Zn/V₂O₅ Aqueous Hybrid-Ion Battery with High Voltage Platform and Long Cycle Life

Abstract

Aqueous zinc-ion batteries attract increasing attention due to their low cost, high safety, and potential application in stationary energy storage. However, the simultaneous realization of high cycling stability and high energy density remains a major challenge. To tackle the above-mentioned challenge, we develop a novel Zn/VO rechargeable aqueous hybrid-ion battery system by using porous VO as the cathode and metallic zinc as the anode. The VO cathode delivers a high discharge capacity of 238 mAh g at 50 mA g. 80% of the initial discharge capacity can be retained after 2000 cycles at a high current density of 2000 mA g. Meanwhile, the application of a "water-in-salt" electrolyte results in the increase of discharge platform from 0.6 to 1.0 V. This work provides an effective strategy to simultaneously enhance the energy density and cycling stability of aqueous zinc ion-based batteries.

Highly Reversible Zn Anode Enabled by Controllable Formation of Nucleation Sites for Zn‐Based Batteries

“…In comparison, the Zn–V 2 O 5 battery using the ZrO 2 ‐coated Zn anode can deliver a high capacity retention of 42.3% and a long cycle life up to 3000 cycles, along with a high CE of ≈100%. Additionally, the capacities of Zn–V 2 O 5 batteries using bare Zn anode and ZrO 2 ‐coated Zn anode both present the increasing trend in the initial 60 cycles and gradually decrease in the following cycles, which could be ascribed to the gradual activation process of active materials at high current density of 1 A g −1 , the similar phenomenon can be found in other Zn–V 2 O 5 batteries as well 62,63. Because of the stable cycling ability and high reversibility of the ZrO 2 ‐coated Zn anode, the Zn–V 2 O 5 batteries using the ZrO 2 ‐coated Zn anode deliver both the good cycling stability and high capacity retention.…”

“…In this regard, metallic zinc (Zn) has been considered to be one of the alternatives due to its low potential (−0.762 V vs standard hydrogen electrode (SHE)), high theoretical capacity (820 mAh g −1 ), large abundance, environmental‐friendly properties, and inherent safety 7–9. Up to now, various Zn‐based batteries have been widely investigated, such as Zn–air battery,10–13 Zn–NiOOH battery,14–16 Zn–V 2 O 5 battery,17–19 Zn–MnO 2 battery,20–23 etc. However, besides the dendrite growth in the electrolyte, the Zn anode corrosion and the formation of ZnO densification on the Zn electrode surface have become the challenges for the development of rechargeable Zn‐based batteries, which would result in poor reversibility, low Coulombic efficiency (CE), and the decayed capacity 24.…”

Dendrite Growth Suppression by Zn2+‐Integrated Nafion Ionomer Membranes: Beyond Porous Separators toward Aqueous Zn/V2O5 Batteries with Extended Cycle Life

“…At the different power densities of 195 and 7800 W kg −1 , the device delivers high energy densities of 398 and 257 Wh kg −1 , respectively (energy density of the cell is evaluated, considering the loading of V 2 O 5 on cathode, and the corresponding calculations are given in SI, Section S1 and S20, Supporting Information). This is far higher than extant AZIBs, which use conventional separators . The combination of high energy and power density of the V‐3M‐Nafion cell can narrow the gap between the supercapacitors and batteries.…”

“…Compared with the previously known Zn/MnO 2 nonrechargeable aqueous batteries based on corrosive alkaline electrolytes, discussions regarding the aforementioned system have dominated research in recent years. This has opened up new challenges as well as opportunities in the realization of more efficient aqueous ZIBs (AZIBs) with a variety of other cathode materials . Although other chemistries based on Al/Al 3+ and Mg/Mg 2+ have been proposed, the Zn/Zn 2+ systems are considered to be the leading candidate due to the high theoretical capacity (820 mAh g −1 ), low redox potential (−0.76 V vs standard hydrogen electrode [SHE]), natural abundance, and low cost of Zn metal …”

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

“…As is well known, there are several valence states of V in vanadium oxides (mainly V 3+ , V 4+ , and V 5+ ), and recent studies have witnessed a series of investigations on vanadium oxides as cathodes in aqueous ZIBs, for example, V 2 O 5 and VO 2 . The layered structure of V 2 O 5 is composed of interconnected VO 5 pyramids that share edges and corners, with the van der Waals forces solely linking the layers (Figure a) .…”