Investigation of Modified Graphene for Energy Storage Applications

Abstract

Lithium-ion batteries (LIB) have been receiving extensive attention because of the high specific energy density for wide applications such as electronic vehicles, commercial mobile electronics, and military applications. In LIB, graphite is the most commonly used anode material; however, lithium-ion intercalation in graphite is limited, hindering the battery charge rate and capacity. To overcome this obstacle, nanostructured anode assembly has been extensively studied to increase the lithium-ion diffusion rate. Among these approaches, high specific surface area metal oxide nanowires connecting nanostructured carbon materials accumulation have shown propitious results for enhanced lithium intercalation. Recently, nanowire/graphene hybrids were developed for the enhancement of LIB performance; however, almost all previous efforts employed nanowires on graphene in a random fashion, which limited lithium-ion diffusion rate. Therefore, we demonstrate a new approach by hydrothermally growing uniform nanowires on graphene aerogel to further improve the performance. This nanowire/graphene aerogel hybrid not only uses the high surface area of the graphene aerogel but also increases the specific surface area for electrode-electrolyte interaction. Therefore, this new nanowire/graphene aerogel hybrid anode material could enhance the specific capacity and charge-discharge rate. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) are used for materials characterization. Battery analyzer and potentio-galvanostat are used for measuring the electrical performance of the battery. The testing results show that nanowire graphene hybrid anode gives significantly improved performance compared to graphene anode.

Attenuation of the in vitro neurotoxicity of 316L SS by graphene oxide surface coating

“…The measured values of hardness and elastic modulus of GO coating were higher than the hardness and elastic modulus of other common implant coatings on 316L SS (71, 72, 75). Substrate hardness plays an important role in the determination of the wear and tear properties of a material and generally, a higher hardness indicates a lower wear rate (76).…”

“…FTIR spectra analysis revealed the structure and functional groups of the in-house synthesized GO (71, 72) (Figure 2A). The spectrum showed the presence of C=O stretching vibration centred at 1728 cm −1 , graphene sheet aromatic C=C stretching vibration at 1622 cm −1 , broad O–H stretching at 3400 cm −1 , C-OH bending at 1368 cm −1 , C-O stretching at 1045 cm −1 and C–OH stretching at 1222 cm −1 .…”

“…In addition to GO, the presence of reduced GO could be related to the in-house synthesis of GO which involved the oxidation of graphite (71, 72). In the case of GO coating, the peak corresponding to GO was of highest intensity among the other phases.…”

Crystal structure, dielectric, ferroelectric and energy storage properties of La-doped BaTiO3 semiconducting ceramics

“…The energy density of dielectric capacitors is typically much lower than high specific energy electrochemical super capacitors, which is limiting their usage in device applications. [20][21][22] One realistic problem with ceramic capacitors is their low breakdown strength (BDS) and that the nonlinear permittivity rapidly drops with an increase in the electric field, which is detrimental to applications. There is an increasing demand to improve the energy density of dielectric capacitors for satisfying next generation material systems.…”

Multifunctional composites for energy storage

“…The clean carbon cloth was taken on a glass petri dish to soak in the nanoparticle solution for 10 minutes and subsequently annealed on a hot plate at 150 °C for 10 minutes to enhance adhesion between the substrates and nanoparticles. This soaking and annealing was repeated two more times to ensure the mass coating of ZnO nanoparticle all over the carbon fibers [33,39].…”