Sodium-ion packs 25% less carbon-intensive than LFP, say researchers

From ESS News

A new Chinese life cycle assessment (LCA) based on factory data has found that layered-oxide sodium-ion battery packs are cleaner to produce than LFP packs, but recent European studies have reached the opposite conclusion for cells.

Producing a 1 kWh sodium-ion battery pack in China generates 56.8 kg of carbon dioxide equivalent, 24.9% less than the 75.5 kg for an LFP pack, according to researchers who collected inventory data on site from gigawatt-hour-scale Chinese battery manufacturers.

For both chemistries, emissions are concentrated in manufacturing electricity, reflecting China’s coal-heavy grid. The researchers said that sodium-ion’s footprint can fall further through process optimization and cleaner power, while LFP makers should focus on raw-material substitution and using less material.

The scientists said earlier studies, including Peters et al. in 2016 and Guo et al. in 2023, found sodium-ion’s footprint slightly higher than lithium-ion’s because they relied on lab-scale data and default European databases.

A 2025 study by researchers at Fraunhofer and RWTH Aachen University, also based on primary factory data, reached the opposite result. It put cradle-to-gate emissions for layered-oxide sodium-ion cells at 75 kg to 87 kg of CO₂ equivalent per kilowatt-hour, against 59 kg to 70 kg for LFP cells. That study measured cells rather than packs, so the figures are not directly comparable.

Because both studies stop at the factory gate, neither accounts for cycle life, so they compare manufacturing impacts rather than emissions per unit of lifetime energy delivered. Both also cover only layered-oxide cathodes. HiNa Battery, for example, uses layered oxides, while Hithium’s 785 Ah storage cell uses a sodium iron pyrophosphate cathode.

The Chinese researchers also model a scenario in which wider sodium-ion adoption avoids 147 million metric tons of CO₂ equivalent in 2035. They used a cradle-to-gate boundary covering raw materials through manufacturing. They determined that the sodium-ion pack’s total environmental impact is 27.3% lower than LFP’s.

The scientists described their findings in “Comparative life cycle assessment and carbon footprint of sodium-ion and Lithium Iron phosphate batteries,” which was recently published in Environmental Impact Assessment Review.