Calcination

Catalysis

Engineering

Capacitance

Mesoporous material

Electrochemistry

Materials science

Layer (electronics)

Etching (microfabrication)

Chemical engineering

Food science

Porosity

Physical chemistry

Supercapacitor

Nanotechnology

Organic chemistry

Composite material

Chemistry

Electrode

Yolk

Applied Surface Science

A simple etching and calcination strategy is developed for achieving NiCo 2 O 4 /MnCo 2 O 4 yolk-shelled hollow structure (YSHS), which perform excellent electrochemical performance in supercapacitors. • NiCo 2 O 4 /MnCo 2 O 4 yolk-shelled hollow structure is synthesized via etching and calcination route. • The synthesized NiCo 2 O 4 /MnCo 2 O 4 performs excellent performance in supercapacitors. • A solid-state asymmetric supercapacitor configured by NiCo 2 O 4 /MnCo 2 O 4 exhibits desired performance. Rational construct the micro architecture of electrode materials is verified as a feasible strategy for advancing the performance. Herein, controllable design of NiCo 2 O 4 /MnCo 2 O 4 yolk-shelled hollow sphere from Ni-Mn-Co glycerate is presented via etching and calcination methods. For comparison, utilizing the Ni-Mn-Co glycerate, NiCo 2 O 4 /MnCo 2 O 4 hollow and solid sphere are also achieved. Due to its distinctive textural with high surface area and mesoporous, the NiCo 2 O 4 /MnCo 2 O 4 yolk-shelled hollow sphere possesses a large specific capacitance (1636 F g -1 at 4.0 A g -1 ) and cycling durability (10% reduction over 6000 cycles at 15 A g -1 ) in comparison with hollow and solid structures. In-depth evaluating the practical application for supercapacitor, a solid-state asymmetric supercapacitor is designed with NiCo 2 O 4 /MnCo 2 O 4 yolk-shelled hollow sphere and active carbon. An energy density of 62.8 Wh kg -1 is obtained at 1650.4 W kg -1 , while retaining 23.2 Wh kg -1 even in larger 12367.7 W kg -1 . These results reveal that the NiCo 2 O 4 /MnCo 2 O 4 yolk-shelled hollow sphere is a promotion material for supercapacitor. This work is expected to be promoted the synthesis of hollow structured hybrid ternary oxides, which are regard as latent candidates for energy storage.

Designed synthesis of yolk-shelled NiCo2O4/MnCo2O4 hollow sphere with boosted performance for supercapacitors