Mesoporous Transition Metal Oxides for Supercapacitors.

Junfeng Shao,Yan Wang,Tingfeng Wang,Ying-Wei Yang,Jin Guo,Dong Wang

doi:10.3390/nano5041667

Abstract

Recently, transition metal oxides, such as ruthenium oxide (RuO2), manganese dioxide (MnO2), nickel oxides (NiO) and cobalt oxide (Co3O4), have been widely investigated as electrode materials for pseudo-capacitors. In particular, these metal oxides with mesoporous structures have become very hot nanomaterials in the field of supercapacitors owing to their large specific surface areas and suitable pore size distributions. The high specific capacities of these mesoporous metal oxides are resulted from the effective contacts between electrode materials and electrolytes as well as fast transportation of ions and electrons in the bulk of electrode and at the interface of electrode and electrolyte. During the past decade, many achievements on mesoporous transition metal oxides have been made. In this mini-review, we select several typical nanomaterials, such as RuO2, MnO2, NiO, Co3O4 and nickel cobaltite (NiCo2O4), and briefly summarize the recent research progress of these mesoporous transition metal oxides-based electrodes in the field of supercapacitors.

Highlights

Energy crisis and environmental pollution have triggered the development of clean and renewable energy storage systems
50 times lower than lithium ion batteries supercapacitors with a near unlimited cycle life are useful in the fields of power system, memory storage, and vehicle assistant equipment (Figure 1)
Based on the principle of energy storage, supercapacitors can be classified into electric double layer capacitors (EDLCs) and pseudo-capacitors [4]

Summary

Introduction

Energy crisis and environmental pollution have triggered the development of clean and renewable energy storage systems. Supercapacitors possess higher specific capacity and specific energy They exhibit higher specific power, shorter charging time, more efficient discharging than batteries, and they cause no pollution in the environment [3]. EDLCs store charges using the very thin double layer structure formed at the interface between electrode and electrolyte, while pseudo-capacitors use fast and reversible redox reactions on the surface and bulk near the surface of electrodes for energy storage. Nickel cobaltite (NiCo2O4) exhibits high capacitance values at short charge-discharge times recently, and redox behaviors of both nickel and cobalt are involved in energy storage [21,22]. We briefly summarize the recent progress on these mesoporous transition metal oxide-based electrodes in the field of supercapacitors

Transition Metal Oxides for Pseudo-Capacitors

Findings

Conclusions