Regulating the structure of hard carbon derived from industrial waste to boost sodium storage performance

Biomass-derived hard carbon materials stand out in the research of anode materials for sodium-ion batteries (SIBs) due to their low cost, high performance, and broad range of raw materials. However, the low carbonization yields of biomass-derived hard carbons and the waste produced during industrial production processes contribute to the high production cost of these hard carbons. Furthermore, it is essential to discuss the use of various electrolytes aimed at enhancing the ion storage capacity within SIBs. Herein, the high-temperature carbonization was proposed to recycle waste precursors for fabricating the hard carbon materials and regulating its ordering degree to boost the sodium storage ability. Meanwhile, it was found that ether-based electrolytes have positive effects on sodium storage by in-situ Raman characterization compared to ester-based electrolytes. Moreover, the assembled pouch cells and 18,650 cylindrical cells utilizing obtained hard carbon materials exhibit excellent reversible capacities of 406 and 674 mAh, respectively, indicating their promising potential for applications. This work presents simple recycling methods and compares the differences between the materials in ester-based and ether-based electrolytes, providing guidance for reducing material costs and developing high-performance anodes for SIBs.