Electrode-free bioelectrochemical intercalation for scalable lithium recovery.

Electrochemical intercalation materials offer selective lithium recovery from saline streams, but conventional electrode architectures impose scale-up constraints. Here we report an electrode-free bioelectrochemical intercalation process in which a dissimilatory metal-reducing bacterium, Shewanella oneidensis MR-1, drives lithium uptake into λ-MnO2. The system self-assembles into microbe-mineral agglomerates that sustain electrochemical-rate intercalation without external wiring, forming a recoverable lithiated slurry. Over 95% of lithium was recovered from seawater within hours, with less than 1% co-intercalation of competing metal ions. Bottom-up self-agglomeration, in which extracellular and cell-surface cytochromes facilitate efficient electron transfer, enables scale-up. The generality and energetic basis of this mechanism are further supported by reproducing the key behaviour in an orthogonal FePO4 host with negligible abiotic reactivity. Techno-economic and life-cycle analyses for Li2CO3 production suggest that the process reduces brine water loss while maintaining competitive costs. These results establish self-assembled bioelectrochemical intercalation as a route to lithium recovery from saline streams.