High-performance Aqueous Zinc-ion Batteries Research Articles

Investigation of sodium vanadate as a high-performance aqueous zinc-ion battery cathode

Investigation of sodium vanadate as a high-performance aqueous zinc-ion battery cathode

Hybridizing δ-type NaxV2O5·nH2O with graphene towards high-performance aqueous zinc-ion batteries

Thanks to low cost and high safety, aqueous zinc-ion batteries (AZIBs) are attractive candidates for large-scale energy storage applications, while suitable cathode materials are needed urgently. In this work, δ-NaxV2O5·nH2O with a large interlayer spacing of 10.6 Å is reported as the cathode material for aqueous zinc-ion batteries for the first time. It is found that δ-NaxV2O5·nH2O performs better than Na2V6O16·nH2O under the same condition, and its electrochemical performances can be significantly improved after hybridizing it with reduced graphene oxide. The obtained nanocomposite can deliver high reversible capacity of 433.5 mAh g−1 at 0.1 A g−1, superior rate capability of 244.1 mAh g−1 at 5 A g−1, and good cyclability of 70.5% over 1000 cycles. Such great performances origin from the synergetic effect of δ-NaxV2O5·nH2O and graphene, which enables rapid Zn2+ diffusion and large capacitive contribution. Besides, the ex-situ measurement results demonstrate good structural stability and reversible Zn2+ ion storage behavior of reduced graphene oxide/δ-NaxV2O5·nH2O nanocomposite. This work extends the knowledge into the material technology of AZIBs.

Electrochemical activation of commercial MnO microsized particles for high-performance aqueous zinc-ion batteries

Manganese oxides represent a class of promising cathode materials for rechargeable aqueous zinc-ion batteries (ZIBs) due to their high energy density, safety, low cost, eco-friendliness and non-toxicity. However, manganese monooxide (MnO) is considered to be inactive for Zn2+ energy storage. Herein, for the first time, we demonstrate the possible application of commercial MnO microsized particles as cathodes for high performance ZIBs. It is interesting to note that electrochemical activation (or oxidation) is observed during the initial charging process, which leads to the formation of porous layered-type MnO2 nanosheets surrounding the MnO surface. As a result, the activated cathode could deliver a maximum specific capacity of 330 mAh g−1 in ZnSO4 aqueous electrolyte at a current density of 0.1 A g−1. In addition, the underlying energy storage mechanism is systematically investigated. The present work provides a new insight into the electrochemical activation strategy for developing advanced cathodes for high-performance zinc-ion batteries.

Transition metal ion-preintercalated V2O5 as high-performance aqueous zinc-ion battery cathode with broad temperature adaptability

Rechargeable aqueous zinc-ion batteries (ZIBs) with advantages of high safety and low-cost gradually show potential in large-scale energy storage/supply application. Yet the further development of aqueous ZIBs is hindered by finding suitable cathodes. Here we demonstrate that the chemical pre-intercalated transition metal ions (e.g. Fe2+, Co2+, Ni2+, Mn2+, Zn2+ and Cu2+, etc.) into the interlayer of V2O5, could effectively improve the electrochemical performance of aqueous ZIBs, in terms of high capacity, rate capability and long-term cycling stability, as well as excellent broad temperature adaptability. For instance, Cu2+-intercalated V2O5 cathode exhibits high capacity of 180 mA h g−1 after 10000 cycles at 10 A g−1 and 122 mA h g−1 after 3000 cycles at 20 A g−1. This universal strategy of pre-intercalated metal ions in the host materials is found to enable fast Zn2+ diffusion, enhanced electrical conductivity, and excellent structural reversibility, which can be applicable for other well-established aqueous ZIBs cathodes (i.e. MnO2), or other advanced battery systems.

Expanded hydrated vanadate for high-performance aqueous zinc-ion batteries

Expanding hydrated vanadate with transition metal cations collectively promotes and catalyzes fast and more Zn-ion intercalation in aqueous batteries.

Structural Modification of V2O5 as High-Performance Aqueous Zinc-Ion Battery Cathode

We report the NH4+ intercalated V2O5, i.e. (NH4)2V10O25•8H2O, with excellent electrochemical performance as cathode in aqueous zinc-ion battery (ZIBs), as compared to V2O5, Na5V12O32 and K2V8O21. This work reveals that the ionic conductivity of Zn2+ can be enhanced by introducing cations into the V2O5 framework and the vanadium oxygen structural units will be rearranged. Compared to a single layer of vanadium pentoxide consisting solely of VO5 units, the electrochemical performance of the structural units rearranged vanadates shows a significant improvement. As a result, the obtained (NH4)2V10O25•8H2O delivers high discharge capacity (376 mA h g−1 at 0.5 A g−1), superior rate capability up to 10 A g−1, excellent cycling stability (a capacity retention over 93% for 1000 cycles) and high energy density (341 Wh kg−1).