Further advances in rechargeable batteries are essential to meet the demand for electric vehicles and energy storage. A novel two-dimensional (2D) material may be the solution to mitigating the so-called ‘shuttle effect’ in lithium-sulfur battery technology.��

As renewable energy production technologies improve and shrink, and electric vehicles become more popular, the demand for portable energy storage is increasing.

Currently, lithium-ion batteries are the standard, but energy density and cost must continually improve to achieve the levels of deployment needed for the most ambitious sustainability targets. Alkali metal-sulfur batteries, a type of lithium-ion battery, have emerged as a promising option, especially in applications requiring high energy storage capacity. However, one issue with metal-sulfur batteries is the so-called ‘shuttle effect’: metal particles called polysulphides dissolve into the battery’s electrolyte and are transported from the sulfur cathode to the metal anode. This reduces capacity and charging performance of the battery.

Finding a way to suppress the shuttle effect is crucial to metal-sulfur battery performance and lifetime. Khalifa University’s Hiba Al-Jayyousi, Master’s student, Department of Mechanical Engineering, Dr. Nirpendra Singh, and Dr. Muhammad Sajjad, both Department of Physics, and Prof. Kin Liao, Department of Aerospace Engineering investigated the use of 2D biphenylene sheet as a material to ‘anchor’ the metal particles and prevent them from shuttling. Their results were published in.

“Over the last three decades, lithium-ion rechargeable batteries have gained vast popularity due to their low self-discharge, ample energy storage, stable cycling performance, higher theoretical capacity and specific energy density, which directly affects the development of energy storage technologies,” Dr. Singh said. “Li-ion batteries are environmentally-friendly and suitable for portable electronics, as they offer much higher energy density than other rechargeable systems.”

Although lithium sulfur batteries have high theoretical capacity and energy density, the shuttle effect seriously hinders this technology’s development. The research team found that trapping lithium polysulfides on a biphenylene sheet effectively suppresses the shuttle effect and enhances the cycling stability of Li-S batteries. The biphenylene is a newly synthesized two-dimensional material, where the carbon atoms are arranged in a square, hexagonal, and octagonal rings. Compared with other reported two-dimensional materials such as graphene and phosphorene, the biphenylene sheet used by the research team exhibited higher binding energies with the polysulfides.

A suitable anchoring material should have excellent conductivity, high surface area, porous structure, and high binding energy with the polysulfides to prevent them from dissolving into electrolytes. Several 2D materials have been proposed and investigated, including and nonpolar polyaniline previously investigated by Dr. Singh.

“Our study shows that the biphenylene sheet is an excellent anchoring material for lithium-sulfur batteries for suppressing the shuttle effect because of its superior conductivity, porosity, and strong anchoring ability,” Al-Jayyousi said.

As energy consumption continues to rise, finding new materials that can make renewable energy generation and storage cleaner and more efficient will be key to meeting the world’s growing energy demands sustainably.��

Jade Sterling
Science Writer
20 May 2022

The post A Promising Anchoring Material for Lithium-sulfur Batteries appeared first on Khalifa University.

Abu Dhabi company Aspire will invest $54m to fund new research in priority sectors

Two Abu Dhabi universities will open new research institutes in three sectors facing urgent challenges: precision medicine, food security and sustainable energy production.

Aspire, an entity of Abu Dhabi’s Advanced Technology Research Council, has pledged to fund the research by investing at least $54 million over five years.

UAE University will have two research institutes while Khalifa University will have one.

“With the growing focus on sustainability in all spheres of life today, we are now able to support world-leading research in these priority areas,” said Arthur Morrish, chief executive of Aspire.

“We look forward to seeing the long-term impact the [research institutes] will have and to their recommendations that can enhance the quality of life of the local population with far-reaching implications for health care, food security and sustainable energy.”

Read the rest of the story here:

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Hydrogen offers a potential solution to the problem of supporting more sustainable industries, but technical, economic, social, and political factors stand in its way, according to a new paper produced by an international team of experts from a variety of disciplines.��

Using decarbonized hydrogen, so-called green hydrogen, is an avenue to a low-carbon economy that is attracting renewed interest. Technological developments and cost reductions could allow hydrogen to contribute significantly to a decarbonized economy as a fuel and a feedstock. As a fuel, hydrogen offers considerable potential because it generates no carbon dioxide on combustion. As a feedstock, low-carbon hydrogen could replace high-carbon feedstocks in processes such as steel production.

At a critical juncture for the industry and global climate, Dr. Steve Griffiths, SVP Research and Development and Professor of Practice, offers a critical, systematic and interdisciplinary assessment of industrial decarbonization via hydrogen. Dr. Griffiths and his team reviewed more than 2,100 sources of evidence, referencing over 700 papers and studies, using a sociotechnical lens to examine hydrogen production and use across multiple industries. The work on hydrogen is part of a broader set of studies that the team has undertaken with support from the Industrial Decarbonisation Research and Innovation Centre (IDRIC) in the United Kingdom.

Team members were Dr. Benjamin Sovacool, University of Sussex, UK; Dr. Jinsoo Kim, Hanyang University, Republic of Korea; Dr. Morgan Bazilian, Colorado School of Mines, USA; and Joao Uratani, a research engineer also from Khalifa University.

Their review was published in.

“Hydrogen is increasingly being positioned as a key energy vector due to its versatility as a chemical store of energy for use in the power, buildings, transport, and industrial sectors,” Dr. Griffiths said. “More importantly, hydrogen is one of the key options for many decarbonizing industrial sectors, particularly those that require hydrogen as a feedstock for process chemistry.”

Hydrogen is the most common element in the universe but hydrogen atoms do not exist in nature by themselves. To produce hydrogen, its atoms need to be decoupled from other elements in resources like�� water, plants or fossil fuels. The method by which hydrogen is produced largely determines its sustainability.

“,” Dr. Griffiths said. “Its properties make it an excellent fuel but hydrogen requires considerable care in processing and handling. Further, transporting it long distances in a liquid form is currently very expensive.”

Although the use of hydrogen is somewhat limited in scope today, a very different future may be on the horizon. The industrial processes used to make steel, cement, ceramics, glass and chemicals all require varying amounts of high-temperature heat. For these sectors, hydrogen is one of the very few long-term options for replacing fossil fuels at large scale.

The use of hydrogen in shipping, particularly in the form of ammonia, is the major opportunity here.

However, the main challenge with scaling up the hydrogen-supply chain is to lower the costs of transporting it. The existing technologies for transporting and distributing hydrogen long distances in a volumetrically energy dense liquid form are still significantly more expensive than those of other fuels, such as oil and natural gas. Hydrogen, or one of its derivatives, particularly ammonia, may play a prominent role in such long distance transport. However, pipeline transmission of hydrogen gas is currently the economic means of moving hydrogen at large scale.

Compressed hydrogen could use converted natural-gas pipelines, or newly built ones, or even be co-transported with natural gas to partially decarbonize natural gas already used in the energy sector. A lack of dedicated global hydrogen pipeline networks is, however, a current challenge to be overcome if regional and national hydrogen trade is to be established. Once transported, hydrogen storage becomes the priority, but hydrogen’s low volumetric energy density can make it difficult to store. Fortunately, there appears to be no insurmountable technical barrier to storing hydrogen over the longer term in high capacity geologic formations like aquifers and rock caverns.

The final cost of hydrogen in international trade will depend on what it costs to produce and transport it, Dr. Griffiths said. “Connecting suppliers and consumers at the global level via the most cost-effective means will be a great challenge.”

Such considerations are particularly relevant for connecting global supply and demand. This said, sociopolitical factors could hinder hydrogen’s growing role in industrial decarbonization and so must also be considered.

The review paper considers the social and technical systems involved in making, distributing, and using hydrogen, with the authors accounting for institutional inputs, policy and regulatory frameworks, and financial and economic enablers. There are many socio-technical elements at play:

“Industry decarbonization via hydrogen will require policy mechanisms that stimulate both hydrogen supply and demand and support development of the necessary supply-chain infrastructure,” Dr. Griffiths said. “While policy toolkits can be built upon existing efforts targeting renewable-energy generation and use, specific hydrogen-targeted policy instruments will be needed.”

Further, policies can spur innovation, and dedicated funds will be required to support research and development in academia and industry.

In this context, dedicated hydrogen-research centers are appearing, and public-private partnerships for the demonstration and scale up of hydrogen technologies and projects can be found around the world. Regulatory and certification frameworks are emerging that cover the production, supply-chain and industrial-use elements of hydrogen at the national level. Internationally, seventeen standards had been published and fifteen more were under development at the time the paper was written. These standards cover most elements of the technical pathways for hydrogen production and use.

However, the degree to which countries have been able to implement regulation varies. National and regional regulatory bodies will need to adopt harmonized policy instruments to avoid being excluded from accessing international hydrogen markets. Additionally, the regulatory frameworks on safety and quality control will need to be particularly robust.

“The absence of comprehensive, national and international policy and regulatory frameworks for hydrogen adoption, particularly for�� industrial systems, is a major challenge,” Dr. Griffiths said. “Despite increasing interest in hydrogen, policy support in the form of roadmaps, action and strategic plans is still not fully implemented on a global level.”

The future of hydrogen trade relationships will also rely heavily on geopolitics. The role that renewable hydrogen could play on the energy geopolitics stage remains to be seen. Particularly as transport costs are reduced, the importance of where resources are found will be reduced. Contrasting this to the geopolitical clout afforded to countries located on top of robust oil reserves suggests how global geopolitical dynamics could be affected.

“Whether countries will adopt particular roles in a hydrogen-economy transition is likely to depend on existing resources and infrastructure,” Dr. Griffiths said. “Some countries are more likely than others to lead the global markets in production capacity and export heavily, while others will focus on importation to meet demand. Countries that are more likely to import are already net energy importers under the current fossil-energy paradigm.” Industrial adoption of low-carbon hydrogen still faces a significant number of barriers. Regulatory and standardization instruments are perhaps the key means of driving rapid hydrogen utilization, according to the study authors, but support for R&D is also critical.

“Decarbonizing hydrogen is key to decarbonizing the chemical and refining industries, but it will also help decarbonize a number of other industries,” Dr. Griffiths said.

Applying decarbonized hydrogen across a wide range of sectors could benefit a large number of companies and economies. Of these, perhaps the most significant are the oil and gas firms that are increasingly facing calls to halt fossil-fuel production. As these companies look to diversify their portfolios, green hydrogen or hydrogen produced from fossil sources coupled with carbon capture, could be critical. Cutting the costs to achieve global industrial adoption of low-carbon hydrogen will require massive investment and scale, which oil majors could provide.

The authors noted that moving forward, the most ambitious targets for hydrogen use will require additional study, ranging from R&D to market stimulation, with further consideration of potential geopolitical ramifications and also further consideration of opportunities and challenges for hydrogen adoption in developing countries.

Most articles about hydrogen involve engineering and the natural sciences with social sciences representing a small fraction of total papers published. This suggests there is a lot of room to study in more detail the sociotechnical aspects of hydrogen use.

Jade Sterling
Science Writer
29 September 2021

The post Industrial Decarbonization via Hydrogen appeared first on Khalifa University.

For the third time in a decade, solar energy prices are tumbling in the Arabian Gulf. As demand for solar installations picks up dramatically, so falls the cost of solar energy, particularly in the Middle East.

Read Arabic story��.

When it comes to the cost of energy from new power plants, onshore wind and utility-scale solar are now the cheapest sources, costing less than gas, geothermal, coal or nuclear. Ten years ago, solar was the most expensive option for building a new power plant.

In a paper published in, KU researchers Dr. Harry Apostoleris, Post-Doctoral Fellow, Dr. Amal Al Ghaferi, Associate Professor, and Prof. Matteo Chiesa, Professor, show how local conditions and global macroeconomic factors have conspired to bring solar energy into a new realm of extreme affordability in the Middle East.

They argue that the Gulf market, especially the United Arab Emirates and Saudi Arabia, represents the leading edge of the global learning curve and offers a window into the likely near future of large-scale photovoltaics around the world.

As with most technologies, the more people invested in solar power, the cheaper it became. The Middle East has emerged as a global leader in photovoltaic deployment and pricing, with large utility-scale projects launched across the region.

In a previous study, the KU research team found that rapidly declining hardware prices, local business conditions, and access to generous financing packages were the major factors contributing to the low prices, with the market validating that assessment. Global average prices in comparable climates around the world have declined to nearly match the prices observed in the Gulf region, but now, countries in the GCC are seeing a new drop in prices. It is at this point that the researchers believe solar energy has solidified itself as the economically favorable energy source, continuing impressive price drops that began in 2016.

“If pricing at this level spreads around the world, simple business sense would suggest a rapid decarbonization of electricity generation, where coal and gas plants are retired as quickly as possible and replaced with photovoltaics, simply to save money,” explained Dr. Apostoleris. “The target of deep decarbonization by 2030 being held up by many climate scientists and advocates would suddenly enter the realm of feasibility with far less disruptive interventions than were previously believed necessary.”

Global learning curves are part of the cause of these price drops. The more that solar panels were produced, the more the technologies improved and economies of scale came into play. Fossil fuels in comparison can’t compete with this pace. Additionally, sunshine is free and in the Middle East, practically guaranteed every day. The costs of tapping into this solar power was bound to decline sharply as technology improved and the industry grew.

“The UAE leadership also deserves credit for recognizing the potential of solar energy and investing in it when many countries and entities were still sceptical,” said Dr. Apostoleris. “This is one of the main reasons why the UAE is ahead of the global curve in solar energy adoption.”

Often, the low prices are also secured as part of tenders for projects only implemented a couple years later, which further drives down prices for the projects to come after.

“Auction bids have been characterized by forward-looking cost projections—developers will tend to bid not based on the market price of hardware at the time of bidding, but on the prices they expect to pay a year or more in the future when the hardware is actually being ordered,” explained Dr. Apostoleris. “As strong downward pricing trends continue, this pattern of aggressive forward-bidding can be expected to hold.”

Additionally, the prominence of major international players in the Gulf’s solar development is helping to realize below-market costs. Large firms with an established presence in the region have�� relatively lower costs of doing business and are able to set their prices for large orders of hardware to a significant degree, and even factor in reputational elements—the ‘bragging rights’—of landing a large contract and gaining market share. Coupled with generous financing packages and a consistent solar resource, the low cost of solar energy in the Gulf begins to make sense.

“It is possible that developers accept lower margins in exchange for a benefit that larger projects provide for their overall business model,” explained Dr. Apostoleris. “The developer has its own learning curve, and building larger projects allows it to move faster down this learning curve and reduce its costs for future projects.”

For the KU researchers, the solar energy economics in the Gulf follow the same general patterns as global trends, but at a substantially advanced pace. They regard this as evidence that trends in the Gulf are best viewed not as an aberration but as an indicator of the how the global market is likely to evolve in the future.

“As the future increasingly appears to be one of previously unimaginably cheap energy, the future trajectory of this industry is exceptionally promising,” said Dr. Apostoleris. “This would herald a revolution in not only solar energy but in the energy sector generally, with a new age of ultra-cheap electricity transforming our lives, economies and environment. With such dramatic change on the horizon, it makes sense to consider the next steps to take full advantage of the coming energy transformation.”

In any energy revolution, there will be opportunities as well as challenges. Renewable energies are notoriously inconsistent throughout the day and the year, although less so in regions blessed with almost constant sunshine, such as the Middle East. The existing power grids don’t have the ability to distribute power from renewables over long distances, and storing power for use during the nights when power generation from solar is impossible is another major concern. These challenges of intermittency and geography are not insurmountable, but they do require investment to develop and build the necessary infrastructure.

“There are myriad ways to modify our energy systems to enhance the value of this low-cost solar electricity,” said Dr. Apostoleris. “This is before considering the potential of demand-side management strategies that aim to shift the energy demand curve to match the solar generation curve, minimizing the need for storage. However, this is a challenge that must be met not only from a technical perspective but also from that of society more broadly.”

It is clear that the Gulf solar market can offer a window into the likely future trajectory of photovoltaics globally. While the KU researchers point to a future of immense benefit, they also point out the challenges the market will face along the way. Thankfully, the region’s solar energy pioneers are rising to the challenge.

“Interestingly, in recent months, solar panel prices have actually risen for the first time in a decade,” added Dr. Apostoleris. “This seems to be caused by a bottleneck in the supply of polysilicon, the raw material for solar cells, as global demand increases. This might be an opportunity for the UAE to move into polysilicon production, leveraging cheap clean energy and the country’s central location to become a supplier, not just a consumer, of the solar industry.”

Researchers at Khalifa University are supporting the UAE in its advancement of regional knowledge and leadership in renewable energy, as the country announces ambitious and defined renewable energy targets. Innovative research taking place at Khalifa University is driving down costs and increasing the efficiency of solar cells, investigating the effects of climate change on renewable energy production, and even demonstrating the ability to provide solar energy 24/7.��

Jade Sterling
Science Writer
24 May 2021

The post What is Going on With Middle Eastern Solar Prices and What Does It Mean for the Rest of Us? appeared first on Khalifa University.

As global energy demand from air conditioners continues to rise, finding a way to replace energy-intensive systems is paramount.

Read Arabic story .

As the mercury rises in the UAE, Dr. Lourdes Vega, Director of the Khalifa University Research and Innovation Center on CO2 and hydrogen (RICH), and KU Research Scientists Dr. Edder Garcia and Dr. Daniel Bahamon are turning their attention to finding efficient and environmentally-friendly forms of air conditioning systems.

“Due to global warming and a boost of wealth in tropical regions, the demand for refrigeration and air-conditioning is likely to increase in the coming years,” explained Dr. Vega. “This process already accounts for around 10 percent of the global electricity consumption, so finding green alternatives is of utmost importance.”

Global energy demand from air conditioners is expected to triple by 2050, and supplying power to these AC units comes with large costs and environmental implications.

Dr. Vega and her team are investigating a cleaner cooling process known as ‘absorption refrigeration,’ which could replace conventional energy-intensive vapor compression refrigeration, and could even be used as a way to store solar energy.

Conventional AC systems rely on vapor-compression cycles and a mechanical compressor. This is how it works: Refrigerant flows through a compressor, where it gets pressurized. Then the refrigerant flows through a condenser, where it condenses from vapor form to liquid form, giving off heat in the process. From the condenser, the refrigerant goes through an expansion valve and its pressure drops. Finally, the refrigerant travels to the evaporator, where it draws heat from the air around it (the air that needs to be cooled), which causes the refrigerant to vaporize. The vaporized refrigerant then goes back to the compressor to restart the cycle. In addition to the electricity consumption associated with air conditioning, in current vapor-compression cycles the refrigerant is usually a fluorinated gas (F-gas) with high global warming potential, making the phase out of such gases an urgent environmental need.

An adsorption-based refrigeration system is much simpler. It has two main components: a tank, where the liquid refrigerant is stored, and a bed filled with a solid material known as an ‘adsorbent.’ The refrigerant molecules ‘adsorb’, or attach, onto the surface of this material instead of dissolving into a liquid, creating a film on the surface where refrigerant vapor accumulates.

The adsorbent is a highly porous material with a large internal surface, full of holes that collect the refrigerant vapor. These systems transform energy into cooling power without any moving parts, making them low maintenance and more durable than conventional vapor-compression refrigeration systems.

Importantly, adsorption refrigeration can be powered by renewable energy sources, like the sun.

During energy production peaks, such as during the middle of the day for solar power supplies, heat is transferred to the adsorbent, causing the refrigerant to vaporize and desorb from the solid adsorbent. It detaches from the pores in the adsorbent and is condensed into a liquid for storage in the tank.

When it is time to cool down the air outside the unit, the liquid refrigerant is released to the evaporator, removing a heat from the surrounding area.

“When the refrigerant adsorbs onto the solid surface adsorbent, energy is released,” explained Dr. Vega. “Therefore, the adsorbent can be used as a thermal energy storage unit. Energy is stored during the removal of the refrigerant from the adsorbent material. The stored energy is recovered during the adsorption step and can be used as a low-temperature energy source. In this way, we can make a unit that both cools the air and stores energy.”

Developing such a unit however requires finding the perfect adsorbent-refrigerant pair. Currently, the most common refrigerants for domestic and automobile air conditioning and for vapor-compression cycles are hydrofluorocarbons, but these have tremendous global warming potential and are being phased out globally.

Using computational simulations, Dr. Vega and her team are trying to find the best adsorbent-refrigerant pair, and they are specifically looking for the ideal pairing with compounds known as metal-organic frameworks, or MOFs, combined with low global warming potential refrigerants including hydrofluoroolefins (HFO). They published their results in

“Several criteria can be used to select an adsorbent-refrigerant working pair,” said Dr. Vega. “The energy density that can be stored by adsorbent per unit of volume is an important indicator of performance. The difference in the adsorbed amount of refrigerant between adsorption and desorption—the working capacity—can also be considered. However, given the large number of potential materials that could be utilized, experimental evaluation is an expensive, time-consuming and tedious endeavor.”

Rather than individually test each pairing, the research team conducted simulations to guide selection of MOFs for thermal-storage applications. A total of 40 MOFs were studied using three refrigerants based on HFO, which has much lower global warming potential than the traditional hydrofluorocarbons.

The research team established a relationship between the adsorptive capacity and the properties of the materials, finding that MOFs with open metal sites interact strongly with the refrigerants, making them more suitable for thermal energy storage applications.

For cold thermal energy storage, MOFs with larger pore sizes showed a considerably higher energy density than the materials currently used commercially.

Jade Sterling
Science Writer
30 March 2021

The post Searching for Suitable Materials and Refrigerants for AC Units That Also Store Heat for Energy appeared first on Khalifa University.