Solar Energy

Bipartisan bill addressing lithium-ion battery fires awaits congressional action

Published

1 year ago

January 30, 2024

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Bipartisan bill addressing lithium-ion battery fires awaits congressional action

by Dana Forsythe

Washington DC (UPI) Jan 29, 2024

With electric bikes growing in popularity, poorly manufactured lithium-ion batteries and electronics have led to a spate of fires. New congressional legislation aims to fix the problem.

With bipartisan support, members of the House and Senate, including U.S. Rep. Ritchie Torres, D-N.Y., hope to implement safety standards for manufacturing the small but powerful batteries.

According to Torres, deaths associated with e-bike fires have steadily risen since 2019. In an interview with Bronx12 in January, Torres said he was optimistic the bill that provides more safety measures, will move forward.

“I’m confident that we’re going to pass it on a bipartisan basis this year,” he said.

In addition to powering devices like smartphones, laptops and power tools, lithium-ion batteries are in many of the devices used every day, including e-bikes. When these batteries are damaged, they can overheat, catch on fire and potentially lead to explosions.

According to the National Fire Protection Association, e-bike and e-scooter battery fires have been associated with faulty charging equipment, improper charging practices and overloaded electrical circuits.

In December, HR 1797, also known as the “Setting Consumer Standards for Lithium-Ion Batteries Act,” was introduced in the House and referred to the Energy and Commerce Committee.

If passed, it would require the Consumer Product Safety Commission “to promulgate a consumer product safety standard with respect to rechargeable lithium-ion batteries used in micromobility devices, and for other purposes.”

A companion bill in the Senate, S.1008, was introduced March 28 and referred to the Commerce, Science and Transportation Committee.

Gabe Knight, safety policy analyst for Consumer Reports, said that in New York City alone, 267 fires and 18 deaths linked to unsafe lithium-ion batteries in micro mobility devices occurred in 2023.

“Tragically, some of those deaths involved children,” he told UPI. “This marks a significant increase from 2022, in which there were six such deaths in New York City. Nationally, the Consumer Product Safety Commission recorded 19 deaths linked to micro mobility fires from Jan. 1, 2021, through Nov. 28, 2022.”

The U.S. e-bike market size was valued at $1.98 billion in 2022 and is expected to grow some 15.6% a year from 2023 to 2030, according to Grandview Research.

The boom results largely from people adopting electric bikes for daily commutes, growing environmental concern for reducing carbon emissions and the increased support by the U.S. government.

By 2030, the global market for e-bokes is projected to reach just under 77.3 million e-bikes by 2030, according to Statista.

Knight said Consumer Reports strongly supports the bill and has urged every member of Congress to join the effort. The bill has has received endorsement from the Fire Department of New York, the International Association of Fire Chiefs, delivery services like GrubHub and Doordash, and organizations like PeopleForBikes.

“Some people see all e-bikes as dangerous and others will understand that some are safer than others, said Brandale Randolph, CEO and founder of the 1854 Cycling Co., an electric bike manufacturer based in Boston.

The company is preparing to deliver the Bowditch e-bike to law enforcement agencies this summer.

“The e-bike fires are very similar to the fires happening with low quality scooters, hoverboards and even fully electric vehicles in that companies are looking for lower-cost ways of making lithium-Ion based storage systems,” Randolph said.

Randolph said his company has transitioned away from lithium-ion batteries and developed “safer higher quality energy systems,” which has priced them out of the retail market.

Kevin Cox, President of Electra Bicycle Co., said his firm has focused on safety and aesthetics with its most recent lines of e-bikes. Electra makes a wide variety of e-bikes from cruisers to commuter models like the Ponto Go!

“Motors and batteries that have undergone testing and meet U.S. and global regulatory standards are a must, as are quality components and safety features,” Cox said. “Consumers must make sure their e-bike or any e-bike they are thinking of purchasing is equipped with a battery that is UL2849 certified.”

UL 2849 is “the standard for electrical systems for e-Bikes, for the electrical system of any powered bicycle sold, distributed, leased or rented in New York City,” according to Consumer Product Safety Commission.

In addition , Cox said, riders should only use the manufacturer’s battery charger that came with their e-bike and store the bike in a cool, dry place when put away for long periods of time.

“While many bikes these days are sold online, it’s essential consumers know whether their local bike shop can provide the necessary support and service for their new purchase,” he said.

“E-bikes are more complex and will require additional servicing to keep them in the best and safest condition. Pay attention to who you buy an e-bike from. This purchase should be no different than any other large purchase one would make.”

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Solar Energy

Advancing safer lithium energy storage

Published

1 day ago

February 4, 2025

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Advancing safer lithium energy storage

by Erica Marchand

Paris, France (SPX) Feb 04, 2025

Charging our phones has become so routine that we rarely reflect on the breakthrough that made it possible. Rechargeable lithium-ion batteries, introduced commercially in the 1990s, propelled a technological revolution that earned their creators the 2019 Nobel Prize in Chemistry. This key innovation underpins the functionality of today’s smartphones, wireless headphones, and electric vehicles, making them both financially and environmentally practical.

As our devices grow more advanced, the demand for batteries that pack more power while remaining safe continues to rise. Yet engineering such power sources is far from simple. One promising design is the lithium metal battery, which could deliver more stored energy than standard battery types. Unfortunately, its potential is curtailed by a persistent issue: the emergence of tiny threads, or dendrites, that accumulate with each charge. When dendrites build up, they can form metallic connections that degrade battery functionality and pose a serious fire hazard. Until recently, researchers had limited approaches to probe and understand dendrite formation. In a new study led by Dr. Ayan Maity in the lab of Prof. Michal Leskes at the Weizmann Institute of Science’s Molecular Chemistry and Materials Science Department, scientists developed a novel method to identify the factors that spark dendrite growth, as well as to rapidly evaluate various battery components for improved safety and performance.

Rechargeable batteries function by allowing positively charged ions to migrate between the anode (negative electrode) and the cathode (positive electrode) through an electrolyte. Charging forces the ions back into the anode, counter to the usual flow in a typical chemical reaction, thus preparing the battery for another cycle of use. Lithium metal batteries take a different approach by employing a pure lithium metal anode, enabling higher energy storage. However, lithium metal is chemically reactive and quickly forms dendrites when it interacts with the electrolyte. Over time, enough dendrites can short-circuit the battery and raise the likelihood of combustion.

One way to avoid fire risks is to replace the volatile liquid electrolyte with a solid, nonflammable one, often comprising a polymer-ceramic composite. While altering the ratio of polymer to ceramic can influence dendrite growth, finding the ideal formulation remains a challenge for extending battery life.

To investigate, the team employed nuclear magnetic resonance (NMR) spectroscopy, a standard tool for pinpointing chemical structures, and tracked both dendrite formation and the chemical interplay within the electrolyte. “When we examined the dendrites in batteries with differing ratios of polymer and ceramic, we found a kind of ‘golden ratio’: Electrolytes that are composed of 40 percent ceramic had the longest lives,” Leskes explains. “When we went above 40 percent ceramic, we encountered structural and functional problems that impeded battery performance, while less than 40 percent led to reduced battery life.” Intriguingly, batteries with that optimal ratio displayed more dendrites overall, but those dendrites were effectively confined in a way that prevented destructive bridging.

These insights prompted a larger question: what halts the extension of the dendrites? The team hypothesized that a thin covering on the surface of dendrites, called the solid electrolyte interphase (SEI), might be crucial. This layer, formed when dendrites interact with the electrolyte, can affect how lithium ions travel through the battery, and it can also either prevent or accelerate the movement of harmful substances between electrodes. Both of these factors, in turn, can stifle or foster further dendrite development.

Probing the chemical composition of such thin SEI films is inherently difficult, since they measure only a few dozen nanometers thick. The researchers tackled this problem by enhancing the signals in their NMR data using dynamic nuclear polarization. This specialized technique leverages the strong spin of polarized lithium electrons, bolstering signals from the atomic nuclei in the SEI and exposing its chemical makeup. Through this refined lens, the researchers discovered precisely how lithium metal interacts with polymer or ceramic materials, revealing that certain SEI layers can simultaneously improve ion transport and block hazardous substances.

Their findings pave the way to design sturdier, safer, and more powerful batteries that will store greater energy for a longer duration with reduced environmental and economic costs. Such next-generation batteries could power larger devices without having to increase the physical size of the battery itself, while also extending the battery’s life cycle.

“One of the things I love most about this study is that, without a profound scientific understanding of fundamental physics, we would not have been able to understand what happens inside a battery. Our process was very typical of the work here at the Weizmann Institute. We started with a purely scientific question that had nothing to do with dendrites, and this led us to a study with practical applications that could improve everybody’s life,” Leskes says.

Research Report:Tracking dendrites and solid electrolyte interphase formation with dynamic nuclear polarization-NMR spectroscopy

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Solar Energy

Role of barrier films in maintaining the stability of perovskite solar cells

Published

2 days ago

February 3, 2025

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Role of barrier films in maintaining the stability of perovskite solar cells

by Riko Seibo

Tokyo, Japan (SPX) Jan 31, 2025

Perovskite solar cells (PSCs) offer a promising advancement in renewable energy due to their high efficiency, lightweight, and flexible properties. However, their commercial viability is challenged by their vulnerability to environmental conditions, particularly heat and humidity.

To tackle this issue, a research team led by Professor Takashi Minemoto, a Fellow at the Ritsumeikan Advanced Research Academy, alongside Dr. Abdurashid Mavlonov from Ritsumeikan University’s Research Organization of Science and Technology and Dr. Akinobu Hayakawa from Sekisui Chemical Co., Ltd., conducted an in-depth study on the durability of PSC modules under harsh environmental conditions. Their research, published in Volume 286 of *Solar Energy* on January 15, 2025, was first made available online on December 17, 2024.

Discussing the study’s motivation, Prof. Minemoto stated, “Perovskite solar cells stand out as particularly promising due to their low-temperature wet-coating process and compatibility with flexible substrates, offering unique opportunities for the solar industry. However, the stability of perovskite is weak compared with conventional material, which can be improved by fabrication processes such as encapsulation with barrier films.”

For this research, the team analyzed the durability of flexible PSC modules made from methylammonium lead iodide (MAPbI3) and encapsulated them using polyethylene terephthalate (PET) substrates with barrier films of varying water vapor transmission rates (WVTR). These modules were subjected to a damp heat test at 85 C and 85% relative humidity to replicate long-term outdoor conditions.

After 2,000 hours of exposure, researchers measured photovoltaic (PV) performance and assessed module degradation using current-voltage characteristics, spectral reflectance, and electroluminescence imaging. The findings confirmed that high humidity caused the MAPbI3 layer to break down into lead iodide, obstructing charge transport and significantly reducing the efficiency of the PSC modules.

Moreover, the study demonstrated the critical role of barrier films in maintaining module stability. Notably, the module with the lowest WVTR barrier retained 84% of its initial power conversion efficiency, whereas modules with higher WVTR deteriorated rapidly, ceasing to function after just 1,000 hours.

“Our study is the first to report the durability of encapsulated flexible MAPbI3-based PSC modules. When considering solar energy applications for walls and rooftops with weight limits or for mobile platforms, flexible PSCs are a great alternative to the traditional silicon panels. Insights from our study could help industries optimize these modules for highly stable and durable constructs,” explained Prof. Minemoto.

This research underscores the essential role of barrier films in ensuring the long-term viability of flexible PSC modules, which could reshape the photovoltaic industry. By enabling energy generation in a variety of locations, these advancements help alleviate pressure on power grids. Additionally, enhancing the durability of PSCs expands their usability across different environments, further accelerating the global transition to cleaner and more sustainable energy solutions.

Research Report:Perovskite solar cell modules: Understanding the device degradation via damp heat testing

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Solar Energy

Enhancing Durability and Efficiency in Tin-based Perovskite Solar Cells

Published

2 days ago

February 3, 2025

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Enhancing Durability and Efficiency in Tin-based Perovskite Solar Cells

by Riko Seibo

Tokyo, Japan (SPX) Jan 30, 2025

Tin-based perovskite solar cells are being hailed as a promising alternative for next-generation solar energy solutions due to their high efficiency, flexibility, and the potential for low-cost printing. However, replacing lead with tin to avoid environmental issues linked to lead toxicity presents its own challenges. Tin’s propensity to oxidize quickly results in reduced performance and durability compared to lead-based counterparts.

Researchers have developed a method to enhance the stability of tin-based perovskite by incorporating large organic cations into the perovskite structure. This results in a unique two-dimensional layered configuration known as Ruddlesden-Popper (RP) tin-based perovskites. Despite its potential, the precise internal structure and the mechanism through which this configuration improves performance have remained unclear.

In this study, researchers employed electron spin resonance (ESR) to analyze the internal behavior of the RP perovskite solar cell during operation at a microscopic level. Their findings revealed two key insights about the interaction of the materials under different conditions.

First, when the RP perovskite solar cell was not exposed to light, the holes in the hole transport layer diffused into the RP perovskite. This movement created an energy barrier at the interface between the hole transport layer and the RP tin perovskite, preventing electron backflow and leading to better performance.

Second, when exposed to sunlight, the high-energy electrons produced by short-wavelength light (such as ultraviolet rays) moved from the RP tin perovskite to the hole transport layer. This transfer further elevated the energy barrier, thereby enhancing the device’s efficiency.

Understanding the mechanisms behind these performance improvements is crucial for developing tin-based perovskite solar cells with greater efficiency and longer lifespans. These findings could provide important insights for future advancements in the field of solar energy.

Research Report:Operando spin observation elucidating performance-improvement mechanisms during operation of Ruddlesden-Popper Sn-based perovskite solar cells