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Advancing safer lithium energy storage

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Advancing safer lithium energy storage


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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Machine Learning Enhances Solar Power Forecast Accuracy

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Machine Learning Enhances Solar Power Forecast Accuracy


Machine Learning Enhances Solar Power Forecast Accuracy

by Simon Mansfield

Sydney, Australia (SPX) Feb 18, 2025






As solar power becomes a more significant component of the global energy grid, improving the accuracy of photovoltaic (PV) generation forecasts is crucial for balancing supply and demand. A recent study published in Advances in Atmospheric Sciences examines how machine learning and statistical techniques can enhance these predictions by refining errors in weather models.

Since PV forecasting depends heavily on weather predictions, inaccuracies in meteorological models can impact power output estimates. Researchers from the Institute of Statistics at the Karlsruhe Institute of Technology investigated ways to improve forecast precision through post-processing techniques. Their study evaluated three methods: adjusting weather forecasts before inputting them into PV models, refining solar power predictions after processing, and leveraging machine learning to predict solar power directly from weather data.



“Weather forecasts aren’t perfect, and those errors get carried into solar power predictions,” explained Nina Horat, lead author of the study. “By tweaking the forecasts at different stages, we can significantly improve how well we predict solar energy production.”



The study found that applying post-processing techniques to power predictions, rather than weather forecasts, yielded the most significant improvements. While machine learning models generally outperformed conventional statistical methods, their advantage was marginal in this case, likely due to the constraints of the available input data. Researchers also highlighted the importance of including time-of-day information in models to enhance forecast accuracy.



“One of our biggest takeaways was just how important the time of day is,” said Sebastian Lerch, corresponding author of the study. “We saw major improvements when we trained separate models for each hour of the day or fed time directly into the algorithms.”



A particularly promising approach involves bypassing traditional PV models altogether by using machine learning algorithms to predict solar power directly from weather data. This technique eliminates the need for detailed knowledge of a solar plant’s configuration, relying instead on historical weather and performance data for training.



The findings pave the way for further advancements in machine learning-based forecasting, including the integration of additional weather variables and the application of these methods across multiple solar installations. As renewable energy adoption accelerates, improving solar power forecasting will be key to maintaining grid stability and efficiency.



Research Report:Improving Model Chain Approaches for Probabilistic Solar Energy Forecasting through Post-processing and Machine Learning


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The next-generation solar cell is fully recyclable

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The next-generation solar cell is fully recyclable


The next-generation solar cell is fully recyclable

by Robert Schreiber

Berlin, Germany (SPX) Feb 18, 2025






Researchers at Linkoping University have developed a groundbreaking method for recycling all components of a perovskite solar cell without the use of hazardous solvents. The process ensures that recycled solar cells maintain the same efficiency as newly manufactured ones, marking a significant step toward sustainable solar technology. The primary solvent used in this method is water, offering an environmentally friendly alternative to conventional recycling processes.

With the anticipated surge in electricity demand due to the expansion of artificial intelligence and the electrification of transportation, sustainable energy sources must advance to prevent further environmental impact. Solar power has long been considered a viable renewable energy source, with silicon-based panels dominating the market for over three decades. However, as first-generation silicon panels reach the end of their lifespan, waste management poses a major challenge.



“There is currently no effective technology to handle the waste from silicon solar panels. As a result, outdated panels are being discarded in landfills, leading to vast amounts of electronic waste,” explained Xun Xiao, postdoctoral researcher at Linkoping University’s Department of Physics, Chemistry, and Biology (IFM).



Feng Gao, a professor of optoelectronics at the same department, emphasized the importance of considering recyclability in emerging solar technologies: “If we don’t have a recycling solution in place, perhaps we shouldn’t introduce new solar cell technologies to the market.”



Perovskite solar cells are among the most promising alternatives for next-generation solar technology. These cells are lightweight, flexible, and transparent, making them suitable for various surfaces, including windows. Additionally, they achieve energy conversion efficiencies of up to 25 percent, rivaling silicon-based solar cells.



“Many companies are eager to commercialize perovskite solar cells, but we must ensure that they do not contribute to landfill waste. Our project introduces a method where all components of perovskite solar cells can be reused without sacrificing performance,” said Niansheng Xu, postdoctoral researcher at Linkoping University.



Although perovskite solar cells have a shorter lifespan than their silicon counterparts, it is crucial to develop an efficient and environmentally friendly recycling process. Additionally, these cells contain a small amount of lead, essential for high efficiency but requiring proper handling to prevent environmental contamination. In many parts of the world, manufacturers are legally obligated to recycle end-of-life solar cells sustainably.



Existing recycling methods for perovskite solar cells often rely on dimethylformamide, a toxic and potentially carcinogenic solvent commonly found in paint removers. The Linkoping researchers have devised an innovative approach that replaces this hazardous chemical with water, significantly reducing environmental risks. This method enables the recovery of high-quality perovskite materials from the water-based solution.



“We can recover every component-the glass covers, electrodes, perovskite layers, and charge transport layers,” Xiao added.



The next phase of research will focus on scaling up this process for industrial applications. In the long term, scientists believe that perovskite solar cells will become a key component of the global energy transition, particularly as supporting infrastructure and supply chains evolve.




Research Report:Aqueous based recycling of perovskite photovoltaics


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China to further shrink renewables subsidies in market reform push

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China to further shrink renewables subsidies in market reform push


China to further shrink renewables subsidies in market reform push

by AFP Staff Writers

Shanghai (AFP) Feb 9, 2025






China’s top economic planner said on Sunday it would reduce some renewable energy subsidies in reforms intended to open the booming sector to market forces.

China has sought to scale back government support for renewable energy companies in recent years as the sector reaches critical mass.

It installed a record amount of renewable energy last year and has already surpassed a target to have at least 1,200 gigawatts of solar and wind capacity installed by 2030.

New clean energy projects completed after June 1 must sell electricity at rates determined by the market rather than at preferential rates previously used to support China’s energy transition, the National Development and Reform Commission (NDRC) said in a statement.

The NDRC urged energy producers to “push forward clean energy’s participation in market transactions”.

The commission also said it “encourages electricity providers and electricity buyers to sign multi-year purchase agreements and pre-emptively manage market risks”.

Beijing invested more than $50 billion in new solar supply capacity from 2011 to 2022, according to the International Energy Agency.

It has built almost twice as much wind and solar capacity as every other country combined, according to research published last year.

However, China’s grid is struggling to keep up.

Renewable supply is increasingly being blocked to prevent the grid from becoming overwhelmed, a process known as curtailment.

Beijing has rolled out a series of measures over the past decade aimed at weaning renewable energy providers off state financial support.

It ended subsidies for new solar power stations and onshore wind power projects in 2021.

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