Circularity-oriented recycling of spent lithium-ion batteries: Large-scale process integration and sustainability evaluation

Abstract

The rapid shift from fossil fuels to sustainable energy systems is accelerating global battery demand, resulting in a growing volume of spent lithium-ion batteries (LIBs). This trend emphasizes the need for circular strategies that enable the recovery and reuse of critical materials. This study proposes a large-scale integrated recycling system connecting four core processes: LIB recycling, re-manufacturing, sodium bicarbonate production, and integrated gasification combined cycle. Techno-economic and environmental assessments were conducted to evaluate feasibility, along with qualitative and quantitative indicators for circularity such as the ReSOLVE framework and the material circularity indicator. A South Korea-based case study targeting 200,000 t of spent LIBs per year showed reductions of about 24 % in unit cost (US$/kg) and approximately 51 % in global warming potential (kg CO<inf>2</inf>-eq.) compared to a linear model, based on a functional unit of 1 kg of reproduced NMC 111 cells. Sensitivity analysis across different allocation methods confirmed the robustness of environmental outcomes. The material circularity indicator was calculated at 0.696, indicating a significant reduction in virgin material input. The proposed system establishes cross-industry recycling links that enable industrial symbiosis between CO<inf>2</inf>-emitting and material recovery industries, thereby maximizing resource utilization efficiency. These results demonstrate the potential of integrated recycling systems to support circular economy transitions in the battery sector through enhanced resource efficiency and industrial symbiosis. © 2025 Elsevier B.V., All rights reserved.