The growing demand for sustainable and cost-effective energy storage technologies has stimulated interest in alternatives to lithium-ion batteries. Sodium-ion batteries (SIBs) are considered a promising candidate due to the abundance and low cost of sodium resources. However, the larger ionic radius of sodium ions faces challenges for electrode materials, requiring suitable anode structures that can accommodate sodium insertion while maintaining structural stability.
Carbon-based materials are widely investigated as anode materials for SIBs, particularly hard carbons with enlarged interlayer spacing and defect-rich structures. Although biomass-derived hard carbons have shown promising electrochemical performance, their relatively high cost and limited scalability may hinder large-scale applications. In contrast, petroleum by-products offer a potentially economical and abundant precursor for carbon materials.
In this work, oilsands-derived asphaltenes were explored as a precursor for producing carbon materials suitable for sodium-ion battery anodes. As an initial step, a reference Raman spectral library of various commercially available carbon materials was established under different excitation wavelengths and nitrogen purged conditions.
The structural properties of the oilsands-derived carbon heat treated at different temperatures were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and Raman spectroscopy, followed by spectral fitting and quantitative analysis to evaluate both short-range ordering and long-range disorder within the carbon structure. To further investigate the sodium storage mechanism, galvanostatic discharge measurements were combined with an in-house-built operando Raman spectroscopy setup to monitor structural evolution during electrochemical cycling.
Overall, this study demonstrates the feasibility of converting oilsands-derived asphaltenes into carbon materials and highlights their potential as a cost-effective precursor for sodium-ion battery anodes.