Mobile phones, notebook computers, iPods—the boom in portable computing and communications devices is dependent on rechargeable lithium-ion batteries to deliver power. These batteries offer the highest energy density, allow laptops to function for useful amounts of time, and do not display a memory effect when compared to other types of rechargeable batteries.
However, modern rechargeable batteries are still not truly satisfactory. Modern, efficient, rechargeable batteries and fuel cells require materials with an enhanced ability to conduct lithium ions. German researchers have now developed a new class of inorganic ionic conductor with a structure analogous to that of the mineral argyrodite.
A team led by Hans-Jörg Deiseroth in Siegen, Germany reports, in the journal Angewandte Chemie, the characterization of the most conductive representative of the man-made argyrodite minerals made of lithium, phosphorus, sulfur, and bromine atoms.
In ionic conductors, charge is not transported in the form of electrons as it is in metals; instead, the charge is transported in the form of charged particles—typically, lithium ions. This transport requires materials in which the lithium ions can move as freely as possible. The team from the University of Siegen, in cooperation with scientists at the University of Münster, started from a long-known mineral: argyrodite is a silver-, germanium-, and sulfur-containing mineral discovered near Freiberg, Germany in 1885 and the silver ions in this material are very mobile.
The individual components of argyrodite can be replaced by a number of other atoms without altering the typical structure of the mineral. The term argyrodite now refers to an entire class of compounds that have a specific arrangement of atoms and type of structure. The team led by Deiseroth produced a version of the mineral in which silver is replaced by lithium, germanium by phosphorus, and some of the sulfur atoms by halides (chloride, bromide, or iodide), resulting in argyrodite-like structures that have a composition of Li6PS5X (X: Cl-, Br-, or I-).
In the crystal lattice the phosphorus, sulfur, and halide atoms adopt a dense tetrahedral packing arrangment in which the gaps are filled somewhat regularly with lithium ions. The lithium ions can “jump” from gap to gap. The freely moving ions indicate that the solid has a high ionic conductivity and the reported bromine-containing structure has the highest ionic conductivity of lithium ions known for any argyrodite to date.
The scientists have thoroughly examined the lithium argyrodites by single-crystal X-ray crystallography and nuclear magnetic resonance spectroscopy. This analysis allowed precise characterization of the crystal structures of these compounds and provided fascinating insights into the dynamics of the mobile lithium ions.
Author: Hans-Jörg Deiseroth, Universität Siegen (Germany), http://www.uni-siegen.de/fb8/ac/hjd/index.html?lang=de
Title: Li6PS5X: A Class of Crystalline Li-Rich Solids With an Unusually High Li+ Mobility
Angewandte Chemie International Edition 2008, 47, No. 4, 755–758, doi: 10.1002/anie.200703900
Hans-Jörg Deiseroth | Angewandte Chemie
New eDNA technology used to quickly assess coral reefs
18.04.2019 | University of Hawaii at Manoa
New automated biological-sample analysis systems to accelerate disease detection
18.04.2019 | Polytechnique Montréal
A stellar flare 10 times more powerful than anything seen on our sun has burst from an ultracool star almost the same size as Jupiter
A localization phenomenon boosts the accuracy of solving quantum many-body problems with quantum computers which are otherwise challenging for conventional computers. This brings such digital quantum simulation within reach on quantum devices available today.
Quantum computers promise to solve certain computational problems exponentially faster than any classical machine. “A particularly promising application is the...
The technology could revolutionize how information travels through data centers and artificial intelligence networks
Engineers at the University of California, Berkeley have built a new photonic switch that can control the direction of light passing through optical fibers...
Physicists observe how electron-hole pairs drift apart at ultrafast speed, but still remain strongly bound.
Modern electronics relies on ultrafast charge motion on ever shorter length scales. Physicists from Regensburg and Gothenburg have now succeeded in resolving a...
Engineers create novel optical devices, including a moth eye-inspired omnidirectional microwave antenna
A team of engineers at Tufts University has developed a series of 3D printed metamaterials with unique microwave or optical properties that go beyond what is...
17.04.2019 | Event News
15.04.2019 | Event News
09.04.2019 | Event News
18.04.2019 | Life Sciences
18.04.2019 | Physics and Astronomy
18.04.2019 | Life Sciences