Critically Assessing Environmental and Resource Competitiveness for Layered Oxide Sodium-Ion Batteries against Lithium-Ion Batteries

Sodium-ion batteries (SIBs) have garnered widespread attention as a highly promising alternative technology to lithium-ion batteries (LIBs). Based on life cycle assessment and supply risk evaluation methods, this study establishes an evaluation framework to compare the resource–environment impacts of two SIBs and four LIBs. Results indicate that layered oxide SIBs reduce toxicity and human health impacts by more than 50% compared to LiCoxNiyMn1–x–yO2 (NCM) batteries, primarily due to their avoidance of copper and cobalt. Among LIBs, LiFePO4 (LFP) exhibits the lowest greenhouse gas emissions, endpoint environmental impacts, and supply risks. The environmental burden of NCM batteries alleviates with increasing nickel content, but emissions from cathode materials remain above 37% of the total. Due to the geographical concentration and geopolitical instability of lithium, cobalt, and nickel in LIBs, their supply risk (208–815 × 107) is higher than that of SIBs (18–26 × 107). Competitiveness evaluation indicates that layered oxide SIBs exhibit superior sustainability (0.393–0.489) compared to high-nickel NCM (0.959). Moreover, optimizing production layout can reduce the carbon footprint by 15%, and increasing energy density can lower environmental burden and resource demand by 66%. This study provides a quantitative decision-making basis for battery technology selection, supply chain risk management, and global low-carbon layouts, holding significant importance for advancing the energy transition.