Cobalt-catalyzed soft-hard carbon composite anodes for enhanced sodium-ion storage

• Published in: Solid state ionics 2024-08, Vol.411, p.116555, Article 116555
• Main Authors: Zhao, Pei, Shi, Gejun, Hu, Lulu, Zhang, Zongliang, Ding, Kun, Meng, Xinjing, Wang, Baofeng
• Format: Article
• Language: English
• Subjects: Biomass-derived hard carbon; Catalytic graphitization; Initial coulombic efficiency; Sodium-ion battery
• ISSN: 0167-2738; 1872-7689
• DOI: 10.1016/j.ssi.2024.116555

Hard carbon is expected to be a high-capacity anode material for sodium-ion batteries (SIBs). However, its Na+ storage performance, especially the low discharge capacity, remains a great challenge. Herein, the soft-hard carbon composite anodes with high degree of graphitization were synthesized via low-temperature pyrolysis (at only 900 °C) of Cobalt-catalyzed perylene tetracarboxylic dianhydride (PTCDA-Co) and cotton, with subsequent removal of cobalt. The composite resulting from a 2:3 mass ratio of soft to hard carbon exhibits a good discharge capacity of 355.81 mAh g−1 at a current density of 50 mA g−1 and an enhanced initial Coulombic efficiency (ICE) of 81.41%. The enhanced electrochemical storage performance of cotton is attributed to the introduction of PTCDA-Co, which creates low-defect graphitic layer, hierarchical porous channels, and carbon shielding coating on hard carbon. [Display omitted] •Highly graphitized carbon composite anodes synthesized from cotton carbon and PTCDA-Co at 900 °C.•PCo-HC2–3 shows 355.81 mAh/g discharge capacity at 50 mA g−1 with ICE 81.41%.•The Na+ storage mechanism in PCo-HC2–3 is an adsorption-insertion/filling mechanism.