Electrochemical capacitors, also called supercapacitors, store energy using either ion adsorption (electrochemical double layer capacitors) or fast surface redox reactions (pseudo-capacitors). They can complement or replace batteries in electrical energy storage and harvesting applications, when high power delivery or uptake is needed. A notable improvement in performance has been achieved through recent advances in understanding charge storage mechanisms and the development of advanced nanostructured materials. The discovery that ion desolvation occurs in pores smaller than the solvated ions has led to higher capacitance for electrochemical double layer capacitors using carbon electrodes with subnanometre pores, and opened the door to designing high-energy density devices using a variety of electrolytes. Combination of pseudo-capacitive nanomaterials, including oxides, nitrides and polymers, with the latest generation of nanostructured lithium electrodes has brought the energy density of electrochemical capacitors closer to that of batteries. The use of carbon nanotubes has further advanced micro-electrochemical capacitors, enabling flexible and adaptable devices to be made. Mathematical modelling and simulation will be the key to success in designing tomorrow's high-energy and high-power devices.

https://hal.archives-ouvertes.fr/hal-02417326/document

Materials for electrochemical capacitors

Atom transfer radical polymerization.

As a fascinating conjugated polymer, graphitic carbon nitride (g-C3N4) has become a new research hotspot and drawn broad interdisciplinary attention as a metal-free and visible-light-responsive photocatalyst in the arena of solar energy conversion and environmental remediation. This is due to its appealing electronic band structure, high physicochemical stability, and “earth-abundant” nature. This critical review summarizes a panorama of the latest progress related to the design and construction of pristine g-C3N4 and g-C3N4-based nanocomposites, including (1) nanoarchitecture design of bare g-C3N4, such as hard and soft templating approaches, supramolecular preorganization assembly, exfoliation, and template-free synthesis routes, (2) functionalization of g-C3N4 at an atomic level (elemental doping) and molecular level (copolymerization), and (3) modification of g-C3N4 with well-matched energy levels of another semiconductor or a metal as a cocatalyst to form heterojunction nanostructures. The constructi...

Graphitic Carbon Nitride (g-C3N4)-Based Photocatalysts for Artificial Photosynthesis and Environmental Remediation: Are We a Step Closer To Achieving Sustainability?

[Liu, Chang; Li, Feng; Ma, Lai-Peng; Cheng, Hui-Ming] Chinese Acad Sci, Inst Met Res, Shenyang Natl Lab Mat Sci, Shenyang 110016, Peoples R China.;Cheng, HM (reprint author), Chinese Acad Sci, Inst Met Res, Shenyang Natl Lab Mat Sci, 72 Wenhua Rd, Shenyang 110016, Peoples R China;cheng@imr.ac.cn

Advanced Materials for Energy Storage

Polydopamine and Its Derivative Materials: Synthesis and Promising Applications in Energy, Environmental, and Biomedical Fields

Lithium Storage in Ordered Mesoporous Carbon (CMK-3) with High Reversible Specific Energy Capacity and Good Cycling Performance

Synthesis and properties of magnetic Fe3O4-activated carbon nanocomposite particles for dye removal

A sonochemical method has been successfully used in order to incorporate MnO2 nanoparticles inside the pore channels of CMK-3 ordered mesoporous carbon. Modification of the intrachannel surfaces of CMK-3 to make them hydrophilic enables KMnO4 to readily penetrate the pore channels. At the same time, the modification changes the surface reactivity, enabling the formation of MnO2 nanoparticles inside the pores of CMK-3 by the sonochemical reduction of metal ions. The resultant structures were characterized by X-ray diffraction (XRD), nitrogen adsorption, and transmission electron microscopy (TEM). CMK-3 with 20 wt.-% loading of MnO2 inside CMK-3 delivered an improved discharge performance of 223 mA h g–1 at a relatively high rate of 1 A g–1. Almost no decrease in specific capacity is observed for the second cycle, and a discharge capacity of more than 165 mA h g–1 is retained after 100 cycles. This is attributed to the nanometer-sized MnO2 formed inside CMK-3 and the high surface area of the mesopores (3.1 nm) in which the MnO2 nanoparticles are formed.

Shenmin Zhu

Papers

Lithium Storage in Ordered Mesoporous Carbon (CMK-3) with High Reversible Specific Energy Capacity and Good Cycling Performance

Synthesis and properties of magnetic Fe3O4-activated carbon nanocomposite particles for dye removal

Synthesis of MnO2 Nanoparticles Confined in Ordered Mesoporous Carbon Using a Sonochemical Method

Sonochemical synthesis of TiO2 nanoparticles on graphene for use as photocatalyst

Electrochemical capacitance of self-ordered mesoporous carbon