A Review on the Conventional Capacitors, Supercapacitors, and Emerging Hybrid Ion Capacitors: Past, Present, and Future

Abstract

Electrochemical energy storage (EES) devices with high‐power density such as capacitors, supercapacitors, and hybrid ion capacitors arouse intensive research passion. Recently, there are many review articles reporting the materials and structural design of the electrode and electrolyte for supercapacitors and hybrid capacitors (HCs), though these reviews always focus on individual supercapacitors or single HCs. Herein, the conventional capacitor, supercapacitor, and hybrid ion capacitor are incorporated, as the detailed description of conventional capacitors is very fundamental and necessary for the better understanding and development of supercapacitors and hybrid ion capacitors, which are often ignored. Therefore, herein, the fundamentals and recent advances of conventional capacitors, supercapacitors, and emerging hybrid ion capacitors are comprehensively and systematically summarized in terms of history, mechanisms, electrode materials, existing challenges, and perspectives. At the same time, it is believed that a comprehensive and fundamental understanding for capacitor‐related EES devices is provided in the review and has a great guiding role for future development.

Synergetic Effect of Polyaniline and Graphene in Their Composite Supercapacitor Electrodes: Impact of Components and Parameters of Chemical Oxidative Polymerization

“…Light, thin, eco-friendly, and flexible energy storage systems are also essential for portable and flexible electronic devices needs. Thus, high-efficiency electrochemical energy-storage devices, particularly supercapacitors (SCs), are receiving intensive interest due to their high power density and rate performance as well as their long cycling life [ 1 , 2 , 3 ]. In addition, SCs have shown high specific capacitance, rapid charge-discharge processes, and low maintenance cost in comparison to batteries.…”

Experimental and Computational Aspects of Electrochemical Reflection Anisotropy Spectroscopy: A Review

“…Electrochemical energy conversion and storage is expected to play a crucial role in a global sustainable energy system based on renewable energy. Potential applications are for example electrolyzers, [1] photoelectrochemical (PEC) [2] as well as photocatalytic water splitting, [3] batteries [4] , supercapacitors, [5] and carbon dioxide removal. [6] At the heart of any of such electrochemical energy conversion and storage systems is the electrode/electrolyte interface.…”

Revealing the Self-Doping Defects in Carbon Materials for the Compact Capacitive Energy Storage of Zn-Ion Capacitors

“…Hybrid ion capacitors are promising energy storage devices thanks to the integrated merits of both high energy and power densities originating from the battery-type anode and the capacitor-type cathode. − Zn-ion capacitors typically assembled by a Zn anode, zinc salt electrolytes, and a porous carbon cathode have received great attention in recent years owing to the high theoretical capacity (823 mAh g –1 /5855 mAh cm –3 ), low redox potential (−0.76 V vs standard hydrogen reference), robust electrochemical kinetics, and resource abundance of Zn. − Large-surface-area porous carbons (1000–4000 m 2 g –1 ) with the electrical double-layer behavior are commonly used as the cathode materials , but show unsatisfactory capacitance to match the Zn anode due to their low specific areal capacitance contribution ( C s < 0.2 F m –2 as summarized from the literature in Table S1). − What is more, a highly developed porous structure usually causes a low density of porous carbons (<0.6 g cm –3 ), resulting in an unsatisfactory volumetric performance that cannot meet the ever-increasing requirements for lightweight and miniaturized devices. , Therefore, improving the capacitance of dense carbon materials by novel active site design is urgently needed yet still challenging for future development of Zn-ion capacitors.…”