Enhanced cycling stability and rate capability of a graphene-supported commercialized Vat Blue 4 anode for advanced Li-ion batteries

Design of Linear-Polymer-Coated Graphene Nanosheets with π-Conjugated Structure and Multi-Active-Center for Long-Lifespan and High-Rate Li-Storage Performance

Organic material holds immense potential for Li-ion batteries (LIBs) due to their eco-friendly nature, high structural designability, abundant sources, and high theoretical capacity. However, the limited redox-active sites, low electronic conductivity, sluggish ionic diffusion, and high solubility hinder their practical application. Here, we reported the use of a linear polymer called poly(naphthalenetetracarboxylic dianhydride-pyrene-4,5,9,10-tetraone)-coated graphene nanosheets (NPT/rGO) as a cathode material for LIBs. The NPT polymer has a rotation angle of approximately 63° between each plane, which helps in exposing the active sites and preventing structural pulverization during cycling. The highly conjugated skeleton of the polymer, along with graphene, forms a synergistic effect through a π-π interaction. This combination enhances the conductivity and restricts solubility. Additionally, the linear structure of NPT and the two-dimensional rGO substrates work together to enhance charge transfer and ion diffusion rates, resulting in faster reaction kinetics. Consequently, NPT/rGO exhibits excellent electrochemical performance in terms of high capacity, superior cyclic stability, and good rate capability for LIBs. Moreover, through the combination of experimental investigations and theoretical simulations, a multiple electron reaction mechanism, an efficient Li-ion storage behavior, and a reversible dynamic evolution have been revealed. This study introduces a rational molecular design approach to enhance the electrochemical performance of polyimide derivatives, thereby contributing to the advancement of cutting-edge organic electrode materials for LIBs.

Recent progress in graphene and its derived hybrid materials for high-performance supercapacitor electrode applications

Graphene, the most fascinating 2D form of carbon with closely packed carbon atoms arranged in a layer, needs more attention in various fields. For its unique electrical, mechanical, and chemical properties with a large surface area, graphene has been in the limelight since its first report. Graphene has extraordinary properties, making it the most promising electrode component for applications in supercapacitors. However, the persistent re-stacking of carbon layers in graphene, caused by firm interlayer van der Waals attractions, significantly impairs the performance of supercapacitors. As a result, many strategies have been used to get around the aforementioned problems. The utilization of graphene-based nanomaterials has been implemented to surmount the aforementioned constraints and considerably enhance the performance of supercapacitors. This review highlights recent progress in graphene-based nanomaterials with metal oxide, sulfides, phosphides, nitrides, carbides, and conducting polymers, focusing on their synthetic approach, configurations, and electrochemical properties for supercapacitors. It discusses new possibilities that could increase the performance of next-generation supercapacitors.