This review addresses concepts, approaches, tools, and outcomes of multiscale modeling used to design and optimize the current and next generation rechargeable battery cells. Different kinds of multiscale models are discussed and demystified with a particular emphasis on methodological aspects. The outcome is compared both to results of other modeling strategies as well as to the vast pool of experimental data available. Finally, the main challenges remaining and future developments are discussed.

Polyanionic electrode materials offer a compelling combination of safety benefits and tunable redox potentials. Thus far, phosphate-based phases have drawn the most interest with a subsequent surge of activity focused on the newly discovered family of fluorosulfate phases.Here, we report the preparation of a new potassium-based fluorosulfate, KFeSO 4 F, which, with removal of K, leads to a new polymorph of FeSO 4 F crystallizing in the high-temperature structure of KTiOPO 4 . This new phase which contains large, empty channels, is capable of reversibly inserting 0.9 Li + per unit formula, and can accommodate a wide variety of alkali ions including Li + , Na + , or K + . This finding not only expands the rich crystal chemistry of the fluorosulfate family, but further suggests that a similar strategy can apply to other K-based polyanionic compounds in view of stabilizing new attractive hosts structures for insertion reactions.