO2 – a step toward making liquid fuels. (Courtesy of Professor David Hahn, University of Florida, Author provided)|
|Speeding up nature|
|The production of solar fuels is particularly attractive because it addresses both the conversion and storage problem endemic to sunlight; namely, the sun is available for only one-third of the day. This is a distinct advantage compared to other solar conversion technologies. Solar photovoltaic panels, for instance, must be coupled to a complex distribution and storage network, such as batteries, when production of electric power doesn’t equal demand.|
|The term “solar fuel” is a bit of a misnomer. In fact, all fossil fuels are technically solar-derived. Solar energy drives photosynthesis to form plant matter through the reaction of carbon dioxide (CO2) and water (H2O) and, over millions of years, the decay of plant matter creates the hydrocarbons we use to power our society.|
|One thermochemical approach strips oxygen from steam and carbon dioxide gas using the sun’s heat. Then, the resulting gases are combined chemically in a separate process to make liquid fuels. (Image: Jonathan Scheffe, Author provided)|
|The downside of this process is that nature’s efficiency at producing hydrocarbons is excruciatingly low, and humankind’s hunger for energy has never been greater. The result is that the current rate of fossil fuel consumption is much larger than the rate they are produced by nature alone, which provides the motivation to increase nature’s efficiencies and speed up the process of solar fuel production through artificial means.|
|This is the true meaning of “solar fuel” as it is used today, but the ultimate goal is the same: namely, the conversion of solar energy, CO2 and H2O to chemical forms such as gasoline.|
|To the lab|
|The first step in creating manmade solar fuels is to break down CO2 and/or H2O molecules, often to carbon monoxide (CO) or carbon and hydrogen (H2). This is no easy feat, as both of these molecules are very stable (H2 does not form spontaneously from H2O!) and therefore this step requires a substantial amount of energy supplied from sunlight, either directly in the form of photons or indirectly as electricity or heat.|
|This step is often the most crucial component of the process and represents the greatest roadblock to commercialization of solar fuel technologies today, as it largely defines the efficiency of the overall fuel production process and therefore the cost.|
|Downstream of this step, the resulting molecules – in this case, a mixture of CO and hydrogen called synthesis gas – may be converted through a variety of existing technologies depending on the final product desired. This step of converting hydrocarbon gases to liquid form is already performed at an industrial scale, thanks to large corporations such as Shell Global Solutions and Sasol that use these technologies to leverage to low cost of today’s natural gas to make more valuable liquid fuels.|
|Recently, a European Union-sponsored project called SOLAR-JET (Solar chemical reactor demonstration and Optimization for Long-term Availability of Renewable JET fuel) demonstrated the first-ever conversion of solar energy to jet fuel, or kerosene. Researchers coupled the solar-driven production of synthesis gas, also called syngas, from CO2 and H2O with a downstream gas-to-liquids reactor – in this case a Fischer-Tropsch reactor at Shell’s Headquarters in Amsterdam.|
|The production of liquid fuels is especially important for the aviation industry that relies on energy-dense fuels and represents another important advantage of solar fuel production compared to solar electricity.|
|The SOLAR-JET project, which I worked on with several other researchers, utilized a process called solar thermochemical fuel production, in which solar energy is concentrated using optics – mirrors and lenses – much the way a magnifying glass can start a fire. The resulting heat is then absorbed in a chamber that acts as a chemical reactor. The absorbed heat is then used to dissociate H2O and/or CO2 through a catalytic-type process – one of the most technically challenging steps for all solar fuel conversion processes. The resulting products (hydrogen or synthesis gas) can then be captured and further converted to liquid fuels downstream.|
|There are numerous other strategies to drive these reactions needed for the first step of solar fuel production, including those that utilize light – photons – directly or indirectly in the form of electricity.|
|For example, so-called artificial photosynthesis utilizes photons directly in a catalytic process, rather than absorbing them as heat, to break down H2O and CO2 molecules.|
|Former Energy Secretary Steven Chu visiting the Joint Center for Artificial Photosynthesis, which received an additional US$75 million in funding earlier this year. The lab is pursuing converting light (not heat) directly into fuels. (Image: Lawrence Berkeley National Laboratory)|
|Electrochemical approaches utilize electricity that could be generated from a photovoltaic cell to drive the separation of H2O and CO2 through a process known as electrolysis.|
|To date, the key barriers to commercialization of all of these technologies are primarily related to their low efficiencies – that is related to the amount of energy needed to produce a liquid fuel – and overall robustness. For example, the efficiency of the SOLAR-JET thermochemical conversion project discussed above is still less than 2%, but for this technology to become commercially viable, efficiencies greater than 10% will need to be achieved.|
|A team working at the University of Florida funded by research agency ARPA-E is working toward these efficiency goals using another thermochemical process that uses optics to generate heat. Yet robustness because of extreme temperatures (greater than 1200 Celsius or over 2000 Farenheit) is still a major concern that is being addressed.|
|Furthermore, for solar fuel production to truly reduce greenhouse gas levels, it must be coupled with methods to capture CO2 from the air. This is still a relatively immature technology, but companies such as Climeworks are working to make this a reality.|
|Add in the complexity of integrating a temporally varying energy input (the sun) with a chemical reactor and the overall scope of the challenge can appear large. Nevertheless, advances are being made daily that give hope that solar fuels at higher efficiencies will soon be a reality.|
|Source: By Jonathan Scheffe, Associate Professor Department of Mechanical and Aerospace Enginering at University of Florida, via The Conversation|
22 Jun 2015
Aiming to completely overhaul the lithium-ion battery industry, MIT-based scientist Yet-Ming Chiang on Monday publicly unveiled his latest startup, called 24M.
The company uses a novel battery composition based on a semi-solid material that eliminates much of the bulk of conventional lithium-ion batteries—which are typically made up mostly of inactive, non-energy-storing materials—while dramatically increasing the energy density. Chiang and 24M CEO Throop Wilder also say that they can reduce the time needed to make a battery by 80 percent and the cost by 30 to 50 percent.
After five years of research and development, 24M has raised $50 million in funding from Charles River Ventures, North Bridge Venture Partners, and its strategic partners, along with a $4.5 million grant from the U.S. Department of Energy. It has strategic partnerships with the Japanese heavy-industry giant IHI and from PTT, the formerly state-owned Thai oil and gas company, which is increasingly moving into alternative energy.
Since a 2011 paper in the journal Advanced Energy Materials previewed 24M’s technology, the company has received a large amount of press coverage for a stealth-mode startup, including articles in this publication as well as a long, adulatory profile on the website Quartz. The company calls its new battery “the most significant advancement in lithium-ion technology since its debut more than 20 years ago.”
That would be a remarkable accomplishment, with the potential to drive the electric-vehicle market to a new level and accelerate the spread of renewable energy. But 24M faces a challenge that many previous companies with promising technology have failed to solve: how to revolutionize a manufacturing industry with huge amounts of capital sunk into extensive existing capacity.
Yet-Ming Chiang is personally familiar with this quandary: he was one of the founders of A123, the lithium-ion startup that received nearly a quarter of a million dollars in funding from the U.S. government, went public in the largest IPO of 2009, and filed for bankruptcy in 2012. A123 was done in by an EV market that grew slower than expected and by its close relationship with EV maker Fisker, which itself failed in 2013 and was purchased by the Chinese auto parts company Wanxiang Group. But it also stumbled in trying to compete with more established battery makers such as LG and Panasonic.
Chiang acknowledges the dilemma: “In the last decade, there have been a lot of new lithium-ion plants built, and the EV market has not materialized to fill these factories.”
Now, energy storage demand is soaring—for vehicles, for power grids, and for residences with distributed renewable generation, such as rooftop solar arrays. Capacity in the United States is expected to more than triple this year, and rapid growth will continue through the end of the decade, according to GTM Research.
That means that demand for a less expensive, more efficient technology should be robust. But the building boom of the previous decade means there’s also excess manufacturing capacity available to supply that market. LG Chem’s plant in Holland, Michigan, which makes batteries for the Chevrolet Volt and the Cadillac ELR, currently operates at about 30 percent of capacity, according to CEO Prabhakar Patil.
And established players are already increasing their output. Mercedes-Benz parent company Daimler, for instance, announced late last year it will invest 100 million euros ($113 million) to expand its lithium-ion manufacturing capacity through its subsidiary Deutsche ACCUmotive.
Then there’s the Gigafactory. Tesla’s giant Nevada plant will produce 35 gigawatt-hours’ worth of batteries a year, dwarfing any previous manufacturing ventures for lithium-ion batteries.
Meanwhile, improvements in the manufacturing of conventional lithium-ion batteries are reducing the cost per kilowatt-hour of existing systems—even as research into next-generation chemistries, such as lithium-sulfur and lithium-air, continues at institutions around the world.
In short, 24M is attempting to transform a worldwide manufacturing industry in which established players with deep pockets are investing hundreds of millions in the expansion of existing processes. That’s a tough road even for a startup with a novel and exciting technology.
Chiang and CEO Wilder are undeterred. “This is the next great mega-market,” says Wilder. “To quote Elon Musk, the world is going to need multiple gigafactories.”