A Ternary Fe_1−xS@Porous Carbon Nanowires/Reduced Graphene Oxide Hybrid Film Electrode with Superior Volumetric and Gravimetric Capacities for Flexible Sodium Ion Batteries

Abstract

Smart construction of ultraflexible electrodes with superior gravimetric and volumetric capacities is still challenging yet significant for sodium ion batteries (SIBs) toward wearable electronic devices. Herein, a hybrid film made of hierarchical Fe1−xS‐filled porous carbon nanowires/reduced graphene oxide (Fe1−xS@PCNWs/rGO) is synthesized through a facile assembly and sulfuration strategy. The resultant hybrid paper exhibits high flexibility and structural stability. The multidimensional paper architecture possesses several advantages, including rendering an efficient electron/ion transport network, buffering the volume expansion of Fe1−xS nanoparticles, mitigating the dissolution of polysulfides, and enabling superior kinetics toward efficient sodium storage. When evaluated as a self‐supporting anode for SIBs, the Fe1−xS@PCNWs/rGO paper electrode exhibits remarkable reversible capacities of 573–89 mAh g−1 over 100 consecutive cycles at 0.1 A g−1 with areal mass loadings of 0.9–11.2 mg cm−2 and high volumetric capacities of 424–180 mAh cm−3 in the current density range of 0.2–5 A g−1. More competitively, a SIB based on this flexible Fe1−xS@PCNWs/rGO anode demonstrates outstanding electrochemical properties, thus highlighting its enormous potential in versatile flexible and wearable applications.

A Universal Strategy toward Ultrasmall Hollow Nanostructures with Remarkable Electrochemical Performance

“…TheS -H-Fe 2 O 3 /RGO delivered an excellent rate capability with highly reversible capacities of 1167, 1087, 1012, 936, and 701 mAh g À1 at 0.2, 0.5, 1, 2, and 5Ag À1 , respectively (Figure 5b S19) based on the following relationship: i p = av b ,w here i p and v are peak current and scan rate,r espectively,w hile aa nd b are variables,w ith the b-value determined from the slope of the plot of log i p versus log v. A b value of 0.5 indicates that the electrochemical process is diffusion-limited behavior, when b = 1.0, it indicates as urface-controlled capacitive process. [42][43][44][45][46][47] The b value of the S-H-Fe 2 O 3 /RGO was calculated to be 0.92 at scan rates from 0.1 to 2mVs À1 , which is higher than that of the L-H-Fe 2 O 3 /RGO (0.85) and the Fe 2 O 3 /RGO (0.71) (Figure 5c), demonstrating more dominant surface-controlled kinetics for the S-H-Fe 2 O 3 / RGO and in accordance with its remarkable rate performance.…”

Recent progress in graphene‐based electrodes for flexible batteries

“…In order to further increase the capacity, one effective strategy is to introduce other high‐capacity active materials into the graphene substrate. Lou's group fabricated a flexible and foldable Fe 1‐x S@PCNWs/rGO hybrid paper through a facile assembly and sulfuration strategy. As shown in Figure A, the hybrid paper could be randomly bent, rolled, twisted, and folded.…”

“…A, Digital images for the appearance and flexibility (bending, rolling, twisting, and folding) of the Fe 1‐x S@PCNWs/rGO paper. B, Digital photos of the flexible SIB lightening a LED under various states . Copyright 2019, Wiley‐VCH.…”

One‐Pot Synthesis of Sulfur and Nitrogen Co‐Functionalized Graphene Material using Deep Eutectic Solvents for Supercapacitors

“…[26] Liu et al designed and fabricated at ernary FeS@porous carbon nanowires/reducedg raphene oxide (rGO) hybrid film anode throughs caleup assembly and sulfuration methodologies. [27] Li et al reported an efficient approach exploiting biomass as the precursorf or the preparation of 3D N/O-doped carbon frameworks with pyrolysis temperatures from 500 to 800 8Cb yu sing hydrothermala nd pyrolysis/activation methods. [28] Sun et al reported methods for porous carbon materials with Na nd S doping through the use of ionic liquidsf ollowed by pyrolization and activation at highert emperatures.…”