Selective recovery of lithium from spent coin cell cathode leachates using ion imprinted blended chitosan microfibers: Pilot scale studies provide insights on scalability

We report an approach on specific and scalable recovery of lithium ions from coin cells using functionalized chitosan microfibers. Low swelling ratios and high degree of crosslinking resulted from a dual combination of blended viscosities and crosslinking. Owing to their defined structure (pore diameter: 2.29±0.31 µm; fiber diameter: 176.5±3.44 µm; ion exchange capacity: 8.45 meq/g), imprinted microfibers exhibited high lithium uptake potential (100 mg/g), high distribution coefficient (6969.7 mL/g) and high separation factors (90) in a multi-metal system generated from leachates (co-ions: Co(II), Ag(I), Mn(II), Cu(II), Al(III), Ni(II), Na(I), K(I) and Ca(II)). The uptake phenomena followed a homogeneous monolayer adsorption mode and a spontaneous endothermic nature (ΔG:-20.3 KJ/mol). High values of relative lithium sorbed (RLS) (>20) and relative lithium released (RLR) (>9) in case of imprinted microfibers suggested high selectivity. Batch conditions showed a selective recovery of 45.7%/g/L of leachates (< 50 cathodes) at pH of 6.1. However, packed bed column studies showed that 14.3 g of biosorbent could recover up to 99.1% lithium (recovered lithium of up to 971.19 mg/L) over 9 cycles (250 cathodes; CoLi: 976.33 mg/L). The present study suggested blended and imprinted chitosan microfibers as a useful matrix towards scalable lithium recovery. [Display omitted] •Swelling and crosslinking in blended chitosan microfibers affected lithium uptake.•Imprinting resulted in high recovery, selectivity, thermal strength, pH tolerance.•Recovery monitored in terms of relative lithium sorbed, relative lithium released.•Biomass dosage of 14.3 g recovered 99% Li(I) from 250 LCC leachate (Co:976.33 mg/L).•Blended, imprinted, porous fibrous matrix as a suitable agent for Li(I) recovery.