Identification of solid oxygen‐containing Na‐electrolytes: An assessment based on crystallographic and economic parameters

Abstract

We have scanned the inorganic crystal structure database using Voronoi‐Dirichlet methodology for inorganic, crystalline, solid Na electrolytes and applied a total of nine different crystallographic and economic parameters in order to evaluate the potential of each material. Especially for stationary electrochemical energy storage — used to counteract the capricious nature of renewable energy sources and momentary variations of energy consumption — Na‐based chemistries have a considerable market share. They rely on solid Na electrolytes separating the Na and S electrode compartments. We used data generated from the currently widest‐spread Na electrolytes to lay a foundation for the crystallographic data mining and Voronoi‐Dirichlet partitioning of the database. The structural data is the basis for the calculation of the above‐mentioned parameters. We introduced an evaluation and scoring scheme to systematise the results and — depending on the weighting scheme — point towards the most promising materials. Aluminosilicates and transition metal oxides seem especially interesting but, depending on the weighting, any of the more than 400 candidates could be the next‐generation solid Na electrolyte.