New materials for sustainable, low-cost batteries

The researchers produced aluminum button cells in the laboratory. The battery case is made of stainless steel coated with titanium nitride on the inside to make it corrosion resistant. Credit: ETH Zurich / Kostiantyn Kravchyk

A new conductor material and a new electrode material could pave the way for inexpensive batteries and therefore the large-scale storage of renewable energy.

Scientists from ETH Zurich and Empa, led by Maksym Kovalenko, Professor of Functional Inorganic Materials, are among those involved in researching and developing batteries of this kind. The researchers have now identified two new materials that could bring about key advances in the development of aluminium batteries. The first is a corrosion-resistant material for the conductive parts of the battery; the second is a novel material for the battery’s positive pole that can be adapted to a wide range of technical requirements.

As the electrolyte fluid in aluminium batteries corrodes stainless steel, gold and platinum, scientists are searching for corrosion-resistant materials for the conductive parts of these batteries. Titanium nitride, a ceramic material that exhibits sufficiently high conductivity, is such a conductor. “This compound is made up of the highly abundant elements titanium and nitrogen, and it’s easy to manufacture,” explains Kovalenko.

The scientists have successfully made aluminium batteries with conductive parts made of titanium nitride in the laboratory. The material can easily be produced in the form of thin films, also as a coating over other materials such as polymer foils. Kovalenko believes it would also be possible to manufacture the conductors from a conventional metal and coat them with titanium nitride, or even to print conductive titanium nitride tracks on to plastic. “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,” says Kovalenko.

Read more: New materials for sustainable, low-cost batteries

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