Conductive Ceramics

Conductive Ceramics


Conductive two-dimensional titanium carbide ‘clay’ with high volumetric capacitance

A class of electrochemically active two-dimensional materials known as 'MXenes' has recently shown potential for energy-storage applications. Michael Ghidiu et al. now report a new method for producing these materials that has the advantage of using safer processing conditions.This yields a water-swelling material that can be shaped like clay to produce electrodes with volumetric capacitances that are significantly improved over their predecessors.

(full article at link)

http://www.nature.com/nature/journal/v516/n7529/full/nature13970.html

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Conductive clay rolled out to store energy
27 November 2014Katrina Kramer


A conductive clay made by US researchers might provide a novel way of storing energy that could, one day, surpass batteries. The team developed a cheaper, safer and simpler method to make supercapacitors, tripling the amount of electric energy they can store. Production of the material should be easy to scale-up too.
Unlike batteries, which convert chemical energy into electrical, capacitors store energy as electrostatic potential –similar to creating a static charge by rubbing a balloon on a jumper. Supercapacitors have a number of advantages over batteries in that they charge almost instantly, can release energy in large, quick bursts and are extremely durable. ‘There are some applications where supercapacitors can already replace lithium ion batteries, for example in buses or cars, because of their fast charging time and good cyclability,’ explains Yury Gogotsi from Drexel University in the US, who is part of the team that developed the new capacitor synthesis.

In 2011 Gogotsi and colleagues discovered an entirely new family of two-dimensional supercapacitors, which they called, in homage to graphene, MXenes – M being a transition metal and X carbon or nitrogen. The cheap material can store three times as much energy as standard carbon capacitors. However, MXene synthesis required hydrofluoric acid, which is highly toxic and corrosive. ‘You don’t need to be a materials chemist to know that HF is pretty nasty stuff,’ says Gogotsi.

(full article at link)

http://www.rsc.org/chemistryworld/2014/11/conductive-clay-rolled-out-store-energy


http://www.sciencedaily.com/releases/2014/11/141126132632.htm

http://uwire.com/2014/12/05/conductive-clay-yields-new-front-for-energy-storage/

New technique for growing high-efficiency perovskite solar cells


January 29, 2015

DOE/Los Alamos National Laboratory


Summary:
Researchers have revealed a new solution-based hot-casting technique that allows growth of highly efficient and reproducible solar cells from large-area perovskite crystals. The researchers fabricated planar solar cells from pervoskite materials with large crystalline grains that had efficiencies approaching 18%.
(more at link...)

"These perovskite crystals offer promising routes for developing low-cost, solar-based, clean global energy solutions for the future," said Aditya Mohite, the Los Alamos scientist leading the project.
State-of-the-art photovoltaics using high-purity, large-area, wafer-scale single-crystalline semiconductors grown by sophisticated, high temperature crystal-growth processes are seen as the future of efficient solar technology. Solar cells composed of organic-inorganic perovskites offer efficiencies approaching that of silicon, but they have been plagued with some important deficiencies limiting their commercial viability. It is this failure that the Los Alamos technique successfully corrects.

The researchers fabricated planar solar cells from pervoskite materials with large crystalline grains that had efficiencies approaching 18%, among the highest reported in the field of perovskite-based light-to-energy conversion devices. The cells demonstrate little cell-to-cell variability, resulting in devices showing hysteresis-free photovoltaic response, which had been a fundamental bottleneck for stable operation of perovskite devices.

"Characterization and modeling attribute the improved performance to reduced bulk defects and improved charge-carrier mobility in large-grain pervoskite materials," said Mohite, "and we've demonstrated that the crystalline quality is on par with that observed for high-quality semiconductors like silicon and gallium arsenides."

http://www.sciencedaily.com/releases/2015/01/150129151619.htm