Abstract
The rapid development of portable electronics and hybrid vehicles requires electrochemical capacitors (ECs) with excellent integrated performances. Herein, we report such an EC based on the dense graphene hydrogel films (packing density = 1.18 ± 0.01 g cm−3) prepared by hydrothermal reduction of highly oxidized graphene oxide (HGO) sheets with lateral dimensions of 1–2 μm, followed by mechanical compression. This EC exhibited high areal (366 ± 6 mF cm−2), gravimetric (232 ± 3 F g−1) and volumetric (273 ± 1 F cm−3) specific capacitances at 1 A g−1, ultrahigh rate-capability (80% capacitance retention at 100 A g−1), and good electrochemical stability. The effects of the structural defects and lateral sizes of graphene sheets on their electrochemical performances are studied, offering a guidance of rational designing graphene materials for their applications in ECs.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.