MIT Technology Review: Sustainable Energy: The daunting math of climate change means we’ll need carbon capture … eventually


 

MIT CC Friedman unknown-1_4

 Net Power’s pilot natural gas plant with carbon capture, near Houston, Texas.

An Interview with Julio Friedmann

At current rates of greenhouse-gas emissions, the world could lock in 1.5 ˚C of warming as soon as 2021, an analysis by the website Carbon Brief has found. We’re on track to blow the carbon budget for 2 ˚C by 2036.

Amid this daunting climate math, many researchers argue that capturing carbon dioxide from power plants, factories, and the air will have to play a big part in any realistic efforts to limit the dangers of global warming.

If it can be done economically, carbon capture and storage (CCS) offers the world additional flexibility and time to make the leap to cleaner systems. It means we can retrofit, rather than replace, vast parts of the global energy infrastructure. And once we reach disastrous levels of warming, so-called direct air capture offers one of the only ways to dig our way out of trouble, since carbon dioxide otherwise stays in the atmosphere for thousands of years.

Julio Friedmann has emerged as one of the most ardent advocates of these technologies. He oversaw research and development efforts on clean coal and carbon capture at the US Department of Energy’s Office of Fossil Energy under the last administration. Among other roles, he’s now working with or advising the Global CCS Institute, the Energy Futures Initiative, and Climeworks, a Switzerland-based company already building pilot plants that pull carbon dioxide from the air.

In an interview with MIT Technology Review, Friedmann argues that the technology is approaching a tipping point: a growing number of projects demonstrate that it works in the real world, and that it is becoming more reliable and affordable. He adds that the boosted US tax credit for capturing and storing carbon, passed in the form of the Future Act as part of the federal budget earlier this year, will push forward many more projects and help create new markets for products derived from carbon dioxide (see “The carbon-capture era may finally be starting”).

But serious challenges remain. Even with the tax credit, companies will incur steep costs by adding carbon capture systems to existing power plants. And a widely cited 2011 study, coauthored by MIT researcher Howard Herzog, found that direct air capture will require vast amounts of energy and cost 10 times as much as scrubbing carbon from power plants.

(This interview has been edited for length and clarity.)

In late February, you wrote a Medium post saying that with the passage of the increased tax credit for carbon capture and storage, we’ve “launched the climate counter-strike.” Why is that a big deal?

It actually sets a price on carbon formally. It says you should get paid to not emit carbon dioxide, and you should get paid somewhere between $35 a ton and $50 a ton. So that is already a massive change. In addition to that, it says you can do one of three things: you can store CO2, you can use it for enhanced oil recovery, or you can turn it into stuff. Fundamentally, it says not emitting has value.

As I’ve said many times before, the lack of progress in deploying CCS up until this point is not a question of cost. It’s really been a question of finance.

The Future Act creates that financing.

I identified an additional provision which said not only can you consider a power plant a source or an industrial site a source, you can consider the air a source.

Even if we zeroed out all our emissions today, we still have a legacy of harm of two trillion tons of CO2 in the air, and we need to do something about that.

And this law says, yeah, we should. It says we can take carbon dioxide out of the air and turn it into stuff.

At the Petra Nova plant in Texas, my understanding is the carbon capture costs are something like $60 to $70 a ton, which is still going to outstrip the tax credit today. How are we going to close that gap?

There are many different ways to go about it. For example, the state of New Jersey today passed a 90 percent clean energy portfolio standard. Changing the policy from a renewable portfolio standard [which would exclude CCS technologies] to a clean energy standard [which would allow them] allowed higher ambition.

In that context, somebody who would build a CCS project and would get a contract to deliver that power, or deliver that emissions abatement, can actually again get staked, get financed, and get built. That can happen without any technology advancement.

The technology today is already cost competitive. CCS today, as a retrofit, is cheaper than a whole bunch of stuff. It’s cheaper than new-build nuclear, it’s cheaper than offshore wind. It’s cheaper than a whole bunch of things we like, and it’s cheaper than rooftop solar, almost everywhere. It’s cheaper than utility-scale concentrating solar pretty much everywhere, and it is cheaper than what solar and wind were 10 years ago.

What do you make of the critique that this is all just going to perpetuate the fossil-fuel industry?

The enemy is not fossil fuels; the enemy is emissions.

In a place like California that has terrific renewable resources and a good infrastructure for renewable energy, maybe you can get to zero [fossil fuels] someday.

If you’re in Saskatchewan, you really can’t do that. It is too cold for too much of the year, and they don’t have solar resources, and their wind resources are problematic because they’re so strong they tear up the turbines. Which is why they did the CCS project in Saskatchewan. For them it was the right solution.

Shifting gears to direct air capture, the basic math says that you’re moving 2,500 molecules to capture one of CO2. How good are we getting at this, and how cheaply can we do this at this point?

If you want to optimize the way that you would reduce carbon dioxide economy-wide, direct air capture is the last thing you would tackle. Turns out, though, that we don’t live in that society. We are not optimizing anything in any way.

So instead we realize we have this legacy of emissions in the atmosphere and we need tools to manage that. So there are companies like ClimeworksCarbon Engineering, and Global Thermostat. Those guys said we know we’re going to need this technology, so I’m going to work now. They’ve got decent financing, and the costs are coming down and improving (see “Can sucking CO2 out of the atmosphere really work?”).

The cost for all of these things now today, all-in costs, is somewhere between $300 and $600 a ton. I’ve looked inside all those companies and I believe all of them are on a glide path to get to below $200 a ton by somewhere between 2022 and 2025. And I believe that they’re going to get down to $100 a ton by 2030. At that point, these are real options.

At $200 a ton, we know today unambiguously that pulling CO2 out of the air is cheaper than trying to make a zero-carbon airplane, by a lot. So it becomes an option that you use to go after carbon in the hard-to-scrub parts of the economy.

Is it ever going to work as a business, or is it always going to be kind of a public-supported enterprise to buy ourselves out of climate catastrophes?

Direct air capture is not competitive today broadly, but there are places where the value proposition is real. So let me give you a couple of examples.

In many parts of the world there are no sources of CO2. If you’re running a Pepsi or a Coca-Cola plant in Sri Lanka, you literally burn diesel fuel and capture the CO2 from it to put into your cola, at a bonkers price. It can cost $300 to $800 a ton to get that CO2. So there are already going to be places in some people’s supply chain where direct air capture could be cheaper.

We talk to companies like Goodyear, Firestone, or Michelin. They make tires, and right now the way that they get their carbon black [a material used in tire production that’s derived from fossil fuel] is basically you pyrolize bunker fuel in the Gulf Coast, which is a horrible, environmentally destructive process. And then you ship it by rail cars to wherever they’re making the tires.

If they can decouple from that market by gathering CO2 wherever they are and turn that into carbon black, they can actually avoid market shocks. So even if it costs a little more, the value to that company might be high enough to bring it into the market. That’s where I see direct air actually gaining real traction in the next few years.

It’s not going to be enough for climate. We know that we will have to do carbon storage, for sure, if we want to really manage the atmospheric emissions. But there’s a lot of ground to chase this, and we never know quite where technology goes.

In one of your earlier Medium posts you said that we’re ultimately going to have to pull 10 billion tons of CO2 out of the atmosphere every year. Climeworks is doing about 50 [at their pilot plant in Iceland]. So what does that scale-up look like?

You don’t have to get all 10 billion tons with direct air capture. So let’s say you just want one billion.

Right now, Royal Dutch Shell as a company moves 300 million tons of refined product every year. This means that you need three to four companies the size of Royal Dutch Shell to pull CO2 out of the atmosphere.

The good news is we don’t need that billion tons today. We have 10 or 20 or 30 years to get to a billion tons of direct air capture. But in fact we’ve seen that kind of scaling in other kinds of clean-tech markets. There’s nothing in the laws of physics or chemistry that stops that.

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MIT Technolgy Review: This battery advance could make electric vehicles far cheaper


Sila Nanotechnologies has pulled off double-digit performance gains for lithium-ion batteries, promising to lower costs or add capabilities for cars and phones.

For the last seven years, a startup based in Alameda, California, has quietly worked on a novel anode material that promises to significantly boost the performance of lithium-ion batteries.

Sila Nanotechnologies emerged from stealth mode last month, partnering with BMW to put the company’s silicon-based anode materials in at least some of the German automaker’s electric vehicles by 2023.

A BMW spokesman told the Wall Street Journal the company expects that the deal will lead to a 10 to 15 percent increase in the amount of energy you can pack into a battery cell of a given volume. Sila’s CEO Gene Berdichevsky says the materials could eventually produce as much as a 40 percent improvement (see “35 Innovators Under 35: Gene Berdichevsky”).

For EVs, an increase in so-called energy density either significantly extends the mileage range possible on a single charge or decreases the cost of the batteries needed to reach standard ranges. For consumer gadgets, it could alleviate the frustration of cell phones that can’t make it through the day, or it might enable power-hungry next-generation features like bigger cameras or ultrafast 5G networks.

Researchers have spent decades working to advance the capabilities of lithium-ion batteries, but those gains usually only come a few percentage points at a time. So how did Sila Nanotechnologies make such a big leap?

Berdichevsky, who was employee number seven at Tesla, and CTO Gleb Yushin, a professor of materials science at the Georgia Institute of Technology, recently provided a deeper explanation of the battery technology in an interview with MIT Technology Review.

Sila co-founders (from left to right), Gleb Yushin, Gene Berdichevsky and Alex Jacobs.

An anode is the battery’s negative electrode, which in this case stores lithium ions when a battery is charged. Engineers have long believed that silicon holds great potential as an anode material for a simple reason: it can bond with 25 times more lithium ions than graphite, the main material used in lithium-ion batteries today.

But this comes with a big catch. When silicon accommodates that many lithium ions, its volume expands, stressing the material in a way that tends to make it crumble during charging. That swelling also triggers electrochemical side reactions that reduce battery performance.

In 2010, Yushin coauthored a scientific paper that identified a method for producing rigid silicon-based nanoparticles that are internally porous enough to accommodate significant volume changes. He teamed up with Berdichevsky and another former Tesla battery engineer, Alex Jacobs, to form Sila the following year.

The company has been working to commercialize that basic concept ever since, developing, producing, and testing tens of thousands of different varieties of increasingly sophisticated anode nanoparticles. It figured out ways to alter the internal structure to prevent the battery electrolyte from seeping into the particles, and it achieved dozens of incremental gains in energy density that ultimately added up to an improvement of about 20 percent over the best existing technology.

Ultimately, Sila created a robust, micrometer-size spherical particle with a porous core, which directs much of the swelling within the internal structure. The outside of the particle doesn’t change shape or size during charging, ensuring otherwise normal performance and cycle life.

The resulting composite anode powders work as a drop-in material for existing manufacturers of lithium-ion cells.

With any new battery technology, it takes at least five years to work through the automotive industry’s quality and safety assurance processes—hence the 2023 timeline with BMW. But Sila is on a faster track with consumer electronics, where it expects to see products carrying its battery materials on shelves early next year.

Venkat Viswanathan, a mechanical engineer at Carnegie Mellon, says Sila is “making great progress.” But he cautions that gains in one battery metric often come at the expense of others—like safety, charging time, or cycle life—and that what works in the lab doesn’t always translate perfectly into end products.

Companies including Enovix and Enevate are also developing silicon-dominant anode materials. Meanwhile, other businesses are pursuing entirely different routes to higher-capacity storage, notably including solid-state batteries. These use materials such as glass, ceramics, or polymers to replace liquid electrolytes, which help carry lithium ions between the cathode and anode.

BMW has also partnered with Solid Power, a spinout from the University of Colorado Boulder, which claims that its solid-state technology relying on lithium-metal anodes can store two to three times more energy than traditional lithium-ion batteries. Meanwhile, Ionic Materials, which recently raised $65 million from Dyson and others, has developed a solid polymer electrolyte that it claims will enable safer, cheaper batteries that can operate at room temperature and will also work with lithium metal.

Some battery experts believe that solid-state technology ultimately promises bigger gains in energy density, if researchers can surmount some large remaining technical obstacles.

But Berdichevsky stresses that Sila’s materials are ready for products now and, unlike solid-state lithium-metal batteries, don’t require any expensive equipment upgrades on the part of battery manufacturers.

As the company develops additional ways to limit volume change in the silicon-based particles, Berdichevsky and Yushin believe they’ll be able to extend energy density further, while also improving charging times and total cycle life.

This story was updated to clarify that Samsung didn’t invest in Ionic Material’s most recent funding round.

Read and Watch More:

Tenka Energy, Inc. Building Ultra-Thin Energy Dense SuperCaps and NexGen Nano-Enabled Pouch & Cylindrical Batteries – Energy Storage Made Small and POWERFUL! YouTube Video:

High efficiency solar power conversion allowed by a novel composite material


A composite thin film made of two different inorganic oxide materials significantly improves the performance of solar cells, as recently demonstrated by a joint team of researchers led by Professor Federico Rosei at the Institut national de la recherche scientifique (INRS), and Dr. Riad Nechache from École de technologie supérieure (ÉTS), both in the Montreal Area (Canada).

Following an original device concept, Mr. Joyprokash Chakrabartty, the researchers have developed this new composite thin film material which combines two different crystal phases comprising the atomic elements bismuth, manganese, and oxygen.

The combination of phases with two different compositions optimizes this material’s ability to absorb solar radiation and transform it into electricity. The results are highly promising for the development of future solar technologies, and also potentially useful in other optoelectronic devices.

The results of this research are discussed in an article published in Nature Photonics (“Improved photovoltaic performance from inorganic perovskite oxide thin films with mixed crystal phases”) by researchers and lead author Mr. Joyprokash Chakrabartty.

The key discovery consists in the observation that the composite thin film—barely 110 nanometres thick—absorbs a broader portion of the solar spectrum compared to the wavelengths absorbed in the thin films made of the two individual materials. The interfaces between the two different phases within the composite film play a crucial role in converting more sunlight into electricity. This is a surprising, novel phenomenon in the field of inorganic perovskite oxide-based solar cells.

The composite material leads to a power conversion efficiency of up to 4.2%, which is a record value for this class of materials.

Source: INRS

Paper Biomass Could Yield Lithium-Sulfur Batteries


Rensselaer Polytechnic Institute

A byproduct of the papermaking industry could be the answer to creating long-lasting lithium-sulfur batteries.

A team from Rensselaer Polytechnic Institute has created a method to use sulfonated carbon waste called lignosulfonate to build a rechargeable lithium-sulfur battery.

Lignosulfonate is typically combusted on site, releasing carbon dioxide into the atmosphere after sulfur has been captured for reuse. A battery built with the abundant and cheap material could be used to power big data centers, as well as provide a cheaper energy-storage option for microgrids and the traditional electric grid.

“Our research demonstrates the potential of using industrial paper-mill byproducts to design sustainable, low-cost electrode materials for lithium-sulfur batteries,” Trevor Simmons, a Rensselaer research scientist who developed the technology with his colleagues at the Center for Future Energy Systems (CFES), said in a statement.

Rechargeable batteries have two electrodes—a positive cathode and a negative anode. A liquid electrolyte is placed in between the electrodes to serve as a medium for the chemical reactions that produce electric current. In a lithium-sulfur battery, the cathode is made of a sulfur-carbon matrix and the anode is comprised of a lithium metal oxide.

Sulfur is nonconductive in its elemental form. When combined with carbon at elevated temperatures it becomes highly conductive, but can easily dissolve into a battery’s electrolyte, causing the electrodes on either side to deteriorate after only a few cycles.

Different forms of carbon, like nanotubes and complex carbon foams, have been tried to confine the sulfur in place, but have not been successful.

“Our method provides a simple way to create an optimal sulfur-based cathode from a single raw material,” Simmons said.

The research team developed a dark syrupy substance dubbed “brown liquor,” which they dried and then heated to about 700 degrees Celsius in a quartz tube furnace.

The high heat drives off most of the sulfur gas, while retaining some of the sulfur as polysulfides—chains of sulfur atoms—that are embedded deep within an activated carbon matrix. The heating process is then repeated until the correct amount of sulfur is trapped within the carbon matrix.

The researchers then ground up the material and mix it with an inert polymer binder to create a cathode coating on aluminum foil.

Thus far, the team has created a lithium-sulfur battery prototype the size of a watch battery that can cycle approximately 200 times.

They will now attempt to scale up the prototype to markedly increase the discharge rate and the battery’s cycle life.

“In repurposing this biomass, the researchers working with CFES are making a significant contribution to environmental preservation while building a more efficient battery that could provide a much-needed boost for the energy storage industry,” Martin Byrne, CFES director of business development, said in a statement.

New Electricity-Generating Backpack Lightens the Load on Soldiers


Soldier Pack 1 newlightning_0

Most soldiers carry a heavy burden in the field, including an 80-pound backpack filled with essential supplies and tools.

If that’s not heavy enough, soldiers often carry an additional 20 to 30 pounds in backup batteries to power their radios and other necessary electronics.

However, a new innovation offers a solution.

Lightning Pack—a 2017 R&D 100 Award Winner—is able to generate electricity as soldiers walk and run through the field, eliminating the need for them to carry batteries. They received the award at the R&D 100 Awards Gala held in Orlando, Florida on Nov. 17, 2017.

The backpack works by harvesting kinetic energy, while also reducing the heavy load soldiers have to carry around the field, said Lawrence Rome, PhD, the founder and chief scientific officer of Lightning Packs LLC, in an interview with R&D Magazine.

“Essentially in our backpacks there are two frames, there’s a frame connected to the person with a hip belt and shoulder straps and there is a second frame called a moving frame in which the bag is attached and the whole load sits there,” he said. “In normal backpacks, the two frames are locked together and move in unison.

“What we did is we suspended the moving frame from the fixed frame attached to the body by a spring mechanism,” he added. “So essentially as you walk up and down the moving frame moves in respect to the fixed frame and that generates electricity.”

By reducing the need for extra disposable batteries, soldiers using the backpack can opt to either reduce the overall weight of their backpacks or use the extra space to carry other necessary supplies. The packs also permits longer mission durations and reduces the demand for resupply operations.

In addition to providing a benefit for soldiers, the electricity-generating backpack could provide wearable, renewable electricity for disaster-relief workers operating in remote locations, as well as forestry service workers, medical aid relief workers, hikers, campers, and hunters.

The inspiration for Lightning Pack

Rome was a muscle physiologist in 2002 studying how fish swim when the U.S. Navy approached him unexpectedly on a possible project to develop a submarine that maneuvers similar to a fish.

During conversations with members of the military regarding the submarine, Rome learned about the heavy backpacks that many soldiers must regularly wear.

Although the task of designing a backpack was outside his expertise at the time, Rome was inspired to take on the challenge of eliminating some of the weight from the extra batteries using his knowledge of biomechanics.

“I know from teaching biomechanics that every step they take their hip goes up and down two-to-three inches,” Rome said. “So if their 80 pound backpack is connected at the hip then you have 80 pounds going up and down in every step. That winds up being a lot of mechanical energy.”

Benefits of Lightning Pack

According to Rome, prior to Lightning Pack’s creation the most electricity that was ever derived from walking was 20 milliwatts.

Lightning Packs can generate 12 to 15 watts of electricity by walking at a relaxed pace, 20 to 35 watts by walking at a hump pace, 33 to 40 watts by running and 30 to 50 watts by hand pumping.

Walking can also reduce the accelerative force by 82 percent and running reduces the accelerative force by 86 percent, allowing soldiers to have greater mobility in the field.

The electricity-generating backpacks currently come equipped in three sizes for a military assault pack, a mid-sized molle and a large molle ruck.

Rome explained how the extra electricity is ultimately used.

“Essentially what happens is the electricity that we generate goes to a few different places,” Rome said. “If you have a radio, it could power the radio directly. The excess electricity goes onto a battery, so the output plugs into a military battery.”

Rome said that radio communications are one of the largest drains of battery power for soldiers.

By having soldiers generate electricity by themselves, the military can reduce logistical support, dangerous supply routes and the over environmental impact due to having fewer disposable batteries.

Some of the other benefits include allowing soldiers to manage heavy loads with less stress on the body and minimizing acute and long-term musculoskeletal injuries, while also increasing force readiness and retention.

Lightning Packs are currently being developed with funding from the U.S. military and the National Institutes of Health. The military is currently undergoing stringent field tests on the backpacks.

The next step for Rome and the Lightning Pack team is to focus on creating a non-military version of the backpack that consumers can potentially use to power cell phones, GPS devices and other electronics.

3 Questions for Innovating the Clean Energy Economy (MIT Energy Initiative)


daniel-kammen-mit-energy-initiative-mitei-2018_0Daniel Kammen, professor of energy at the University of California at Berkeley, spoke on clean energy innovation and implementation in a talk at MIT. Photo: Francesca McCaffrey/MIT Energy Initiative

Daniel Kammen of the University of California at Berkeley discusses current efforts in clean energy innovation and implementation, and what’s coming next.

Daniel Kammen is a professor of energy at the University of California at Berkeley, with parallel appointments in the Energy and Resources Group (which he chairs), the Goldman School of Public Policy, and the Department of Nuclear Science and Engineering.

Recently, he gave a talk at MIT examining the current state of clean energy innovation and implementation, both in the U.S. and internationally. Using a combination of analytical and empirical approaches, he discussed the strengths and weaknesses of clean energy efforts on the household, city, and regional levels. The MIT Energy Initiative (MITEI) followed up with him on these topics.

Q: Your team has built energy transition models for several countries, including Chile, Nicaragua, China, and India. Can you describe how these models work and how they can inform global climate negotiations like the Paris Accords?

Clean Energy Storage I header1

A: My laboratory has worked with three governments to build open-source models of the current state of their energy systems and possible opportunities for improvement. This model, SWITCH , is an exceptionally high-resolution platform for examining the costs, reliability, and carbon emissions of energy systems as small as Nicaragua’s and as large as China’s. The exciting recent developments in the cost and performance improvements of solar, wind, energy storage, and electric vehicles permit the planning of dramatically decarbonized systems that have a wide range of ancillary benefits: increased reliability, improved air quality, and monetizing energy efficiency, to name just a few. With the Paris Climate Accords placing 80 percent or greater decarbonization targets on all nations’ agendas (sadly, except for the U.S. federal government), the need for an “honest broker” for the costs and operational issues around power systems is key.

Q: At the end of your talk, you mentioned a carbon footprint calculator that you helped create. How much do individual behaviors matter in addressing climate change?

A: The carbon footprint, or CoolClimate project, is a visualization and behavioral economics tool that can be used to highlight the impacts of individual decisions at the household, school, and city level. We have used it to support city-city competitions for “California’s coolest city,” to explore the relative impacts of lifetime choices (buying an electric vehicle versus or along with changes of diet), and more.

Q: You touched on the topic of the “high ambition coalition,” a 2015 United Nations Climate Change Conference goal of keeping warming under 1.5 degrees Celsius. Can you expand on this movement and the carbon negative strategies it would require?

A: As we look at paths to a sustainable global energy system, efforts to limit warming to 1.5 degrees Celsius will require not only zeroing out industrial and agricultural emissions, but also removing carbon from the atmosphere. This demands increasing natural carbon sinks by preserving or expanding forests, sustaining ocean systems, and making agriculture climate- and water-smart. One pathway, biomass energy with carbon capture and sequestration, has both supporters and detractors. It involves growing biomass, using it for energy, and then sequestering the emissions.

This talk was one in a series of MITEI seminars supported by IHS Markit.

Why Your EV Battery Will Last Longer than Your Mobile Phone Battery


How Usage and Management Affect Longevity

Car makers are extending the driving range of the electric vehicle to resemble a gasoline-powered car. This requires larger batteries that grow exponentially with the distance driven. Figure 1 illustrates the estimated driving ranges with different battery systems and hydrogen as a function of size.

Doubling battery size does not extend the driving range linearly and the vehicle becomes inefficient with increasing weight. Li-ion performs better than lead acid in energy density, but no battery meets hydrogen with a fuel cell, or fossil fuel feeding the traditional internal combustion engine (not shown). Extending the driving range with a larger tank is almost negligible compared to oversizing a battery.

There is a threshold as to battery size and weight in a vehicle; going beyond a critical point has a negative return. The vehicle becomes environmentally unsustainable.

Figure 1: Battery size as a function of driving range.

Oversizing the battery does not expand the driving range linearly.

Note: 35MPa hydrogen tank refers to 5,000psi.

Source:  International Journal of Hydrogen Energy, 34, 6005-6020 (2009)

Batteries have low calorific value compared to fossil fuel and it makes little sense to power a freight train, ocean-going ship or large airplane with batteries. A study reveals that replacing kerosene with batteries could keep an aircraft airborne for less than 10 minutes. Cost is another issue and batteries take long to charge. A fill-up that is quickly and conveniently as topping a tank with liquid or gaseous fuel is impossible with an electrochemical device.

Charging also needs high power. An ultra-fast EV charge draws the equivalent electrical power of five households. Charging a fleet of EVs could dim a city.

Conversely, fossil fuel cannot match the qualities of a battery that is clean, quiet, and has an instant start-up with the flick of a switch. Although fossil fuel is cheap and readily available, frivolous burning of this resource must stop to save our planet. Finding alternatives that are environmentally friendly, economical and durable is a challenge; the battery fills this requirement only in part.

Advancements made in battery technology in the last 20 years are insufficient to replace fossil fuel. Pushing the boundaries of the battery reminds us of its many limitations, which include low energy density; long charging times, high cost and a short life before the packs quits, often without warning. Table 2 illustrates the energy densities of common fuels, including the battery.

Fuel – Energy by mass (Wh/kg)

Hydrogen (350 bar)

39,300

Gasoline, diesel, natural gas (250 bar)

12,000–13,000

Body fat

10,500

Black coal (solid), Methanol

6,000–7,000

Wood (average)

2,300

Lithium-ion battery

100–250

Lead acid battery

40

Compressed air

34

Supercapacitor

5

Table 2: Energy densities of fossil fuel and batteries.

Fossil fuel carries many times the energy per mass compared to batteries, but electrical power can be utilized more efficiently than burning fossil fuel.

Compiled from various sources. Values are approximate

Fossil fuel carries many times the energy per mass compared to batteries, but electrical power can be utilized more efficiently than burning fossil fuel.

Compiled from various sources. Values are approximate.

How to Prolong Battery Life

Driving range is a key consideration when buying an EV. Cost also plays a role but seldom is battery life mentioned. This may not be the concern for a tire-kicker, nor does the salesman want to alarm the buyer of possible service issues later on. What sells is the joy of electric propulsion that is clean, quiet and exhilarating. Taxpayer subsidies also help.

Batteries have a defined life span and this is apparent with the decreasing runtime in our mobile phones. EV advocates may argue that a smartphone battery cannot be compared to an EV battery; these products are totally different.

That is true, but ironically both use lithium-ion systems. This article looks at the battery in an EV and mobile phone in terms of runtime and longevity.

The battery in the mobile phone is consumer grade, optimized for maximum runtime at low cost. the EV battery, on the other hand, is made to industry standards with longevity in mind. The dissimilarities do not stop there and a key difference is how the energy is dispensed.

A mobile phone gets charged at the end of a day and the stored energy can be fully utilized until the battery goes empty. In other words, the user has full access to the stored energy. When the battery is new, the phone provides good runtimes but this decreases with use. In this full cycle mode, Li-ion delivers about 500 cycles.

The user adjusts to the decreasing runtime, and being a consumer product, the end of battery life often corresponds with a broken screen or the introduction of a new model. Built-in obsolescence serves well for device manufacturers and retailers.

The EV battery also ages and the capacity fades, but the EV manufacturer must guarantee the battery for eight years. This is done by oversizing the battery. When the battery is new, only about half of the available energy is utilized. This is done by charging the pack to only 80% instead of a full charge, and discharging to 30% when the available driving range is spent. As the battery fades, more of the battery storage is demanded. The driving range stays constant but unknown to the driver, the battery is gradually charged to a higher level and discharged deeper to compensate for the fade.

Once the battery capacity has dropped to 80%, the oversize protection is consumed and the battery maintenance system (BMS) applies a full charge and discharge. This exposes the EV battery to a similar stress level of a mobile phone and the driver begins noticing reduced driving range. Battery replacement may become necessary but the cost will be steep and higher than a combustion engine.

The EV begins to impersonate a mobile phone in terms of obsolescence when the battery fades. This may be the time when the buyer is flooded with faster and flashier models; something the smartphone user is all too familiar with, but price will be the shocker. It’s still too early to tell how long an EV battery will last. Some say the battery will outlive the car and find secondary application in energy storage systems.

Driving habits and temperature also affects aging, a characteristic that came to light when EV batteries operating in a warm climate faded prematurely. It was learned that keeping a battery at elevated temperature and high state-of-charge causes more stress than aggressive driving. In other words, keeping a fully charged Li-ion at 30°C (86°F) and above hastens the aging process more than driving at a moderate temperature. Many EV batteries include liquid cooling to reduce heat-related battery fade.

Harsh loading also reduces battery life. Because of its large size, the EV battery is only being stressed moderately, even during acceleration. In comparison, the mobile phone draws continuous high current from a small battery when transmitting and crunching data. This puts more stress on a mobile phone battery than driving an EV. A battery is also negatively impacted by the pulsed load of a mobile phone rather than the DC load of an EV. (See BU-501: Basic about Discharging.)

The EV does not disclose the battery capacity to the driver and only reveals state-of-charge (SoC) in the form of driving range. This is done in part for fear of customer complaints should the capacity drop below the mandated level at the end of the warranty period. Less knowledge is often better. The same restriction applies to a mobile phone battery, although access codes for service personnel are often available. A new battery has (should have) a capacity of 100%; 80% is the typical end of battery life.

Dynamic Stress Tests (DST) on Li-ion

All Li-ion batteries fade with time and use, whether in consumer products or enduring industrial use. Figure 3 explores the longevity of Li-ion batteries with different charge and discharge end points.

Figure 3: Capacity loss of Li-ion as a function of charge and discharge cut-off points.

Limiting a full charge and discharge prolongs battery life but lowers utilization.

Source: ResearchGate – Modeling of Lithium-Ion Battery Degradation for Cell Life Assessment.  ResearchGate is a social networking site for scientists and researchers founded in 2008 to share papers, ask and answer questions, and to find collaborators.

The Li-ion batteries in the above table perform well but the largest capacity loss occurs with the pack that is charged to 100% and discharged to 25% (black stars). Cycling between 85% and 25% (green) provides longer service life than charging to 100% and discharging to 50% (dark blue).

The lowest capacity loss occurs when charging Li-ion to 75% and discharging to 65%. This, however, takes oversizing to the extreme and the battery is underutilized. Such practice is applied in satellites to achieve high cycle life and less for terrestrial applications as it increases cost, size and weight beyond a reasonable point of return. The dynamic stress test does not include a battery that is charged to 100% and discharged to zero, as is the case with a mobile phone. A full cycle provides the best battery utilization but reduces longevity.

Batteries tested in a laboratory do not always replicate true life conditions, and the results tend to be better than experienced in field use. In a lab environment, batteries are cycled over a period of a few months, often at controlled temperature and with an ideal charge and discharge regime. Random usage in real life adds the exposure to heat, vibration and harsh charging practices.

Summary

Batteries do not have a fixed life span, nor do they die suddenly but fade gradually. Environmental conditions, and not cycling alone, govern longevity. The user has some control to prolong battery life by avoiding ultra-fast charges, operating at moderate temperature and avoiding full charges. Avoiding harsh loads and full discharges also helps. Heat is the enemy of most batteries and the worst condition is keeping a fully charged Li-ion battery at elevated temperatures. Even with the best of care, a battery only lives for a season and the pack will eventually face retirement when power fades.

About the Author

Isidor Buchmann is the founder and CEO of Cadex Electronics Inc. For three decades, Buchmann has studied the behavior of rechargeable batteries in practical, everyday applications, has written award-winning articles including the best-selling book “Batteries in a Portable World,” now in its fourth edition. Cadex specializes in the design and manufacturing of battery chargers, analyzers and monitoring devices. For more information on batteries, visit www.batteryuniversity.com; product information is on www.cadex.com.

Research Focus: “BIG” Things Coming from Nanotechnology (very small things)


It may be a cliché, but in the world of nanotechnology, big things really do come in small packages.

The study and application of nanotechnology—science, engineering, and technology conducted at 1 to 100 nanometers—is rapidly growing across medicine, chemistry, physics, materials science, engineering and more.

According to the U.S. National Nanotechnology Initiative (NNI), nanotechnology as we now know it has only been around approximately 30 years. Despite the field’s relatively young lifespan, it has already made significant strides.

Today, researchers are developing everything from next-generation electronics to more effective drug delivery systems at the nanoscale. In February, R&D Magazine took a special focus on this up-and-coming area of research.

Electronics

We kicked off our nanotechnology coverage highlighting a new method to enhance the capabilities of the memristor—an emerging nanotechnology that offers a simpler and smaller alternative to the transistor. In our article, “Memristor Could Enable More Data Storage” we outlined a new memristor technology that can store up to 128 discernible memory states per switch, which is almost four times higher than what has been previously reported.

In another article, “Achieving Printed Power Electronics Means Going Beyond Silver Nanoparticles we outlined the limitations of 3D printed electronics using silver nanoparticle inks for systems that use high-current density known as “power electronics.” In the article, Greg Fritz, a material scientist in the Charles Stark Draper Laboratory, outlined the challenges with silver nanoparticle inks and his team’s research into alternative nano-layered materials for printing power electronics.

Expert contributor Ahmed A. Busnaina, the director of the Center for High-rate Nanomanufacturing (CHN) at Northeastern University, also shared an article outlining his research on nanoscale high-throughput printing technology. He explained a directed assembly-based printing processes developed by CHN in his article, “Scalable Printing Sensors and Electronics at the Nanoscale.”

In Researchers Use Tin Oxide Nanocrystals to Improve Battery Performance, we highlighted scientists at Washington State University’s School of Mechanical and Materials Engineering who utilized tin oxide nanocrystals to improve the performance of both sodium-ion and lithium-ion batteries.

Medicine

Nanotechnology is not limited to applications within traditional ‘technology.’ Nanoscale science also has a growing presence in the medical field, as nanomaterials are being formulated with conventional pharmaceutical agents to create more effective, safer, and more targeted drug delivery systems. We outlined the overall benefits of this approach in “Nanotechnology Can Improve Safety, Effectiveness in Drug Delivery.”The article highlights the work of the Center for Nanotechnology in Drug Delivery at the UNC Eshelman School of Pharmacy which is investigating nanotechnology to treat stroke, neurodegenerative and neurodevelopmental disorders, nerve agent and pesticide poisoning and other diseases and injuries.

One disease area at the forefront of nanomedicine is oncology. We spoke with Piotr Grodzinski, PhD, the Chief of Nanodelivery Systems and Devices Branch at the Cancer Imaging Program of the National Cancer Institute (NCI), to learn more about the role of nanotechnology in oncology for our article, Nanoparticle-Based Cancer Treatment: A Look at its Origins and What’s Next.” The first nanoparticle-based cancer treatment—a formulation of the chemotherapy agent doxorubicin delivered via the nanoparticle material liposome—was approved in 1995. Today, researchers are working on more complex innovations, such as nanoparticle combination therapies and nanoparticles for delivery of immunostimulatory or immunomodulatory molecules.

Material Science

Graphene—a 2D nanomaterial consisting of a single layer of carbon atoms arranged in a hexagonal lattice—has a host of applications. We highlighted one that could improve food safety in, New Lasing Method Enables Edible Graphene Food Trackers.” The article highlighted researchers from Rice University who had enhanced their laser-induced graphene technique to “write” graphene patterns onto food and other materials, enabling embed conductive identification tags and sensors onto products.

We also highlighted a way nanotechnology could be used to create a safer and cleaner environment in, Nano-Crystals Key to Continuously Self-Cleaning Surfaces.”  The article features New Clean NanoSeptic Self-Cleaning Surfaces—skins and mats that can be adhered to most any surface that utilize mineral nano-crystals to create an oxidation reaction stronger than bleach, without using poisons, heavy metals or chemicals. The nano-crystals, charged by visible light, act as a catalyst and the oxidation reaction breaks down organic material into base components including CO2, enabling the surface to continuously oxidize organic contaminants at the microscopic level.

Chemistry

Finally, we tackled the benefits of nanotechnology in the field of chemistry. In the article “Membrane Allows More Precise Chemical Separation Using Charged Nanochannels,” we highlighted a new type of filter has been designed to allow manufacturers to separate organic compounds not only by their size, but also by their electrostatic charge. The highly selective membrane filters could enable manufacturers to separate and purify chemicals in ways that are currently impossible, allowing them to potentially use less energy and cut carbon emissions.

Next Month’s Special Focus

Next month, R&D Magazine is focusing on technologies that are sustainable and clean, known as “green” technologies. Green technologies are created to mitigate or reverse the effects of human activity on the environment, providing a better future for all.

Check back in April for more on what’s happening within the green technology space in R&D.

Watch Our YouTube Video: Nano-Enabled Energy Storage: Super Capacitors and Batteries

PROTON TRANSPORT IN GRAPHENE SHOWS PROMISE FOR RENEWABLE ENERGY


RESEARCHERS AT THE UNIVERSITY OF MANCHESTER HAVE DISCOVERED ANOTHER NEW AND UNEXPECTED PHYSICAL EFFECT IN GRAPHENE – MEMBRANES THAT COULD BE USED IN DEVICES TO ARTIFICIALLY MIMIC PHOTOSYNTHESIS.

National Graphene Association

The new findings demonstrated an increase in the rate at which the material conducts protons when it is simply illuminated with sunlight. The ‘photo-proton’ effect, as it has been dubbed, could be exploited to design devices able to directly harvest solar energy to produce hydrogen gas, a promising green fuel. It might also be of interest for other applications, such as light-induced water splitting, photo-catalysis and for making new types of highly efficient photodetectors.

Graphene is a sheet of carbon atoms just one atom thick and has numerous unique physical and mechanical properties. It is an excellent conductor of electrons and can absorb light of all wavelengths.

Researchers recently found that it is also permeable to thermal protons (the nuclei of hydrogen atoms), which means that it might be employed as a proton-conducting membrane in various technology applications.

To find out how light affects the behaviour of protons permeating through the carbon sheet, a team led by Dr Marcelo Lozada-Hidalgo and Professor Sir Andre Geim fabricated pristine graphene membranes and decorated them on one side with platinum nanoparticles. The Manchester scientists were surprised to find that the proton conductivity of these membranes was enhanced 10 times when they were illuminated with sunlight.

Dr Lozada-Hidalgo said: “By far the most interesting application is producing hydrogen in an artificial photosynthetic system based on these membranes.”

Prof Geim is also optimistic: “This is essentially a new experimental system in which protons, electrons and photons are all packed together in an atomically thin volume. I am sure that there is a lot of new physics to be unearthed, and new applications will follow.”

img_0455Scientists around the world are busy looking into how to directly use solar energy to produce renewable fuels (such as hydrogen) by mimicking photosynthesis in plants. These man-made ‘leaves’ will require membranes with very sophisticated properties – including mixed proton-electron conductivity, permeability to gases, mechanical robustness and optical transparency.

Currently, researchers use a mixture of proton and electron-conducting polymers to make such structures, but these require some important trade-offs that could be avoided by using graphene.

Using electrical measurements and mass spectrometry, the researchers say that they measured a photoresponsivity of around 104 A/W, which translates into around 5000 hydrogen molecules being formed in response to every solar photon (light particle) incident on the membrane. This is a huge number if compared with the existing photovoltaic devices where many thousands of photons are needed to produce just a single hydrogen molecule.

“We knew that graphene absorbs light of all frequencies and that it is also permeable to protons, but there was no reason for us to expect that the photons absorbed by the material could enhance the permeation rate of protons through it.” says Lozada-Hidalgo.

“The result is even more surprising when we realised that the membrane was many orders of magnitude more sensitive to light than devices that are specifically designed to be light-sensitive. Examples of such devices include commercial photodiodes or those made from novel 2D materials.”

Photodetectors typically harvest light to produce just electricity but graphene membranes produce both electricity and, as a by-product, hydrogen. The speed at which they respond to light in the microsecond range is faster than most commercial photodiodes.

The authors acknowledge support from the Lloyd’s Register Foundation, EPSRC (EP/ N010345/1), the European Research Council ARTIMATTER project (ERC-2012-ADG) and from Graphene Flagship. M.L.-H. acknowledges a Leverhulme Early Career Fellowship.

Source: The University of Manchester