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In lithium–oxygen batteries, the solubility of LiO₂ intermediates in the electrolyte regulates the formation routes of the Li₂O₂ discharge product. High-donor-number electrolytes with a high solubility of LiO₂ tend to promote the formation of Li₂O₂ large particles following the solution route, which eventually benefits the cell capacity and cycle life. Here, we propose that facet engineering of cathode catalysts could be another direction in tuning the formation routes of Li₂O₂. In this work, β-MnO₂ crystals with high occupancies of {111} or {100} facets were adopted as cathode catalysts in Li–O₂ batteries with a tetra(ethylene)glycol dimethyl ether electrolyte. The {111}-dominated β-MnO₂ catalyzed the formation of the Li₂O₂ discharge product into large toroids following the solution routes, while {100}-dominated β-MnO₂ facilitated the formation of Li₂O₂ thin films through the surface routes. Further computational studies …