Ultra‐light Hierarchical Graphene Electrode for Binder‐Free Supercapacitors and Lithium‐Ion Battery Anodes

Abstract

A mild and environmental-friendly method is developed for fabricating a 3D interconnected graphene electrode with large-scale continuity. Such material has interlayer pores between reduced graphene oxide nanosheets and in-plane pores. Hence, a specific surface area up to 835 m(2) g(-1) and a high powder conductivity up to 400 S m(-1) are achieved. For electrochemical applications, the interlayer pores can serve as "ion-buffering reservoirs" while in-plane ones act as "channels" for shortening the mass cross-plane diffusion length, reducing the ion response time, and prevent the interlayer restacking. As binder-free supercapacitor electrode, it delivers a specific capacitance up to 169 F g(-1) with surface-normalized capacitance close to 21 μF cm(-2) (intrinsic capacitance) and power density up to 7.5 kW kg(-1), in 6 m KOH aqueous electrolyte. In the case of lithium-ion battery anode, it shows remarkable advantages in terms of the initiate reversible Coulombic efficiency (61.3%), high specific capacity (932 mAh g(-1) at 100 mA g(-1)), and robust long-term retention (93.5% after 600 cycles at 2000 mAh g(-1)).

Heteroatom‐Containing Porous Carbons Derived from Ionic Liquid‐Doped Alkali Organic Salts for Supercapacitors

“…The C‐NaGlu shows the specific surface area of 549.25 m 2 g −1 and pore volume of 0.31 cm 3 g −1 , respectively. The formed porous network may be due to the reactions between carbon and in situ formed sodium compounds (for example, Na 2 CO 3, Na 2 O, Na) . Compared with C‐NaGlu, C‐BMIm‐NaGlu‐0.5 exhibits higher specific surface area and pore volume of 941.63 m 2 g −1 and 0.50 cm 3 g −1 , respectively.…”

Recent Advances in 3D Graphene Architectures and Their Composites for Energy Storage Applications

“…The interconnected structure of 3DGAs effectively improves their Li + /Na + storage performance. Zuo et al fabricated a 3D graphene foam with large‐scale continuity and used it as a binder‐free anode for LIBs ( Figure a) . This 3D graphene anode had interlayer pores and a high SSA of 835 m 2 g −1 (Figure b).…”

“…Based on its interconnected porous structure, it delivered a discharge capacity and a charge capacity of 1519 and 932 mAh g −1 respectively, with an initial Coulombic efficiency (ICE) of 61.3%. Even at the high discharge rate of 2 A g −1 , the capacity still reached 342 mAh g −1 (Figure c) . Zhang et al used hydrothermal, freeze‐drying, and annealing methods to synthesize a N‐doped 3D free‐standing rGO aerogel (Figure d) .…”

Neue Mitglieder der Chinesischen Akademie der Wissenschaften

“…Sein Interesse gilt dem Design und der Synthese von photo‐ und elektroaktiven molekularen Heteroübergangsmaterialien sowie von nanoskaligen und nanostrukturierten Materialien. In Small ist eine Arbeit von ihm über Graphenelektroden erschienen …”