Water molecules and oxygen-vacancy modulation of vanadium pentoxide with fast kinetics toward ultrahigh power density and durable flexible all-solid-state zinc ion battery

Unveiling the Ultrahigh-Voltage Platform of Hydrated V3O7 in Carbon Network for Enhancing Aqueous Zinc-Ion Batteries Performance

“…From Figure c, it clearly shows that the intercalation capacitive contribution steadily increases from 57 to 72% with the scan rates ranging from 0.5 to 2.0 mV s –1 . In addition to that, the capacitive and diffusion contribution for the specific scan rate 1.5 mV s –1 is clearly shown in Figure d. − From the Randles–Sevcik equation as shown in eq we can calculate the Zn 2+ ions diffusion coefficient. i p = 0.4463 n 3 / 2 F 3 / 2 C A R F − 1 / 2 T − 1 / 2 F D cv V 1 / 2 F where i p corresponds to peak current value, n is the number of electrons, F denotes the Faraday constant (96485 C mol –1 ), C represents bulk concentration (mol cm –3 ), A is the electrode area (cm 2 ), R is the gas constant (8.314 J mol –1 K –1 ), T is the absolute temperature (K), D cv denotes the coefficient of diffusion of Zn 2+ ions (cm 2 s –1 ), and V represents the various scan rates (mV s –1 ) seen in the CV curves. , Zn 2+ ions diffusion coefficient values ( D Zn 2+ ) calculated from the different redox peaks are ≈10 –15 order and the calculated values vary between 2.82 × 10 –15 and 3.30 × 10 –15 cm 2 s –1 .…”

Sodium ion pre-intercalation regulates the electron density and structural stability of vanadium oxide nanowires for Ca–ion batteries

“…In the V 2 O 5 NW, the V 2p spectrum displays a distinctive pair of peaks associated with the spin–orbit states of V 2p 1/2 and V 2p 3/2 , and these may be further differentiated into two distinct peaks approximately situated at 516.8/523.8 eV (V 4+ ) and 517.5/524.9 eV (V 5+ ). 49 By incorporating sodium ions, there is a progressive decline in the peak area corresponding to V 5+ , accompanied by a simultaneous increase in the peak area attributed to V 4+ . This phenomenon is attributed to the partial reduction of V 5+ to V 4+ in order to maintain charge equilibrium.…”

Bi-intercalated vanadium pentoxide synthesized via hydrogen peroxide-induced phase transition for highly stable cathode in aqueous zinc ion batteries

“…Aqueous zinc-ion batteries (ZIBs) are becoming important candidates for energy storage devices, [1][2][3][4] as shown in Table S1, † owing to their following advantages: (i) zinc is abundant in the earth and inexpensive; (ii) the replacement of organic electrolytes by environment-friendly neutral electrolyte salts to reduce pollution; (iii) a low redox potential of Zn/Zn 2+ (−0.76 V vs. the standard hydrogen electrode), high theoretical volumetric charge capacity (5.854 mA h cm −3 ) and reversible Zn/Zn 2+ redox kinetics. [5][6][7][8] However, considering the uncertainty of the aquatic environment, zinc ion electrodes need to withstand a harsh environment, especially dissolution, resulting in their capacity and serious cycle degradation. [9][10][11] The choice of a positive electrode is critical to match the aquatic environment.…”