Electrodeposited Polyaniline Nanofibers and MoO3 Nanobelts for High-Performance Asymmetric Supercapacitor with Redox Active Electrolyte.

Wei Meng,Xusheng Du,Yanlin Xia,Chuanguo Ma

doi:10.3390/polym12102303

Wei Meng, Xusheng Du + Show 2 more

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https://doi.org/10.3390/polym12102303

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Abstract

Transition molybdenum oxides (MoO3) and conductive polymer (polyaniline, PANI) nanomaterials were fabricated and asymmetric supercapacitor (ASC) was assembled with MoO3 nanobelts as negative electrode and PANI nanofibers as a positive electrode. Branched PANI nanofibers with a diameter of 100 nm were electrodeposited on Ti mesh substrate and MoO3 nanobelts with width of 30–700 nm were obtained by the hydrothermal reaction method in an autoclave. Redox active electrolyte containing 0.1 M Fe2+/3+ redox couple was adopted in order to enhance the electrochemical performance of the electrode nano-materials. As a result, the PANI electrode shows a great capacitance of 3330 F g−1 at 1 A g−1 in 0.1 M Fe2+/3+/0.5 M H2SO4 electrolyte. The as-assembled ASC achieved a great energy density of 54 Wh kg−1 at power density of 900 W kg−1. In addition, it displayed significant cycle stability and its capacitance even increased to 109% of the original value after 1000 charge–discharge cycles. The superior performance of the capacitors indicates their promising application as energy storage devices.

Highlights

As an important type of energy storage device, the super-capacitor has been widely used in many electronic devices, including the automobile braking energy recovery/release system, due to its superior power density, fast charging speed, and a wide range of working temperature
The sample morphology was observed by scanning electron microscopy (SEM; Zeiss ULTRA plus, ZEISS, Jena, Germany)
The sustainably increasing of the specific capacitance of the asymmetric supercapacitor (ASC) with the cycle number (Figure 5c) could be due to the gradually increasing extent of the infiltration of both the porous PANI nanofiber and MoO3 nanobelt electrode by the redox active electrolyte during the multi-cycling test

Summary

Introduction

As an important type of energy storage device, the super-capacitor has been widely used in many electronic devices, including the automobile braking energy recovery/release system, due to its superior power density, fast charging speed, and a wide range of working temperature. The transition metal oxides and conductive polymers are well-known electrode materials with high theoretical specific capacitance, little information regarding the utilization of them together to assemble asymmetric super-capacitor (ASC) with electrochemical redox active electrolyte is available so far. Transition metal oxide (MoO3 ) and conductive polymer (PANI) nano-materials were both fabricated and utilized as negative and positive electrodes in an ASC with redox active electrolyte, respectively. MoO3 and PANI electrode will be investigated, as well as the effect on the performance of the ASC that was assembled with them This novel all-pseudocapacitive-asymmetric design with larger operating voltage is expected to generate a higher capacitive performance and it has a prospect to bridge the gap between dielectric capacitors and rechargeable batteries [20,21]

Materials

Synthesis of MoO3 Electrode

Electrochemical Measurements

Results and Discussion

Results

Conclusions