An alternate synthetic pathway to nanoscopic Li2FeS2 for energy storage†

Lithium-rich iron sulphide, Li₂FeS₂, exhibits reversible charge-storage via both cationic and anionic sites, storing nearly 400 mA h g⁻¹, but its synthesis is limited to solid-state methods that result in large primary particles. We describe an alternate solution-based, redox-mediated method to lithiate pyrite FeS₂, ultimately forming nanoscale Li₂FeS₂.