Solar Energy

A new type of battery that can charge ten times faster than a lithium-ion battery created

Published

4 years ago

April 7, 2021

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A new type of battery that can charge ten times faster than a lithium-ion battery created

It is difficult to imagine our daily life without lithium-ion batteries. They dominate the small format battery market for portable electronic devices, and are also commonly used in electric vehicles. At the same time, lithium-ion batteries have a number of serious issues, including: a potential fire hazard and performance loss at cold temperatures; as well as a considerable environmental impact of spent battery disposal.

According to the leader of the team of researchers, Professor in the Department of Electrochemistry at St Petersburg University Oleg Levin, the chemists have been exploring redox-active nitroxyl-containing polymers as materials for electrochemical energy storage.

These polymers are characterised by a high energy density and fast charging and discharging speed due to fast redox kinetics. One challenge towards the implementation of such a technology is the insufficient electrical conductivity. This impedes the charge collection even with highly conductive additives, such as carbon.

Looking for solutions to overcome this problem, the researchers from St Petersburg University synthesised a polymer based on the nickel-salen complex (NiSalen). The molecules of this metallopolymer act as a molecular wire to which energy-intensive nitroxyl pendants are attached. The molecular architecture of the material enables high capacitance performance to be achieved over a wide temperature range.

‘We came up with the concept of this material in 2016. At that time, we began to develop a fundamental project “Electrode materials for lithium-ion batteries based on organometallic polymers”.

It was supported by a grant from the Russian Science Foundation. When studying the charge transport mechanism in this class of compounds, we discovered that there are two keys directions of development. Firstly, these compounds can be used as a protective layer to cover the main conductor cable of the battery, which would be otherwise made of traditional lithium-ion battery materials. And secondly, they can be used as an active component of electrochemical energy storage materials,’ explains Oleg Levin.

The polymer took over three years to develop. In the first year, the scientists tested the concept of the new material: they combined individual components to simulate the electrically conducting backbone and redox-active nitroxyl-containing pendants. It was essential to make certain that all parts of the structure worked in conjunction and reinforced each other.

The next stage was the chemical synthesis of the compound. It was the most challenging part of the project. This is because some of the components are extremely sensitive and even the slightest error of a scientist may cause degradation of the samples.

Of the several polymer specimens obtained, only one was found to be sufficiently stable and efficient. The main chain of the new compound is formed by complexes of nickel with salen ligands. A stable free radical, capable of rapid oxidation and reduction (charge and discharge), has been linked to the main chain via covalent bonds.

‘A battery manufactured using our polymer will charge in seconds – about ten times faster than a traditional lithium-ion battery. This has already been demonstrated through a series of experiments. However, at this stage, it is still lagging behind in terms of capacity – 30 to 40% lower than in lithium-ion batteries. We are currently working to improve this indicator while maintaining the charge-discharge rate,’ says Oleg Levin.

The cathode for the new battery has been fabricated – a positive electrode for use in chemical current sources. Now we need the negative electrode – the anode. In fact, it does not have to be created from scratch – it can be selected from the existing ones. Paired together they will form a system that, in some areas, may soon supersede lithium-ion batteries.

”The new battery is capable of operating at low temperatures and will be an excellent option where fast charging is crucial. It is safe to use – there is nothing that may pose a combustion hazard, unlike the cobalt-based batteries that are widespread today. It also contains significantly less metals that can cause environmental harm. Nickel is present in our polymer in a small amount, but there is much less of it than in lithium-ion batteries,’ says Oleg Levin.

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Solar Energy

Scientists Probe Declining Earbud Battery Longevity

Published

8 hours ago

February 5, 2025

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Scientists Probe Declining Earbud Battery Longevity

by Clarence Oxford

Los Angeles CA (SPX) Feb 05, 2025

Have you ever noticed how electronic devices, including wireless earbuds, seem to lose battery capacity faster the longer you use them? An international research team from The University of Texas at Austin set out to examine this familiar issue, known as battery degradation, by focusing on the earbuds that many people rely on daily. Through a series of x-ray, infrared, and other imaging approaches, the researchers investigated the hidden complexities behind these tiny devices and revealed why their battery life declines over time.

“This started with my personal headphones; I only wear the right one, and I found that after two years, the left earbud had a much longer battery life,” said Yijin Liu, an associate professor in the Cockrell School of Engineering’s Walker Department of Mechanical Engineering, who led the new research published in Advanced Materials. “So, we decided to look into it and see what we could find.”

Their analysis showed that crucial earbud features – like the Bluetooth antenna, microphones, and circuits – compete with the battery in a very confined space, producing a microenvironment that is less than ideal. This situation results in a temperature gradient that damages the battery over time, with different sections of the cell experiencing variable temperatures.

Real-world factors also complicate matters. Frequent changes in climate, shifts in air quality, and a host of other environmental variables challenge the battery’s resilience. While cells are generally designed to endure harsh conditions, constant fluctuations can take their toll.

These discoveries highlight the importance of considering how batteries interact with devices such as phones, laptops, and even electric vehicles. Packaging solutions, strategic design decisions, and adaptations for user habits may all play a role in extending battery performance.

“Using devices differently changes how the battery behaves and performs,” said Guannan Qian, the first author of this paper and a postdoctoral researcher in Liu’s lab. “They could be exposed to different temperatures; one person has different charging habits than another; and every electric vehicle owner has their own driving style. This all matters.”

In conducting this study, Liu and his team worked closely with UT’s Fire Research Group, led by mechanical engineer Ofodike Ezekoye. They paired infrared imaging methods with their in-house x-ray technology at UT Austin and Sigray Inc. To expand their scope, they then teamed up with some of the world’s most advanced x-ray facilities.

Their collaborators included researchers from SLAC National Accelerator Laboratory’s Stanford Synchrotron Radiation Lightsource, Brookhaven National Laboratory’s National Synchrotron Light Source II, Argonne National Laboratory’s Advanced Photon Source, and the European Synchrotron Radiation Facility (ESRF) in France. These partnerships allowed them to observe battery behavior under more authentic operating conditions.

“Most of the time, in the lab, we’re looking at either pristine and stable conditions or extremes,” said Xiaojing Huang, a physicist at Brookhaven National Laboratory. “As we discover and develop new types of batteries, we must understand the differences between lab conditions and the unpredictability of the real world and react accordingly. X-ray imaging can offer valuable insights for this.”

Looking ahead, Liu says his team will continue analyzing battery performance in the settings people experience every day. They plan to expand their approach to larger batteries, such as those in smartphones, laptops, and electric vehicles, to learn more about their degradation patterns.

Research Report:In-device Battery Failure Analysis

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Solar Energy

Quantum factors elevate plant energy transport efficiency

Published

8 hours ago

February 5, 2025

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Quantum factors elevate plant energy transport efficiency

by Robert Schreiber

Munich, Germany (SPX) Feb 05, 2025

For countless engineers, converting sunlight into easily stored chemical energy stands as an enduring goal. Yet nature perfected this challenge billions of years ago. A recent study reveals that quantum mechanics, once thought to be limited to physics, is also essential for key biological processes.

Green plants and other photosynthetic organisms draw on quantum mechanical mechanisms to capture the sun’s energy. According to Prof. Jurgen Hauer: “When light is absorbed in a leaf, for example, the electronic excitation energy is distributed over several states of each excited chlorophyll molecule; this is called a superposition of excited states. It is the first stage of an almost loss-free energy transfer within and between the molecules and makes the efficient onward transport of solar energy possible. Quantum mechanics is therefore central to understanding the first steps of energy transfer and charge separation.”

Classical physics alone cannot completely describe how this phenomenon unfolds throughout green plants and in certain photosynthetic bacteria. Although the exact details remain only partly understood, Prof. Hauer and first author Erika Keil consider their new findings an important step toward uncovering how chlorophyll, the pigment behind leaf coloration, functions. Applying these insights to engineered photosynthesis devices could unlock unprecedented solar energy conversion efficiencies for both power production and photochemical applications.

In their investigation, the researchers focused on two portions of the light spectrum absorbed by chlorophyll: the low-energy Q band (yellow to red) and the high-energy B band (blue to green). In the Q region, two electronic states are quantum mechanically coupled, promoting virtually loss-free energy movement. The system subsequently relaxes via “cooling”, i.e. by releasing energy in the form of heat. These observations demonstrate that quantum mechanical processes can play a major role in shaping key biological functions.

Research Report:Reassessing the role and lifetime of Qx in the energy transfer dynamics of chlorophyll a

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Solar Energy

HZB sets new efficiency record for CIGS perovskite tandem solar cells

Published

9 hours ago

February 5, 2025

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HZB sets new efficiency record for CIGS perovskite tandem solar cells

by Robert Schreiber

Berlin, Germany (SPX) Feb 05, 2025

Researchers at Helmholtz Center Berlin for Materials and Energy (HZB) and Humboldt University Berlin have developed a CIGS-perovskite tandem solar cell that has set a new world record for efficiency, achieving 24.6%. The performance of the cell has been officially certified by the Fraunhofer Institute for Solar Energy Systems.

Thin-film solar cells, such as those based on copper, indium, gallium, and selenium (CIGS), require minimal material and energy to manufacture, making them an environmentally friendly alternative to conventional silicon-based solar cells. CIGS thin films can also be applied to flexible substrates, expanding their potential applications.

The new tandem solar cell developed by HZB and Humboldt University combines a CIGS bottom cell with a perovskite top cell. By optimizing the contact layers between these two components, the research team successfully increased efficiency to a record-breaking 24.6%. This milestone was confirmed by the Fraunhofer Institute for Solar Energy Systems ISE in Freiburg, Germany.

This achievement was made possible through a collaborative effort among researchers. The top cell was developed by Thede Mehlhop, a master’s student at TU Berlin, under the supervision of Stefan Gall. The perovskite absorber layer was created in the joint laboratory of HZB and Humboldt University Berlin, while the CIGS sub-cell and contact layers were fabricated by HZB researcher Guillermo Farias Basulto. Additionally, the KOALA high-performance cluster system at HZB was used to deposit the perovskite and contact layers in a vacuum.

“At HZB, we have highly specialized laboratories and experts who are top performers in their fields. With this world record tandem cell, they have once again shown how fruitfully they work together,” said Prof. Rutger Schlatmann, spokesman for the Solar Energy Department at HZB.

HZB has a strong track record in achieving world records in solar cell efficiency, including past accomplishments in silicon-perovskite tandem cells and now in CIGS-perovskite tandem technology.

“We are confident that CIGS-perovskite tandem cells can achieve much higher efficiencies, probably more than 30%,” said Prof. Rutger Schlatmann.