Researchers discover new materials for sustainable, cost-effective batteries

New materials could lead to the development of more environmentally friendly batteries

A group of scientists based in Switzerland have discovered two new materials that, they believe, could pave the way for more sustainable batteries.

The researchers, from ETH Zurich and Empa, have been researching batteries capable of generating electricity from renewable sources.

Led by materials expert Maksym Kovalenko, the researchers claim that aluminium is one of the best candidates because it makes use of cheap and abundant raw materials.

While requiring a lot of energy to process from bauxite - which is typically done in countries with plentiful resources of renewable energy - aluminium can be easily and cheaply recycled.

And the researchers claim to have discovered new materials that could accelerate the development of aluminium batteries. The first of these is a corrosion-resistant material that acts as the conductor of the battery.

Meanwhile, the researchers have also discovered a novel material that could act as the battery's positive pole. They said it "can be adapted to a wide range of technical requirements".

One of the challenges with aluminium batteries is that they rely on an electrolyte fluid that is aggressive and corrodes stainless steel, as well as gold and platinum.

This has led scientists to try and find corrosion-resistant materials that can take over the conductive elements of batteries.

Kovalenko and his colleagues claim to have found the answer with titanium nitride, a ceramic material that sports high conductivity.

"This compound is made up of the highly abundant elements titanium and nitrogen, and it's easy to manufacture," said Kovalenko.

In a lab setting, the scientists were able to create a set of prototype aluminium batteries using titanium nitride as the conductive part.

They said the main benefit of the material is that it can "easily be produced in the form of thin films" and be used as "a coating over other materials such as polymer foils".

Kovalenko has high hopes for the material, continuing: "The potential applications of titanium nitride are not limited to aluminium batteries.

"The material could also be used in other types of batteries; for example, in those based on magnesium or sodium, or in high-voltage lithium-ion batteries."

The second material, claimed the researchers, can "rival graphite in terms of the amount of energy a battery is able to store".

Called polypyrene, it is a type of hydrocarbon that is underpinned by a chain-like, molecular structure. It could potentially form the basis of aluminium batteries.

"A lot of space remains between the molecular chains. This allows the relatively large ions of the electrolyte fluid to penetrate and charge the electrode material easily," added Kovalenko.