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.