Synthetic accessibility and stability rules of NASICONs

In this paper we develop the stability rules for NASICON-structured materials, as an example of compounds with complex bond topology and composition. By first-principles high-throughput computation of 3881 potential NASICON phases, we have developed guiding stability rules of NASICON and validated the ab initio predictive capability through the synthesis of six attempted materials, five of which were successful. A simple two-dimensional descriptor for predicting NASICON stability was extracted with sure independence screening and machine learned ranking, which classifies NASICON phases in terms of their synthetic accessibility. This machine-learned tolerance factor is based on the Na content, elemental radii and electronegativities, and the Madelung energy and can offer reasonable accuracy for separating stable and unstable NASICONs. This work will not only provide tools to understand the synthetic accessibility of NASICON-type materials, but also demonstrates an efficient paradigm for discovering new materials with complicated composition and atomic structure. Sodium super ionic conductors are a class of promising energy storage materials owing to their high ionic conductivity. Here, the authors conducted high throughput calculations to understand the synthetic accessibility of NASICON-type materials and demonstrate an efficient paradigm for discovering new complex materials.

Automated summary

This paper presents stability rules for NASICON-structured materials, developed through high-throughput computations and validated through synthesis. A machine-learned tolerance factor based on specific descriptors offers reasonable accuracy in predicting the stability of NASICON phases. This work not only provides tools for understanding the synthetic accessibility of NASICON-type materials, but also demonstrates an efficient paradigm for discovering new materials with complicated composition and atomic structure.