. Scientific Frontline: Material Science
Showing posts with label Material Science. Show all posts
Showing posts with label Material Science. Show all posts

Thursday, April 20, 2023

Nagoya University researchers develop a new ultra-high-density sulfonic acid polymer electrolyte membrane for fuel cells

Researchers develop a new ultra-high-density sulfonic acid polymer electrolyte membrane  for fuel cells, which can be used for vehicles and combined heat and power systems. 
Illustration Credit: Atsushi Noro

In a project commissioned by the New Energy and Industrial Technology Development Organization (NEDO), researchers at Nagoya University in Japan have developed poly (styrenesulfonic acid)-based PEMs with a high density of sulfonic acid groups.

One of the key components of environmentally friendly polymer electrolyte fuel cells is a polymer electrolyte membrane (PEM). It generates electrical energy through a reaction between hydrogen and oxygen gases. Examples of practical fuel cells include fuel cell vehicles (FCVs) and fuel cell combined heat and power (CHP) systems.

The best-known PEM is a membrane based on a perfluorosulfonic acid polymer, such as Nafion, which was developed by DuPont in the 1960s. It has a good proton conductivity of 0.1 S/cm at 70-90 °C under humidified conditions. Under these conditions, protons can be released from sulfonic acid groups. Proton conduction in such membranes typically depends on the proton transport mechanism between protons, sulfonic acid groups, and water molecules. Typically, the higher the density of the sulfonic acid groups in the membrane, the higher the density of protons that can be released from the sulfonic acid groups; therefore, the higher density of the sulfonic acid groups usually results in higher proton conductivities.

Towards More Efficient and Eco-Friendly Thermoelectric Oxides with Hydrogen Substitution

Hydrogen substitution is an innovative strategy for boosting the performance of thermoelectric oxide SrTiO3, find researchers at Tokyo Tech. Their latest study reveals that the approach lowers the thermal conductivity and also realizes high electronic conductivity, paving the way for a more efficient thermoelectric energy conversion of waste heat without using costly or environmentally hazardous elements.

Today, over half of the total energy produced from fossil fuels is discarded as waste heat, which accelerates global warming. If we could convert the waste heat into a more useful form of energy like electricity, we could minimize fuel consumption and reduce our carbon footprint. In this regard, thermoelectric energy conversion has gained momentum as a technology for generating electricity from waste heat.

For efficient conversion, a thermoelectric material must have a high conversion efficiency (ZT). So far, realizing a high ZT has been possible only with the use of heavy elements like lead, bismuth, and tellurium. However, the use of rare, expensive, and environmentally toxic elements such as these has limited the large-scale application of thermoelectric energy conversion.

Wednesday, April 19, 2023

I’ll Have My Nano-Sized Donuts with Extra Swirls

Donut shaped skyrmions (left) show polarization swirls in one direction, while half-donut-shaped merons (right) are able to swirl in multiple directions.
Image Credit: Yu-Tsun Shao.

Swirling donuts. That’s what Yu-Tsun Shao thinks about when describing his atomic-scale materials research.

Shao, an assistant professor in the Mork Family Department of Chemical Engineering and Materials Science, aims to understand the atomic-scale behavior of donut-shaped particles that can enable low-power electronics. He has uncovered how strain and heat can shift the shape of the donut particle to give it powerful new energy-efficient and stabilizing properties. His latest work was recently published in Nature Communications.

Shao is working with skyrmions — nanometer-sized objects that resemble donut-like swirling vortexes. The skyrmions have electric polarization in the form of positive or negative charges (dipoles) that move in a continuous direction up and out from the center ‘donut hole” and down and in from the outer edge of the particle.

Lithium can be obtained from hot deep water

View of the laboratory: An adsorbent based on a lithium-manganese oxide with a special crystal structure serves as a lithium-ion sieve.
Photo Credit: Dr. Monika Bäuerle, IAM-ESS / KIT

Researchers at KIT and EnBW show lithium-ion sieve for geothermal soles - lithium extraction can complement electricity generation and heat supply

Geothermal energy not only enables a sustainable supply of electricity and heat, but also a regional lithium extraction. Researchers at the Karlsruhe Institute of Technology (KIT) and EnBW have produced a lithium-ion sieve from a lithium-manganese oxide and used it to adsorb lithium from geothermal brines. The use of domestic lithium sources can help to meet the increasing demand for light metal, which is indispensable as energy storage material. The researchers reported in the journal Energy Advances, who now recognizes the work as one of the "Outstanding Paper 2022". 

A sustainable energy supply requires efficient energy storage. Lithium is indispensable - the light metal is in the batteries of many technical devices and vehicles, from smartphones to notebooks to electric cars. Demand has risen sharply worldwide in recent years. Europe is still dependent on imports. However, there are also European lithium deposits, namely thermal waters a few kilometers deep. They contain high concentrations of lithium ions. In this way, geothermal plants that extract hot water from the depths can not only be used for sustainable electricity and heat supply, but also for environmentally friendly regional lithium production.

The wound dressing that can reveal infection

The wound dressing is made of tight mesh nanocellulose, preventing bacteria and other microbes from getting in. At the same time, the material lets gases and liquid through.
Photo Credit: Olof Planthaber

A nanocellulose wound dressing that can reveal early signs of infection without interfering with the healing process has been developed by researchers at Linköping University. Their study, published in Materials Today Bio, is one further step on the road to a new type of wound care.

The skin is the largest organ of the human body. A wound disrupts the normal function of the skin and can take a long time to heal, be very painful for the patient and may, in a worst-case scenario, lead to death if not treated correctly. Also, hard-to-heal wounds pose a great burden on society, representing about half of all costs in out-patient care.

In traditional wound care, dressings are changed regularly, about every two days. To check whether the wound is infected, care staff have to lift the dressing and make an assessment based on appearance and tests. This is a painful procedure that disturbs wound healing as the scab breaks repeatedly. The risk of infection also increases every time the wound is exposed.

Chemists Have Developed a Guide to Oxygen Electrode Design Strategies

Structure of perovskite materials for solid oxide electrochemical devices.
Illustration Credit: Et al., Sustainable Energy Technologies and Assessments

The group of scientists created a guide to oxygen electrode design strategies for solid oxide electrochemical devices. The researchers formulated key directions for the chemical and structural design of oxygen electrodes for solid oxide fuel cells (SOFC) and solid oxide electrolysis cells (SOEC). The scientists published their work on current strategies for improving the electrochemical performance of oxygen electrodes at reduced operating temperatures in the journal Sustainable Energy Technologies and Assessments.

According to the authors of the study, the guide will be useful to scientists whose work is related to the development and design of air electrodes for electrochemical cells.

"Many of the processes in hydrogen energy technology are implemented using fuel cells and electrolysis, in which SOFCs and SOECs are involved. These electrochemical devices are very promising due to their high energy conversion efficiency and wide range of operating characteristics," explains Dmitry Medvedev, Head of the Scientific Laboratory of Hydrogen Energy at UrFU.

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