Solar Energy

Batteries are a hot topic for SPARRCI researchers

Published

3 years ago

March 2, 2021

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Batteries are a hot topic for SPARRCI researchers

If you have flown commercially in recent years, you may have noticed that certain items with large lithium-ion batteries can’t be checked. Instead, they must be in your carry-on and turned off.

Objects with these batteries, such as hoverboards or even cell phones, have been known to spontaneously combust, especially if they are physically damaged somehow. The resulting fire presents a danger to people in their vicinity.

So, if these batteries aren’t allowed on airplanes unsupervised, using them to propel the fully electric aircraft of the future may come with some challenges and questions about safety.

Exploring the feasibility of predicting and preventing battery fires before they happen is the idea behind a NASA research activity called SPARRCI, or “Sensor-based Prognostics to Avoid Runaway Reactions and Catastrophic Ignition.”

The big goal is to create a “smart” battery system that would self-monitor, learn about itself as it goes, and if needed say “hey, I’m developing a problem, shut me down” well before it endangers the safety of its aircraft.

“Batteries are a hot topic. Pun intended,” said Brianne DeMattia, lead researcher for SPARRCI at NASA’s Glenn Research Center in Cleveland.

One of the safety threats posed by batteries in electrically propelled aircraft is fire. These larger batteries, like those needed to power hoverboards and cars, have been known to catch fire because of an effect called “thermal runaway.”

Large batteries are basically many cells of small batteries packaged together. If one cell has a malfunction and starts to heat up in temperature, it causes the neighboring cell to do the same. Eventually, the whole battery overheats and could start a fire.

Battery sensors like the ones used by our phones and computers only measure the temperature outside the battery. SPARRCI is designing batteries with sensors inside them to identify the conditions that lead to thermal runaway, then alert the aircraft’s operator to the potential trouble.

The operator would then be able to correct the problem or replace the battery before the dangerous overheating ever occurs. This new, fine-tuned view of the inside of a battery could lead to safer and better performing energy storage – a new generation of batteries.

“With current batteries, we just try to contain fire so it doesn’t spread. But the best approach is to try and prevent the overheating and fire entirely. That’s what we’re trying to do with SPARRCI,” DeMattia said.

Size Matters

Another research area of SPARRCI is battery size and power storage.

A typical remote control for a television uses a couple of AA-sized batteries. A small electric aircraft such as the X-57 Maxwell, NASA’s first all-electric aircraft, may need a battery with the equivalent power of more than 5,000 AA-sized batteries.

Currently, large batteries providing that kind of power must be packaged in bulky containers to make sure that if something gets hot or catches fire, the heat is insulated, protecting other battery cells and the vehicle.

The size and weight of these containers could be reduced in the future with SPARRCI’s ability to show what’s going on inside the battery.

If the aircraft’s pilot or maintenance crew know that thermal runaway could occur, the battery can be replaced and never have a chance to catch fire.

If fire isn’t a threat anymore, extra insulation isn’t required, and the battery’s overall size and weight can be reduced. This would allow more space inside the vehicle to be dedicated to energy storage, improving its range and available power.

Since the activity began in 2020, SPARCCI researchers have successfully begun working out how to install sensors inside batteries. The next step? Identify what conditions the sensors inside the battery should look for to detect imminent battery problems or failures.

The View Inside

SPARRCI is part of the Convergent Aeronautics Solutions (CAS) project, which is designed to give NASA researchers the resources they need to determine if their ideas to solve some of aviation’s biggest technical challenges are feasible and perhaps worthy of additional pursuit within NASA or industry.

One of the things that makes CAS activities like SPARRCI unique is the requirement for researchers from different technical disciplines and NASA field centers to collaborate and bring their unique expertise to bear on the problem.

For SPARRCI, that collaboration led to some memorable moments for battery and sensor researchers at NASA’s Langley Research Center in Virginia, who have been working with their counterparts at NASA Glenn.

The Langley researchers evaluated batteries from Glenn using a Scanning Electron Microscope (SEM), a device similar to the ultrasound machines used in doctors’ offices and hospitals.

“Our goal was to collect images of the guts of the battery during a test without having to open them up post-mortem. This allowed us to see conditions changing in real time and run non-destructive scans to get a sense of the ‘topography’ of the internal surfaces as they morphed during operation,” DeMattia said.

What they saw during the scans was, well, out of this world.

“As we used the SEM to scan images of these lithium metal surfaces inside the battery they sometimes looked like the surface of the Moon! It was one of the coolest things. We spent hours around the computer, ‘oohs’ and ‘ahs’ often thrown around, with an occasional ‘What on Earth is that?’ thrown in for good measure.”

“It’s not something that any of us have done or seen before, but the images did help us tie together the data we collected,” DeMattia said. “”We couldn’t have done this without the different disciplines coming together. It has been really exciting.”

SPARRCI was selected to be a two-year activity that began on Oct. 1, 2019. Interruptions in the pursuit prompted by the COVID-19 pandemic might lead to an extension, although nothing has been decided yet.

Once completed, information gathered, and experience gained during SPARRCI will be shared with others within NASA and the broader aviation community.

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Solar Energy

New Layered Perovskite Structure Explored for Enhanced Optical Properties

Published

19 hours ago

April 19, 2024

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New Layered Perovskite Structure Explored for Enhanced Optical Properties

by Riko Seibo

Tokyo, Japan (SPX) Apr 19, 2024

Perovskites are critically important in the field of materials science due to their distinct and varied properties arising from their unique crystal structure. These properties have potential revolutionary applications in advanced technology areas. A method to harness these properties involves precise manipulation of defects within the perovskite structure, such as missing atoms or substituting one type of atom for another.

In the realm of oxide chemistry, it’s well-established that such defects in oxides can self-organize within the crystal structure when they reach a certain threshold, leading to enhanced material properties. While this phenomenon of defect ordering is well-documented in perovskite oxides, it has not been as prevalent in hybrid halide perovskites, which consist of an organic component, a metal, and a halogen.

A recent study highlighted in ACS Materials Letters reveals findings by Associate Professor Takafumi Yamamoto and his team at Tokyo Institute of Technology, who discovered a novel defect-ordered layered halide perovskite. The research builds on earlier work where the introduction of thiocyanate ions (SCN-) into the FAPbI3 lattice led to structured defect formations. Dr. Yamamoto suggests, “Increasing the SCN concentration might amplify the formation of these defect structures, similar to those observed in vacancy-ordered oxide perovskites.”

The research involved synthesizing FAPbI3 in powder and crystal forms, using specific ratios of SCN-. When a high enough SCN- ratio was used, the resulting perovskite was FA4Pb2I7.5(SCN)0.5. This compound displayed organized defects throughout its layers-more so than its predecessor, FA6Pb4I13.5(SCN)0.5, where fewer defects were organized.

The study identifies this material as part of a ‘homologous series’-a sequence where systematic alterations to the chemical formula yield predictable changes in properties, here observed as variations in the optical bandgap correlated with defect concentration.

“This marks the first instance of a homologous series based on defect ordering in hybrid organic-inorganic perovskites,” notes Dr. Yamamoto. “Our findings set a foundational strategy for manipulating defect structures to adjust the optical properties of perovskites, offering a promising avenue for materials science innovation.”

The implications of this research are significant, potentially paving the way for new perovskite materials with tailored properties for future technological applications.

Research Report:FA4Pb2I7.5(SCN)0.5: n = 3 Member of Perovskite Homologous Series FAn+1Pbn-1I3n-1.5(SCN)0.5 with Organized Defects

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Solar Energy

Solar energy adoption challenges in rural Ethiopia

Published

20 hours ago

April 19, 2024

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Solar energy adoption challenges in rural Ethiopia

by Clarence Oxford

Los Angeles CA (SPX) Apr 19, 2024

Despite decreasing costs and increasing accessibility of solar home systems, significant obstacles hinder their widespread use in remote areas of developing countries, such as Ethiopia, where they could greatly improve health and education.

Inexpensive, yet uncertified and inferior solar panels, along with limited government engagement in rural energy transition, impede access to dependable electricity for these communities.

When homes do incorporate solar energy, it replaces harmful kerosene lamps, offering a healthier, eco-friendly alternative and enabling children to study after dark.

“Understanding the dynamics of renewable energy adoption in rural sectors of the Global South is crucial,” said Yujin Lee, a doctoral student at Cornell University’s Department of City and Regional Planning and first author of a related study in Energy Policy.

Chuan Liao, the study’s senior author and assistant professor in the Department of Global Development at Cornell, emphasized, “The global shift to renewable and clean energy sources must include remote and rural populations in the developing world.”

Ethiopia’s national electrification strategy aims to power all homes within 25 kilometers of the grid by 2030. Those further away are slated for long-term off-grid solutions.

However, the prevalence of low-quality solar panels, which often fail and contribute to environmental waste, poses a barrier to adoption. Additionally, the infrequency of government visits to rural, off-grid or road-less villages leads to misinformed policies.

“Government reports often do not reflect the true situation in rural areas,” noted Lee, who found actual solar adoption rates to be markedly lower than official claims.

Lee advocates for increased governmental presence in rural communities, enhanced public engagement in energy management, and improved communication between governments, private sectors, international organizations, and end-users to support sustainable energy solutions.

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Solar Energy

The role of Floating Solar in achieving Africa’s energy targets as an alternative to dams

Published

21 hours ago

April 19, 2024

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The role of Floating Solar in achieving Africa’s energy targets as an alternative to dams

by Hugo Ritmico

Madrid, Spain (SPX) Apr 19, 2024

Researchers from Politecnico di Milano have identified floating solar photovoltaics (FPV) as a viable alternative to traditional hydropower in meeting Africa’s energy goals, according to a new study published in Nature Energy. The study shows that FPV installed at existing major reservoirs could generate 20-100% of the electricity projected from planned hydropower dams across Africa.

The research, conducted using a comprehensive energy planning model, reveals that FPV is not only cost-effective compared to other renewable resources but also plays a crucial role in Africa’s energy future. “Floating solar has emerged as cost-competitive and could potentially eliminate the need for many new dams,” stated Wyatt Arnold, the lead author of the study.

A detailed analysis of the transboundary Zambezi watercourse indicated that capital investments for new dams could be more effectively utilized by constructing fewer reservoirs and augmenting them with floating solar panels. This strategy could decrease interannual variability in electricity supply by 12% and enhance resilience against long-term droughts exacerbated by climate change.

“Adopting floating solar can provide developing economies with a stable energy supply less susceptible to hydrological changes,” explained Prof. Andrea Castelletti. “Additionally, it mitigates adverse effects on downstream communities and river ecosystems compared to new dam projects.”

The study also underscores the significance of integrated resource planning and the need to consider transboundary effects in sustainable development. It promotes multisector modeling that integrates energy, agriculture, environmental protection, and economic growth within river basins.

Prof. Matteo Giuliani noted, “The strategic deployment of floating solar might outweigh potential drawbacks on reservoir uses like fishing or recreation. Yet, ongoing enhancements in FPV technology and effective planning are essential for its responsible implementation.”

While floating solar offers substantial environmental benefits, the study acknowledges challenges in technology and social acceptance that may limit its deployment. Nevertheless, these challenges are likely to be less impactful than the negative consequences of new hydropower projects, which can disrupt river ecologies, displace populations, and increase regional conflicts over water use.

Research Report:Floating solar emerges as a sustainable energy solution for Africa’s future