Searching Infinite Space for New Materials

by Adil Aftab

Mon, 21, 2021

Discovering new materials is usually a lengthy process of trial and error. The process today uses researchers’ knowledge and experience to investigate chemical compounds — often huge numbers of them — that are similar to existing useful materials. However, this can limit discoveries to materials with properties similar to what we already have available.

The trouble is that chemical space is infinite, made of an infinite number of potential combinations of the chemical elements. We do not know which areas of this space will produce useful materials; all we can do is use our knowledge and experience to select areas for investigation. Because each potential material requires experimental confirmation, it is a laborious task.

Researchers at the University of Liverpool have been using artificial intelligence to try to discover new useful chemical compounds that are further from known materials than ever before. Their tool combines human knowledge with AI’s ability to look for patterns in data at a scale beyond human capabilities.

The AI uses unsupervised learning — that is, it is fed a huge amount of unlabeled data about materials. It then infers relationships between the several-hundred–thousand known materials and their properties. These relationships are used to generate combinations of elements that could hold promise, giving each combination a ranking. Humans use these rankings to explore the infinite chemical space in a more targeted way. AI effectively offers a different perspective, sparking different avenues of investigation.

The most exciting results that this technique has produced so far are four new compounds that the researchers deemed worthy of making in the lab. All are materials that conduct lithium ions, which could potentially be used in future solid-state batteries.

The invention of lithium-ion batteries is a great illustration of how important a single material can be; today’s macro challenges, such as sustainability, will rely on new materials. New materials will enable the next generations of solar panels, electronics, and batteries, hopefully with less toxic materials and fewer scarce elements.