In this critical review, metal oxides-based materials for electrochemical supercapacitor (ES) electrodes are reviewed in detail together with a brief review of carbon materials and conducting polymers. Their advantages, disadvantages, and performance in ES electrodes are discussed through extensive analysis of the literature, and new trends in material development are also reviewed. Two important future research directions are indicated and summarized, based on results published in the literature: the development of composite and nanostructured ES materials to overcome the major challenge posed by the low energy density of ES (476 references).

/pdf/a-review-of-electrode-materials-for-electrochemical-2cok5em0bo.pdf

A review of electrode materials for electrochemical supercapacitors

Li-ion battery materials: present and future

Herein we report on the synthesis of two-dimensional transition metal carbides and carbonitrides by immersing select MAX phase powders in hydrofluoric acid, HF. The MAX phases represent a large (>60 members) family of ternary, layered, machinable transition metal carbides, nitrides, and carbonitrides. Herein we present evidence for the exfoliation of the following MAX phases: Ti2AlC, Ta4AlC3, (Ti0.5,Nb0.5)2AlC, (V0.5,Cr0.5)3AlC2, and Ti3AlCN by the simple immersion of their powders, at room temperature, in HF of varying concentrations for times varying between 10 and 72 h followed by sonication. The removal of the “A” group layer from the MAX phases results in 2-D layers that we are labeling MXenes to denote the loss of the A element and emphasize their structural similarities with graphene. The sheet resistances of the MXenes were found to be comparable to multilayer graphene. Contact angle measurements with water on pressed MXene surfaces showed hydrophilic behavior.

Two-dimensional transition metal carbides.

Graphene oxide: preparation, functionalization, and electrochemical applications.

Capacitive energy storage is technologically attractive because of its short charging times and its ability to deliver more power than batteries. The capacitive charge-storage properties of mesoporous films of MoO3 with iso-oriented grains now lead to pseudocapacitive materials that offer increased energy density while still maintaining high power density.

Ordered mesoporous [alpha]-MoO3 with iso-oriented nanocrystalline walls for thin-film pseudocapacitors

The plate-type negative electrodes for Li-ion rechargeable battery were prepared by pressure-pulsed chemical vapor infiltration of pyrolytic carbon at 950°C from C 3 H 8 (30%)-H 2 into the TiN-based electroconductive forms having the fibrous structure. The electrodes had the three-dimensional current paths in the layers of active materials without the organic binders and the conductive additives. The charge-discharge profiles were similar to that observed in non-graphitizable carbon having disordered structure. Reversible capacity of pyrolytic carbon at current density of 0.2 mA cm -2 and coulombic efficiency at the first cycle were ∼500 mA h g -1 and ∼72%, respectively. The capacity at current density of 8mA cm -2 maintained 80% of that at 0.2mA cm -2 .

Pressure-pulsed chemical vapor infiltration of pyrolytic carbon into fibrous tin prepared from carbonized paper preform

Intercalation reactions in CuCl2-FeCl3 system

https://www.jstage.jst.go.jp/article/tanso1949/1993/157/1993_157_69/_pdf

Synthesis and Exfoliation Behavior of Ternary Molybdenum Chloride-Chloroform-Graphite Intercalation Compound

The mechanical properties of graphene and reduced graphene oxide (rGO) and their applications are reviewed. Single-layer graphene has excellent mechanical properties, as Young’s modulus of 1 TPa. However, the practical applications of graphenes, mostly rGOs, are very limited; nano-sized additives for some lubricants, sensing component of mechanical sensors, and reinforcing fillers for plastics and metals, although they have the certain advantage as additives and fillers to need only a small amount, such as 0.5∼1 wt%. rGO fibers prepared by spinning of rGO suspension might be the way to use more effectively the excellent mechanical properties of graphene layers.

Michio Inagaki

Papers

Pressure-pulsed chemical vapor infiltration of pyrolytic carbon into fibrous tin prepared from carbonized paper preform

Intercalation reactions in CuCl2-FeCl3 system

Synthesis and Exfoliation Behavior of Ternary Molybdenum Chloride-Chloroform-Graphite Intercalation Compound

Mechanical properties and applications

Effect of crystallinity on electrochemical insertion/extraction of Li in transition metal oxides - Part II: TiO2, V2O5 and MoO3