New Sulfur-CNF-composites to Boost Performance of Lithium Sulfur Batteries

The researchers from Toyohashi University of Technology have found that cathode composites made by combining a sulfur active material and carbon nanofiber (CNF) developed using an electrostatic assembly method shows high discharge capacity equivalent to the theoretical capacity of sulfur and maintained high capacity after repeated charge-discharge cycles.

All-solid-state lithium sulfur batteries using sulfur-CNF composites and electrochemically stable Li2S-P2S5-LiI solid electrolytes synthesized by liquid phase process showed better results.

Low-cost Sulfur-carbon Composite

It is required that a sulfur active material and a carbon material are appropriately combined for making high-performance all-solid-state lithium sulfur batteries.

Conventionally, sulfur-carbon composites were synthesized by mechanical mixing, liquid mixing using a special organic solvent and complicated methods, in which sulfur is combined with a porous carbon material with a high specific surface area.

However, there were few reports that all-solid-state lithium sulfur batteries showed high capacity almost equivalent to the theoretical capacity of sulfur and high cycle stability.

Therefore, researchers focused on making a sulfur-carbon composite using a low-cost and simple electrostatic adsorption method which can uniformly combine nanomaterials. It was confirmed that sulfur at the sulfur-carbon composite synthesized by electrostatic adsorption method was accumulated on carbon nanofiber in the form of sheets.

Besides, researchers constructed all-solid-state lithium sulfur batteries and found that sulfur was fully utilized as an active material. The other merit is that this sulfur-carbon composite can be produced by lower cost than conventional processes.

Electrostatic Adsorption Method

In the electrostatic adsorption method, larger mother particles and smaller particles are electrostatically adsorbed by adjusting surface charges of the particles using polyelectrolytes in order to induce an electrostatic interaction. Although design of a variety of ceramic composites by the electrostatic adsorption were already reported, the adjustment of the surface charges of sulfur is difficult. However, our research group succeeded in the charge adjustment by using chemical reactions, in which Na2S and S reacted in ion-exchanged water to form aqueous soluble Na2S3. Therefore, this study achieved a new chemical process by applying the basic principle of electrostatic adsorption.

This method is a low-cost and relatively simple method for preparing sulfur-carbon composites, so it is suitable for mass production. All-solid-state lithium-sulfur batteries using a sulfur active material will be put to practical use by this method. Besides, it is expected the exponential improvement in the energy density of electric vehicles, large-sized power source batteries for household and business use.

Source: Toyohashi University of Technology

Lubrizol’s Powder TPU for 3DP Passes Skin Sensitization and Cytotoxicity Tests

Lubrizol Engineered Polymers has announced that their ESTANE® 3D TPU M95A powder TPU has passed skin sensitization and cytotoxicity tests in accordance with ISO 10993-5 and 10993-10. This enables ESTANE® 3D TPU M95A to be a valuable material solution for product designers exploring 3DP for end-use applications that require skin contact. This achievement builds on Lubrizol’s long legacy of developing innovative materials safe for use in skin contact applications – from consumer products to medical devices – and reflects Lubrizol’s ongoing mission to improve lives.

Broad List of Benefits

Skin contact suitability is the latest attribute to round out a broader list of benefits that ESTANE® 3D TPU M95A brings to applications, including high levels of flexibility, durability, impact and chemical resistance, and energy rebound. Commercially available, ESTANE® 3D TPU M95A is certified for use on the HP Jet Fusion™ 4200 series 3D printing solution – the only TPU certified as such. With an existing installed base, 3DP can be immediately deployed to helping solve critical supply shortages for Personal Protection Equipment needed to battle the COVID-19 pandemic.
David Pascual, Lubrizol’s global commercial 3D Printing lead, announced, “After first developing a new innovative powder TPU for use with the market leading HP 3D printing platform, it is a great step forward for this material to pass this skin sensitivity testing protocol.”

Fighting COVID-19 Battle

Pascual adds, “This will benefit product designers who are developing applications that require skin contact including personal protection devices so urgently needed right now to protect responders and caregivers fighting the COVID-19 battle. TPU’s versatility, durability and barrier properties bring value in these vital applications”.

Skin contact clearance also benefits applications in footwear, prosthetic and orthotic devices, and wearables for electronic devices where the benefits of energy rebound and impact absorption are particularly important.

Source: Lubrizol

New Nano-rubber-like Material to Replace Ruptured Human Tissues

Researchers from Chalmers University of Technology, Sweden, have created a new, rubber-like material with a unique set of properties, which could act as a replacement for human tissue in medical procedures. The material has the potential to make a big difference to many people's lives.

New Risk-free Adaptable Material Based on Nanostructuring

In the new study, the Chalmers researchers developed a material consisting solely of components that have already been shown to work well in the body.

The foundation of the material is the same as plexiglass, a material which is common in medical technology applications. Through redesigning its makeup, and through a process called nanostructuring, they gave the newly patented material a unique combination of properties. The researchers' initial intention was to produce a hard bone-like material, but they were met with surprising results.

Soft, Flexible and Extremely Elastic Material

“We were really surprised that the material turned to be very soft, flexible and extremely elastic. It would not work as a bone replacement material, we concluded. But the new and unexpected properties made our discovery just as exciting,” says Anand Kumar Rajasekharan, PhD in Materials Science and one of the researchers behind the study.

Multiple Application and Properties

The results showed that the new rubber-like material may be appropriate for many applications which require an uncommon combination of properties – high elasticity, easy processability, and suitability for medical uses.

“The first application we are looking at now is urinary catheters. The material can be constructed in such a way that prevents bacteria from growing on the surface, meaning it is very well suited for medical uses,” says Martin Andersson, research leader for the study and Professor of Chemistry at Chalmers.

Inducing Antibacterial Property Possible Too

The structure of the new nano-rubber material allows its surface to be treated so that it becomes antibacterial, in a natural, non-toxic way. This is achieved by sticking antimicrobial peptides – small proteins which are part of our innate immune system – onto its surface. This can help reduce the need for antibiotics, an important contribution to the fight against growing antibiotic resistance.

Reducing the Need for Drastic Surgery

Because the new material can be injected and inserted via keyhole surgery, it can also help reduce the need for drastic surgery and operations to rebuild parts of the body. The material can be injected via a standard cannula as a viscous fluid, so that it forms its own elastic structures within the body. Or, the material can also be 3D printed into specific structures as required.

“There are many diseases where the cartilage breaks down and friction results between bones, causing great pain for the affected person. This material could potentially act as a replacement in those cases,” Martin Andersson continues.

Presence of Three-dimensionally Ordered Nanopores

A further advantage of the material is that it contains three-dimensionally ordered nanopores. This means it can be loaded with medicine, for various therapeutic purposes such as improving healing and reducing inflammation. This allows for localized treatment, avoiding, for example, having to treat the entire body with drugs, something that could help reduce problems associated with side effects. Since it is non-toxic, it also works well as a filler – the researchers see plastic surgery therefore as another very interesting potential area of application for the new material.

“I am now working full time with our newly founded company, Amferia, to get the research out to industry. I have been pleased to see a lot of real interest in our material. It’s promising in terms of achieving our goal, which is to provide real societal benefit,” Anand concludes.

Source: Chalmers University of Technology

New High-speed Method to 3D Print Soft Objects for Medical Applications

Researchers at EPFL have developed a new, high-precision method for 3D-printing small, soft objects. The process, which takes less than 30 seconds from start to finish, has potential applications in a wide range of fields, including 3D bioprinting.

Making Tiny Objects with Precision and Resolution

It all starts with a translucent liquid. Then darker spots begin to form in the small, spinning container until, barely half a minute later, the finished product takes shape. This groundbreaking 3D-printing method can be used to make tiny objects with unprecedented precision and resolution – all in record time. The team has set up a spin-off, Readily3D, to develop and market the system.

The system is currently capable of making two-centimeter structures with a precision of 80 micrometers, about the same as the diameter of a strand of hair. But as the team develops new devices, they should be able to build much bigger objects, potentially up to 15 centimeters. “The process could also be used to quickly build small silicone or acrylic parts that don’t need finishing after printing,” says Christophe Moser, who heads the LAPD. Interior design could be a potentially lucrative market for the new printer.

Hardened by Light

The new technique draws on the principles of tomography, a method used mainly in medical imaging to build a model of an object based on surface scans.

The printer works by sending a laser through the translucent gel – either a biological gel or liquid plastic, as required. “It’s all about the light,” explains Paul Delrot, Readily3D’s CTO. “The laser hardens the liquid through a process of polymerization. Depending on what we’re building, we use algorithms to calculate exactly where we need to aim the beams, from what angles, and at what dose.”

Applications for Medicine and Biology

The technology could have innovative applications in a wide range of fields, but its advantages over existing methods – the ability to print solid parts of different textures – make it ideally suited for medicine and biology. The process could be used, for instance, to make soft objects such as tissue, organs, hearing aids and mouthguards.

“Conventional 3D printing techniques, known as additive manufacturing, build parts layer by layer,” explains Damien Loterie, the CEO of Readily3D. “The problem is that soft objects made that way quickly fall apart.” What’s more, the process can be used to make delicate cell-laden scaffolds in which cells can develop in a pressure-free 3D environment. The researchers teamed up with a surgeon to test 3D-printed arteries made using the technique. “The trial results were extremely encouraging,” says Loterie.

https://youtu.be/ONBHkzimRbg

Source: EPFL

Researcher Unveils Way to Develop Fire-resistant Cellulose-based Polymers

A team of researchers from Montana State University is developing methods to infuse polymers with particles called nanocrystals that are made from cellulose, a primary component of plants. Whereas many regular plastics can combust when subjected to fire or very intense heat, the nanoparticles are designed to limit the flames and prevent their spread.

Cellulose: The Building Blocks for Chemical Technologies

By processing wood pulp of other plant matter using special chemical reactions, cellulose molecules become building blocks for chemical technologies that operate at the nano scale, which concerns things as small as one-billionth of a meter.
Because the particles are so tiny, a relatively small volume of them can be mixed throughout a much larger amount of polymer. When the particles are coated in zinc oxide, a common ingredient found in many sunscreens, the zinc oxide's fire-resistant properties are imparted to the plastic.

Nanocrystals for Fire-safety and Light-weighting

The resulting plastic is a major improvement over fire-resistant polymers currently on the market, which rely on particles of glass or earthen minerals like talc. Because those particles are much bigger, they constitute up to one-fifth of the mass of product, making it much heavier. Those additives also make the plastic brittle, whereas nanocrystals can make it stronger.

But the cellulose crystals' nano size, combined with their polar charge like static electricity, makes them difficult to mix into the plastic. By their nature, they want to clump up instead of dispersing into the plastic.

Overcoming that is a focus of his research under the new NIST grant, which builds on research being funded by 149,000 USD from the U.S. Department of Agriculture's National Institute of Food and Agriculture.

New Kinds of Mechanical Mixers Being Tested

Dilpreet Bajwa, professor at MSU's Norm Asbjornson College of Engineering, will develop new kinds of mechanical mixers as well other treatments, such as zapping the nanocrystals with electrically charged gases, in order to mix the fire-resistant particles into plastic in his lab. The goal is to develop methods that can be integrated with existing machinery used in industry to form plastic parts, so that the technology could easily be adopted by manufacturers.

Plans for Future Commercialization

Nicole Stark, research chemical engineer at the Forest Products Lab, will oversee fire testing of the plastics the team makes. Another partner on the project, Mohiuddin Quadir, assistant professor in the Department of Coatings and Polymeric Materials at North Dakota State University, will develop methods for effectively coating the nanoparticles.

While the primary application would be in the automotive industry, the nanocrystal-infused plastic could improve upon products such as home siding as well as a variety of durable consumer goods where fire-resistance is important. "We think we'll be able to move this technology forward. We have proven the concept and now we will be working on how to move it toward commercialization," said Bajwa.

Source: Montana State University

Indiana’s largest biogas plant opens, will supply LNG to Midwest fleets

Kinetrex Energy, EDL and South Side Landfill celebrated the completion of the Indy High BTU plant at the Indianapolis South Side Landfill. The plant, which will be fully operational March 20, will convert landfill methane gas into approximately 8 million gallons of pipeline-quality renewable natural gas each year, and in the process, reduce greenhouse gas air emissions in Central Indiana, develop a local renewable resource and lower fuel costs. Indy High BTU is the largest biomethane plant in Indiana.

“This is an exciting day for our city,” said Indianapolis Mayor Joe Hogsett. “We are pleased to see Kinetrex Energy, a homegrown-Indianapolis company, spearheading the effort to provide cleaner, renewable fuel for transportation across the Midwest.”

With construction now complete, Indy High BTU will begin supplying Kinetrex Energy with renewable natural gas, which Kinetrex will turn into LNG and sell to Midwest transportation fleets. Kinetrex recently announced a six-year agreement with UPS to supply the global shipping company with up to 52.5 million gallons of LNG for its Class 8, LNG-powered fleets in Chicago, Toledo, Columbus, St. Louis and Indianapolis.

“Indy High BTU is a major milestone for Kinetrex Energy, our partners and central Indiana,” said Kinetrex Energy President and CEO Aaron Johnson. “The plant strengthens our position as leaders in the creation of renewable fuel and natural gas delivery. The biomethane from the landfill will replace over 8 million gallons of diesel. It is cheaper than diesel and significantly reduces the emission of methane and other greenhouse gases.”

“South Side Landfill has been proactively capturing gas at the landfill for commercial use for more than 30 years, and this is the latest step in reducing emissions to make our city safer and healthier for our residents,” commented South Side Landfill President Mike Balkema.

“We are excited to harness the full potential of renewable natural gas to help decarbonize the transportation industry,” added EDL Head of North American Operations, Central Region, Jim Grant.

Source: Kinetrex Energy

New flame-resistant thermoset composite for automotive battery packs

IDI Composites International is introducing a new thermoset composite material delivering critical performance benefits for the "new energy vehicles" market.

Deployed in electric vehicle (EV) new energy vehicles (NEV) applications, Flamevex is a flame-resistant lightweight composite. Flamevex has been used on battery packs, which have passed the stringent Chinese Standard GB/T 31467.3 test, commonly known as the China bonfire test. This new thermoset, offers designers a strong, lightweight and cost-effective alternative to steel and aluminum materials traditionally used to enclose battery packs in EVs and NEVs.

EV and NEV designers have long faced the dilemma of balancing flame resistance, strength and light weighting requirements as they develop solutions for critical applications like the vehicle battery enclosure. Battery packs take up significant space in vehicle designs and must offer dimensional strength as well as resistance to flame and high temperatures. Strong and durable, steel has long been a preferred material, but the heavy weight burden makes it a poor choice. While aluminum and carbon fiber provide designers lightweight options, these technologies are still in development stages making them inherently risky and very costly. Flamevex brings to market a thermoset composite technology that is both easy to use and proven in research studies and "on-the road" actual applications.

Yves Longueville, General Manager for IDI Composite Materials (Shanghai) - China said:

"Thermoset composites represent an ideal replacement for metals in these kinds of battery enclosures. Thermoset materials can be formed into complex shapes and they are also strong and lightweight. Beyond these benefits, a high level of fire performance distinguishes Flamevex from traditional SMC composites. Flamevex maintains its impressive fire performance even at low thicknesses, and without compromising the strength or moldability of the compound. It is the best choice for designers developing high performing and affordable products."

Working in collaboration with OEMs and Tier 1 partners, IDI Flamevex materials have been used on battery packs which have passed the Chinese bonfire test—the world's most stringent fire resistance standard—at thicknesses as low as 2.5 mm. Battery packs made with Flamevex also meet the UL 5VA standard. Recognizing that industry standards are continuing to evolve, Flamevex materials can be manufactured to fit specific flame resistance standards for OEMs and Tier 1 manufacturers.

The market for EV and NEV vehicles is growing exponentially, with sales expected to double in 2020, reaching four million new cars globally.

Ramon Rodriguez-Irizarry, IDI Vice President and Group Director of EV Market Development explained:

"As cost of ownership goes down, range increases and emissions requirements become tighter, electric and alternative fuel vehicles are only becoming more attractive to buyers. With Flamevex, we're not only helping to meet a need for OEMs and designers, we're introducing a material that contributes to the strength, safety and affordability of this next generation of vehicles for consumers around the world.

Our vast experience in moldable compounds puts IDI in a unique position to keep pace with the changing landscape of requirements for EV and NEV parts. IDI Composites has worked closely with OEMs and Tier 1 suppliers to meet their flame performance targets and optimize materials to fit the special shapes their newest designs call for. With these composites now in mass production, we look forward to introducing Flamevex SMC to even more manufacturers to help them fulfill their goals for strength, design and safety in not only battery pack covers, but all areas of EV and NEV design."

Source:www.idicomposites.com