The Graphene-Info newsletter (November 9, 2021)

Three companies in China recently launched graphene-enhanced lead-acid batteries on the market, as they claim the graphene materials boost the performance of the batteries. While it is difficult to verify, this could prove to be a very good market for graphene.

First up is Tianneng battery, which offers its TNEH Series Deep Cycle Black Gold Battery. The company says that the graphene expands the cycle life of the batteries and improves the performance at low temperatures. The TNEH series offers a 20% longer cycle life compared to the company's non-graphene batteries. The same battery also offers a 5% increase in capacity at low temperatures.

Scientists at The University of Texas at Dallas, along with colleagues in Ludwig-Maximilians-Universität München, have observed a rare phenomenon called the quantum anomalous Hall effect in bi-layer graphene. Previous experiments have detected it only in complex or delicate materials.

The quantum Hall effect is a macroscopic phenomenon in which the transverse resistance in a material changes by quantized values in a stepwise fashion. It occurs in two-dimensional electron systems at low temperatures and under strong magnetic fields. In the absence of an external magnetic field, however, a 2D system may spontaneously generate its own magnetic field, for example, through an orbital ferromagnetism that is produced by interactions among electrons. This behavior is called the quantum anomalous Hall effect.

US-based NeoGraf Solutions, a leading graphite developer and producer, announced that it has started to produce graphene (GNP) materials, branded as Graf-X. The company mainly targets thermoset and thermoset and thermoplastic applications.

NeoGraf says that it has an annual capacity of over 750 metric tons for its GNP material, and over 1,300 tons of its graphene precursors (GP), which are graphite products design to enable efficient conversion into graphene materials. The company produces its graphene in Lakewood, Ohio.

In 'magic angle' graphene, especially near the angle of 1 degree, the electrons slow down dramatically, favoring interactions between the electrons. Such interactions give rise to a new type of superconductivity and insulating phases in twisted bilayer graphene. Along with many other fascinating properties discovered in the past three years, this material has proven to display extremely rich physical phenomena, but most importantly, it has shown to be an easily controllable quantum material. Up until now, the interaction between twisted bilayer graphene and light was shown to have fascinating outcomes on a theoretical level, but no experiment has so far been able to clearly show how this interaction works.

In a recent work, ICFO researchers Niels Hesp, Iacopo Torre, David Barcons-Ruiz and Hanan Herzig Sheinfux, led by ICREA Prof. at ICFO Frank Koppens, in collaboration with the research groups of Prof. Pablo Jarillo-Herrero (MIT), Prof. Marco Polini (University of Pisa), Prof. Efthimios Kaxiras (Harvard), Prof. Dmitri Efetov (ICFO) and NIMS (Japan), have found that twisted bilayer graphene can be used to guide and control light at the nanometer scale. This is possible thanks to the interaction between light and the collective movement of the electrons in the material.

Sweden-based graphene fabric developer Grafren launched a new graphene-coated textile, branded G-HEATEX. The company says that this is the world's first active heating fabric.

According to Grafren, G-HEATEX fabrics supply powerful and uniform heat, while being soft, flexible, breathable and ultralightweight.

A team of researchers from universities in Loughborough, Nottingham, Manchester, Lancaster and Kansas (US) has revealed that sonic boom and Doppler-shifted sound waves can be created in a graphene transistor.

When a police car speeds past you with its siren blaring, you hear a distinct change in the frequency of the siren’s noise. This is the Doppler effect. When a jet aircraft’s speed exceeds the speed of sound (about 760 mph), the pressure it exerts upon the air produces a shock wave which can be heard as a loud supersonic boom or thunderclap. This is the Mach effect. The scientists discovered that a quantum mechanical version of these phenomena occurs in an electronic transistor made from high-purity graphene.