Highly Reversible Phase Transition Endows V₆O₁₃ with Enhanced Performance as Aqueous Zinc‐Ion Battery Cathode

Abstract

Aqueous zinc‐ion batteries (ZIBs), with favorable merits of high security and low cost, have gained much interest in the energy storage field. However, their development is still in its infancy. Herein, V6O13 is investigated as aqueous ZIB cathodes with excellent Zn2+ storage performance, as compared with VO2 and V2O5. The intrinsic open structure of V6O13 with mixed‐valance states of vanadium (V4+/V5+) is favorable to enable fast Zn2+ ion diffusion and improved electronic conductivity, outperforming VO2 and V2O5. Significantly, the highly reversible phase transition of zinc vanadate (Zn0.25V2O5·H2O) can be detected during discharging, which enables the insertion of more Zn2+ ions into the host structure. As a result, V6O13 can exhibit enhanced electrochemical properties, including high capacity and excellent long‐term cyclability (206 mA h g−1 at 10 A g−1 after 3000 cycles).

Electrochemical Performance of Hybrid Cationic Aqueous-Based Rechargeable Battery with Different Current Collectors and Electrolytes

“…To further compare the difference of the zinc foils by electrowinning with or without mixed additives, galvanostatic charge/discharge was conducted between 1.4 and 2.1 V at 4 C-rate. As shown in Figure 5(a), there are two distinguished plateaus using the electrowinning zinc adding TU and GL that reflect two-stage Li-ion extraction/insertion behavior and are consistent with the previous reports [27]. In Figure 5(b), the capacity retentions after 300 cycles are 1.62%, 34.88%, and 45.63%, respectively, for three parallel batteries, of which the zinc current collectors were cut from the same piece of zinc foil by electrowinning from a sulfate solution containing 58 g/L Zn 2+ and 150 g/L H 2 SO 4 without additives in the electrolyte, and the consistency of the zinc is very bad.…”

“…Based on the defects and limitations of aqueous rechargeable lithium ion batteries (ARLIBs), a hybrid cationic aqueousbased rechargeable battery system based on lithium intercalation cathode with undoped LiMn 2 O 4 and low equilibrium potential and low-cost zinc anode was first reported by Chen's group [19]. Since then, they have attracted increasing concerns about aqueous batteries [20,21] and the similar systems such as Na 0.44 MnO 2 //Zn [22], LiMnPO 4 //Zn [23], LiCo 1/3 Mn 1/3 Ni 1/3 PO 4 //Zn [24], and so on [25][26][27][28].…”

Understanding the Design Principles of Advanced Aqueous Zinc‐Ion Battery Cathodes: From Transport Kinetics to Structural Engineering, and Future Perspectives

“…Specifically, the introduction of metal ions enables the vanadium-oxide layers transformed into VO 5 square pyramidals and VO 6 octahedras, thus leading to the c-axis extension, which synergistically constructed a more stable bilayered V 3 O 8 structure along the b-axis, demonstrating higher stability than the structure only containing VO 5 square pyramidals during charging/discharging process. [176][177][178] Besides, to explore the influence of metal ions on the transport kinetics, GITT measurement was carried out to calculate the corresponding Zn 2+ diffusivity coefficient (D). As displayed in Figure 6b, the calculated D results showed that all the preintercalated V 2 O 5 samples exhibit about one order of magnitude higher than that of the pristine one.…”

Interlayer Doping in Layered Vanadium Oxides for Low‐cost Energy Storage: Sodium‐ion Batteries and Aqueous Zinc‐ion Batteries

“…On the one hand, the V 5+/4+ redox pair could provide high specific capacity. On the other hand, the unique electronic characteristics endow them with considerable pseudocapacitance behaviour especially in aqueous systems (such as more than 400 mAh g −1 of V 6 O 13 in AZIBs) [7] . Furthermore, most vanadium‐based oxides, including the VO 2 , [8,9] V 2 O 5 , [10] V 3 O 7 , [11] MV 2 O 6 , [12] M 3 V 2 O 8 , [13] etc.…”