  The Li-Air battery is a very promising candidate for powering future
mobility, but finding a suitable electrolyte solvent for this technology turned
out to be a major problem. We present a systematic computational investigation
of the known chemical space for possible Li-Air electrolyte solvents. It is
shown that the problem of finding better Li-Air electrolyte solvents is not
only - as previously suggested - about maximizing Li+ and O2- solubilities, but
about finding the optimal balance of these solubilities with the viscosity of
the solvent. As our results also show that trial-and-error experiments on known
chemicals are unlikely to succeed, full chemical sub-spaces for the most
promising compound classes are investigated, and suggestions are made for
further experiments. The proposed screening approach is transferable and robust
and can readily be applied to optimize electrolytes for other electrochemical
devices. It goes beyond the current state-of-the-art both in width (considering
the number of compounds screened and the way they are selected), as well as
depth (considering the number and complexity of properties included).
