Flexible asymmetric supercapacitors based on ultrathin two-dimensional nanosheets with outstanding electrochemical performance and aesthetic property

Shan Shi,Yanyi Chen,Cheng Yang,Juanjuan Liu,Chengjun Xu,Feiyu Kang

doi:10.1038/srep02598

Abstract

Flexible asymmetric supercapacitors with excellent electrochemical performance and aesthetic property are realized by using ultrathin two-dimensional (2D) MnO2 and graphene nanosheets as cathode and anode materials, respectively. 2D MnO2 nanosheets (MSs) with a thickness of ca. 2 nm are synthesized with a soft template method for the first time, which achieve a high specific capacitance of 774 F g−1 even after 10000 cycles. Asymmetric supercapacitors based on ultrathin MSs and graphene exhibit a very high energy density up to 97.2 Wh kg−1 with no more than 3% capacitance loss after 10000 cycles in aqueous electrolyte. Most interestingly, we show that the energy storage device can have an aesthetic property. For instance, a “Chinese panda” supercapacitor is capable of lighting up a red light emitting diode. This work has another, quite different aspect that a supercapacitor is no longer a cold industry product, but could have the meaning of art.

Highlights

Flexible asymmetric supercapacitors with excellent electrochemical performance and aesthetic property are realized by using ultrathin two-dimensional (2D) MnO2 and graphene nanosheets as cathode and anode materials, respectively. 2D MnO2 nanosheets (MSs) with a thickness of ca. 2 nm are synthesized with a soft template method for the first time, which achieve a high specific capacitance of 774 F g21 even after 10000 cycles
We show that the energy storage device can have an aesthetic property
In such G phase, there are alternately extended aqueous and organic lamellae. The thickness of these lamellae is about several nanometers. The inorganic salts such as KMnO4 can be dissolved mainly within the aqueous region, which indicates a binary liquid lamellar structure consisting of surfactant AOT and KMnO4 aqueous solution

Summary

Introduction

Flexible asymmetric supercapacitors with excellent electrochemical performance and aesthetic property are realized by using ultrathin two-dimensional (2D) MnO2 and graphene nanosheets as cathode and anode materials, respectively. 2D MnO2 nanosheets (MSs) with a thickness of ca. 2 nm are synthesized with a soft template method for the first time, which achieve a high specific capacitance of 774 F g21 even after 10000 cycles. Flexible asymmetric supercapacitors using the ultrathin 2D MSs and graphene in aqueous Ca(NO3)2-SiO2 gel electrolyte realized excellent electrochemical performance (such as an energy density up to 97.2 Wh kg[21] much higher than traditional MnO2 based supercapacitor and no more than 3% capacitance loss even after 10000 cycles). Most interestingly, these supercapacitors can be designed to show desirably aesthetic property, for example letters, words and patterns. Quite different aspect that a battery or supercapacitor is no longer a cold industry product, but could have the meaning of art

Methods

Results

Conclusion