Battery Science 101


What is a battery?

ARGONNE NATIONAL LABORATORY

Batteries power our lives by transforming energy from one type to another.

Whether a traditional disposable battery (e.g. AA) or a rechargeable lithium-ion battery (used in cell phones, laptops and cars), a battery stores chemical energy and releases electrical energy.

There are four key parts in a battery — the cathode (positive side of the battery), the anode (negative side of the battery), a separator that prevents contact between the cathode and anode and a chemical solution known as an electrolyte that allows the flow of electrical charge between the cathode and anode.

Lithium-ion batteries that power cell phones, for example, typically consist of a cathode made of cobalt, manganese, and nickel oxides and an anode made out of graphite, the same material found in many pencils. The cathode and anode store the lithium.

When a lithium-ion battery is turned on, positively charged particles of lithium (ions) move through the electrolyte from the anode to cathode. Chemical reactions occur that generate electrons and convert stored chemical energy in the battery to electrical current.

When you plug in your cell phone to charge the lithium-ion battery, the chemical reactions go in reverse: the lithium ions move back from the cathode to the anode.

As long as lithium ions shuttle back and forth between the anode and cathode, there is a constant flow of electrons. This provides the energy to keep your devices running. Since this cycle can be repeated hundreds of times, this type of battery is rechargeable.

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HOW DOES A LITHIUM-ION BATTERY WORK?

Lithium-based batteries power our daily lives, from consumer electronics to national defense

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A lithium-ion battery is a type of rechargeable battery. It has four key parts:

  • 1The cathode (the positive side), typically a combination of nickel, manganese and cobalt oxides.
  • 2The anode (the negative side), commonly made out of graphite, the same material found in many pencils.
  • 3separator that prevents contact between the anode and cathode.
  • 4A chemical solution known as an electrolyte that moves lithium ions between the cathode and anode. The anode and cathode store lithium.

When the battery is in use, positively charged particles of lithium (ions) move through the electrolyte from the anode to cathode. Chemical reactions occur that generate electrons and convert stored chemical energy in the battery to electrical current.

When the battery is charging, the chemical reactions go
in reverse: the lithium ions move back from the cathode to the anode.

How does an X-ray light source work?
Batteries and the U.S. Department of Energy’s (DOE) Argonne National Laboratory

Argonne is recognized as a global leader in battery science and technology. Over the past sixty years, the lab’s pivotal discoveries have strengthened the U.S. battery manufacturing industry, aided the transition of the U.S. automotive fleet toward plug-in hybrid and electric vehicles, and enabled greater use of renewable energy, such as wind and solar power.

The lab’s research spans every aspect of battery development, from the breakthrough fundamental science of the Argonne-led Joint Center for Energy Storage Research, a DOE Energy Innovation Hub, to the Argonne Collaborative Center for Energy Storage Science, a cross-lab collective of scientists and engineers that solves complex battery problems through multidisciplinary research.

Argonne researchers are also exploring how to accelerate the recycling of lithium-ion batteries through the DOE’s ReCell Center, a collaboration led by Argonne that includes the National Renewable Energy Laboratory, Oak Ridge National Laboratory, as well as Worcester Polytechnic Institute, University of California at San Diego and Michigan Technological University.

For another take on “Batteries 101,” check out DOE Explains.

Eliminating the bottlenecks in performance of lithium-sulfur batteries


Graphical abstract. Credit: Chem (2022). DOI: 10.1016/j.chempr.2022.03.001

Energy storage in lithium-sulfur batteries is potentially higher than in lithium-ion batteries but they are hampered by a short life. Researchers from Uppsala University in Sweden have now identified the main bottlenecks in performance.

Lithium-sulfur batteries are high on the wish-list for future batteries as they are made from cheaper and more environmentally friendly materials than lithium-ion batteries. They also have higher energy storage capacity and work well at much lower temperatures. However, they suffer from short lifetimes and energy loss. An article just published in the journal Chem by a research group from Uppsala University has now identified the processes that are limiting the performance of the sulfur electrodes that in turn reduces the current that can be delivered. Various different materials are formed during the discharge/charge cycles and these cause various problems. Often a localized shortage of lithium causes a bottleneck.

“Learning about problems allows us to develop new strategies and materials to improve battery performance. Identifying the real bottlenecks is needed to take the next steps. This is big research challenge in a system as complex as lithium-sulfur,” says Daniel Brandell, Professor of Materials Chemistry at Uppsala University who works at the Ångström Advanced Battery Centre.

The study combined various radiation scattering techniques: X-ray analyses were made in Uppsala, Sweden and neutron results came from a large research facility, the Institut Laue Langevin, in Grenoble, France.

“The study demonstrates the importance of using these infrastructures to tackle problems in materials science,” says Professor Adrian Rennie. “These instruments are expensive but are necessary to understand such complex systems as these batteries. Many different reactions happen at the same time and materials are formed and can disappear quickly during operation.”

The study was carried-out as part of a co-operation with Scania CV AB.

“Electric power is needed for the heavy truck business and not just personal vehicles. They must keep up with developments of a range of different batteries that may soon become highly relevant,” says Daniel Brandell.

Ola eyes 5-minute electric scooter charging with StoreDot battery tech


Could this audacious electric scooter be the Honda Cub of the 21st Century? Ola is betting big on the S1

Ola is building the world’s largest motorcycle “Futurefactory,” and planning a staggeringly massive push into India’s electric scooter market. It has now made a “multi-million dollar investment” in an ultra-fast charging battery company from Israel.

It’s no understatement to say the Ola S1 could end up being one of the most important vehicles in the world, full stop. It’s a feature-packed, highway-capable electric scooter designed to sell from as little as US$1,345 – or just under 100,000 Indian Rupees. Even at double the money, it’d be a steal for commuters in Western cities.

Part of that rock-bottom price comes from serious volume; Ola is building the biggest motorcycle factory in history. The Futurefactory under construction now is a colossal, 500-acre, carbon-negative production complex that will be capable of pouring out up to an astonishing 10 million bikes per year once it reaches full capacity – that’s around 15 percent of the entire current global motorcycle production run. So there’s enormous hopes and dreams behind these scoots, and considerable pressure to get the S1 right.

Now, it seems Ola has made a move that could give its bikes some extreme fast-charging capabilities.

The company has made a “multi-million dollar investment” in Israel’s StoreDot, which makes it a “strategic partner” and will allow it to “incorporate and manufacture StoreDot’s fast charging technologies for future vehicles in India.”

Ola’s Futurefactory, now under construction, will be the world’s largest motorcycle manufacturing plant, capable of building 10 million bikes a year

StoreDot claims that its nanodot-enhanced, silicon-dominant anode, XFC lithium-ion cells will go into mass manufacture in 2024 as pouch cells and 4680-family cylinder cells, and they’ll initially be able to deliver 100 miles (160 km) of scooter range in a 5-minute charge, with an impressive 300 Wh/kg specific energy – considerably more energy-dense than today’s state of the art commercial cells. 

Its second-gen solid-state cells, slated for 2028, promise a sky-high 450 Wh/kg, so they’ll be significantly lighter, as well as even faster to charge – StoreDot claims 100 miles in 3 minutes.

And in 10 years’ time, the company says it’s got plans for a “post-lithium” design capable of 100-mile charges in 2 minutes, with a monstrous 550 Wh/kg of energy on board. Such is the “clear, hype-free technology roadmap” that StoreDot CEO Doron Myersdorf promises partners.

“The future of EVs lies in better, faster and high energy density batteries, capable of rapid charging and delivering higher range,” said Ola founder and CEO Bhavish Aggarwal in a press release. “We are increasing our investments in core cell and battery technologies and ramping up our in-house capabilities and global talent hiring, as well as partnering with global companies doing cutting edge work in this field. Our partnership with StoreDot, a pioneer of extreme fast charging battery technologies, is of strategic importance and a first of many.”

It all sounds great, but the big unknown here is whether StoreDot will actually finally deliver on its fast-charge battery promises.

We first encountered this company in 2014, when it was planning mass production of smartphone batteries with 30-second charging timeswithin two years. These did not materialize. By 2017, it was saying it’d have 5-minute electric car battery packs popping up as OEM equipment by 2020. These have not yet materialized.

The company has been sending sample batteries to EV manufacturers for testing. “We are not releasing a lab prototype,” Myersdorf told The Guardian in January 2021. “We are releasing engineering samples from a mass production line.

This demonstrates it is feasible and it’s commercially ready.” And yet the nanodot technology in these samples was based on highly expensive germanium, rather than the cheap and widely available silicon, indicating that it was perhaps not quite ready.

Still, StoreDot has taken on at least US$190 million in investments and formed similar strategic partnerships with companies including VinFast, BP, Daimler, Samsung, TDK and Eve Energy – so along with Ola Electric, plenty of serious players have liked what they’ve seen enough to put their money on the line. Last November, StoreDot announced that Eve Energy had managed to produce “A-series samples” of the silicon-dominant batteries in a factory in China. 

We’d all like to see EV charge times drop to the level where a top-up takes no longer than filling a tank of gas. Will StoreDot be the company that makes that a reality? Stay tuned!

Source: StoreDot

Scientists discover new electrolyte for solid-state lithium-ion batteries


Chlorine-based electrolytes like the one shown here are offering improved performance for solid-state lithium-ion batteries. Credit: Linda Nazar/University of Waterloo

In the quest for the perfect battery, scientists have two primary goals: create a device that can store a great deal of energy and do it safely. Many batteries contain liquid electrolytes, which are potentially flammable.

As a result, solid-state lithium-ion batteries, which consist of entirely solid components, have become increasingly attractive to scientists because they offer an enticing combination of higher safety and increased energy density—which is how much energy the battery can store for a given volume.

Researchers from the University of Waterloo, Canada, who are members of the Joint Center for Energy Storage Research (JCESR), headquartered at the U.S. Department of Energy’s (DOE) Argonne National Laboratory, have discovered a new solid electrolyte that offers several important advantages.

This electrolyte, composed of lithium, scandium, indium and chlorine, conducts lithium ions well but electrons poorly. This combination is essential to creating an all-solid-state battery that functions without significantly losing capacity for over a hundred cycles at high voltage (above 4 volts) and thousands of cycles at intermediate voltage.

The chloride nature of the electrolyte is key to its stability at operating conditions above 4 volts—meaning it is suitable for typical cathode materials that form the mainstay of today’s lithium-ion cells.

“The main attraction of a solid-state electrolyte is that it can’t catch fire, and it allows for efficient placement in the battery cell; we were pleased to demonstrate stable high-voltage operation,” said Linda Nazar, a Distinguished Research Professor of Chemistry at UWaterloo and a long-time member of JCESR. 

Current iterations of solid-state electrolytes focus heavily on sulfides, which oxidize and degrade above 2.5 volts. Therefore, they require the incorporation of an insulating coating around the cathode material that operates above 4 volts, which impairs the ability of electrons and lithium ions to move from the electrolyte and into the cathode.

“With sulfide electrolytes, you have a kind of conundrum—you want to electronically isolate the electrolyte from the cathode so it doesn’t oxidize, but you still require electronic conductivity in the cathode material,” Nazar said.

While Nazar’s group wasn’t the first to devise a chloride electrolyte, the decision to swap out half of the indium for scandium based on their previous work proved to be a winner in terms of lower electronic and higher ionic conductivity. “Chloride electrolytes have become increasingly attractive because they oxidize only at high voltages, and some are chemically compatible with the best cathodes we have,” Nazar said. “There’s been a few of them reported recently, but we designed one with distinct advantages.

One chemical key to the ionic conductivity lay in the material’s crisscrossing 3D structure called a spinel. The researchers had to balance two competing desires—to load the spinel with as many charge carrying ions as possible, but also to leave sites open for the ions to move through. “You might think of it like trying to a host a dance—you want people to come, but you don’t want it to be too crowded,” Nazar said.

According to Nazar, an ideal situation would be to have half the sites in the spinel structure be lithium occupied while the other half remained open, but she explained that creating that situation is hard to design.

In addition to the good ionic conductivity of the lithium, Nazar and her colleagues needed to make sure that the electrons could not move easily through the electrolyte to trigger its decomposition at high voltage. “Imagine a game of hopscotch,” she said. “Even if you’re only trying to hop from the first square to the second square, if you can create a wall that makes it difficult for the electrons, in our case, to jump over, that is another advantage of this solid electrolyte.”

Nazar said that it is not yet clear why the electronic conductivity is lower than many previously reported chloride electrolytes, but it helps establish a clean interface between the cathode material and solid electrolyte, a fact that is largely responsible for the stable performance even with high amounts of active material in the cathode.

A paper based on the research, “High areal capacity, long cycle life 4 V ceramic all-solid-state Li-ion batteries enabled by chloride solid electrolytes,” appeared in the January 3 online edition of Nature Energy.

Other authors of the paper include Nazar’s graduate student, Laidong Zhou, a JCESR member who was responsible for the majority of the work, and Se Young Kim, Chun Yuen Kwok and Abdeljalil Assoud, all of UWaterloo. Additional authors included Tong-Tong Zuo and Professor Juergen Janek of Justus Liebig University, Germany and Qiang Zhang of the DOE’s Oak Ridge National Laboratory.

Explore further

New solid electrolyte promises cheaper, better all-solid-state lithium batteries

More information: Laidong Zhou et al, High areal capacity, long cycle life 4 V ceramic all-solid-state Li-ion batteries enabled by chloride solid electrolytes, Nature Energy (2022). DOI: 10.1038/s41560-021-00952-0

Journal information: Nature Energy 

Provided by Argonne National Laboratory

EV’s Benefit from Intense Competition in the Silicon Anode for NextGen Batteries Market – $1.9 Billion in Start-Up Funding … So Far


Commercial interest in silicon anodes and investments into start-up companies has continued through 2021 – IDTechEx estimates that $1.9B of funding has now made its way into silicon anode start-ups.

Beyond investments, there has also been greater activity regarding companies beginning to license technologies, enter into supply relationships or commercialize technologies in early adopter markets, highlighting that the promise of silicon anode technology may soon be realized.

For example:• Enevate entered into a license agreement with batterymanufacturer EnerTech International• Enovix went public via a SPAC that valued the company at $1.1B• Elkem established a separate silicon anode company Vianode• Group 14 entered into a joint venture with SK materials for the supply of silane gas• Sila Nano launched their battery technology in the Whoop fitness wearable

IDTechEx estimates that cumulative funding for silicon anode start-ups has reached $1.9B. Source: IDTechEx – “Advanced Li-ion and Beyond Lithium Batteries 2022-2032: Technologies, Players, Trends, Markets

The above examples of commercial development and investment highlight the ongoing and significant interest in silicon anode technology. Much of this stems from the potential for silicon to significantly improve energy density. But beyond energy density, silicon anodes also have the potential to improve fast charge capability, cost, and safety.

In short, fast-charge capability is feasible due to the high porosity inherent to silicon anode solutions, cost can be reduced due to the high capacity of silicon material resulting in lower material requirements while safety improvements stem from the reduced risk of lithium plating and dendrite formation.

Though cycle and calendar life may need to be further demonstrated, improvements are being made. Combined, silicon anodes present a highly valuable proposition for electric vehicles and indeed the largest opportunity for silicon anode material lies in BEVs with the possibility of silicon being used as an additive or as the dominant active material.

Demand from other EV segments and consumer devices still represent a significant opportunity for silicon anode material and IDTechEx forecast that by 2032, demand for silicon anode material will reach $12.9B.

However, with nearly 30 start-up companies looking to commercialize silicon anode solutions, not to mention development at more established materials and battery players, competition in the silicon anode space is intensifying.

Start-ups and earlier stage companies find themselves in a race to lock in investments, partnerships, and orders. While the market is beginning to look increasingly crowded, the rewards for succeeding will be significant, and this competition will play a role in accelerating the commercialization of the better, cheaper, and more environmentally friendly batteries that are needed for better products and electric vehicles.

Watch GNT’s Short Presentation Video

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

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


silicon-anodes-muscle
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


a-high-energy-density battery 071421
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.


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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