Core–Sheath Porous Polyaniline Nanorods/Graphene Fiber-Shaped Supercapacitors with High Specific Capacitance and Rate Capability

Abstract

Fiber and/or yarn-shaped supercapacitors (FSSCs) have tremendous potential applications in portable and wearable electronics because of their light weight, good flexibility, and weavability. However, FSSCs usually show low energy density, which hinders their wide applications in wearable electronics. It remains challenging for the FSSCs to enhance their energy densities without sacrificing the flexibility and mechanical properties. Herein, we develop a chemical polymerization strategy to fabricate core–sheath porous polyaniline nanorods/graphene fibers which are used as the FSSCs electrode and show excellent electrochemical performances. The assembled polyaniline nanorods/graphene FSSCs exhibit an ultrahigh capacitance of 357.1 mF/cm2, a high energy density of 7.93 μWh/cm2 (5.7 mWh/cm3), and a power density of 0.23 mW/cm2 (167.7 mW/cm3). In addition, the FSSCs show ultralong cycling life (3.8% capacitance loss, 5000 charge–discharge tests), good rate capability (78.9% capacitance retention), and flexibility. The electrochemical performance of polyaniline nanorods/graphene FSSCs exceeds most reported hybrid FSSCs containing conducting polymers and/or metal oxide. This work may pave the way in structure design for portable and wearable energy storage devices.

2D Graphene‐Based Macroscopic Assemblies for Micro‐Supercapacitors

“…Recently, Zhang and co-workers reported ac ore-sheath MSC consisting of porous PANI nanorods/graphene fiber (PANI@GF), which gave rise to ah igh capacitance of 357.1 mF cm À2 and ag ood cycling performance of 96.2 %a fter 5000 cycles. [36] Its excellent performance resultedf rom the 1D PANI nanorods sheath being able to relieve the volumee xpansion during cycling andt he pores induced by PANI nanorods being conducive to electronic Figure 2. a) Construction of PNA/G-based MSC.…”

“…Copyright 2013,Wiley-VCH.d )CVc urves and real devices of GF@PANI MSCs bent at 08,9 0 8 and 1808.e )GCD curves of single and three MSCsc onnected in series and three MSCs powering ar ed LED. [36] Copyright 2019, American Chemical Society. transmission.…”

“…The twisted GF@3D‐G supercapacitors exhibited excellent flexibility in different bending states and could be woven into textiles as flexible devices for practical applications (Figure c). Recently, Zhang and co‐workers reported a core–sheath MSC consisting of porous PANI nanorods/graphene fiber (PANI@GF), which gave rise to a high capacitance of 357.1 mF cm −2 and a good cycling performance of 96.2 % after 5000 cycles . Its excellent performance resulted from the 1D PANI nanorods sheath being able to relieve the volume expansion during cycling and the pores induced by PANI nanorods being conducive to electronic transmission.…”

Unzipped Carbon Nanotube/Graphene Hybrid Fiber with Less “Dead Volume” for Ultrahigh Volumetric Energy Density Supercapacitors

“…Our SC shows a maximum volumetric power density of 2031.2 mW cm –3 and an energy density of 8.63 mWh cm –3 , which is comparable to lithium (Li) thin‐film battery, about 9 times higher than that of commercial AC‐SC. This energy density value is also higher than that of recently reported fiber‐based SCs (Table S1, Supporting Information), including PANI/rGO fiber, [ 16 ] MoS 2 /rGO/MWCNT fiber, [ 19 ] MXene/PEDOT:PSS fiber, [ 42 ] PEDOT/MWCNT fiber [ 43 ] and so on. Furthermore, the SC demonstrates high flexibility (Figure S11, Supporting Information) and electrochemical stability with 98.2% capacitance retention after 1000 times bending cycles with bending angle from 0° to ≈180° (Figure 6C and Figure S12: Supporting Information).…”

“…One important reason for their deteriorating performance is the irreversible agglomeration between graphene sheets caused by strong van der Waals interaction, which reduces the accessible surface area and ion diffusion rate. [9][10] In order to prevent this self-restacking problem, various materials such as carbon nanomaterials, [11][12][13][14] conductive polymers, [15][16] transition metal oxides, and hydroxides [17][18] have been introduced as spacers in graphene hybrid fibers. Although incorporation of pseudocapacitive materials into graphene fibers can greatly increase their energy density, it usually comes at the expense of power performance, rate capability and cyclability.…”