Tag Archives: fires

Layer of tin could prevent short-circuiting in lithium-ion batteries

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Lithium-ion batteries are everywhere; they can be found in cell phones, laptops, e-scooters, e-bikes, and more. There are also some well documented problems with the batteries including the danger of fire. With the proliferating use of lithium-ion batteries, it seems fires are becoming more frequent as Samantha Murphy Kelly documents in her Mach 9, 2023 article for CNN news online, Note: Links have been removed,

Lithium-ion batteries, found in many popular consumer products, are under scrutiny again following a massive fire this week in New York City thought to be caused by the battery that powered an electric scooter.

At least seven people have been injured in a five-alarm fire in the Bronx which required the attention of 200 firefighters. Officials believe the incident stemmed from a lithium-ion battery of a scooter found on the roof of an apartment building. In 2022, the the New York City Fire Department responded to more than 200 e-scooter and e-bike fires, which resulted in six fatalities.

“In all of these fires, these lithium-ion fires, it is not a slow burn; there’s not a small amount of fire, it literally explodes,” FDNY [Fire Dept. New York] Commissioner Laura Kavanagh told reporters. “It’s a tremendous volume of fire as soon as it happens, and it’s very difficult to extinguish and so it’s particularly dangerous.”

A residential fire earlier this week in Carlsbad, California, was suspected to be caused by an e-scooter lithium battery. On Tuesday [March 7, 2023], an alarming video surfaced of a Canadian homeowner running downstairs to find his electric bike battery exploding into flames. [emphasis mine] A fire at a multi-family home in Massachusetts last month is also under investigation for similar issues.

These incidents are becoming more common for a number of reasons. For starters, lithium-ion batteries are now in numerous consumer tech products,powering laptops, cameras, smartphones and more. They allow companies to squeeze hours of battery life into increasingly slim devices. But a combination of manufacturer issues, misuse and aging batteries can heighten the risk from the batteries, which use flammable materials.

“Lithium batteries are generally safe and unlikely to fail, but only so long as there are no defects and the batteries are not damaged or mistreated,” said Steve Kerber, vice president and executive director of Underwriters Laboratory’s (UL) Fire Safety Research Institute (FSRI). “The more batteries that surround us the more incidents we will see.”

In 2016, Samsung issued a global recall of the Galaxy Note 7 in 2016, citing “battery cell issues” that caused the device to catch fire and at times explode. [emphasis mine] HP and Sony later recalled lithium computer batteries for fire hazards, and about 500,000 hoverboards were recalled due to a risk of “catching fire and/or exploding,” according to the U.S. Consumer Product Safety Commission.

In 2020, the Federal Aviation Administration [emphasis mine] banned uninstalled lithium-ion metal batteries from being checked in luggage and said they must remain with a passenger in their carry-on baggage, if approved by the airline and between 101-160 watt hours. “Smoke and fire incidents involving lithium batteries can be mitigated by the cabin crew and passengers inside the aircraft cabin,” the FAA said.

Despite the concerns, lithium-ion batteries continue to be prevalent in many of today’s most popular gadgets. Some tech companies point to their abilities to charge faster, last longer and pack more power into a lighter package.

But not all lithium batteries are the same.

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Kelly’s Mach 9, 2023 article describes the problems (e.g., a short circuit) that may cause fires and includes some recommendations for better safety and for what to do in the event of a lithium-ion battery fire.Her mention of Samsung and the fires brought back memories; it was mentioned here briefly in a December 21, 2016 post titled, “The volatile lithium-ion battery,” which mostly featured then recent research into the batteries and fires.

More recently, I’ve got an update of sorts on lithium-ion batteries and fires on airplanes, from the May/June 2024 posting of the National Business Aviation Association (NBAA) Insider,

A smoke, fire or extreme heat incident involving lithium ion batteries takes place aboard an aircraft more than once per week [emphases mine] on average in the U.S., making it imperative for operators to fully understand these dangerous events and to prepare crews with safety training.

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At any given time, there could be more than 1,000 Li-ion powered devices on board an airliner, while an international business jet might easily be flying with a few dozen. Despite their popularity, few people realize the dangers posed by Li-ion batteries.

Hazards run the gamut, from overheating, to emitting smoke, to bursting into flames or even exploding – spewing bits of white hot gel in all directions. In fact, a Li-ion fire can begin as a seemingly harmless overheat and erupt into a serious hazard in a matter of seconds.

FAA [US Federal Aviation Administration] data shows the scope of the threat: In 2023, more than one Li-ion incident occurred aboard an aircraft each week. Specifically, the agency said there were 208 issues with lithium ion battery packs, 111 with e-cigarettes and vaping devices, 68 with cell phones and 60 with laptop computers. (The FAA doesn’t offer incident data by aircraft type.

Thankfully, the data shows the chances of encountering an unstable mobile device aboard a business aircraft are small. But so is the possibility of a passenger experiencing a heart attack – yet many business aircraft carry defibrillators.

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The threat with lithium ion batteries is known as thermal runaway. When a Li-ion battery overheats due to some previous damage that creates a short circuit [emphasis mine], the unit continues a catastrophic internal chain reaction until it melts or catches fire.

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Short circuits, lithium ion batteries, and the University of Alberta

A July 31, 2024 Canadian Light Source (CLS) news release (also received via email) by Greg Basky announces the University of Alberta research,

Lithium-ion batteries have a lot of advantages. They charge quickly, have a high energy density, and can be repeatedly charged and discharged.

They do have one significant shortcoming, however: they’re prone to short-circuiting.  This occurs when a connection forms between the two electrodes inside the cell. A short circuit can result in a sudden loss of voltage or the rapid discharge of high current, both causing the battery to fail. In extreme cases, a short circuit can cause a cell to overheat, start on fire, or even explode. Video: Thin layer of tin prevents short-circuiting in lithium-ion batteries

A leading cause of short circuits are rough, tree-like crystal structures called dendrites that can form on the surface of one of the electrodes. When dendrites grow all the way across the cell and make contact with the other electrode, a short circuit can occur.

Using the Canadian Light Source (CLS) at the University of Saskatchewan (USask), researchers from the University of Alberta (UAlberta) have come up with a promising approach to prevent formation of dendrites in solid-state lithium-ion batteries. They found that adding a tin-rich layer between the electrode and the electrolyte helps spread the lithium around when it’s being deposited on the battery, creating a smooth surface that suppresses the formation of dendrites. The results are published in the journal ACS Applied Materials and Interfaces [ACS is American Chemical Society]. The team also found that the cell modified with the tin-rich structure can operate at a much higher current and withstand many more charging-discharging cycles than a regular cell.

Researcher Lingzi Sang, an assistant professor in UAlberta’s Faculty of Science (Chemistry), says the CLS played a key role in the research. “The HXMA beamline enabled us to see at a material’s structural level what was happening on the surface of the lithium in an operating battery,” says Sang. “As a chemist, what I find the most intriguing is we were able to access the exact tin structure that we introduced to the interface which can suppress dendrites and fix this short-circuiting problem.” In a related paper the team published earlier this year, they showed that adding a protective layer of tin also suppressed the formation of dendrites in liquid-electrolyte-based lithium-ion batteries.

This novel approach holds considerable potential for industrial applications, according to Sand. “Our next step is to try to find a sustainable, cost-effective approach to applying the protective layer in battery production.”

Here’s a link to and a citation for the latest paper,

Dual-Component Interlayer Enables Uniform Lithium Deposition and Dendrite Suppression for Solid-State Batteries by Xiang You, Ning Chen, Geng Xie, Shihong Xu, Sayed Youssef Sayed, and Lingzi Sang. ACS Appl. Mater. Interfaces 2024, 16, 27, 35761–35770 DOI: https://doi.org/10.1021/acsami.4c05227 Published June 21, 2024 Copyright © 2024 American Chemical Society

This paper is behind a paywall.

No more kevlar-wrapped lithium-ion batteries?

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Current lithium-ion batteries present a fire hazard, which is why, last, year a team of researchers at the University of Michigan came up with a plan to prevent fires by wrapping the batteries in kevlar. My Jan. 30, 2015 post describes the research and provides some information about airplane fires caused by the use of lithium-ion batteries.

This year, a team of researchers at Stanford University (US) have invented a lithium-ion (li-ion) battery that shuts itself down when it overheats, according to a Jan. 12, 2016 news item on Nanotechnology Now,

Stanford researchers have developed the first lithium-ion battery that shuts down before overheating, then restarts immediately when the temperature cools.

The new technology could prevent the kind of fires that have prompted recalls and bans on a wide range of battery-powered devices, from recliners and computers to navigation systems and hoverboards [and on airplanes].

“People have tried different strategies to solve the problem of accidental fires in lithium-ion batteries,” said Zhenan Bao, a professor of chemical engineering at Stanford. “We’ve designed the first battery that can be shut down and revived over repeated heating and cooling cycles without compromising performance.”

Stanford has produced a video of Dr. Bao discussing her latest work,

A Jan. 11, 2016 Stanford University news release by Mark Schwartz, which originated the news item, provides more detail about li-ion batteries and the new fire prevention technology,

A typical lithium-ion battery consists of two electrodes and a liquid or gel electrolyte that carries charged particles between them. Puncturing, shorting or overcharging the battery generates heat. If the temperature reaches about 300 degrees Fahrenheit (150 degrees Celsius), the electrolyte could catch fire and trigger an explosion.

Several techniques have been used to prevent battery fires, such as adding flame retardants to the electrolyte. In 2014, Stanford engineer Yi Cui created a “smart” battery that provides ample warning before it gets too hot.

“Unfortunately, these techniques are irreversible, so the battery is no longer functional after it overheats,” said study co-author Cui, an associate professor of materials science and engineering and of photon science. “Clearly, in spite of the many efforts made thus far, battery safety remains an important concern and requires a new approach.”

Nanospikes

To address the problem Cui, Bao and postdoctoral scholar Zheng Chen turned to nanotechnology. Bao recently invented a wearable sensor to monitor human body temperature. The sensor is made of a plastic material embedded with tiny particles of nickel with nanoscale spikes protruding from their surface.

For the battery experiment, the researchers coated the spiky nickel particles with graphene, an atom-thick layer of carbon, and embedded the particles in a thin film of elastic polyethylene.

“We attached the polyethylene film to one of the battery electrodes so that an electric current could flow through it,” said Chen, lead author of the study. “To conduct electricity, the spiky particles have to physically touch one another. But during thermal expansion, polyethylene stretches. That causes the particles to spread apart, making the film nonconductive so that electricity can no longer flow through the battery.”

When the researchers heated the battery above 160 F (70 C), the polyethylene film quickly expanded like a balloon, causing the spiky particles to separate and the battery to shut down. But when the temperature dropped back down to 160 F (70 C), the polyethylene shrunk, the particles came back into contact, and the battery started generating electricity again.

“We can even tune the temperature higher or lower depending on how many particles we put in or what type of polymer materials we choose,” said Bao, who is also a professor, by courtesy, of chemistry and of materials science and engineering. “For example, we might want the battery to shut down at 50 C or 100 C.”

Reversible strategy

To test the stability of new material, the researchers repeatedly applied heat to the battery with a hot-air gun. Each time, the battery shut down when it got too hot and quickly resumed operating when the temperature cooled.

“Compared with previous approaches, our design provides a reliable, fast, reversible strategy that can achieve both high battery performance and improved safety,” Cui said. “This strategy holds great promise for practical battery applications.”

Here’s a link to and a citation for the paper,

Fast and reversible thermoresponsive polymer switching materials for safer batteries by Zheng Chen, Po-Chun Hsu, Jeffrey Lopez, Yuzhang Li, John W. F. To, Nan Liu, Chao Wang, Sean C. Andrews, Jia Liu, Yi Cui, & Zhenan Bao. Nature Energy 1, Article number: 15009 (2016) doi:10.1038/nenergy.2015.9 Published online: 11 January 2016

This paper appears to be open access.

Life-cycle assessment for electric vehicle lithium-ion batteries and nanotechnology is a risk analysis

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A May 29, 2013 news item on Azonano features a new study for the US Environmental Protection Agency (EPA) on nanoscale technology and lithium-ion (li-ion) batteries for electric vehicles,

Lithium (Li-ion) batteries used to power plug-in hybrid and electric vehicles show overall promise to “fuel” these vehicles and reduce greenhouse gas emissions, but there are areas for improvement to reduce possible environmental and public health impacts, according to a “cradle to grave” study of advanced Li-ion batteries recently completed by Abt Associates for the U.S. Environmental Protection Agency (EPA).

“While Li-ion batteries for electric vehicles are definitely a step in the right direction from traditional gasoline-fueled vehicles and nickel metal-hydride automotive batteries, some of the materials and methods used to manufacture them could be improved,” said Jay Smith, an Abt senior analyst and co-lead of the life-cycle assessment.

Smith said, for example, the study showed that the batteries that use cathodes with nickel and cobalt, as well as solvent-based electrode processing, show the highest potential for certain environmental and human health impacts. The environmental impacts, Smith explained, include resource depletion, global warming, and ecological toxicity—primarily resulting from the production, processing and use of cobalt and nickel metal compounds, which can cause adverse respiratory, pulmonary and neurological effects in those exposed.

There are viable ways to reduce these impacts, he said, including cathode material substitution, solvent-less electrode processing and recycling of metals from the batteries.

The May 28, 2013 Abt Associates news release, which originated the news item, describes some of the findings,

Among other findings, Shanika Amarakoon, an Abt associate who co-led the life-cycle assessment with Smith, said global warming and other environmental and health impacts were shown to be influenced by the electricity grids used to charge the batteries when driving the vehicles.
“These impacts are sensitive to local and regional grid mixes,” Amarakoon said.  “If the batteries in use are drawing power from the grids in the Midwest or South, much of the electricity will be coming from coal-fired plants.  If it’s in New England or California, the grids rely more on renewables and natural gas, which emit less greenhouse gases and other toxic pollutants.” However,” she added, “impacts from the processing and manufacture of these batteries should not be overlooked.”
In terms of battery performance, Smith said that “the nanotechnology applications that Abt assessed were single-walled carbon nanotubes (SWCNTs), which are currently being researched for use as anodes as they show promise for improving the energy density and ultimate performance of the Li-ion batteries in vehicles.  What we found, however, is that the energy needed to produce the SWCNT anodes in these early stages of development is prohibitive. Over time, if researchers focus on reducing the energy intensity of the manufacturing process before commercialization, the environmental profile of the technology has the potential to improve dramatically.”

Abt’s Application of Life-Cycle Assessment to Nanoscale Technology: Lithium-ion Batteries for Electric Vehicles can be found here, all 126 pp.

This assessment was performed under the auspices of an interesting assortment of agencies (from the news release),

The research for the life-cycle assessment was undertaken through the Lithium-ion Batteries and Nanotechnology for Electric Vehicles Partnership, which was led by EPA’s Design for the Environment Program in the Office of Chemical Safety and Pollution Prevention and Toxics, and EPA’s National Risk Management Research Laboratory in the Office of Research and Development.  [emphasis mine] The Partnership also included industry partners (i.e., battery manufacturers, recyclers, and suppliers, and other industry groups), the Department of Energy’s Argonne National Lab, Arizona State University, and the Rochester Institute of Technology

I highlighted the National Risk Management Research Laboratory as it reminded me of the lithium-ion battery fires in airplanes reported in January 2013. I realize that cars and planes are not the same thing but lithium-ion batteries have some well defined problems especially since the summer of 2006 when there was a series of li-ion battery laptop fires. From Tracy V. Wilson’s What causes laptop batteries to overheat? article for How stuff works.com (Note: A link has been removed),

In conjunction with the United States Consumer Product Safety Commission (CPSC), Dell and Apple Computer announced large recalls of laptop batteries in the summer of 2006, followed by Toshiba and Lenovo. Sony manufactured all of the recalled batteries, and in October 2006, the company announced its own large-scale recall. Under the right circumstances, these batteries could overheat, potentially causing burns, an explosion or a fire.

Larry Greenemeier in a Jan. 17, 2013 article for Scientific American offers some details about the lithium-ion battery fires in airplanes and elsewhere,

Boeing’s Dreamliner has likely become a nightmare for the company, its airline customers and regulators worldwide. An inflight lithium-ion battery fire broke out Wednesday [Jan. 16, 2013] on an All Nippon Airways 787 over Japan, forcing an emergency landing. And another battery fire occurred last week aboard a Japan Airlines 787 at Boston’s Logan International Airport. Both battery failures resulted in release of flammable electrolytes, heat damage and smoke on the aircraft, according to the U.S. Federal Aviation Administration (FAA).

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Lithium-ion batteries—used to power mobile phones, laptops and electric vehicles—have summoned plenty of controversy during their relatively brief existence. Introduced commercially in 1991, by the mid 2000s they had become infamous for causing fires in laptop computers.

More recently, the plug-in hybrid electric Chevy Volt’s lithium-ion battery packs burst into flames following several National Highway Traffic Safety Administration (NHTSA) tests to measure the vehicle’s ability to protect occupants from injury in a side collision. The NHTSA investigated and concluded in January 2012 that Chevy Volts and other electric vehicles do not pose a greater risk of fire than gasoline-powered vehicles.

Philip E. Ross in his Jan. 18, 2013 article about the airplane fires for IEEE’s (Institute of Electrical and Electronics Engineers) Spectrum provides some insight into the fires,

It seems that the batteries heated up in a self-accelerating pattern called thermal runaway. Heat from the production of electricity speeds up the production of electricity, and… you’re off. This sort of things happens in a variety of reactions, not just in batteries, let alone the Li-ion kind. But thermal runaway is particularly grave in Li-ion batteries because they pack a lot more power than the tried-and-true metal-hydride ones, not to speak of Ye Olde lead-acid.

It’s because of this very quality that Li-ion batteries found their first application in small mobile devices, where power is critical and fires won’t cost anyone his life. It’s also why it took so long for the new tech to find its way into electric and hybrid-electric cars.

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Perhaps it would have been wiser of Boeing to go for the safest possible Li-ion design, even if it didn’t have quite as much oomph as possible. That’s what today’s main-line electric-drive cars do, as our colleague, John Voelcker, points out.

“The cells in the 787 [Dreamliner], from Japanese company GS Yuasa, use a cobalt oxide (CoO2) chemistry, just as mobile-phone and laptop batteries do,” he writes in greencarreports.com. “That chemistry has the highest energy content, but it is also the most susceptible to overheating that can produce “thermal events” (which is to say, fires). Only one electric car has been built in volume using CoO2 cells, and that’s the Tesla Roadster. Only 2,500 of those cars will ever exist.” Most of today’s electric cars, Voelcker adds, use chemistries that trade some energy density for safety.

The Dreamliner (Boeing 787) is designed to be the lightest of airplanes and using a more energy dense but safer lithium-ion battery seems not to have been an acceptable trade-off.  Interestingly, Boeing according to Ross still had a backlog of orders after the fires.

I find that some of the discussion about risk and nanotechnology-enabled products oddly disconnected. There are the concerns about what happens at the nanoscale (environmental implications, etc.) but that discussion is divorced from some macroscale issues such as battery fires. Taken to absurd lengths, technology at the nanoscale could be considered safe while macroscale issues are completely ignored. It’s as if our institutions are not yet capable of managing multiple scales at once.

For more about an emphasis on scale and other minutiae (pun intended), there’s my May 28, 2013 posting about Steffen Foss Hansen’s plea to revise current European Union legislation to create more categories for nanotechnology regulation, amongst other things.

For more about airplanes and their efforts to get more energy efficient, there’s my May 27, 2013 posting about a biofuel study in Australia.