Recent advances and fundamentals of Pseudocapacitors: Materials, mechanism, and its understanding

Stoichiometry–grain size-specific capacitance interrelationships in nickel oxide

“…Since the whole process either initiates from OH À (in adsorption) or yields the same (in desorption), eqn ( 5) is referred to as adsorption/desorption. 22,[59][60][61][62] A close observation of Fig. 4a shows that there is a gradual current-ramp in the regions where the redox peaks are absent.…”

“…The anodic peak corresponds to the adsorption of hydroxyl ion and the cathodic peak corresponds to the desorption of the same, as this reaction occurs on the surface of the electrode. 22,[59][60][61][62] The redox reaction is shown in eqn (5). [63][64][65][66][67] NiO + OH À # NiOOH + e À…”

Free‐Standing Pearl‐Chains‐like MoO2 Hierarchical Nanowires with Enhanced Pseudocapacitive Energy Storage

“…[10][11][12][13] Various materials have been explored as active electrode materials for pseudocapacitors, including metal salts, transition metal oxides, conducting polymers, and hydroxides. [14][15][16][17][18][19] Among them, MoO 2 is an up-and-coming candidate attributed to its low electrical resistance, the different oxidation states of Mo, and natural abundance. [20][21][22][23] Take Mo (IV)/Mo (VI) as a redox reaction pair, the theoretical capacitance is as high as 2512.6 F g À 1 at the voltage windows of 0.6 V. However, bulk MoO 2 -based PCs still face challenges with low rate ability and inferior cyclability, which are limited by the sluggish charge transportation, restricted accessible active sites, and poor structural durability.…”

“…Various materials have been explored as active electrode materials for pseudocapacitors, including metal salts, transition metal oxides, conducting polymers, and hydroxides [14–19] . Among them, MoO 2 is an up‐and‐coming candidate attributed to its low electrical resistance, the different oxidation states of Mo, and natural abundance [20–23] .…”

Preparation of flexible and free-standing polypyrrole/graphene film electrodes for supercapacitors

“…Compared with EDLCs, pseudocapacitors store the charge on the surface materials through a fast and reversible faradaic reaction, which can provide a much higher specific capacitance. 7 High-surface-area carbon materials, metal oxides and conducting polymers are the main families of electrode materials for supercapacitor applications. Recently, conducting polymers have demonstrated advantages of easy preparation, low density, high conductivity, stable chemical properties and excellent electrochemical properties, so they have broad development prospects in supercapacitors.…”