A Universal Strategy to Fabricate Metal Sulfides@Carbon Fibers As Freestanding and Flexible Anodes for High-Performance Lithium/Sodium Storage

Abstract

The future trend toward flexible electronics creates a demand for flexible power sources using rechargeable batteries, where freestanding and flexible electrodes are of critical importance. The utilization of high capacity anode materials like metal sulfides in flexible batteries is highly desirable for the miniaturization of electronic devices but is nevertheless very challenging in the fabrication of an electrode that is freestanding and flexible. Herein, a universal electrospinning strategy to fabricate freestanding and flexible metal sulfides@carbon electrodes is proposed based on the formation of chelate complexes between l-cysteine and metal cations. Taking SnS as a model material, flexible fiber electrodes are realized with SnS nanoparticles well embedded in the continuous and interwoven carbon fibers. As freestanding electrodes for lithium and sodium storage, a high capacity, good rate capability, and excellent cycling stability are simultaneously achieved. Such a strategy is also successfully extended to the fabrication of Ni3S2/C fibers and Fe7S8/C fibers, suggesting the universality in fabricating freestanding and flexible high capacity electrodes.

Multielectron Conversion: Peculiar Transition Metal Sulfides with Mixed Vulcanized States toward High‐Capacity Metal‐Ion Storage

“…Meanwhile, they usually exhibit high energy density, high mechanical stability, and good flexibility. In this regard, the flexible films with layered V 3 S 4 embedded in carbon nanofiber (V 3 S 4 @CNF), [ 161 ] Co 9 S 8 nanoclusters embedded in honeycomb‐like S‐doped C foam (Co 9 S 8 @SCF, Figure 15K), [ 162 ] Co 9 S 8 Ni 3 S 2 nanoparticles embedded in S‐doped C nanofiber networks (Ni 3 S 2 /Co 9 S 8 @SCNF), [ 163 ] Ni 3 S 2 or Fe 7 S 8 nanoparticles embedded in continuous and interwoven carbon fibers (Ni 3 S 2 /C or Fe 7 S 8 /C), [ 164 ] and Fe 7 S 8 microparticles well‐welded on 3D‐cross‐linked carbon networks and embedded in highly conductive rGO film (CFG, Figure 15L) [ 126 ] were designed to improve Na + /Li + storage properties.…”

Conversion‐Alloying Anode Materials for Sodium Ion Batteries

“…[35,105] For example, the free-standing SnS electrode with embedded nanoparticles in carbon nanofibers exhibits a longer life cycle and a better rate performance for sodium storage in comparison with conventional SnS electrode. [106] Free-standing configuration designs were also realized with other CA materials, such as SnS 2 nanosheets stacking on graphene. [87] This flexible free-standing electrode displayed satisfactory energy and power density, cycle life, and mechanical stability, which is a great inspiration for the future study of flexible batteries and devices.…”

Performance and future directions of transition metal sulfide‐based electrode materials towards supercapacitor/supercapattery

“…In this regard, various synthesis strategies such as hydrothermal (Zhao, Xu, et al, 2020), microwave, ball milling (Karuppannan et al, 2020), chemical layer deposition (Madito et al, 2020), atomic layer deposition (Ansari et al, 2019), electrochemical synthesis (Zhang, Cai, et al, 2018), electrodeposition (Zhao et al, 2019) have been adopted tailor the morphologies of MS to receive desired performance. In addition, research has also focused on exfoliation (Li et al, 2014;Nicolosi et al, 2013) for electrode strategy along with not so vastly reported electrospinning (Du et al, 2019). One of the prioritizing factors considered is interlayer spacing for efficient ionic transport.…”