Category Chemistry/Nanotechnology

Polyhedral representation of the crystal structure of fluoride-phosphate of vanadium and potassium. The yellow denotes a three-dimensional channel system, which provides rapid transport of Li+ ions. Credit: Stanislav Fedotov

A cathode material for li-ion batteries with a very high charge rate – down to 90s – has been created, retaining more than 75% of an initial capacity. The discovery may stipulate the development of batteries where expensive lithium could be replaced with cheaper potassium.

Nowadays Li-ion batteries power a wide range of electronic devices: mobile phones, tablets, laptops. They became popular in 90s and subsequently ousted widespread nickel-metal hydride batteries. However, their capacity may drop when temperature falls below 0...

The new carbon-based material for sodium-ion batteries can be extracted from apples. Credit: KIT/HIU

A carbon-based active material produced from apple leftovers and a material of layered oxides might help reduce the costs of future energy storage systems. Both were found to have excellent electrochemical properties and stand for the environmentally compatible and sustainable use of resources. Sodium-ion batteries are not only far more powerful than nickel-metal hydride or lead acid accumulators, but also represent an alternative to lithium-ion technology, as the initial materials needed are highly abundant, accessible, and low cost. Hence, sodium-ion batteries are a very promising technology for stationary energy storage systems.

Schematic structure of the layered oxides produced...

Doped lithium titanate (LTO) nanoparticles could be incorporated into Li-ion batteries used in, for example, electric or hybrid automotive applications. Credit: Image courtesy of University of Eastern Finland

Lithium-ion batteries are a rapidly growing energy storage method due to their high energy density, especially in mobile applications such as personal electronics and electric cars. However, the materials currently used in Li-ion batteries are expensive, many of them, like lithium cobalt oxide (belonging to the EU Critical Raw Materials, CRMs), are difficult to handle and dispose of. Additionally, batteries using these materials have relatively short lifetimes.

New novel materials are being developed for next generation Li-ion batteries...

Two-dimensional metastructured film with Titanium Oxide is fabricated as a photo-catalytic photoanode with exceptional visible light absorption. Credit: Copyright UNIST

A new multilayered (Au NPs/TiO2/Au) photoelectrode boosts ability of solar water-splitting to produce hydrogen. According to the research team, this special photoelectrode, inspired by the way plants convert sunlight into energy is capable of absorbing visible light from the sun, and then using it to split water molecules (H2O) into H2, O2.

This multilayered photoelectrode takes the form of 2D hybrid metal-dielectric structure, which mainly consists of 3 layers of gold (Au) film, ultrathin TiO2 layer (20 nm), and gold nanoparticles (Au NPs)...