(510q) Life Cycle Comparison of Battery Recycling and Raw Material Extraction

Demand for lithium-ion batteries (LIBs) has skyrocketed in the last decade, causing concern for the rapid depletion of precious metal sources that constitute these products and the environmental impacts of resource extraction. In addition, battery disposal can lead to environmental contamination and economic losses from discarding valuable materials. Battery recycling is being investigated as a solution to sustain the growing demand for LIBs and to address the problems resulting from spent LIB disposal. However, selective component separation and recovery can still be energy-intensive, require harsh chemicals, and cause environmental pollution. Therefore, a life cycle comparison between battery recycling and raw material extraction is essential to ensure adoption of the most sustainable processes going forward. In this work, we conducted a comprehensive evaluation of battery recycling through three objectives: (1) combine data from literature and government databases to characterize and assess life cycle criteria for raw material extraction; (2) analyze the unit processes in a case study to assess life cycle criteria for battery recycling; and (3) compare the results of the first two objectives and produce a final conclusion with recommendations for future research.

Methods

We performed a gate-to-gate life cycle assessment (LCA) of battery recycling and raw material extraction using primary data and the Argonne National Laboratory Greenhouse gases, Regulated Emissions, and Energy use in Technologies (GREET) model. The functional unit employed in the analysis was a 1 kWh lithium nickel manganese cobalt oxide (NMC) battery. The LCA criteria evaluated were global warming potential (CO₂ eq), ozone depletion (CFC-11 eq), primary energy demand, water consumption, and the National Ambient Air Quality Standards (NAAQS) six common air pollutants set by the Environmental Protection Agency (EPA): ozone, carbon monoxide, lead, sulfur dioxide, nitrogen dioxide, and particulate matter. We extracted information regarding raw material extraction for each battery component from peer-reviewed journals and government databases.

Results and Implications

Our review of raw material extraction revealed variations in life cycle results based on the location of extraction, the method of extraction (e.g., mining vs. brines), the type of ore being processed, and the metals being targeted. To facilitate a detailed analysis, the raw extraction assessment was broken down into each NMC battery component, and the results were then combined for an overall evaluation. Variables were built into the model to allow for a diversity of inputs so that multiple scenarios of raw extraction could be compared against recycled materials. The comparison of life cycle metrics for each process indicated battery recycling as a feasible option to supplement virgin materials from mining and brine extraction and as a solution to the growing volume of batteries reaching end-of-life. However, several opportunities for development can improve the case of recycling as a substitute for raw extraction. To expand the reach of this work, we proposed quantitative performance metrics specifically relating to environmental impacts for evaluating other battery recycling methods. This study will guide developments in battery recycling technology, provide sustainability metrics for performance evaluations, and contribute to the movement towards a circular battery economy.