Bismuth oxide can store energy electrochemically in seventeen aqueous metal ion electrolytes with high capacity based on a “quasi-conversion reaction”.

Organic hybrid supercapacitors that consist of a battery electrode and a capacitive electrode show greatly improved energy density, but their power density is generally limited by the poor rate capability of battery-type electrodes. In addition, flexible organic hybrid supercapacitors are rarely reported. To address the above issues, herein an in-plane assembled orthorhombic Nb 2 O 5 nanorod film anode with high-rate Li + intercalation to develop a flexible Li-ion hybrid capacitor (LIC) is reported. The binder-/additive-free film exhibits excellent rate capability (≈73% capacity retention with the rate increased from 0.5 to 20 C) and good cycling stability (>2500 times). Kinetic analyses reveal that the high rate performance is mainly attributed to the excellent in-plane assembly of interconnected single-crystalline two kinds based on the electrolytes used in the cells: one is aqueous and the other is organic system. In general, supercapacitors with organic electrolytes show much higher energy density than that of aqueous system, because the organic electrolytes permit much larger working voltage (≈3.0 V). In order to further improve the energy density of the supercapacitors, Li-ion hybrid capacitors (LICs) were introduced by combining the Li-ion battery electrode with the activated carbon (AC) capacitive electrode. [4] Thereafter, either low-potential anodes such as Li 4 Ti 5 O 12 (LTO) or high-potential cathodes including LiNi 0.5 Mn 1.5 O 4 and graphitic carbons were utilized in the hybrid LICs, [5][6][7] and the energy density of the hybrid systems can be significantly improved by approximately two to threefold.However, a point worth noting is that the power capability of the LIC devices is generally limited by the Li-ion battery electrode side. [3][4][5][6][7] In details, the capacitive electrode in LICs can exhibit very high rate capability as the electrical charges are stored/released by ion adsorption/desorption; by contrast, the Li-ion battery electrode stores the energy via Li-ion intercalation, and thus the rate performance may be significantly limited by the slow Li-ion diffusion in the solid phase. With the purpose to mitigate the rate-imbalance issue in LICs, much research effort has been devoted to the development of Li-ion intercalation materials with both ultrahigh rate capability and long cycle life. In particular, nanostructured materials with pseudocapacitive Li-ion intercalation behavior such as Nb 2 O 5 , V 2 O 5 , MoO 3−x , and MoS 2 , etc. have been investigated. [8][9][10][11][12][13] Among them, Nb 2 O 5 materials with specified crystal phases have attracted great interest due to their advantages of relatively low plateau voltage, high specific capacity (≈200 mA h g −1 ), and good cycling stability. However, Nb 2 O 5 may still suffer poor rate performance due to their limited electrical conductivity and low Li ion-diffusion rate. [14][15][16] Recent work demonstrated that Nb 2 O 5 nanomaterials of orthorhombic phase, which were carefully prepared with ordered porous architecture, showe...

The reaction of meso-triarylcorroles with AgNO2 proceeds with concomitant metalation and peripheral substitution to give the corresponding nitro-substituted silverIII corrole complex. The substitution is highly regioselective, giving only the corresponding 3-nitro derivative, among the different possible isomers. The results obtained indicate that the reaction intermediate is the pi-cation radical of the complex, which is then attacked by nitrite ion. This was proven by the reaction of the copper corrole complexes with NaNO2: in this case, the nitration reaction proceeded without the addition of an oxidant, because of the pi-cation radical character of the copper complex. The reaction is also successful in the case of 2,3,17,18-tetraethyl-8,12-diacetoxymethyl-7,13-dimethylcorrole (AMCorH3), with the formation of the meso-substituted silver corrole derivative (NO2)3AMCorAg (fully characterized by X-ray crystallography), the first of its kind to be reported. Two of the corroles are characterized by cyclic voltammetry and spectroelectrochemistry in dichloromethane, and the site of electron transfer is elucidated.