Reduced Graphene Oxide Aerogels with Functionalization-Mediated Disordered Stacking for Sodium-Ion Batteries

Abstract

Surface modified reduced graphene oxide (rGO) aerogels were synthesized using the hydrothermal method. Ethylene diamine (EDA) and α-cyclodextrin (CD) were used to functionalize the surface of the graphene oxide layers. The oxygen reduction and surface modification occurred in-situ during the hydrothermal self-assembly process. The chemical functionality and structure of the resulting ethylene diamine modified (rGO-EDA) and cyclodextrin modified (rGO-CD) aerogels as well as of the pristine unmodified rGO aerogel were studied using XPS, SEM, XRD, and SANS techniques. The overall surface composition showed a significant decrease in the oxygen content for all synthesized aerogels. The surface modified aerogels were characterized by a disordered stacking of the assembled rGO layers. The surface functionalities resulted in a broad distribution of the interlayer spacing and introduced structural heterogeneities. Such disordered structures can enable a better adsorption mechanism of the sodium ions. Coin cells based on the synthesized aerogels and sodium metal were assembled and tested at several charge and discharge rates. The correlation between the surface functionality of the rGO, the induced structural heterogeneities due to the disordered stacking, and the electrochemical performance of sodium-ion batteries were investigated. Operando XRD measurements were carried out during the battery cycling to investigate the adsorption or intercalation nature of the sodiation mechanism.

Unleashing the Potential of Sodium‐Ion Batteries: Current State and Future Directions for Sustainable Energy Storage

“…[ 297 ] Recently, surface‐modified rGO aerogels with disordered stacking were synthesized via a hydrothermal method. [ 298 ] Surface‐modified rGO in the presence of ethylene diamine and α ‐cyclodextrin (CD) delivered improved electrochemical performance. In the presence of rGO–CD, it delivered a capacity of ≈175 mAh g −1 at 0.1 C for the initial cycle, and still maintained high‐rate capacity of ≈ 60 mAh g −1 at 1 C for 100 cycles.…”

Dispersive solid‐phase extraction of risperidone from plasma samples using graphene oxide aerogels and determination with liquid chromatography

“…The porous nature of the aerogel structure is mainly caused by the spaces which were available between the layers. Due to the presence of many microribbons among the layered structures, the GO-based AGs are shaped in a porous structure [26,27]. Energy dispersive X-ray analysis showed the elemental composition of the GAGs with 48.45%, 2.49%, and 49.06% of carbon, nitrogen, and oxygen (Figure S2).…”

Electrochemical Response of 3D-Printed Free-Standing Reduced Graphene Oxide Electrode for Sodium Ion Batteries Using a Three-Electrode Glass Cell

“…For SIBs, the use of graphite and pristine graphene electrodes does not seem to produce beneficial effects on the Na + intercalation process due to the instability of Nagraphite intercalation compounds [5], and studies to modify the micro-and nanostructure of carbonaceous electrodes have recently intensified [12,13]. Indeed, it has been observed that pore size and morphology, as well as the defective/functionalized surface of reduced graphene oxide (rGO), create appropriate conditions for improving electrolyte wetting and Na adsorption-insertion [14,15]. For instance, Luo et al [16] compared the performances of rGO, CNT, graphitic microbeads, and activated carbon, finding the best response for the rGO-based electrode, achieving 220 mAh g −1 of discharge capacity at 30mA g −1 , and retaining 80% of the initial capacity after 300 cycles.…”