Graphene Aerogel: Introduction and Market News - Page 5

Researchers from Lawrence Livermore National Laboratory (LLNL) and UC Santa Cruz (UCSC) have designed a technique that could double the performance of 3D printed graphene-based supercapacitors. The new technique involves sandwiching lithium ion and perchlorate ion between layers of graphene in aerogel electrodes—a process which greatly improves the capacity of the electrodes while maintaining the high rate capability of the devices.

The 3D printing process used by the researchers to build the supercapacitors is a form of direct ink writing, consisting of two ion-intercalation steps before the hydrolysis of perchlorate ion intercalation compounds. According to the team this two-step electrochemical process increases the surface area of graphene-based materials for charge storage, as well as the number of pseudo-capacitive sites that contribute additional storage capacity.

Researchers at Kansas State University, University of Buffalo and the State University of New York have designed a new technique for 3D printing graphene aerogels with complex microstructures. The technique combines drop-on-demand 3D printing with freeze casting.

Aerogels are light and spongy materials that can be used as both thermal and optical insulators and can potentially be used as batteries and catalysts within electronic components. Recent years have brought about methods in which aerogels can be produced with certain 3D printers. The scientists have now developed a new 3D printing technique for producing graphene aerogels, which they hope will open up new uses for the material.

Scientists at Lawrence Livermore National Laboratory and UC Santa Cruz have demonstrated what might be the world's first 3D-printed graphene composite aerogel supercapacitor, using a technique known as direct-ink writing. The researchers suggest that their ultra-lightweight graphene aerogel supercapacitors may open the door to novel designs of highly efficient energy storage systems for smartphones, wearables, implantable devices, electric cars and wireless sensors.

The key factor in developing these novel aerogels is creating an extrudable graphene oxide-based composite ink and modifying the 3D printing method to accommodate aerogel processing. The 3D-printed graphene composite aerogel (3D-GCA) electrodes are lightweight, highly conductive, and exhibit excellent electrochemical properties. Supercapacitors using these 3D-GCA electrodes with thicknesses on the order of millimeters display exceptional capacitive retention (ca. 90% from 0.5 to 10 A·g−1) and power densities (>4 kW·kg−1).

Researchers at the Lawrence Livermore National Laboratory created graphene aerogel microlattices with an engineered architecture using a 3D printing technique known as direct ink writing. These lightweight aerogels have high surface area, excellent electrical conductivity, mechanical stiffness and exhibit supercompressibility (up to 90% compressive strain). In addition, the researchers claim that these 3D printed graphene aerogel microlattices show great improvement over bulk graphene materials and much better mass transport.

A common problem in creating bulk graphene aerogels is the occurrence of a largely random pore structure, thus excluding the ability to tailor transport and additional mechanical properties of the material for specific applications such as batteries and sensors. Making graphene aerogels with engineered architectures is greatly assisted by 3D printing, which allows to design the pore structure of the aerogel, permitting control over many properties. This development, as per the scientists, could open up the design space for using aerogels in novel and creative applications.

A study conducted at Rice University shows that graphene nanoribbons, formed into a 3D aerogel and enhanced with boron and nitrogen, perform extremely well as catalysts for fuel cells and may even pose an alternative to platinum.

The scientists chemically unzipped carbon nanotubes into ribbons and then turned them into porous metal-free aerogels with various levels of boron and nitrogen, to test their electrochemical properties. It was found that the new material provides a wealth of active sites along the exposed edges for oxygen reduction reactions necessary for fuel cells performance.

Researchers from the Korean Sungkyunkwan University announced the development of a sponge-like electrode material using graphene and a polymer that enables the assembly of a light and efficient graphene battery.

The electrode was made from porous graphene aerogel that was a result of combining alcohol and graphene. The graphene aerogel electrode material is easily compressed and highly durable, with about 90-99.9 percent of it filled with air and pores smaller than 100 nanometers that form a 3D web.

Researchers from Stockholm University managed to develop a super-insulating and fire retardant foam for house insulation by freezing together graphene oxide, cellulose nanofibers and clay nanorods.

The foam is highly porous and boasts lower thermal conductivity than traditional insulators like polystyrene and polyurethane. It is mechanically stiff, able to sustain great loads and also does not need to be laced with organic fire retardants (it is inherently fire retardant). The researchers believe this foam could even be fitted onto older buildings without tampering with their appearance.

Researchers from Lawrence Livermore (LLNL) developed new supercapacitor electrodes made from modified graphene aerogels. Those electrodes feature high surface area, good electrical conductivity, chemical inertness and long-term cycling stability.

The researchers report that the graphene aerogel can improve the performance of commercial carbon-based (carbon black and binder materials) supercapacitor electrodes by more than 100%. The graphene aerogel electrodes have better density and pore size distribution, and increased conductivity.

In March 2013, researchers from China's Zhejiang University developed the world's lightest material ever made, Graphene Aerogel, is made from freeze-dried carbon and graphene oxide. Today it was reported that that bit of Graphene Aerogel was sold in an auction in China for 10 million yuan ($1.6 million).

Graphene Aerogel was developed by a nanometer-macromolecule research group at Zheijang, led by Professor Gao Chao. The material has excellent properties, and may find usages in areas such as oil-absorbent and organic absorbants. Carbon Aerogel can absorb up to 900 times its own weight.

Researchers from Beijing's Tsinghua University managed to create a nacre-like material that's stronger than natural nacre (and most other composite). Nacre (mother of pearl) is made from calcium carbonate and biopolymers in a brickwork structure that's nearly a thousand times stronger than its component parts.

Natural nacre structure

To create the new material, the researchers started with a hyrdogel made from graphene and fibroin (a silk protein), and then solution coated it and dried it to create parallel graphene plates bound with fibroid, which self assembled to create a brickwork structure.