Environmental Impact Assessment of Na3V2(PO4)3 Cathode Production for Sodium-Ion Batteries

Sodium-ion batteries (NIBs) are key enablers of sustainable energy storage. NIBs use Earth-abundant materials and are technologically viable to replace lithium-ion batteries in the medium term. Na3V2(PO4)(3), as a popular cathode for NIBs, requires further improvements to boost its electrochemical performance, particularly regarding the rate capability and operational lifetime. These strategies involve the incorporation of carbonaceous materials, heteroatom doping, morphology modification, or biopolymer incorporation. Considering the circular economy actions to foster environmentally sustainable battery industries, there is an urgent need to disclose the environmental impacts of battery production. A cradle-to-gate life cycle assessment methodology is used to quantify, analyze, and compare the environmental impacts of ten representative state-of-the-art Na3V2(PO4)(3) cathodes. Impacts are disclosed for 18 indicators normalized to 1 kg of cathode considering laboratory-scale approaches. Global warming potential values of 423.9-1380.0 kg CO2-equiv. kg(cathode) (-1) and 539.8-1622.1 kg CO2-equiv. kWh(cathode) (-1) are obtained considering Na3V2(PO4)(3)/Na half-cell configuration. Simple carbon additives mixed with NVP provide a good CO2 footprint-to-storage capacity balance, although the sacrificed capacity retention hinders reuse strategies. A sensitivity analysis demonstrates a 16.9-38.0% reduction transitioning from fossil-based to renewable-based energy mix. Herein, it is aimed to support battery developers and assist future advances in the development of sustainable cathodes applied into beyond-Li-ion technologies.

Automated summary

This study focuses on the environmental impacts of a popular cathode material, Na3V2(PO4)(3), in sodium-ion batteries. The study reveals that incorporating carbon additives can provide a balance between CO2 emissions and storage capacity, but the sacrificed capacity retention hinders reuse strategies. Additionally, transitioning from fossil-based to renewable-based energy sources can significantly reduce emissions.