Tailoring hard carbon interfaces in carbonate-based electrolytes for sodium-ion hybrid capacitors
Year: 2025
Type: article
Abstract: The poor rate performance of hard carbon (HC) in carbonate electrolytes limits its applicability in hybrid capacitors, primarily due to the low working potential and the slow Na+ transport kinetics within the potential plateau region. The slow desolvation of Na+ at the electrode surface and sluggish transport of Na+ through the solid electrolyte interface are the critical factors contributing to this issue. In this study, Co3O4 nanoparticles are uniformly self-grown on the HC surface to modulate the surface chemistry of HC. The introduction of Co3O4 not only facilitates the desolvation of Na+ and reduces internal resistance, but also provides additional active sites for Na+ storage as an active material. As a result of these dual effects, HC125@Co3O4 (a composite with an optimal Co3O4 loading on HC surfaces) exhibits superior rate performance and reversible capacity compared to pure HC. The sodium-ion hybrid capacitor assembled with the HC125@Co3O4 anode and activated carbon cathode demonstrates high energy density (129.5 Wh kg-1 at 583 W kg-1) and high power density (26.5 Wh kg-1 at 11,650 W kg-1), along with excellent long-time cycling stability. This study offers an effective solution to the poor rate performance and slow kinetics of HC in carbonate-based electrolytes, addressing the issue from the perspective of the electrode-electrolyte interface.
Source: Energy Materials
Institutions: Nanjing Tech University, Southeast University
Language: English
Field: Materials Science
Domain: Physical Sciences
Open Access status: hybrid
OpenAlex ID: W4408413826