Silicon Anodes as a Solution for Today’s Battery Technology – Scientists at Pacific Northwest National Laboratory Explore Opportunities for 10X Energy +Safety


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A silicon anode virtually intact after one cycle, with the silicon (green) clearly separate from a component of the solid electrolyte interphase (fluorine, in red). Credit: Chongmin Wang | Pacific Northwest National Laboratory

Silicon is a staple of the digital revolution, shunting loads of signals on a device that’s likely just inches from your eyes at this very moment.

Now, that same plentiful, cheap material is becoming a serious candidate for a big role in the burgeoning battery business. It’s especially attractive because it’s able to hold 10 times as much energy in an important part of a battery, the , than widely used graphite.

But not so fast. While  has a swell reputation among scientists, the material itself swells when it’s part of a battery. It swells so much that the anode flakes and cracks, causing the battery to lose its ability to hold a charge and ultimately to fail.

Now scientists have witnessed the process for the first time, an important step toward making silicon a viable choice that could improve the cost, performance and charging speed of batteries for electric vehicles as well as cell phones, laptops, smart watches and other gadgets.

“Many people have imagined what might be happening but no one had actually demonstrated it before,” said Chongmin Wang, a scientist at the Department of Energy’s Pacific Northwest National Laboratory. Wang is a corresponding author of the paper recently published in Nature Nanotechnology.

Of silicon anodes, peanut butter cups and packed airline passengers

Lithium ions are the energy currency in a , traveling back and forth between two electrodes through liquid called electrolyte. When lithium ions enter an anode made of silicon, they muscle their way into the orderly structure, pushing the silicon atoms askew, like a stout airline passenger squeezing into the middle seat on a packed flight. This “lithium squeeze” makes the anode swell to three or four times its original size.

When the lithium ions depart, things don’t return to normal. Empty spaces known as vacancies remain. Displaced silicon atoms fill in many, but not all, of the vacancies, like passengers quickly taking back the empty space when the middle passenger heads for the restroom. But the lithium ions return, pushing their way in again. The process repeats as the lithium ions scoot back and forth between the anode and cathode, and the empty spaces in the silicon anode merge to form voids or gaps. These gaps translate to battery failure.

Scientists have known about the process for years, but they hadn’t before witnessed precisely how it results in battery failure. Some have attributed the failure to the loss of silicon and lithium. Others have blamed the thickening of a key component known as the solid-electrolyte interphase or SEI. The SEI is a delicate structure at the edge of the anode that is an important gateway between the anode and the liquid electrolyte.

In its experiments, the team watched as the vacancies left by lithium ions in the silicon anode evolved into larger and larger gaps. Then they watched as the liquid electrolyte flowed into the gaps like tiny rivulets along a shoreline, infiltrating the silicon. This inflow allowed the SEI to develop in areas within the silicon where it shouldn’t be, a molecular invader in a part of the battery where it doesn’t belong.

That created dead zones, destroying the ability of the silicon to store lithium and ruining the anode.

Think of a peanut butter cup in pristine shape: The chocolate outside is distinct from the soft peanut butter inside. But if you hold it in your hand too long with too tight a grip, the outer shell softens and mixes with the soft chocolate inside. You’re left with a single disordered mass whose structure is changed irreversibly. You no longer have a true peanut butter cup. Likewise, after the electrolyte and the SEI infiltrate the silicon, scientists no longer have a workable anode.

Silicon anodes muscle in on battery technology
A silicon anode after 100 cycles: The anode is barely recognizable as a silicon structure and is instead a mix of the silicon (green) and the fluorine (red) from the solid electrolyte interphase. Credit: Chongmin Wang | Pacific Northwest National Laboratory

The team witnessed this process begin immediately after just one battery cycle. After 36 cycles, the battery’s ability to hold a charge had fallen dramatically. After 100 cycles, the anode was ruined.

Exploring the promise of silicon anodes

Scientists are working on ways to protect the silicon from the electrolyte. Several groups, including scientists at PNNL, are developing coatings designed to act as gatekeepers, allowing lithium ions to go into and out of the anode while stopping other components of the electrolyte.

Scientists from several institutions pooled their expertise to do the work. Scientists at Los Alamos National Laboratory created the silicon nanowires used in the study. PNNL scientists worked together with counterparts at Thermo Fisher Scientific to modify a cryogenic transmission electron microscope to reduce the damage from the electrons used for imaging. And Penn State University scientists developed an algorithm to simulate the molecular action between the liquid and the silicon.

Altogether, the team used electrons to make ultra-high-resolution images of the process and then reconstructed the images in 3-D, similar to how physicians create a 3-D image of a patient’s limb or organ.

“This work offers a clear roadmap for developing silicon as the anode for a high-capacity battery,” said Wang.


Explore further

Novel method of imaging silicon anode degradation may lead to better batteries


More information: Chongmin Wang et al, Progressive growth of the solid–electrolyte interphase towards the Si anode interior causes capacity fading, Nature Nanotechnology (2021). DOI: 10.1038/s41565-021-00947-8

Journal information: Nature Nanotechnology

Read the Top 4 Articles from Genesis Nanotech This Week Like: New MIT Nano-Kevlar – Hydrogen Fuel from the Sea + More …


An Alternative to Kevlar – MIT and Caltech Create Nanotech Carbon Materials – Can withstand supersonic microparticle impacts

New Nanoscale Material Harvests Hydrogen Fuel From the Sea – University of Central Florida

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Engineers Develop a Simple Way to Desalinate Water Using Solar Energy – Reduced Costs + 4X Production Volume

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Hydrogen Powered Fuel Cell EV’s? Or Battery Powered EV’s? Toyota is Placing a Bet on the Green Future

Hydrogen Powered Fuel Cell EV’s? Or Battery Powered EV’s? Toyota is Placing a Bet on the Green Future


While Toyota has seen success far and wide as an early pioneer of hybrid cars, it’s had much less luck with another technology it has invested heavily in: hydrogen-powered fuel cell EVs.

While the rest of the electric car market is going heavily battery-powered, Toyota is still banking on hydrogen power in many ways—even as competitors like Honda and BMW have seemingly dialed down their hydrogen ambitions. Now we know that Toyota’s conservative battery EV strategy and its big bet on hydrogen are closely related issues.

Toyota’s HFC Car

A recent report from the New York Times shows that the company’s hydrogen play has become further reaching than just internal development; it has also become political.

Toyota’s H2 Mirai

According to the report, a Toyota executive has been traveling to Washington on behalf of the automaker and has taken steps to slow the entire industry’s adoption of electric vehicles. Chris Reynolds, a high-ranking senior executive for Toyota, reportedly has held closed-door meetings with congressional staff members.

At least four people familiar with the matter told the New York Times that Reynolds argued against an aggressive rollout of fully electric vehicles, instead urging for a focus on hybrids (like the Prius) and other alternatively-fueled vehicles, like hydrogen-powered fuel-cell EVs.

This all comes at a time when multiple automakers are planning to go fully or mostly battery electric in the years to come, often driven by tightening emissions rules in China and Europe. Toyota, on the other hand, feels incredibly late to the EV game.

Despite Toyota’s recent ambitious plans to launch 15 fully electric cars by 2025, it has only shown the world a concept of its upcoming bZ4X while other manufacturers like Audi, Ford, Hyundai, Jaguar, Porsche, Volvo, and Volkswagen all have at least one BEV for sale today.

So if Toyota can persuade lawmakers of the importance of hybrids over EVs and successfully stymie funding for EV-related infrastructure and incentives, it could give the automaker more time to separate from its crutch on hybrids and catch up to other manufacturers.

The potential impact of lobbying against BEVs can be seen in the recently proposed infrastructure spending bill, which cuts the government funding for expanding the EV charging infrastructure in half of what was anticipated by President Joe Biden’s staffers to deploy 500,000 EV charging stations nationwide.

In addition to doing a potential disservice to American EV adopters, these actions could potentially impede the already full-speed efforts by other automakers pushing towards aggressive EV rollouts.

It is worth noting, Reynolds was recently named board chair for the Alliance for Automotive Innovation. The alliance is a lobbying organization that represents the interests of many automakers and OEM suppliers, many of which aren’t as heavily invested in hydrogen power or hybrids as Toyota.

Could Form Energy’s “Iron-Air-Exchange Batteries” be the Holy Grail Answer to Large Scale Energy Storage? Ingredients? Rust And Salt


Form Energy Battery System Rendering. Courtesy Form Energy

Salt and rust – the bane of your car’s existence — may be the keys to storing enough renewable energy to power the electric grid for several days. That’s according to two local companies that have emerged with innovative battery designs based on cheap, widely-available materials.

After four years of stealth R&D, Somerville-based Form Energyhas emerged with what could be a breakthrough energy storage technology, based on rust.

Form Energy president and CEO Ted Wiley says the company has produced hundreds of working prototypes of an iron-air-exchange battery that can store large amounts of energy for several days.

“We’ve completed the science,” says Wiley, “what’s left to do is scale up from lab-scale protoypes to grid-scale power plants. “

In full production, “the modules will produce electricity for one-tenth the cost of any technology available today for grid storage,” Wiley says.

If the plan comes to fruition, Form Energy’s batteries could realize what’s called “the renewable energy Holy Grail” — relatively inexpensive, reliable grid-scale energy storage. Because solar and wind do not generate power when the sun is down or the wind isn’t blowing, storing their power for down times is the key to clean energy reliability.

The Form Energy battery is composed of cells filled with thousands of small iron pellets that, rust when exposed to air. When oxygen is removed the rust reverts to iron. By controlling the process the battery is charged and discharged.

The iron anode section of Form Energy's prototype iron-air battery. Courtesy Form Energy
The iron anode section of Form Energy’s prototype iron-air battery. Courtesy Form Energy

The plan is to mount small cells into larger modules, then assemble modules into batteries that can be scaled to power electric grids. Wiley expects to have a 300Mwh, full-scale pilot project, using 500 modules, up and running at the Great River Energy power plant in Minnesota in 2023.

In nearby Cambridge, researchers at Malta, Inc. are working on an energy storage technology based on an equally humble material: molten salt.

Electricity from the grid is converted into thermal energy and stored as heat in trays of molten sodium. When the grid needs energy the process is reversed and the molten sodium is used to generate electricity.

A high-energy density and long-life initial-anode-free lithium battery


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Cathode and electrolyte design strategies for the researchers’ anode-free Li cell system. Credit: Qiao et al.

Lithium-metal batteries (LMBs), an emerging type of rechargeable lithium-based batteries made of solid-state metal instead of lithium-ions, are among the most promising high-energy-density rechargeable battery technologies. Although they have some advantageous characteristics, these batteries have several limitations, including a poor energy density and safety-related issues.

In recent years, researchers have tried to overcome these limitations by introducing an alternative, anode-free lithium battery cell design. This anode-free design could help to increase the  density and safety of .

Researchers at the National Institute of Advanced Industrial Science and Technology recently carried out a study aimed at increasing the energy density of anode-free lithium batteries. Their paper, published in Nature Energy, introduces a new high-energy-density and long-life anode-free lithium battery based on the use of a Li2O sacrificial agent.

Anode-free full-cell battery architectures are typically based on a fully lithiated cathode with a bare anode copper current collector. Remarkably, both the gravimetric and volumetric energy densities of anode-free lithium batteries can be extended to their maximum limit. Anode-free cell architectures have several other advantages over more conventional LMB designs, including a lower cost, greater safety and simpler cell assembly procedures.

To unlock the full potential of anode-free LMBs, researchers should first figure out how to achieve the reversibility/stability of Li-metal plating. While many have tried to solve this problem by engineering and selecting more favorable electrolytes, most of these efforts have so far been unsuccessful.

Others have also explored the potential of using salts or additives that could improve the Li-metal plating/stripping reversibility. After reviewing these previous attempts, the researchers at the National Institute of Advanced Industrial Science and Technology proposed the use of Li2O as a sacrificial agent, which is pre-loaded onto a LiNi0.8Co0.1Mn0.1O2 surface.

“It is challenging to realize high Li reversibility, especially considering the limited Li reservoir (typically zero lithium excess) in the cell configuration,” the researchers wrote in their paper. “In this study we have introduced Li2O as a preloaded sacrificial agent on a LiNi0.8Co0.1Mn0.1O2 cathode, providing an additional Li source to offset the irreversible loss of Li during long-term cycling in an initial-anode-free cell.”

In addition to employing Li2O as a sacrificial agent, the researchers proposed the use of a fluoropropyl ether additive to neutralize nucleophilic O2-, which is released during the oxidation of Li2O, and prevent the additional evolution of gaseous O2 resulting from the fabrication of a LiF-based electrolyte coated on the surface of the battery’s cathode.

“We show that O2– species, released through Li2O oxidation, are synergistically neutralized by a fluorinated ether additive,” the researchers explained in their paper. “This leads to the construction of a LiF-based layer at the cathode/electrolyte interface, which passivates the cathode surface and restrains the detrimental oxidative decomposition of ether solvents.”

Based on the design they devised, Yu Qiao and the rest of the team at the National Institute of Advanced Industrial Science and Technology were able to realize a long-life 2.46 Ah initial-anode-free pouch cell. This cell exhibited a gravimetric  of 320 Wh kg-1, maintaining an 80% capacity after 300 operation cycles.

In the future, the anode-free lithium battery introduced by this research group could help to overcome some of the commonly reported limitations of LMBs. In addition, its design could inspire the creation of safer lithium-based rechargeable batteries with higher energy densities and longer lifetimes.


Explore further

An anode-free zinc battery that could someday store renewable energyMore information: A high-energy-density and long-life initial-anode-free lithium battery enabled by a Li2O sacrificial agent. Nature Energy(2021). DOI: 10.1038/s41560-021-00839-0.

Journal information: Nature Energy

U.S. Lawmakers “Pedal” Tax Credits For E-bikes


E Bike TC 1 Biking-Capitol

Have you heard the big news out of Washington, D.C., this week? No, not that news …

We’re talking about the Electric Bicycle Incentive Kickstart for the Environment Act, also known as the EBIKE Act (clever, right?), that was proposed Tuesday by U.S. House of Representatives co-sponsors Earl Blumenauer (Oregon) and Jimmy Panetta (California).

If passed, this legislation would provide a tax credit of 30 percent off (up to $1,500) a new electric bike priced at under $8,000. If you’re one of the many Americans who end up getting money back from the IRS around tax time, this could add to your refund. If you’re eyeing a new Rad model, that’s a potential average credit of $419 in your pocket.

In a statement, Panetta said that this proposal is rooted in the environmental benefits that come from more people jumping on an ebike rather than driving a car.

“Ebikes are not just a fad for a select few, they are a legitimate and practical form of transportation that can help reduce our carbon emission,” the Congressman explained. “By incentivizing the use of electric bicycles to replace car trips through a consumer tax credit, we can not only encourage more Americans to transition to greener modes of transportation, but also help fight the climate crisis.”

The legislation comes on the heels of other bicycle-friendly bills put forward by Blumenauer, the Co-Chair of the Congressional Bike Caucus, including some that would strengthen the nation’s cycling infrastructure and expand tax credits for commuters who bike to work.

“One of the few positive developments of the last year has been the surge in biking. Communities large and small are driving a bike boom,” Blumenauer said in a statement. “Notably, electric bicycles are expanding the range of people who can participate, making bike commuting even easier.”

Our mission from day one has been to revolutionize the world of mobility, and seeing concrete legislative action that’ll motivate more people to turn to ebikes is a surefire sign we’re on the right path.

But like so many bills floated in the nation’s capital, the EBIKE Act won’t pass without a few riders (some legislative humor for ya). In this case, that means Rad riders like you!

If you want to see a consumer tax credit for new e-bikes, contact your Congressional representative and politely ask them to lend their support. Find Your Rep!

And keep an eye on this issue. We’re not counting on seeing this passed by peak riding season and there’s a long road ahead, including making it to the Senate!

Rad Power Bikes receives $150 million investment


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Rad Power Bikes announced Thursday it received a minority investment of $150 million from several companies.

The investors are Morgan Stanley Counterpoint Global; Fidelity Management & Research Company; The Rise Fund, the global impact investing platform managed by TPG; and funds and accounts advised by T. Rowe Price Associates Inc.

Existing investors Durable Capital Partners LP and Vulcan Capital also participated in this investment round. Rad Power Bikes said the investment reflects a historic commitment to the company’s vision of a world where transportation is energy efficient, enjoyable, and accessible to all.

Rad Power Bikes said it will use the funding to extend its market leadership, drive innovation, and scale retail and service offerings.

“E-bikes will play an important role in the future of mobility, extending far beyond the traditional bike market,” said Sam Chainani, managing director of Morgan Stanley Counterpoint Global. “Our partnership with Rad Power Bikes is exciting as this innovative company is rapidly changing the way the world moves. (CEO) Mike Radenbaugh and his team have already proven the economics of convenient, energy-efficient mobility solutions.”

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Rad Power Bikes has played a role in expanding the e-bike market with its direct-to-consumer models. Since launching its flagship RadRover Electric Fat Tire Bike in 2015, it now offers 11 models for everything from commuting to adventuring to hauling gear.

“We are thrilled to be working with this group of prestigious investors who are known for successful, long-term investments, and share our vision for the future of mobility,” Radenbaugh said. “Demand for our products has outpaced our wildest projections every year, and this partnership is helping us accelerate in-house innovation while creating more of what our customers tell us they love. I can’t wait for everyone to see what we will deliver in 2021 and beyond.”

To meet demand, Rad Power Bikes expanded its workforce to 325 employees in 2020. With plans to expand its global footprint, the company plans to double the size of its team by the end of 2021, hiring throughout North America, Europe and Asia.

“Rad Power Bikes has built an operation with all the earmarks of a company that can be much larger over time,” said Henry Ellenbogen of Durable Capital Partners LP. “Their commitment to innovation and providing excellent customer service to their riders has resulted in a high referral rate. We recognize the opportunity that the company has and are excited about the company’s prospects.”

 
                            Rad Power Bikes receives $150 million investment

How will we get to the next big battery breakthrough?


Battery break through 1 Final-3-qz2-Tsjisse-Talsma1

Electric planes could be the future of aviation. In theory, they will be much quieter, cheaper, and cleaner than the planes we have today. Electric planes with a 1,000 km (620 mile) range on a single charge could be used for half of all commercial aircraft flights today, cutting global aviation’s carbon emissions by about 15%.

It’s the same story with electric cars. An electric car isn’t simply a cleaner version of its pollution-spewing cousin. It is, fundamentally, a better car: Its electric motor makes little noise and provides lightning-fast response to the driver’s decisions. Charging an electric car costs much less than paying for an equivalent amount of gasoline. Electric cars can be built with a fraction of moving parts, which makes them cheaper to maintain.

So why aren’t electric cars everywhere already? It’s because batteries are expensive, making the upfront cost of an electric car much higher than a similar gas-powered model. And unless you drive a lot, the savings on gasoline don’t always offset the higher upfront cost. In short, electric cars still aren’t economical.

Similarly, current batteries don’t pack in enough energy by weight or volume to power passenger aircrafts. We still need fundamental breakthroughs in battery technology before that becomes a reality.

Battery-powered portable devices have transformed our lives. But there’s a lot more that can batteries can disrupt, if only safer, more powerful, and energy-dense batteries could be made cheaply. No law of physics precludes their existence.

And yet, despite over two centuries of close study since the first battery was invented in 1799, scientists still don’t fully understand many of the fundamentals of what exactly happens inside these devices. What we do know is that there are, essentially, three problems to solve in order for batteries to truly transform our lives yet again: power, energy, and safety.

THERE ISN’T A ONE-SIZE-FITS-ALL LITHIUM-ION BATTERY

Every battery has two electrodes: a cathode and an anode. Most anodes of lithium-ion batteries are made of graphite, but cathodes are made of various materials, depending on what the battery will be used for. Below, you can see how different cathode materials change the way battery types perform on six measures.

The power challenge

In common parlance, people use “energy” and “power” interchangeably, but it’s important to differentiate between them when talking about batteries. Power is the rate at which energy can be released.

A battery strong enough to launch and keep aloft a commercial jet for 1,000 km requires a lot of energy to be released in very little time, especially during takeoff. So it’s not just about having lots of energy stored but also having the ability to extract that energy very quickly.

Tackling the power challenge requires us to look inside the black box of commercial batteries. It’s going to get a little nerdy, but bear with me. New battery technologies are often overhyped because most people don’t look closely enough at the details.

The most cutting-edge battery chemistry we currently have is lithium-ion. Most experts agree that no other chemistry is going disrupt lithium-ion for at least another decade or more. A lithium-ion battery has two electrodes (cathode and anode) with a separator (a material that conducts ions but not electrons, designed to prevent shorting) in the middle and an electrolyte (usually liquid) to enable the flow of lithium ions back and forth between the electrodes. When a battery is charging, the ions travel from the cathode to the anode; when the battery is powering something, the ions move in the opposite direction.

Imagine two loaves of sliced bread. Each loaf is an electrode: the left one is the cathode and the right is one the anode. Let’s assume the cathode is made up of slices of nickel, manganese, and cobalt (NMC)—one of the best in the class—and that the anode is made up of graphite, which is essentially layered sheets, or slices, of carbon atoms.

In the discharged state—i.e., after it has been drained of energy—the NMC loaf has lithium ions sandwiched between each slice. When the battery is charging, each lithium ion is extracted from between the slices and forced to travel through the liquid electrolyte. The separator acts as a checkpoint ensuring only lithium ions pass through to the graphite loaf. When fully charged, the battery’s cathode loaf will have no lithium ions left; they will all be neatly sandwiched between the slices of the graphite loaf. As the battery’s energy is consumed, the lithium ions travel back to the cathode, until there are none left in the anode. That’s when the battery needs to be charged again.

The battery’s power capacity is determined by, essentially, how fast this process happens. But it’s not so simple to turn up the speed. Drawing lithium-ions out of the cathode loaf too quickly can cause the slices to develop flaws and eventually break down. It’s one reason why the longer we use our smartphone, laptop, or electric car, the worse their battery life gets. Every charge and discharge causes the loaf to weaken that little bit.

Various companies are working on solutions to the problem. One idea is to replace layered electrodes with something structurally stronger. For example, the 100-year-old Swiss battery company Leclanché is working on a technology that uses lithium iron phosphate (LFP), which has an “olivine” structure, as the cathode, and lithium titanate oxide (LTO), which has a “spinel” structure, as the anode. These structures are better at handling the flow of lithium ions in and out of the material.

Leclanché currently uses its battery cells in autonomous warehouse forklifts, which can be charged to 100% in nine minutes. For comparison, the best Tesla supercharger can charge a Tesla car battery to about 50% in 10 minutes. Leclanché is also deploying its batteries in the UK for fast-charging electric cars. These batteries sit at the charging station slowly drawing small amounts of power over a long period from the grid until they are fully charged. Then, when a car docks, the docking-station batteries quick-charge the car’s battery. When the car leaves, the station battery starts recharging again.

Efforts like Leclanché’s show it’s possible to tinker with battery chemistries to increase their power. Still, nobody has yet built a battery powerful enough to rapidly deliver the energy needed for a commercial plane to defeat gravity. Startups are looking to build smaller planes (seating up to 12 people), which could fly on relatively lower power-dense batteries, or electric hybrid planes, where jet fuel does the hard lifting and batteries do the coasting.

But there’s really no company working in this space anywhere near commercialization. Further, the kind of technological leap required for an all-electric commercial plane will likely take decades, says Venkat Viswanathan, a battery expert at Carnegie Mellon University.

electric-plane-two-seaterREUTERS/ALISTER DOYLE A two-seat electric plane made by Slovenian firm Pipistrel stands outside a hangar at Oslo Airport, Norway.

The energy challenge

The Tesla Model 3, the company’s most affordable model, starts at $35,000. It runs on a 50 kWh battery, which costs approximately $8,750, or 25% of the total car price.

That’s still amazingly affordable compared to not that long ago. According to Bloomberg New Energy Finance, the average global cost for lithium-ion batteries in 2018 was about $175 per kWh—down from nearly $1,200 per kWh in 2010.

The US Department of Energy calculates that once battery costs fall below $125 per kWh, owning and operating an electric car will be cheaper than a gas-powered car in most parts of the world. It doesn’t mean electric vehicles will win over gas-powered vehicles in all niches and domains—for example, long-haul trucks don’t yet have an electric solution. But it’s a tipping point where people will start to prefer electric cars simply because they will make more economical sense in most cases.

One way to get there is to increase the energy density of batteries—to cram more kWh into a battery pack without lowering its price. Battery chemist can do that, in theory, by increasing the energy density of either the cathode or the anode, or both.

The most energy-dense cathode on the way to commercial availability is NMC 811 (each digit in the number represents the ratio of nickel, manganese, and cobalt, respectively, in the mix). It’s not yet perfect. The biggest problem is that it can only withstand a relatively small number of charge-discharge life cycles before it stops working. But experts predict that industry R&D should solve the problems of the NMC 811 within the next five years. When that happens, batteries using NMC 811 will have higher energy density by 10% or more.

However, a 10% increase is not that much in the big picture.
And, while a series of innovations over the past few decades have pushed the energy density of cathodes ever higher, anodes are where the biggest energy-density opportunities lie.

Graphite has been and remains far and away the dominant anode material. It’s cheap, reliable, and relatively energy dense, especially compared to current cathode materials. But it’s fairly weak when stacked up against other potential anode materials, like silicon and lithium.

Silicon, for example, is theoretically much better at absorbing lithium ions as graphite. That’s why a number of battery companies are trying to pepper some silicon in with the graphite in their anode designs; Tesla CEO Elon Musk has said his company is already doing this in its lithium-ion batteries.

A bigger step would be to develop a commercially viable anode made completely from silicon. But the element has traits that make this difficult. When graphite absorbs lithium ions, its volume does not change much. A silicon anode, however, swells to four times its original volume in the same scenario.

Unfortunately, you can’t just make the casing bigger to accommodate that swelling, because the expansion breaks apart what’s called the “solid electrolyte interphase,” or SEI, of the silicon anode.

You can think of the SEI as a sort of protective layer that the anode creates for itself, similar to the way that iron forms rust, also known as iron oxide, to protect itself from the elements: When you leave a piece of newly forged iron outside, it slowly reacts with the oxygen in the air to rust. Underneath the layer of rust, the rest of the iron doesn’t suffer from the same fate and thus retains the structural integrity.

At the end of a battery’s first charge, the electrode forms it’s own “rust” layer—the SEI—separating the uneroded part of the electrode from the electrolyte. The SEI stops additional chemical reactions from consuming the electrode, ensuring that lithium ions can flow as smoothly as possible.

But with a silicon anode, the SEI breaks apart every time the battery is used to power something up, and reforms every time the battery is charged. And during each charge cycle, a little bit of silicon is consumed. Eventually, the silicon dissipates to the point where the battery no longer works.

Over the last decade, a few Silicon Valley startups have been working to solve this problem. For example, Sila Nano’s approach is to encase silicon atoms inside a nano-sized shell with lots of empty room inside. That way, the SEI is formed on the outside of the shell and the expansion of silicon atoms happens inside it without shattering the SEI after each charge-discharge cycle. The company, valued at $350 million, says its technology will power devices as soon as 2020.

Enovix, on the other hand, applies a special manufacturing technique to put a 100% silicon anode under enormous physical pressure, forcing it to absorb fewer lithium ion and thus restricting the expansion of the anode and preventing the SEI from breaking. The company has investments from Intel and Qualcomm, and it also expects to have its batteries in devices by 2020.

These compromises mean the silicon anode can’t reach its theoretical high energy density. However, both companies say their anodes perform better than a graphite anode. Third parties are currently testing both firms’ batteries.

roadster-tesla-1000kmTESLA In 2020, the new Tesla Roadster is set to become the first electric car that offers 1,000 km (620 miles) on a single charge.

The safety challenge

All the molecular tinkering done to pack more energy in batteries can come at the cost of safety. Ever since its invention, the lithium-ion battery has caused headaches because of how often it catches fire. In the 1990s, for example, Canada’s Moli Energy commercialized a lithium-metal battery for use in phones. But out in the real world, its batteries started catching fire, and Moli was forced to make a recall, and, eventually, file for bankruptcy. (Some of its assets were bought by a Taiwanese company and it still sells lithium-ion batteries the brand name E-One Moli Energy.) More recently, Samsung’s Galaxy Note 7 smartphones, which were made with modern lithium-ion batteries, started exploding in people’s pockets. The resulting 2016 product recall cost the South Korean giant $5.3 billion.

Today’s lithium-ion batteries still have inherent risks, because they almost always use flammable liquids as the electrolyte. It’s one of nature’s unfortunate (for us humans) quirks that liquids able to easily transport ions also tend to have a lower threshold to catching fire. One solution is to use solid electrolytes. But that means other compromises. A battery design can easily include a liquid electrolyte that’s in contact with every bit of the electrodes—making it able to efficiently transfer ions. It’s much harder with solids. Imagine dropping a pair of dice into a cup of water. Now imagine dropping those same dice into a cup of sand. Obviously, the water will touch far more surface area of the dice than the sand will.

So far, the commercial use of lithium-ion batteries with solid electrolytes has been limited to low-power applications, such as for internet-connected sensors. The efforts to scale up solid-state batteries—that is, containing no liquid electrolyte—can be broadly classified into two categories: solid polymers at high temperatures and ceramics at room temperature.

SOLID POLYMERS AT HIGH TEMPERATURES

Polymers are long chains of molecules linked up together. They’re extremely common in everyday applications—single-use plastic bags are made of polymers, for example. When some types of polymers are heated, they behave like liquids, but without the flammability of the liquid electrolytes used in most batteries. In other words, they have the high ion conductivity as a liquid electrolyte without the risks.

But they have limitations. They can only operate at temperatures above 105°C (220°F), which means they aren’t practical options for, say, smartphones. But they can be used for storing energy from the grid in home batteries, for example. At least two companies—US-based SEEO and France-based Bolloré—are developing solid-state batteries that use high-temperature polymers as the electrolyte.

CERAMICS AT ROOM TEMPERATURE

Over the last decade, two classes of ceramics—LLZO (lithium, lanthanum, and zirconium oxide) and LGPS (lithium, germanium, phosphorus sulfide)—have proven almost as good at conducting ions at room temperature as liquids.

Toyota, as well as the Silicon Valley startup QuantumScape (which raised $100 million in funding from Volkswagen last year), are both working on deploying ceramics in lithium-ion batteries. The inclusion of big players in the space is indicative that a breakthrough might be nearer than many think.

“We are quite close to seeing something real [using ceramics] in two or three years,” says Carnegie Mellon‘s Viswanathan.

A balancing act

Batteries are already big business, and the market for them keeps growing. All that money attracts a lot of entrepreneurs with even more ideas. But battery startups are difficult bets—they fizzle even more often than software companies, which are known for their high failure rate. That’s because innovation in material sciences is hard.

So far battery chemists have found that, when they try to improve one trait (say energy density), they have to compromise on some other trait (say safety). That kind of balancing act has meant the progress on each front has been slow and fraught with problems.

But with more eyes on the problem—MIT’s Yet-Ming Chiang reckons there are three times as many battery scientists in the US today than just 10 years ago—the chances of success go up. The potential of batteries remains huge, but given the challenges ahead, it’s better to look at every claim about new batteries with a good dose of skepticism.

Article Provided by Quartz

Harley-Davidson officially spins off new electric bicycle company with stunning first model


This is it. Harley-Davidson has been teasing us with the prospect of their own in-house electric bicycles for over two years. And today the bar-and-shield motorcycle manufacturer has finally announced its new dedicated electric bicycle brand known as Serial 1 Cycle Company.

The brand’s name is an homage to the very first motorcycle ever built by Harley-Davidson in 1903, named “Serial Number One.”

Back then, motorcycles were essentially just bicycles with a small engine placed in front of the pedals.

And so it is fitting that the company’s first electric bicycle is a nod to that very first H-D motorcycle. Check out both in the video below to see how well they nailed the tribute.

As Serial 1 Cycle Company’s brand director Aaron Frank explained in a statement provided to Electrek:

When Harley-Davidson first put power to two wheels in 1903, it changed how the world moved, forever. Inspired by the entrepreneurial vision of Harley-Davidson’s founders, we hope to once again change how cyclists and the cycling-curious move around their world with a Serial 1 eBicycle.

The new e-bike brand from H-D actually began life as a skunkworks project in Harley-Davidson’s Product Development Center.

As the company explained, they began with “a small group of passionate motorcycle and bicycle enthusiasts working with a single focus to design and develop an eBicycle worthy of the Harley-Davidson name.”

Ultimately, they decided along with H-D to spin off the brand into a dedicated electric bicycle company that could focus purely on delivering a premium e-bike product and experience.

In addition to Aaron Frank, other major players from H-D’s in-house e-bike program that made the jump to Serial 1 Cycle Company include Jason Huntsman, president; Ben Lund, vice president; and Hannah Altenburg, lead brand marketing specialist.

Serial 1 will officially debut its first electric bicycle models for consumers in March 2021. For now, the company is showing off its first prototype model, which the brand describes as “a styling exercise, not necessarily intended for mass production.”

This prototype has been styled after that original 1903 Serial Number One motorcycle from Harley-Davidson. But interestingly, we can see that it shares the same frame as one of the original three electric bicycle prototypes that I spied last year at the 2019 EICMA Milan Motorcycle Show.

That means that while this specific styling likely won’t see showroom floors, the bike it is based on very well may be here this spring.

As we’ve previously seen, the design includes a mid-drive motor, a belt drive system that looks very much like a Gates Carbon Drive setup (which would make sense, as Harley-Davidson’s other belt-driven motorcycles including the all-electric LiveWire also uses belt drive systems from Gates), frame-integrated headlights and taillights, thru-axle wheel hubs, what appear to be Tektro dual-piston hydraulic disc brakes on 203 mm rotors, a Brooks leather saddle, and beautifully wrapped leather handgrips. 

I’m still left with many questions. Will these parts make it onto Serial 1 Cycle Company’s production models? What power level is the motor? What is the battery capacity? How much will the e-bikes cost?

For these questions and more, we still have no answers. But at least now we have a better idea of when to expect answers, and who we will be receiving them from. Stay tuned, because as soon as Serial 1 has more details for us, we’ll be back to share them with you.

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Mainstream EV Adoption: 5 Speedbumps to Overcome


** Article from the Visual Capitalist **

Many would agree that a global shift to electric vehicles (EV) is an important step in achieving a carbon-free future. However, for various reasons, EVs have so far struggled to break into the mainstream, accounting for just 2.5% of global auto sales in 2019. 

To understand why, this infographic from Castrol identifies the five critical challenges that EVs will need to overcome. All findings are based on a 2020 survey of 10,000 consumers, fleet managers, and industry specialists across eight significant EV markets. 

The Five Challenges to EV Adoption

Cars have relied on the internal combustion engine (ICE) since the early 1900s, and as a result, the ownership experience of an EV can be much more nuanced. This results in the five critical challenges we examine below. 

Challenge #1: Price

The top challenge is price, with 63% of consumers believing that EVs are beyond their current budget. Though many cheaper EV models are being introduced, ICE vehicles still have the upper hand in terms of initialaffordability. Note the emphasis on “initial”, because over the long term, EVs may actually be cheaper to maintain. 

Taking into account all of the running and maintenance costs of [an EV], we have already reached relative cost parity in terms of ownership.

—President, EV consultancy, U.S.

For starters, an EV drivetrain has significantly fewer moving parts than an ICE equivalent, which could result in lower repair costs. Government subsidies and the cost of electricity are other aspects to consider. 

So what is the tipping price that would convince most consumers to buy an EV? According to Castrol, it differs around the world. 

Country EV Adoption Tipping Price ($)
🇯🇵 Japan $42,864
🇨🇳 China  $41,910
🇩🇪 Germany $38,023
🇳🇴 Norway $36,737
🇺🇸 U.S. $35,765
🇫🇷 France $31,820
🇮🇳 India $30,572
🇬🇧 UK $29,883
Global Average $35,947

Many budget-conscious buyers also rely on the used market, in which EVs have little presence. The rapid speed of innovation is another concern, with 57% of survey respondents citing possible depreciation as a factor that prevented them from buying an EV. 

Challenge #2: Charge Time

Most ICE vehicles can be refueled in a matter of minutes, but there is much more uncertainty when it comes to charging an EV. 

Using a standard home charger, it takes 10-20 hours to charge a typical EV to 80%. Even with an upgraded fast charger (3-22kW power), this could still take up to 4 hours. The good news? Next-gen charging systems capable of fully charging an EV in 20 minutes are slowly becoming available around the world. 

Similar to the EV adoption tipping price, Castrol has also identified a charge time tipping point—the charge time required for mainstream EV adoption. 

Country Charge Time Tipping Point (minutes)
🇮🇳 India 35
🇨🇳 China 34
🇺🇸 U.S. 30
🇬🇧 UK 30
🇳🇴 Norway 29
🇩🇪Germany 29
🇯🇵 Japan 29
🇫🇷 France 27
Global Average 31

If the industry can achieve an average 31 minute charge time, EVs could reach $224 billion in annual revenues across these eight markets alone. 

Challenge #3: Range

Over 70% of consumers rank the total range of an EV as being important to them. However, today’s affordable EV models (below the average tipping price of $35,947) all have ranges that fall under 200 miles. 

Traditional gas-powered vehicles, on the other hand, typically have a range between 310-620 miles. While Tesla offers several models boasting a 300+ mile range, their purchase prices are well above the average tipping price. 

For the majority of consumers to consider an EV, the following range requirements will need to be met by vehicle manufacturers.

Country Range Tipping Point (miles)
🇺🇸 U.S. 321
🇳🇴 Norway 315
🇨🇳 China 300
🇩🇪 Germany 293
🇫🇷 France 289
🇯🇵 Japan 283
🇬🇧 UK 283
🇮🇳 India 249
Global Average 291

Fleet managers, those who oversee vehicles for services such as deliveries, reported a higher average EV tipping range of 341 miles. 

Challenge #4: Charging Infrastructure

Charging infrastructure is the fourth most critical challenge, with 64% of consumers saying they would consider an EV if charging was convenient.

Similar to charge times, there is much uncertainty surrounding infrastructure. For example, 65% of consumers living in urban areas have a charging point within 5 miles of their home, compared to just 26% for those in rural areas. 

Significant investment in public charging infrastructure will be necessary to avoid bottlenecks as more people adopt EVs. China is a leader in this regard, with billions spent on EV infrastructure projects. The result is a network of over one million charging stations, providing 82% of Chinese consumers with convenient access. 

Challenge #5: Vehicle Choice

The least important challenge is increasing the variety of EV models available. This issue is unlikely to persist for long, as industry experts believe 488 unique models will exist by 2025. 

Despite variety being less influential than charge times or range, designing models that appeal to various consumer niches will likely help to accelerate EV adoption. Market research will be required, however, because attitudes towards EVs vary by country.

Country Consumers Who Believe EVs Are More Fashionable Than ICE Vehicles (%)
🇮🇳 India 70%
🇨🇳 China 68%
🇫🇷France 46%
🇩🇪Germany 40%
🇺🇸 UK 40%
🇯🇵 Japan 39%
🇺🇸 U.S. 33%
🇳🇴Norway  31%
Global Average 48%

A majority of Chinese and Indian consumers view EVs more favorably than traditional ICE vehicles. This could be the result of a lower familiarity with cars in general—in 2000, for example, China had just four million cars spread across its population of over one billion. 

EVs are the least alluring in the U.S. and Norway, which coincidentally have the highest GDP per capita among the eight countries surveyed. These consumers may be accustomed to a higher standard of quality as a result of their greater relative wealth. 

So When Do EVs Become Mainstream?

As prices fall and capabilities improve, Castrol predicts a majority of consumers will consider buying an EV by 2024. Global mainstream adoption could take slightly longer, arriving in 2030. 

Caution should be exhibited, as these estimates rely on the five critical challenges being solved in the short-term future. This hinges on a number of factors, including technological change, infrastructure investment, and a shift in consumer attitudes. 

New challenges could also arise further down the road. EVs require a significant amount of minerals such as copper and lithium, and a global increase in production could put strain on the planet’s limited supply.