Controlled growth of Co9S8 nanoparticle-embedded carbon nanosheets/carbon nanofibers toward high-performance sodium storage

• Published in: Journal of colloid and interface science Vol. 648; pp. 644 - 653
• Main Authors: Wang, Silan, Zhou, Ziyi, Wen, Bo, Zhang, Zhijie, Yang, Guorui, Yan, Wei
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 15-10-2023
• Subjects: Anode; Co9S8; Nanofibers; Pseudocapacitance; Sodium-ion batteries; Co9S8; Anode; Nanofibers; Pseudocapacitance; Sodium-ion batteries
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2023.06.001

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•Multifunctional Co9S8@CNSs/CNFs flexible self-supporting electrode is designed for Sodium-ion batteries.•The advantages of multi-stage structural synergistic composites are illustrated at the electrode scale.•In-depth analysis of electrode electrochemical reaction kinetics and de-/sodiation mechanism.•High sodium storage half-cells and stable full cell capacity with self-supporting electrodes are achieved.
Transition metal sulfides (TMSs) are considered as promising anodes for sodium-ion batteries (SIBs) due to their high theoretical capacity and low cost. However, TMSs suffer from massive volume expansion, slow sodium-ion diffusion kinetics, and poor electrical conductivity, which severely restrict their practical application. Herein, we design self-supporting Co9S8 nanoparticles embedded carbon nanosheets/carbon nanofibers (Co9S8@CNSs/CNFs) as anode materials for SIBs. The electrospun carbon nanofibers (CNFs) provide continuous conductive networks to accelerate the ion and electron diffusion/transport kinetics, while MOFs-derived carbon nanosheets (CNSs) buffer the volume variation of Co9S8, consequently improving the cycle stability. Benefitting from the unique design and pseudocapacitive features, Co9S8@CNSs/CNFs deliver a stable capacity of 516 mAh g−1 at 200 mA g−1 and a reversible capacity of 313 mAh g−1 after 1500 cycles at 2 A g−1. Note that, it also displays excellent sodium storage performance when assembled into a full cell. The rational design and excellent electrochemical properties endow Co9S8@CNSs/CNFs with the potential stepping into commercial SIBs.