Comparative life cycle assessment and carbon footprint of sodium-ion and Lithium Iron phosphate batteries: A case study in China

To support China's “Dual Carbon” goals, this study applies a life cycle assessment approach to compare the environmental performance of layered-oxide sodium-ion batteries and lithium iron phosphate (LFP) batteries under Chinese manufacturing conditions. A cradle-to-gate system boundary was adopted, with the production of a 1 kWh battery pack defined as the functional unit. Using foreground inventory data collected through on-site investigations of Chinese battery manufacturers, literature sources, and localized Ecoinvent datasets, a localized endpoint damage-oriented life cycle impact assessment model is applied to quantify the potential environmental impacts and carbon footprints of the two battery systems. The results indicate that the total potential environmental impact of sodium-ion batteries is 9.09 Pt, representing a 27.3% reduction compared with LFP batteries (12.50 Pt). In addition, the carbon footprint of sodium-ion batteries is 56.8 kg CO₂-eq, which is 24.9% lower than that of LFP batteries (75.5 kg CO₂-eq). These findings demonstrate the significant potential of layered-oxide sodium-ion batteries in terms of carbon emission reduction and resource security. Further improvements in their environmental performance will depend on manufacturing process optimization and the adoption of cleaner energy sources, while LFP batteries should prioritize raw material substitution and material reduction strategies.