A novel performance–economics framework for upcycling spent Li-ion battery cathodes to accelerate battery circularity

The upcycling of cathode materials from spent Li-ion batteries (LIBs) is crucial for enabling battery circularity. However, upcycling via organic acid leaching faces industry adoption barriers due to high reagent costs, variable recovery rates, and the absence of robust decision-support metrics to integrate both technical efficiency and economic viability. This study aims to identify the most cost-effective LIB upcycling pathway using citric acid leaching to produce lithium carbonate (Li 2 CO 3 ) and composite metal oxides, while optimizing both metal recovery and economic output. A novel techno-economic analysis (TEA) model was developed to incorporate downstream metal loss along with metal prices, reagent and energy costs. In this study, Upcycling Pathway Efficiency Index (PEI) Up was developed for the first time to evaluate the trade-off between metal recovery and expense-to-revenue (E/R) ratio across multiple scenarios. The multivariate TEA parameter analysis showed that the expense-to-revenue (E/R) ratio of optimal upcycling pathway could be reduced from 0.47 to 0.32 for Li 2 CO 3 and from 0.73 to 0.12 for metal oxides through engineering process control. Scenario analysis further showed that the upcycling pathway with 94 % Li recovery yielded lower PEI values (0.49 for Li 2 CO 3 and 0.48 for metal oxides) compared to the pathway with 91 % Li recovery which achieved optimal PEI scores of 1 for both upcycled products. This study findings will further help to enhance the engineering-policy interaction through evidence-based metrics for upcycling process optimization and investment decisions in industry, while aligning with broader policy goals for expediting battery circularity. • Engineered upcycling pathway closes battery circularity loop using organic acid. • Novel TEA model accounts metal losses for downstream precipitation. • E/R ratio drops below 0.32 for Li 2 CO 3 and 0.12 for metal oxides. • PEI metric evaluates trade-offs between Li recovery and E/R ratio. • Minimizing reagent cost and metal loss is key to viable LIB upcycling.