3D hierarchical Co3O4@Co3S4 nanoarrays as cathode materials for asymmetric pseudocapacitors

Author(s): Bo Liu ¹ ^, ² ^, ³ , Dezhi Kong ¹ ^, ² ^, ³ ^, ⁴ ^, ⁵ , Jun Zhang ⁶ ^, ⁷ ^, ⁸ ^, ³ , Ye Wang ¹ ^, ² ^, ³ , Tupei Chen ⁶ ^, ⁷ ^, ⁸ ^, ³ , Chuanwei Cheng ⁴ ^, ⁵ ^, ⁹ ^, ¹⁰ ^, ¹¹ , Hui Ying Yang ¹ ^, ² ^, ³

Publication date (Electronic): 2016

Journal: Journal of Materials Chemistry A

Publisher: Royal Society of Chemistry (RSC)

Read this article at

ScienceOpenPublisher

Bookmark

There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

Abstract

A Co ₃O ₄@Co ₃S ₄ nanoarray electrode is designed by a facile solution synthesis approach and investigated as a cathode material for an ASC.

Abstract

Three-dimensional (3D) hierarchical Co ₃O ₄@Co ₃S ₄ nanoarrays (NAs) were synthesized via a stepwise hydrothermal method involving precipitation and in situ sulfurization of Co ₃O ₄ nanoneedle arrays (NNAs). By controlling both anion exchange and Ostwald ripening reactions during the sulfurization process, 3D hierarchical Co ₃O ₄@Co ₃S ₄ NAs with tailored Co ₃S ₄ nanostructures have been fabricated as electrode materials for electrochemical capacitor applications. Owing to an interconnected matrix within the 3D architecture, the as-prepared Co ₃O ₄@Co ₃S ₄ NAs exhibit excellent electrical conductivity, high specific capacity and high cycling stability. It can deliver a high capacitance of 1284.3 F g ⁻¹ at 2 mV s ⁻¹ and maintain a capacitance retention of 93.1% after 5000 cycles. Moreover, a flexible solid-state asymmetric supercapacitor (ASC) composed of Co ₃O ₄@Co ₃S ₄ NAs as the positive electrode and activated carbon (AC) as the negative electrode exhibited an energy density of 1.5 mW h cm ⁻³ and a power density of 6.1 W cm ⁻³ at a high operating voltage of 1.6 V. Our results not only present the 3D hierarchical nanostructure of Co ₃O ₄@Co ₃S ₄ NAs, but they also demonstrate the potential of electrodes for future generation supercapacitors.

Related collections

Most cited references 40

Record: found
Abstract: found
Article: not found

Laser scribing of high-performance and flexible graphene-based electrochemical capacitors.

Maher F El-Kady, Veronica A. Strong, Sergey Dubin … (2012)

Although electrochemical capacitors (ECs), also known as supercapacitors or ultracapacitors, charge and discharge faster than batteries, they are still limited by low energy densities and slow rate capabilities. We used a standard LightScribe DVD optical drive to do the direct laser reduction of graphite oxide films to graphene. The produced films are mechanically robust, show high electrical conductivity (1738 siemens per meter) and specific surface area (1520 square meters per gram), and can thus be used directly as EC electrodes without the need for binders or current collectors, as is the case for conventional ECs. Devices made with these electrodes exhibit ultrahigh energy density values in different electrolytes while maintaining the high power density and excellent cycle stability of ECs. Moreover, these ECs maintain excellent electrochemical attributes under high mechanical stress and thus hold promise for high-power, flexible electronics.