Physicochemical factors that affect the pseudocapacitance and cyclic stability of Mn oxide electrodes

High-performance α-MnO2 nanowire electrode for supercapacitors

“…It is expected these 1-D nanostructured electrode layers could have favorable porous structures for the electrolyte penetration, leading to incresed double-layer areas for charge storage and less electrochemical polarization. Furthermore, high porosity can easily relieve the internal stress caused by the ion diffusion into the electrode, protecting the electrode from physical and chemical damages such as the dissolution of MnO 2 [29]. Therefore, it is favorable to prepare porous MnO 2 film electrodes with proper 1-D nanostructure for enhancing both the rate capability and cycling stability.…”

A review of electrode materials for electrochemical supercapacitors

“…Hence, the more fibrous or porous the oxide, the better the cycle stability is. 288 It is worth pointing out that both the surface area and the pore-size distribution of MnO 2 can be controlled by adjusting the reaction time and the surfactant content in the aqueous phase. poor ion conductivity as well as loss of pseudocapacitance if the heat treatment temperature is too high.…”

“…Several typical techniques reported in the literature are thermal decomposition, co-precipitation, sol-gel processes, electrodeposition, mechanical milling processes, and hydrothermal synthesis. 50,54,269,273,278,280,288,302,311,[335][336][337][338] Among these, the hydrothermal route has been proven to be an effective and controllable method to produce Mn oxides with various nanostructures such as nanowhiskers, nanoplates, and nanorods. 302,311,339 Note that the mechanical milling process can lead to a sequential phase transition from g-MnO 2 to the thermodynamically stable a-Mn 2 O 3 and subsequently to Mn 3 O 4 , depending on the duration of mechanical grinding.…”

Three-dimensional crisscross porous manganese oxide/carbon composite networks for high performance supercapacitor electrodes

“…As demonstrated, the bigger the binding energy is, the higher the valency of Mn is [41]. The XPS spectrum from Mn 2p 3/2 region can be observed in Fig.…”