Polypyrrole Modified MoS2 Nanorod Composites as Durable Pseudocapacitive Anode Materials for Sodium-Ion Batteries

Abstract

As a typical two-dimensional layered metal sulfide, MoS2 has a high theoretical capacity and large layer spacing, which is beneficial for ion transport. Herein, a facile polymerization method is employed to synthesize polypyrrole (PPy) nanotubes, followed by a hydrothermal method to obtain flower-rod-shaped MoS2/PPy (FR-MoS2/PPy) composites. The FR-MoS2/PPy achieves outstanding electrochemical performance as a sodium-ion battery anode. After 60 cycles under 100 mA g−1, the FR-MoS2/PPy can maintain a capacity of 431.9 mAh g−1. As for rate performance, when the current densities range from 0.1 to 2 A g−1, the capacities only reduce from 489.7 to 363.2 mAh g−1. The excellent performance comes from a high specific surface area provided by the unique structure and the synergistic effect between the components. Additionally, the introduction of conductive PPy improves the conductivity of the material and the internal hollow structure relieves the volume expansion. In addition, kinetic calculations show that the composite material has a high sodium-ion transmission rate, and the external pseudocapacitance behavior can also significantly improve its electrochemical performance. This method provides a new idea for the development of advanced high-capacity anode materials for sodium-ion batteries.

V3S4/PPy nanocomposites with superior high-rate capability as sodium-ion battery anodes

“…Besides, the presence of the broad peak at 24.7° in the XRD patterns of VSP-1 and VSP-1.5 indicates the successful introducing of PPy. 53 For VSP-0.5, the characteristic peak of PPy is not evident, which is likely due to the relatively low PPy content in the composite.…”

Ni0.5Co0.5S nano-chains: a high-performing intercalating pseudocapacitive electrode in asymmetric supercapacitor (ASC) mode for the development of large-scale energy storage devices

“…To better understand the electrochemical characteristics of charge storage of the Ni 0.5 Co 0.5 S electrode, galvanostatic charge-discharge (GCD) studies in 4 M KOH aqueous electrolytes were performed. The electrode's specific capacitance can be determined by analysing the charge-discharge curve using eqn (13). 71,91…”

“…The calculation of the electrode's specific capacity in mA h g −1 requires the modification of eqn (13) as follows:…”

“…Due to their electronic structure and structural properties, TMSs have been extensively researched in optical, electrical and optoelectronic devices, including light-emitting diodes, solar cells, sensors and electrodes for lithium-ion batteries (LIBs). [27][28][29][30][31] Due to their low electronegativity, high specific capacitance, and superior mechanical and thermal stability compared to their analogous oxide counterparts, sulfides of transition metals, such as WS 2 , [32][33][34] FeS 2 , 35,36 MoS 2 , [13][14][15] CuS, 37,38 CoS, [39][40][41][42][43] and NiS, [44][45][46][47][48] have been extensively employed as anode materials for supercapacitors.…”

Carbonized Polymer Dots for Controlling Construction of MoS2 Flower‐Like Nanospheres to Achieve High‐Performance Li/Na Storage Devices

“…[16][17][18] Several strategies have been employed to address and alleviate the above dilemmas of MoS 2 -based materials. Among these approaches, defect engineering, involving vacancy modulation and doping engineering, has been utilized [19] along with the design of MoS 2 materials in unique nanoporous morphologies, such as nanowires, [20] nanorods, [21,22] hollow nanospheres, [23,24] nanofibers, [25,26] and nanoflowers. [27,28] Nanoflower-like porous architecture can make considerable enhancement in the electrochemical performance of MoS 2 by increasing exposed effective edge areas, which facilitates adequate contact between the MoS 2 and electrolytes, mitigate issues like pulverization and aggregation, and allow for volume strain accommodation.…”