26 March 2009 | Donghai Wang, Daiwon Choi, Juan Li, Zhenguo Yang, Zimin Nie, Rong Kou, Dehong Hu, Chongmin Wang, Laxmikant V. Saraf, Jiguang Zhang, Ilhan A. Aksay, and Jun Liu
This article presents a study on self-assembled TiO₂-graphene hybrid nanostructures for enhanced Li-ion insertion. The researchers used anionic sulfate surfactants to stabilize graphene in aqueous solutions and facilitate the self-assembly of in situ grown nanocrystalline TiO₂ with graphene. The resulting hybrid materials showed significantly enhanced Li-ion insertion/extraction in TiO₂. The specific capacity was more than doubled at high charge rates compared to pure TiO₂. The improved capacity at high charge-discharge rates is attributed to increased electrode conductivity due to a percolated graphene network embedded in the metal oxide electrodes.
The study demonstrates that functionalized graphene sheets can serve as an effective conductive additive for hybrid nanostructured electrodes. The hybrid nanostructures were synthesized using a one-step approach, where reduced and highly conductive graphene is hydrophobic and oxides are hydrophilic. The use of surfactants not only solves the hydrophobic/hydrophilic incompatibility problem but also provides a molecular template for controlled nucleation and growth of the nanostructured inorganics.
The hybrid nanostructures were characterized using various techniques, including TEM, SEM, XRD, and Raman spectroscopy. The results showed that the hybrid nanostructures have a well-defined morphology and crystalline structure. The Li-ion insertion/extraction properties of the hybrid nanostructures were investigated, and the results showed that the hybrid materials exhibit enhanced Li-ion insertion/extraction kinetics, especially at high charge/discharge rates.
The study also compared the performance of the hybrid nanostructures with other materials, such as TiO₂-CNT hybrids and LiFePO₄-RuO₂ nanocomposites. The results showed that the hybrid nanostructures outperformed these materials in terms of specific capacity and cycling performance. The high rate performance of the hybrid nanostructures is attributed to the increased conductivity of the hybrid materials, although the synergistic effect on electron and Li ion transport needs further study.
The study concludes that functionalized graphene sheets are a promising conductive additive for Li-ion battery electrode materials. The self-assembly approach discussed in the study can be applied to other metal oxide-graphene hybrid nanostructures to study synergetic properties and improve the performance of oxide electrodes in electrochemical energy storage and conversion. The results suggest that the hybrid nanostructures have potential for large-scale applications in energy storage due to their high surface area, low cost, and high conductivity.This article presents a study on self-assembled TiO₂-graphene hybrid nanostructures for enhanced Li-ion insertion. The researchers used anionic sulfate surfactants to stabilize graphene in aqueous solutions and facilitate the self-assembly of in situ grown nanocrystalline TiO₂ with graphene. The resulting hybrid materials showed significantly enhanced Li-ion insertion/extraction in TiO₂. The specific capacity was more than doubled at high charge rates compared to pure TiO₂. The improved capacity at high charge-discharge rates is attributed to increased electrode conductivity due to a percolated graphene network embedded in the metal oxide electrodes.
The study demonstrates that functionalized graphene sheets can serve as an effective conductive additive for hybrid nanostructured electrodes. The hybrid nanostructures were synthesized using a one-step approach, where reduced and highly conductive graphene is hydrophobic and oxides are hydrophilic. The use of surfactants not only solves the hydrophobic/hydrophilic incompatibility problem but also provides a molecular template for controlled nucleation and growth of the nanostructured inorganics.
The hybrid nanostructures were characterized using various techniques, including TEM, SEM, XRD, and Raman spectroscopy. The results showed that the hybrid nanostructures have a well-defined morphology and crystalline structure. The Li-ion insertion/extraction properties of the hybrid nanostructures were investigated, and the results showed that the hybrid materials exhibit enhanced Li-ion insertion/extraction kinetics, especially at high charge/discharge rates.
The study also compared the performance of the hybrid nanostructures with other materials, such as TiO₂-CNT hybrids and LiFePO₄-RuO₂ nanocomposites. The results showed that the hybrid nanostructures outperformed these materials in terms of specific capacity and cycling performance. The high rate performance of the hybrid nanostructures is attributed to the increased conductivity of the hybrid materials, although the synergistic effect on electron and Li ion transport needs further study.
The study concludes that functionalized graphene sheets are a promising conductive additive for Li-ion battery electrode materials. The self-assembly approach discussed in the study can be applied to other metal oxide-graphene hybrid nanostructures to study synergetic properties and improve the performance of oxide electrodes in electrochemical energy storage and conversion. The results suggest that the hybrid nanostructures have potential for large-scale applications in energy storage due to their high surface area, low cost, and high conductivity.