Co3O4 Supraparticle-Based Bubble Nanofiber and Bubble Nanosheet with Remarkable Electrochemical Performance.

Jun Huang,Yiwang Chen,Kai Yuan,Zhongyou Peng,Yazhou Xu,Yingbo Xiao,Longbin Li,Licheng Tan

doi:10.1002/advs.201900107

Jun Huang, Yiwang Chen + Show 6 more

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https://doi.org/10.1002/advs.201900107

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Abstract

Hollow nanostructures based on transition metal oxides (TMOs) with high surface‐to‐volumetric ratio, low density, and high loading capacity have received great attention for energy‐related applications. However, the controllable fabrication of hybrid TMO‐based hollow nanostructures in a simple and scalable manner remains challenging. Herein, a simple and scalable strategy is used to prepare hierarchical carbon nanofiber (CNF)‐based bubble‐nanofiber‐structured and reduced graphene oxide (RGO)‐based bubble‐nanosheet‐structured Co3O4 hollow supraparticle (HSP) composites (denoted as CNF/HSP‐Co3O4 and RGO/HSP‐Co3O4, respectively) by solution self‐assembly of ultrasmall Co3O4 nanoparticles (NPs) assisting with polydopamine (PDA) modification. It is proved that the electrochemical performance of Co3O4 NPs can be greatly enhanced by the rationally designed nanostructure of bubble‐like supraparticles combined with carbon materials as excellent electrodes for supercapacitors. The favorable structure and composition endow the hybrid electrode with high specific capacitance (1435 F g−1/1360 F g−1 at 1 A g−1/5 mV s−1) as well as fantastic rate capability. The asymmetric supercapacitors achieve an excellent maximum energy density of 51 W h kg−1 and superb electrochemical stability (92.3% retention after 10 000 cycles). This work suggests that the rational design of electrode materials with bubble‐like superstructures provides an opportunity for achieving high‐performance electrode materials for advanced energy storage devices.

Highlights

Hollow nanostructures based on transition metal oxides (TMOs) with devices are urgently needed.[1–3] Supercapacitors (SCs), which can shorten the high surface-to-volumetric ratio, low density, and high loading capacity big gap of power density and energy have received great attention for energy-related applications
A simple and scalable synthesis strategy has been developed for controllable fabrication of hierarchical bubblenanofiber-structured and bubble-nanosheet-structured Co3O4 supraparticle composites
The as-fabricated reduced graphene oxide (RGO)/hollow supraparticle (HSP)-Co3O4 electrode delivered high specific capacitance (1435 F g−1/1360 F g−1 at 1 A g−1/5 mV s−1), excellent rate capability (833 F g−1/786 F g−1 at 60 A g−1/200 mV s−1), and remarkable cycling stability (94.3% retention after 10 000 cycles at 10 A g−1)

Summary

Introduction

Hollow nanostructures based on transition metal oxides (TMOs) with devices are urgently needed.[1–3] Supercapacitors (SCs), which can shorten the high surface-to-volumetric ratio, low density, and high loading capacity big gap of power density and energy have received great attention for energy-related applications. As we expected, synthesizing hollow supraparticles by connecting with highly conductive materials has proved to be an efficient strategy for significantly improving the energy storage performance of Co3O4 NPs. the as-prepared reduced graphene oxide (RGO)/hollow supraparticle (HSP)Co3O4 (bubble-nanosheet-structured Co3O4 supraparticle) electrode delivers a high specific capacitance of 1435 F g−1 at a current density of 1 A g−1 and retain 833 F g−1 even at 60 A g−1 as well as high electrochemical stability, which is higher than most reported Co3O4-based electrodes. Www.advancedscience.com on PDA-modified CNF were prepared, and undoubtedly, a very thin carbon layer coated an individual ultrasmall Co3O4 NP (Figure S4, Supporting Information).

Results

Conclusion