Synergistic Interfacial Bonding in Reduced Graphene Oxide Fiber Cathodes Containing Polypyrrole@sulfur Nanospheres for Flexible Energy Storage

Abstract

Flexible lithium sulfur batteries with high energy density and good mechanical flexibility are highly desirable. Here, we report a synergistic interface bonding enhancement strategy to construct flexible fibershaped composite cathodes, in which polypyrrole@sulfur (PPy@S) nanospheres are homogeneously implanted into the built-in cavity of self-assembled reduced graphene oxide fibers (rGOFs) by a facile microfluidic assembly method. In this architecture, sulfur nanospheres and lithium polysulfides are synergistically hosted by carbon and polymer interface, which work together to provide enhanced interface chemical bonding to endow the cathode with good adsorption ability, fast reaction kinetics, and excellent mechanical flexibility. Consequently, the PPy@S/rGOFs cathode shows enhanced electrochemical performance and high-rate capability. COMSOL Multiphysics simulations and density functional theory (DFT) calculations are conducted to elucidate the enhanced electrochemical performance. In addition, a flexible LiÀ S pouch cell is assembled and delivers a high areal capacity of 5.8 mAh cm À 2 at 0.2 A g À 1 . Our work offers a new strategy for preparation of advanced cathodes for flexible batteries.

Spatially Confined Fe7S8 Nanoparticles Anchored on a Porous Nitrogen-Doped Carbon Nanosheet Skeleton for High-Rate and Durable Sodium Storage

“…51 As depicted in Figure 3E, the N 1s high-resolution spectrum reveals the presence of three contributions, which are mainly attributed to pyridinic N (397.8 eV), pyrrolic N (400.2 eV), and graphitic N (402.8 eV), respectively. 50,52 According to the integrated areas of N 1s in Figure 3E, the contents of pyridinic N and pyrrolic N are measured to be 27.7 and 62.2 atom % (Table S2), much higher than that of graphitic N (10.1 atom %). It is suggested that the introduction of high contents of pyridinic N and pyrrolic N in the carbon matrix is beneficial for creating more electroactive sites and boosting sodium storage performance.…”

Proton‐Induced Defect‐Rich Vanadium Oxides as Reversible Polysulfide Conversion Sites for High‐Performance Lithium Sulfur Batteries

“…The uniform graphene layer with tens of diameters on surface of HNVO nanobelt is beneficial for the electron transfer in charge/discharge process (Figure 1e). [46] The homogeneous distributions of C (derives from the graphene), Na, V and O elemental mapping images in Figure 1f. Such favorable morphology would contribute to the rapid kinetic reaction of charge carries.…”

Microbe‐Mediated Biosynthesis of Multidimensional Carbon‐Based Materials for Energy Storage Applications

“…Lithium-sulfur (Li-S) batteries with high theoretical capacity (1675 mAh g −1 ), high energy density (2567 Wh kg −1 ), environmental friendliness, and abundant resource of sulfur are widely applied in electronic devices and aerospace fields, etc. [214][215][216] However, several scientific and technological issues of sulfur-based cathodes impede the commercial application of Li-S batteries, including: [217][218][219] 1) Poor electron/ion conductivity of active sulfur and the produced lithium sulfide, resulting in low electrochemical reaction kinetics. 2) The high-volume expansion (80%) during the conversion process of sulfur to lithium sulfide, leading to the destruction and pulverization of the structure.…”