Indeed, knowledge of the structure and dynamics of matter at different length scales has enabled replacing serendipity and Edisonian trial-and-error approaches with intention and rational materials engineering, and this has accelerated progresses in a wide range of technologies which are now crucial for our daily lives but could not even be imagined a century ago.

One such example is Li-ion batteries, which was granted the Nobel Prize in Chemistry 2019 to J.B. Goodenough, M.S. Whittingham, and A. Yoshino as it enabled, in the words of the Nobel Committee, “the creation of a rechargeable world”.(1) This technology is now expanding from the portable electronics realm to transportation(2) and even stationary grid applications.

Given the crucial relevance of all these fields of use, it seems evident that as a society we should not rely on a unique technology, neither from a sustainability nor from a geopolitical and social perspective. Despite Li-ion batteries being in themselves not a single technology but a family of technologies for which several materials have been developed ad hoc,(3) the diversification of concepts/chemistries is currently a target for battery researchers worldwide, both in academia and industry (see ref (4) and references in that issue). While the quest for ever increasing energy densities has for long been the main driving force behind progress in battery technology, additional factors are now considered such as cost and sustainability. The latter comprises not only low environmental footprint in terms of toxicity and energy/water consumption but also the avoidance of critical materials.