Metals Tech

Contemporary Amperex Technology (CATL), the world’s largest EV battery maker, is going to build its own $1.83 billion offshore wind farm.

The Chinese EV battery and battery storage giant’s offshore wind farm, which will be sited near the company’s headquarters in Ningde in southeastern Fujian Province, will provide clean energy to power its own operations, reports Caixin.

The Fujian Provincial Development and Reform Commission approved the construction of the 800-megawatt (MW) offshore wind farm on Monday, along with related battery storage projects. CATL is required to start construction within two years.

Fujian Runshi Offshore Wind Power, a subsidiary that CATL registered in April 2023, will develop the project. CATL’s green energy unit owns 96% of the subsidiary company, and state-owned Fujian Mindong Electric Power and PowerChina Fujian Electric Power Engineering own the other 4%.

The world’s largest EV battery maker reducing its carbon manufacturing footprint with offshore wind – that’s a real win.

Lithium-ion batteries are a widely used class of rechargeable batteries in today’s world. One of the processes that can hamper the functioning of these batteries is an internal short circuit caused by direct contact between the cathode and anode (the conductors that complete the circuit within a battery).

To avoid this, separators composed of polyolefins—a type of polymer—can be employed to maintain separation. However, these separators can melt at higher temperatures, and the inadequate absorption of electrolytes (essential for conveying charges between electrodes) can result in short circuits and diminished efficiency. To tackle these issues, several different methods have been proposed.

One such method is to apply ceramic coatings on the separators to improve the way they handle pressure and heat. However, this can increase the thickness of the separators, reduce their adhesion, and harm battery performance. Another technique is to use polymer coatings, in a process known as graft polymerization. This involves the attachment of individual units (monomers) to the separators to give them the desired qualities.

A recent study published in Energy Storage Materials now demonstrates successful graft polymerization on a polypropylene (PP) separator, incorporating a uniform layer of silicon dioxide (SiO₂). The discovery is the result of a joint study that including Assistant Professor Jeongsik Yun from the Department of Energy and Chemical Engineering at Incheon National University.

Dr. Yun was motivated by the need for high-performance battery materials in electric vehicles to achieve longer driving ranges, an area he has been actively working on. Beyond improving battery performance, his goal is to ease consumer concerns about battery explosions, potentially influencing their decisions to embrace electric vehicles.

According to him, “Battery explosions are frequently initiated from the melting of a separator. The commercial battery separator is made of polyolefins, a class of polymers which are vulnerable to heat. We therefore aimed to improve the thermal stability of the commercial separators by coating them with thermally robust materials such as SiO₂ particles.”

In this study, a PP separator was modified in several ways. Initially, it was coated with a layer of polyvinylidene fluoride, a chemical chosen to enhance electrolyte affinity and thermal stability, while also introducing grafting reaction sites. Then, the separator underwent grafting with methacrylate molecules, followed by a final coating with SiO₂ particles. These modifications made the separator stronger and more resistant to heat, suppressed the growth of lithium dendrites, and helped improve the cycling performance.

The modifications not only preserved the energy storage of Li-ion batteries per unit volume, but also outperformed other coating methods in cell performance. This technique thus shows promise for creating robust separators and advancing the use of lithium-ion batteries in electric vehicles and energy storage systems.

“We hope that the results of this study can enable the development of high-safety lithium batteries. We believe that the thermal stability of these batteries will greatly benefit the current fire-sensitive electric vehicle field. In the long term, this can motivate people to choose electric vehicles and in urban areas, reduce the suffering of people from breathing in the polluted air generated by the internal combustion engines,” envisions Dr. Yun.

In summary, this study presents a reliable method for creating an innovative and durable separator for lithium-ion batteries, potentially paving the way for a greener future.

Organic-based optoelectronic technology is increasingly recognized as an energy-efficient solution for low-power indoor electronics and wireless IoT sensors. This is largely due to its superior flexibility and light weight compared to conventional silicon-based devices. Notably, organic photovoltaic cells (OPVs) and organic photodetectors (OPDs) are leading examples in this field.

OPVs have the remarkable ability to absorb energy and generate electricity even under very low light conditions, while OPDs are capable of capturing images. However, despite their potential, the development of these devices has thus far been conducted independently. As a result, they have not yet reached the level of efficiency necessary to be considered practical for next-generation, miniaturized devices.

A Korea Institute of Science and Technology (KIST) research team, led by Dr. Min-Chul Park and Dr. Do Kyung Hwang of the Center for Opto-Electronic Materials and Devices, Prof. Jae Won Shim and Prof. Tae Geun Kim of the School of Electrical Engineering at Korea University, Prof. JaeHong Park of the Department of Chemistry and Nanoscience at Ewha Womans University, have now developed an organic-based optoelectronic device.

The work is published in the journal Advanced Materials.

This innovative device not only integrates the functionalities of OPVs and organic OPDs but also visualizes images in applications requiring low-light conditions, thereby enhancing energy efficiency in indoor environments.

By advancing the organic semiconductor layer into a multicomponent structure, the research team has enhanced the device’s performance. In indoor environments, it achieves an impressive photoelectric conversion efficiency exceeding 32%, along with a linear dynamic range surpassing 130 dB. This significant improvement in contrast ratio, especially in low-light conditions, allows for a much clearer image than conventional silicon devices, which typically offer a linear dynamic range of 100 dB.

The collaborative research team made further strides by successfully applying single-pixel image sensing. This image sensing system captures ambient light, transforms it into electrical energy, and utilize this energy to acquire images.

In contrast to the previous need for specialized cameras in low-light conditions, the newly developed photodetector, featuring a multi-component semiconductor layer, offers a versatile platform. It can function not only as a conventional camera but also as a decorative element on windows or walls, providing sufficient resolution to discern shapes and movements of objects.

Dr. Min-chul Park from KIST highlighted the versatility of this technology, noting, “While primarily functioning as an energy harvester, it can also be applied to detect movement and recognize motion patterns in environments without light.”

He stated, “This holds great promise not only for human-computer interaction (HCI) research but also in various industrial sectors, including smart indoor environments.”

A team of metallurgists in Germany has developed a technique for extracting iron from aluminum production waste. In their paper published in the journal Nature, the group outlines their process and its degree of efficiency. Chenna Rao Borra, with the Indian Institute of Technology Kharagpur, has published a News and Views piece in the same journal issue outlining the work by the team on this new effort.

Aluminum is one of the most produced metals in the world, providing a basic ingredient for a host of products, but it also has a high environmental cost—production of aluminum generates a kind of sludge called “red mud,” a type of bauxite residue.

Each year, approximately 180 million metric tons of red mud are produced around the globe, resulting in the creation of multiple reservoirs that collectively hold 4 billion metric tons of the hazardous material—it is highly alkaline and contains a high concentration of heavy metals.

Prior research has shown that red mud can be used as a building ingredient, but to date, such use accounts for just 3% of all red mud produced. In this new effort, the research team found a way to partially clean up red mud by removing the iron.

To remove the iron, the researchers developed a special chamber that exposed the material to hydrogen plasma for up to 15 minutes. This initially converts the red mud to a viscous melt. Over the following few minutes, it is then reduced to liquid iron and steam and the liquid iron is shunted out as globules.

The research team has already carried out a cost analysis of the process and has found it to be economically viable when scaled up, though they note a pilot-scale facility is required to verify their projections.

Notably, in addition to reducing aluminum production waste, the iron produced from the red mud could be used to make steel. The team notes also that the technique requires augmentation before scaling up, such as processing the fumes that result.

The sustainably powered, electrochemical reduction of carbon dioxide (CO2) into useful chemicals and feedstock could help to mitigate greenhouse gas emissions, allowing industries to reuse released CO2 in beneficial ways. Most of the strategies for realizing this introduced so far, however, have notable limitations, including a poor stability over long periods of time.

Researchers at Hong Kong Polytechnic University, University of Oxford and the National Synchrotron Radiation Research Center recently introduced a new membrane-electrode-assembly system that could facilitate the stable electrocatalytic reduction of CO₂.

Notably, their proposed system, which was first introduced in a paper published in Nature Energy, is fed by pure water (H₂O) and thus does not rely on alkali-metal electrolyte.

“Our modern society heavily depends on fossil fuels to power our economy, but the resulting CO₂ emissions are a major threat to the climate,” Shu Ping Lau, co-author of the paper, told Tech Xplore. “We are looking to harness and re-enter massive amounts of CO₂ into the carbon cycle by using electrocatalytic CO₂ reduction (ECO₂R) technology to combat this. However, previous research has shown that the stability of the ECO₂R system is a major challenge, with current systems lasting less than 200 hours for ECO₂R-to-ethylene (C₂H₄).”

In their recent work, Lau and his collaborators have been trying to overcome the limitations of existing systems for electrocatalytic CO₂ reduction. Their objective is to create a new electrolysis architecture that suppresses carbonate formation during ECO₂R and thus enables a prolonged stable operation.

“Our goal is to maintain an alkaline cathode environment without involving alkali metal cations, ultimately designing the APMA MEA (AEM+PEM assembly membrane-electrode assembly) architecture with pure H₂O as the anolyte,” Lau explained. “In our APMA MEA ECO₂R system, we’ve created a way for CO₂ to react with H₂O to produce C₂H₄ and OH^– at the cathode, while H₂O is oxidized into O₂ and H⁺ at the anode. The resulting OH^– and H⁺ then combine to form H₂O in the middle of the membranes.”

The new system introduced by the researchers is comprised of two distinct membranes (AEM and PEM), a cathode catalyst (stepped-surface Cu), an anode catalyst (Pt/Ti) and pure water as the anolyte. One of its most remarkable advantages is that it does not require any additional chemicals to initiate reactions, and just uses pure H2O as the electrolyte. This means that it could be easily scaled up to an industrial level.

“Even more impressive, the APMA MEA architecture overcomes the thermodynamic limitation of CO2 reacting with the electrogenerated OH- into carbonate, which extends the system’s stability,” Lau said. “With its durability and efficiency, our APMA MEA system has the potential to revolutionize CO2 electrocatalysis technology and transform the modern fossil energy system.”

The hurrying pace of societal electrification is encouraging from a climate perspective. But the transition away from fossil fuels toward renewable sources like wind presents new risks that are not yet fully understood.

Researchers from Concordia and Hydro-Quebec presented a new study on the topic in Glasgow, United Kingdom at the 2023 IEEE International Conference on Communications, Control, and Computing Technologies for Smart Grids (SmartGridComm). Their study explores the risks of cyberattacks faced by offshore wind farms. Specifically, the researchers considered wind farms that use voltage-source-converter high-voltage direct-current (VSC-HVDC) connections, which are rapidly becoming the most cost-effective solution to harvest offshore wind energy around the world.

“As we advance the integration of renewable energies, it is imperative to recognize that we are venturing into uncharted territory, with unknown vulnerabilities and cyber threats,” says Juanwei Chen, a Ph.D. student at the Concordia Institute for Information Systems Engineering (CIISE) at the Gina Cody School of Engineering and Computer Science.

“Offshore wind farms are connected to the main power grid using HVDC technologies. These farms may face new operational challenges,” Chen explains. “Our focus is to investigate how these challenges could be intensified by cyber threats and to assess the broader impact these threats might have on our power grid.”

Concordia Ph.D. student Hang Du, CIISE associate professor Jun Yan and Gina Cody School dean Mourad Debbabi, along with Rawad Zgheib from the Hydro-Quebec Research Institute (IREQ), also contributed to the study. This work is part of a broad research collaboration project involving the group of Prof. Debbabi and the IREQ cybersecurity research group led by Dr. Marthe Kassouf and involving a team of researchers including Dr. Zgheib.

Complex and vulnerable systems

Offshore wind farms require more cyber infrastructure than onshore wind farms, given that offshore farms are often dozens of kilometers from land and are operated remotely. Offshore wind farms need to communicate with onshore systems via a wide area network. Meanwhile, the turbines also communicate with maintenance vessels and inspection drones, as well as with each other.

This complex, hybrid-communication architecture presents multiple access points for cyberattacks. If malicious actors were able to penetrate the local area network of the converter station on the wind farm side, these actors could tamper with the system’s sensors. This tampering could lead to the replacement of actual data with false information. As a result, electrical disturbances would affect the offshore wind farm at the points of common coupling.

In turn, these disturbances could trigger poorly dampened power oscillations from the offshore wind farms when all the offshore wind farms are generating their maximum output. If these cyber-induced electrical disturbances are repetitive and match the frequency of the poorly dampened power oscillations, the oscillations could be amplified.

These amplified oscillations might then be transmitted through the HVDC system, potentially reaching and affecting the stability of the main power grid. While existing systems usually have redundancies built in to protect them against physical contingencies, such protection is rare against cyber security breaches.