Electrochemical extraction offers a promising alternative to conventional hydrometallurgy for lithium recovery from spent batteries, yet its environmental performance remains underexplored. This study presents the first life cycle assessment (LCA) of electrochemical lithium extraction from battery leachates at laboratory scale, comparing lithium manganese oxide (LMO) and lithium nickel manganese oxide (LNMO) electrode systems. The LNMO system reduced carbon emission by 53% compared to LMO system (33.1 vs 68.0 kg CO₂-eq/kg Li2CO3), with N-methyl-2-pyrrolidone (NMP) solvent identified as the primary environmental hotspot across both electrode systems. Scenario analysis of six alternative process designs demonstrated that NMP-related optimization strategies achieved carbon emission reductions of 28–43%. Under industrial-scale assumptions with combined implementation, the optimized electrochemical extraction process exhibited competitive environmental performance relative to conventional spodumene-based lithium carbonate production. These findings redirect research priorities from energy optimization toward material efficiency and demonstrate the role of early-stage LCA in guiding sustainable battery recycling.