Graphene Film with a Controllable Microstructure for Efficient Electrochemical Energy Storage

Abstract

The agglomeration of graphene sheets and undesired pore size distribution usually lead to unsatisfactory electrochemical properties of reduced graphene oxide (RGO) film electrodes. Herein, crumpled exfoliated graphene (EG) sheets are adopted as the microstructure-regulating agent to tune the morphology and micro-/mesopore amounts with the aim of increasing active surface sites and ion transportation paths in electrodes. With the optimum ratio between EG and GO, the resulting 75%-EG/RGO shows significantly improved specific gravimetric capacitance (C s ) and rate capability when compared with pure RGO electrodes in a symmetrical supercapacitor system. Moreover, when coupling the 75%-EG/RGO cathode with a Zn anode to form a Zn ion hybrid supercapacitor (ZHS), the 75%-EG/RGO exhibits a much higher C s of 327.39 F g −1 at 0.1 A g −1 and can maintain 91.7% capacitance after 8000 cycles. Systematic ex situ X-ray diffraction (XRD) and X-ray photoelectron spectra (XPS) measurements reveal that the charge storage mechanism is based on both reversible physical adsorption and dual ion uptake. Furthermore, the quasi-solid-state flexible ZHS also presents high capacitive performance and can maintain ∼100% capacitance under various bending states, demonstrating potential application in wearable electronics. This strategy opens up a new path for constructing high-performance graphene film electrodes.

Advances of Nanobiomaterials for Treating Skin Pathological Fibrosis

“…Another promising avenue of research focuses on the integration of anti-inflammatory NPs made from polyphenols, such as pyrogallol, [82] tannic acid, [83] salvianolic acid, [84] and humic acid [85] into hydrogels. For example, the copper-epigallocatechin gallate (Cu-EGCG) capsules were incorporated into bio-printed dermal hydrogels for treating diabetic wounds.…”

CNT@SrTiO3 Nanocomposites Synthesized by In Situ Reaction for a High-Performance Flexible Supercapacitor

“…Thereby, the energy storage performance of flexible supercapacitor can be enhanced from these two aspects . Normally, carbon materials and their derivatives, , such as carbon gel, carbon nanotubes (CNTs), and graphene, are considered as popular flexible electrode materials due to their superior comprehensive mechanical properties and good capacitance performance . Previous studies suggest that it is appropriate to promote their specific capacitance or adjust voltage window through introducing oxygen- and nitrogen-containing functional groups on the surface of carbon materials or combining metallic oxide materials to fabricate hybrid electrodes. − For example, Prakash and Manivannan synthesized a N,B codoped graphene oxide (NB-GO) to improve the electrochemical properties of GO.…”