High-Throughput Screening of Na-Ion Cathodes

Abstract

In the search for better performing battery materials, high-throughput approaches have the potential to screen large composition spaces in a short period of time and thereby greatly accelerate the development of advanced materials. The challenges are numerous both in terms of synthesis which is often done at much smaller scale than in commercial settings (e.g. milligrams) and in terms of characterization. Herein, we develop high-throughput synthesis of Na-ion cathodes in the Na-Mn-Fe-O pseudo-ternary system. The sol-gel approach is adapted to high-throughput and shows that single-phase materials are made whereas co-precipitation does not yield sufficiently intimate mixing of the cations and phase separation occurs. The samples made by sol-gel are further characterized using both X-ray diffraction and cyclic voltammetry (both in high-throughput) and yield results that match up very well with those obtained by making bulk amounts of the samples. This demonstrates scale-up of the combinatorial results will be possible. Preliminary data on the entire Na-Mn-Fe-O pseudoternary system will be shown for the first time revealing the structure-property relations taking place in this important system. This work will serve as both a screening tool and also help guide future research in the design of Na-ion cathodes.