Recent Developments of Transition Metal Compounds-Carbon Hybrid Electrodes for High Energy/Power Supercapacitors

Abstract

Due to their rapid power delivery, fast charging, and long cycle life, supercapacitors have become an important energy storage technology recently. However, to meet the continuously increasing demands in the fields of portable electronics, transportation, and future robotic technologies, supercapacitors with higher energy densities without sacrificing high power densities and cycle stabilities are still challenged. Transition metal compounds (TMCs) possessing high theoretical capacitance are always used as electrode materials to improve the energy densities of supercapacitors. However, the power densities and cycle lives of such TMCs-based electrodes are still inferior due to their low intrinsic conductivity and large volume expansion during the charge/discharge process, which greatly impede their large-scale applications. Most recently, the ideal integrating of TMCs and conductive carbon skeletons is considered as an effective solution to solve the above challenges. Herein, we summarize the recent developments of TMCs/carbon hybrid electrodes which exhibit both high energy/power densities from the aspects of structural design strategies, including conductive carbon skeleton, interface engineering, and electronic structure. Furthermore, the remaining challenges and future perspectives are also highlighted so as to provide strategies for the high energy/power TMCs/carbon-based supercapacitors.

A Better Zn-Ion Storage Device: Recent Progress for Zn-Ion Hybrid Supercapacitors

“…TMCs electrode materials such as transition metal oxides (TMOs), nitrides (TMNs), hydroxides and sulfides have been widely investigated in the metal-ion batteries and capacitors on account of their outstanding characteristics like multiple metal valences, high theoretical capacitance, abundant natural source and diversiform synthetic methods [161,162]. Hydrous RuO 2 •H 2 O, as the first demonstrated pseudocapacitive materials, have been used as the advanced Cap electrode materials in many ESSs [163,164] Benefiting from the high conductivity (> 100 S cm −1 ) and abundant surface redox reactions of hydrous RuO 2 •H 2 O, the assembled Zn//RuO 2 •H 2 O ZHSCs enabled ultra-fast Zn-ion storage speed and presented splendid energy density of 119 Wh kg −1 with a voltage window of 0.4-1.6 V. Particularly, it still kept a high energy density of 82 Wh kg −1 under an ultra-high power output of 16,740 W kg −1 .…”

“…TMCs electrode materials such as transition metal oxides (TMOs), nitrides (TMNs), hydroxides and sulfides have been widely investigated in the metal-ion batteries and capacitors on account of their outstanding characteristics like multiple metal valences, high theoretical capacitance, abundant natural source and diversiform synthetic methods [ 161 , 162 ]. Hydrous RuO 2 ·H 2 O, as the first demonstrated pseudocapacitive materials, have been used as the advanced Cap electrode materials in many ESSs [ 163 , 164 ].…”

Supercapacitor performances of titanium–polymeric nanocomposites: a review study

“…TiO 2 is one of the most important redox active materials used for these systems. It can be mostly used in solar photovoltaics [177], photo-electrochemical cells [178,179], supercapacitors [180] and batteries [181]. Among the different types of energy storage systems, supercapacitors are of great interest due to their high specific capacitance, superior power density, eco-friendless, reversible character, and self-durability [182].…”

Porous Carbon from Corn Flour Prepared by H<sub>3</sub>PO<sub>4</sub> Carbonization Combined with KOH Activation for Supercapacitors

“…Due to its high power density, the ability of quick charge and discharge, and stability and safety, the supercapacitor has become one of the most valuable and applicable potential research projects [1] [2]. Supercapacitors can be classified as electric double-layer capacitors, faraday pseudocapacitors, and hybrid supercapacitors [3] [4]. With its high power density and long life expectancy, supercapacitors are an ideal replacement for certain battery applications.…”