C–S@PANI composite with a polymer spherical network structure for high performance lithium–sulfur batteries

Abstract

A unique C-S@PANI composite with a conductive polymer spherical network (PSN) has been successfully designed and synthesized by a simple processing approach. The PSN framework is formed at the surface of the oxidized carbon black by conductive polymer self-assembly and grafting, followed by pouring elemental sulfur into the pores of the polymer matrix. As the cathode material for lithium-sulfur batteries, the C-S@PANI composite delivered a high specific capacity of 1453 mA h g(-1) at a 0.1 C current rate and a stable cycling performance of 948 mA h g(-1) after 200 cycles. The composite also demonstrated high capacities of 922 and 581 mA h g(-1) at 50 °C and 0 °C, respectively, after 200 cycles. The conductive PANI coatings were connected with the C-S core-shell composites to form a three-dimensional conducting network, which improves the utilization of the active mass and dual conduction of Li(+) and electrons, while at the same time encapsulating sulfur into the PANI hollow spherical network. The structure effectively inhibits the dissolution and migration of polysulfides into the electrolyte, while improving the cycling stability and the coulombic efficiency of the electrode at high current rates, especially the low temperature electrochemical properties of Li-S batteries.

Performance Enhancement of a Sulfur/Carbon Cathode by Polydopamine as an Efficient Shell for High‐Performance Lithium–Sulfur Batteries

“…[14,48] The peak at 1650 cm À1 is assigned to the stretching vibration of C=Og enerated from the oxidization reactions of catechol groups in DA molecules. [31,39] The surface composition of S/C@pDA composites is investigated by X-ray photoelectron spectroscopy (XPS)a nalysis. The survey scan spectrum demonstrates the existence of C, S, N and Oi nt he S/C@pDA composites (Figure 3d), consistent with the EDS analysis.…”

“…porous carbon, carbon black, carbonn anofibers, carbon nanotubes and graphene), [24][25][26][27][28] and conductive polymers (e.g. polyethylene oxide, polypyrrole,a nd polyaniline) [29][30][31] are frequently employed as hosts for sulfur cathodes. As an example, Ji et al used hierarchical porousc arbonC MK-3 as the sulfur carrier, which not only supplies stable nanosized electrochemical reaction chambers, but also offersf ast electronic channelf or active material.…”

The use of polymers in Li‐S batteries: A review

“…Polymers have also been introduced to composite cathodes as a supplement to the formal polymer binder to modify the interface between the carbon and sulfur constituents and/or act as polysulfide hosts during battery operation . Conjugated polymers have been the focus of many examples implementing this strategy . An initial report by Yu et al demonstrated the use of poly(pyrrole) (PPy) nanowires as sulfur hosts.…”

Dual confinement of sulphur with rGO-wrapped microporous carbon from β-cyclodextrin nanosponges as a cathode material for Li–S batteries

“…Others reported ball mixing, melt infusion, and vapour phase diffusion to achieve homogenous impregnation of sulphur into the pores [5,8,10]. Wrapping of carbon sulphur composites in various conductive polymers such as polyaniline and in conductive carbon matrices as graphene sheets was also realized with some success [19,26,27]. A promising strategy for the development of high-performance Li-S batteries relies on both S8 and S2-4 incorporation.…”