Synthesis of petaloid and origami-lantern shaped MnO2/Co2CH@C hierarchical core-shell nanorod arrays for portable asymmetric supercapacitor

Freestanding electrodes fabricated with hierarchical core-shell micro-/nano-structured materials synthesized from redox-type metal oxides show enormous potential for portable electronic devices. In this, a novel and facile strategy for the preparation of petaloid and origami-lantern shaped MnO2/Co2CH@C hierarchical porous coreshell nanorod arrays is proposed. The fabricated electrode based on MnO2/Co2CH@C hybrid composite exhibits superior capability of 2022 mF cm-2 under high current density of 5 mA cm-2, which can be explained by the well-oriented petal-like and origami-lantern shaped nanosheets as well as the 3D core-shell porous hierarchical structure. Additionally, a solid-state asymmetric supercapacitor equipment is assembled on basis of the synthesized hierarchical MnO2/Co2CH@C hybrid, exhibiting an energy density of 15 Wh kg-1 at the power density of 255 W kg- 1. Notably, the multifunctional instrument can be operated by the assembled device for 8 min, while monitoring time, temperature and air humidity in a portable outdoor environment. Moreover, a blue indicator can also be operated for 9 min long, evidencing their potential commercial applications. Overall, this work demonstrates the promising potential of the synthesized novel origami-lantern shaped and highly oriented hierarchical composites for electrochemical energy storage applications.

Automated summary

Freestanding electrodes made from hierarchical core-shell micro/nanostructured materials synthesized from redox-type metal oxides demonstrate great potential for portable electronic devices. The electrodes, based on petaloid and origami-lantern shaped nanosheets and 3D core-shell porous hierarchical structures, exhibit superior capability and energy density, showing promise for commercial applications in electrochemical energy storage.