Sodium ion stabilized ammonium vanadate as a high-performance aqueous zinc-ion battery cathode

Multiscale modulation of vanadium oxidesviaone-step facile reduction to synergistically boost zinc-ion battery performance

“…In addition, the three pairs of redox peaks suggest a multi-step reaction in the zinc-storage process. 37,38 This is in agreement with the galvanostatic charge–discharge profiles shown in Fig. 4b, which display multiple platforms.…”

Tuning ionic conduction and structure stability of ammonium vanadate by intercalating polyaniline molecules for advanced aqueous zinc-ion batteries

“…The phenomenon of R ct reduction after several cycles has been reported in previous studies. 37,44,54 And the relevant comparison result of NNVO/PANI120 and other reported cathodes is displayed in Table S2,† in which the NVO/PANI120 electrode exhibits small charge transfer resistivities after the cycles, further confirming that the intercalation of PANI can promote the electron transfer and electrochemical reaction. Meanwhile, the electrical conductivity of NVO/PANI120 is about 0.001214 S cm −1 by the four-probe test, which is much larger than the 0.0002755 S cm −1 of the NH 4 V 4 O 10 , further confirming the enhancement of electron transport with PANI intercalation.…”

“…Subsequently, the second step weight loss (3.44%) between 170 °C and 350 °C may be attributed to the loss of NH 4 + and crystal water. 44 A rapid weight loss (13.84%) above 350 °C can be due to the decomposition of PANI in air. 29…”

In Situ Electrochemically Oxidative Activation Inducing Ultrahigh Rate Capability of Vanadium Oxynitride/Carbon Cathode for Zinc-Ion Batteries

“…Moreover, the galvanostatic charge/discharge curves (GCD) at current densities from 0.2 to 30 A g −1 (Figure 2b) show a similar trend and observably settled platforms with small polarization. The outstanding rate capabilities of VN x O y /C are well demonstrated by a comparison with some other reported cathode materials for ZIBs in Figure 2c, such as 244 mAh g −1 at 5 A g −1 for Na x V 2 O 5 , 38 164 mAh g −1 at 10 A g −1 for PEDOT-NH 4 V 3 O 8 , 39 100 mAh g −1 at 16 A g −1 for (NH 4 ) 0.125 MnO 2 (NHMO), 40 237 mAh g −1 at 20 A g −1 for amorphous-V 2 O 5 /graphene, 41 150 mAh g −1 at 25 A g −1 for Nadoped NH 4 V 4 O 10 (NVO-Na), 42 and 163 mAh g −1 at 30 A g −1 for PANI@V 2 O 5 . 43 Correspondingly, an outstanding energy density of 429 Wh kg −1 at 173 W kg −1 and an extremely high power density of 34800 W kg −1 at 58 Wh kg −1 were obtained by the VN x O y /C electrode based on the mass of the cathode material as shown in the Ragone plot (Figure 2d) and Table S1 (Supporting Information), which is also better than most cathode materials for ZIBs, including VS 4 @rGO (180 Wh kg −1 at 145 W kg −1 ), 44 VSe 2 (107.3 Wh kg −1 at 81.2 W kg −1 ), 45 K 2 Zn 2 V 10 O 28 (182.9 Wh kg −1 at 40.38 W kg −1 ), 46 V 3 O 7 •H 2 O/ rGO (77 Wh kg −1 at 8400 W kg −1 ), 47 hollow carbon spheres (59.7 Wh kg −1 at 447.8 W kg −1 ), 48 49 MnO 2 -CNTs (29.7 Wh kg −1 at 2480.6 W kg −1 ), 50 TiS 2 (35 Wh kg −1 at 3600 W kg −1 ), 51 self-doped PANI (181.1 W h kg −1 at 501.8 W kg −1 ), 52 and zinc orthovanadate array (115 Wh kg −1 at 5100 W kg −1 ).…”