The increasing demand for accessing renewable sources of energy and energy storage has promoted investment and research in the battery field. Li ion batteries have historically fulfilled these needs but faces sustainability concerns due to the scarcity of material. Recent reports have focused on sodium as an alternative material for its natural abundance and promising potential. A crucial challenge facing sodium ion battery (SIB) research is lackluster performance in electrode materials. One of the most common materials for Li ion batteries (LIB), graphite, is not a suitable anode for SIBs due to the larger ions not having enough space to intercalate efficiently. Hard carbon has received attention for its ability to house Na ions by incorporating defects into a graphitic structure via pyrolysis. However, its specific capacity is often low, and the mechanism of sodiation in hard carbon is currently debated, influenced by various aspects of the hard carbon structures (e.g., porosity, crystallinity, and defects). In this work, Na ion batteries using hard carbon derived from distinct blended polymer mixtures and block copolymer precursors in combination with two drying methods and two solvents are prepared first to unveil the structure-property-performance relationship. Then the best performance hard carbon is mad in composite with Sn to boost the performance. Overall, this work helps to observe the effects each precursor and pathway of anode synthesis has on surface area, porosity, local structure, and electrochemical performance, providing guidance for future design and engineering of high-performance SIB anodes.
