Binary MnO₂/Co₃O₄Metal Oxides Wrapped on Superaligned Electrospun Carbon Nanofibers as Binder Free Supercapacitor Electrodes

Abstract

Increasing the performance of energy storage systems using different metal oxides and carbon nanomaterial as support scaffolds in electrode manufacture is of great importance. However, deposition of active material using binders or conductive agents results in reduced effective contact areas in the electrodes and between the electrolytes, lowering the energy storage capacity. In this work, a homogeneous and stable low current electrodeposition of binary metal oxides MnO2/Co3O4 on superaligned electrospun carbon nanofibers (SA-ECNFs) greatly overcomes these shortcomings. The morphology tests revealed that the manganese oxide (MnO2) and cobalt oxide (Co3O4) were uniformly wrapped around the carbon nanofibers to form a porous morphology, rendering high energy storage capacity from both the pseudocapacitance and electrochemical double layer (ECDL). Electrochemical tests indicated that the as-prepared MnO2/Co3O4@SA-ECNFs electrode displays a specific capacitance of 728 F g–1 in 6 M KOH electrolyte in CV vs 622 F g–1 of MnO2@SA-ECNFs electrode at 5 mV s–1. The performance of galvanic charge–discharge (GCD) at 2 A g–1 of the electrode demonstrated 64.5 Wh kg–1 for energy density and 1276 W kg–1 for power density and a capacity retention of 71.8% over 11 000 cycles.

Nanoarchitectured transition metal oxides and their composites for supercapacitors

“…fabricated binder‐free bimetallic oxide composite. [ 204 ] δ‐MnO 2 /Co 3 O 4 metal oxide composites were deposited on super‐aligned electrospun carbon nanofibers (SA‐ECNFs) by low‐current slow electrodeposition method. δ‐MnO 2 /Co 3 O 4 @SA‐ECNFs exhibited a specific capacitance of 728 F/g whereas δ‐MnO 2 @ SA‐ECNFs could achieve only 622 F/g at a scan rate of 5 mV/s in 6 M KOH electrolyte.…”

Carbon Nanofibers as Potential Catalyst Support for Fuel Cell Cathodes: A Review

“…Among all carbon supports, graphitic carbon nanofibers (GNFs), sometimes also termed as carbon nanofibers (CNFs), have received great attention as catalyst support material due to (i) their unique fibrous structure, (ii) their highly graphitic nature, (iii) the unique interaction of the deposited metal nanoparticles with the nanofiber surface, (iv) the attainment of specific crystallographic orientation of supported metal nanoparticles, (v) their excellent electronic conducting properties, and (vi) the lower susceptibility of the deposited nanoparticles toward CO poisoning, in comparison with traditional catalyst systems. − The carbon nanofibers are synthesized by the two most popular synthesis methods: (i) chemical vapor deposition (CVD) , and (ii) electrospinning. − The nanofibers synthesized by these two methods differ in many ways, including morphology, graphitization, electrical conductivity, graphene layer arrangement, and synthesis conditions themselves. Hence, this Review is limited to the nanofibers synthesized by the CVD method.…”

Advances and Perspectives for the Application of Perovskite Oxides in Supercapacitors

“…One approach is to apply or press the active material directly onto the substrate (e.g., carbon cloth or nickle foam) using a binder. This has a tendency to increase the interfacial resistance of the material . The other approach is to combine perovskite oxide with a flexible substrate by a suitable anchoring process, like other metal oxides .…”

“…This has a tendency to increase the interfacial resistance of the material. 149 The other approach is to combine perovskite oxide with a flexible substrate by a suitable anchoring process, like other metal oxides. 150 Some 3D flexible substrates can be chosen as the substrate, e.g., carbon aerogel.…”