Transforming CO2 to Porous Carbon as a High-Performing Sodium-Ion Battery Anode via Electrochemical Reduction in Molten Carbonates

The prevalence of sodium over lithium prompts exploration of sodium-ion batteries (SIBs) as a viable alternative to lithium-ion batteries (LIBs). Hard carbon has emerged as a promising anode material for SIBs, yet its synthesis poses sustainability challenges and emits pollutants. Here, we introduce CO₂-derived porous carbon (graphitic and amorphous) as an anode for SIBs via electrochemical reduction of CO₂ in a molten eutectic carbonate salt at a lower temperature that yields materials with controlled microstructure, morphology, and porosity conducive to energy storage. Our CO₂-derived carbon demonstrates remarkable specific capacity, superior rate capability, and stable cycling performance as a SIB anode. This innovative strategy harnesses waste CO₂ toward advancing SIB energy technology.