High-performance Zn-ion Research Articles

Redox-active sodium 3,4-dihydroxy anthraquinone-2-sulfonate anchored on reduced graphene oxide for high-performance Zn-ion hybrid capacitors

A high-performance ARS anchored on reduced graphene oxide aerogel film cathode with fast transmission dynamics, pseudo-capacitance characteristics, high energy and power density, flexibility, and applicability.

A flexible Zinc-ion hybrid supercapacitor constructed by porous carbon with controllable structure

The demand for developing sustainable energy storage renders biomass-based electrode materials a timely and important goal. However, the desirable electrochemical performance of the supercapacitor has still been hindered by insufficient contact chance between the active material and the electrolyte when both energy density and power density are required. Herein, the porous bamboo carbons were managed and used as the cathode to construct a flexible and high-performance Zn-ion hybrid supercapacitor (ZHSC) by combining the merit of capacitor-type and battery-type electrode materials. The porous material with high porosity is obtained via a controllable structural optimization. Consequently, the as-constructed hybrid supercapacitor delivers a superior specific capacitance of 321.3F g−1 at 1 A g−1 together with a high energy density of 114.2 Wh kg−1 when the power density is 800.0 W kg−1. Meanwhile, the assembled flexible hybrid supercapacitor displays remarkable cycling stability with 78% capacitance retention after 20,000 cycles and enough to suffer various deformations with no noticeable degradation of capacitance. Finally, the potential practical value of the flexible hybrid supercapacitor is demonstrated by an eye-catching orbital diagram. This work reveals that the flexible supercapacitor mainly constructed by porous biomass carbon is a promising candidate for energy storage devices.

Achieving both high reversible and stable Zn anode by a practical glucose electrolyte additive toward high-performance Zn-ion batteries

Achieving both high reversible and stable Zn anode by a practical glucose electrolyte additive toward high-performance Zn-ion batteries

Boosting the zinc ion storage capacity and cycling stability of interlayer-expanded vanadium disulfide through in-situ electrochemical oxidation strategy

Metallic vanadium dichalcogenides with high conductivity and large layer spacing are fantastically potential to be cathode candidates for aqueous zinc ion batteries. However, simply reliance on the reversible Zn2+ intercalation/deintercalation process in the layer structure of vanadium dichalcogenides makes it suffer from low specific capacity and limited cycling number. Here we report a facile in-situ electrochemical oxidation strategy to boost the zinc ion storage capacity of interlayer-expanded vanadium disulfide (VS2·NH3) hollow spheres with satisfying cyclic stability. The hydrated vanadium oxide (V2O5·nH2O) generated from oxidized VS2·NH3, are endowed with reduced nanosheet size and subordinated porous structure, which provides abundant accessible sites and accelerates the zinc ion diffusion process. As a result, the VS2·NH3 derived cathode after the electrochemical oxidation process delivers a high reversible capacity of 392 mA h g−1 at 0.1 A g−1 and long cyclic stability (110% capacity retention at 3 A g−1 after 2000 cycles). The efficient oxidation process of VS2·NH3 cathode and the storage mechanism in the subsequent cycles are schematically investigated. This work not only reveals the zinc ion storage mechanism of the oxidized VS2·NH3 but also sheds light on advanced design for high-performance Zn ion cathode materials.

K-preintercalated MnO2 nanosheets as cathode for high-performance Zn-ion batteries

Manganese oxides are regarded as promising cathode materials for aqueous zinc ion batteries (ZIBs) due to their low cost and high theoretical capacity. However, their practical application is seriously hindered because of the inferior electronic conductivity, sluggish diffusion kinetics and structural instability. Herein, we develop a new K-preintercalated MnO 2 (K 0.19 MnO 2 ·0.56H 2 O, KMO) nanosheet by a facile hydrothermal method. Preintercalation of K + ions into the MnO 2 crystal layers with structural reconstruction can activate more active sites, strengthen the crystal structural stability and facilitate the insertion/extraction of Zn 2+ ions. The charge shielding effect of crystal water promotes the diffusion kinetics of Zn 2+ ions. The obtained KMO electrode delivers high specific capacity (107 mAh g −1 ) and good cycling stability (~87.5% capacity retention after 2000 cycles), revealing its potential application for aqueous ZIBs.

Ultra-Fast and Scalable Saline Immersion Strategy Enabling Uniform Zn Nucleation and Deposition for High-Performance Zn-Ion Batteries.

Although aqueous Zn-ion batteries (ZIBs) with low cost and high safety show great potential in large-scale energy storage system, metallic Zn anode still suffers from unsatisfactory cycle stability due to unregulated growth of Zn dendrites, corrosion, and formation of various side products during electrochemical reaction. Here, an ultrafast and simple method to achieve a stable Zn anode is developed. By simply immersing a Zn plate into an aqueous solution of CuSO4 for only 10-60 s, a uniform and robust protective layer (Zn4 SO4 (OH)6 ·5H2 O/Cu2 O) is formed on commercial Zn plate (Zn/ZCO), which enables uniform electric field distribution and controllable dendrite growth, leading to a long-term cycle life of over 1400 h and high average Coulombic efficiency (CE) of 99.2% at 2.0mA cm-2 and 2.0 mAh cm-2 . These excellent characteristics of the prepared Zn anode show great potential in practical applications for high-performance aqueous Zn-ion batteries.

Molten salt strategy and plasma technology induced MnO2 with oxygen vacancy for high performance Zn-ion batteries

The oxygen vacancy-rich MnO2 was synthesized by the molten salt method and the plasma etching strategy. The amorphous layer increased the active sites and the oxygen vacancies on the surface of MnO2 that promoted the rapid transfer of charges.

A liquid metal assisted dendrite-free anode for high-performance Zn-ion batteries

A self-healing zinc anode is achieved by introducing a liquid Ga–In–Zn alloy as a protective layer on zinc foil. The high fluidity and deformability of the liquid alloy ensure an ultralong cycling life by enabling dendrite-free Zn deposition.

Enabling Multi-Chemisorption Sites on Carbon Nanofibers Cathodes by an In-Situ Exfoliation Strategy for High-Performance Zn-Ion Hybrid Capacitors

Enabling Multi-Chemisorption Sites on Carbon Nanofibers Cathodes by an In-Situ Exfoliation Strategy for High-Performance Zn-Ion Hybrid Capacitors

Cu-MOF-derived and porous Cu0.26V2O5@C composite cathode for aqueous zinc-ion batteries

One fundamental issue for developing high-performance Zn-ion batteries (ZIBs) is the exploration of stable and efficient cathode materials that can reversibly intercalate zinc ions at a high capacity and potential. Layered vanadium oxides have been regarded as a suitable candidate for this purpose due to their high zinc-ion storage capacity. However, the sluggish kinetics of zinc-ion intercalation/deintercalation and the poor conductivity of vanadium oxides are still the bottle bottlenecks that impede the further enhancement of their performance for ZIBs. Addressing this issue, we herein demonstrate a direct impregnation and conversion strategy to prepare a Cu-doped V2O5 and hierarchical porous carbon (Cu0.26V2O5@C) composite as the cathode for ZIBs. In this protocol, the Cu doping can promote the zinc-ion migration by broadening and stabilizing the layered structure of V2O5, the hierarchical porosity can enlarge the contact between the active material and the electrolyte to achieve efficient infiltration of the electrolyte into the material, while the carbon host can improve the electronic conductivity. The combination of these merits thus delivers a high specific capacity (328.8 mAh g−1 at 0.2 A g−1), high rate performance (163.8 mAh g−1 at 2 A g−1), and excellent long-term cyclic stability with 93.5% capacity retention after 500 cycles.

Tuning Zn2+ coordination environment to suppress dendrite formation for high-performance Zn-ion batteries

The short-circuit issue induced by Zn dendrite growth restricts the commercialization of rechargeable aqueous Zn-ion batteries (ZIBs). Herein, ethylene glycol (EG), a representative of dihydric alcohols, is applied in the aqueous electrolyte to inhibit the detrimental dendrite growth on Zn anode. Our work demonstrates a uniform Zn plating/stripping in H2O/EG hybrid electrolyte with cycling lifespan of up to 2668 h at 0.5 mA cm−2, which is made possible by the substitution of EG for H2O in the solvation sheath of Zn2+ ions. Such a change in the coordination environment of Zn2+ gives rise to decreased diffusivity of the ions and increased over-potential for nucleation, further resulting in even deposition morphology rather than large-scale dendrites. Side reactions are also circumvented by the formation of hydrogen bonds. All these aspects work in synergy to promote the cyclability of the assembled full battery. The low-cost aqueous electrolyte identified in this work opens up new opportunities for manipulating the coordination environments of Zn2+ ions and optimizing the Zn deposition morphology during the design of high-performance ZIBs.

Reversible V3+/V5+ double redox in lithium vanadium oxide cathode for zinc storage

Zn ion batteries show great potential for large-scale energy storage owing to their low-cost, safe and environment-friendly features. There is an urgent need for cathode material with high-energy-density and long-service-life. Vanadium-based cathodes would be particularly desirable due to the bi-electronic transfer reaction (V5+/V4+/V3+). Herein, we present a reversible V3+/V5+ double redox in lithium vanadium oxide (LiV3O8) with the insertion of Zn2+ for ZIBs. In this way, six-electron transition in LiV3O8 was achieved with only 7.64% volumetric expansion, yielding the highest capacity of 557.5 ​mA ​h ​g−1, and good cycling retention of 85% over 4000 cycles. The use of V3+/V5+ double redox will open-up new opportunities for designing vanadium-rich cathodes for high-performance Zn ion battery.

VS4 with a chain crystal structure used as an intercalation cathode for aqueous Zn-ion batteries

Vanadium tetrasulfide (VS4) with a beneficial one-dimensional atomic-chain structure is reported to be able to serve as a favorable intercalation cathode material for a high-performance Zn-ion battery.

A N, O co-doped hierarchical carbon cathode for high-performance Zn-ion hybrid supercapacitors with enhanced pseudocapacitance

A novel carbon cathode was fabricated for high-performance Zn-ion supercapacitors with enhanced pseudocapacitance.

Mechanistic investigation of silver vanadate as superior cathode for high rate and durable zinc-ion batteries

Rechargeable aqueous Zn-ion batteries have shown considerable potential for stationary grid-scale energy storage systems owing to their characteristics of low cost and non-pollution. Nevertheless, the development of high-performance cathode materials is still a formidable challenge. In this work, for the first time, we report a superior silver vanadate (β-AgVO3) cathode for Zn-ion batteries, and demonstrate the fundamental Zn2+ storage mechanism in detail. In sharp contrast to the previously-reported layered vandium-based materials, the β-AgVO3 cathode experiences an initial phase transition to form a layered Zn3V2O7(OH)2·2H2O through a displacement/reduction reaction of Zn2+/Ag+ in the first discharge process. The in situ generated Ag0 along with the residual Ag+ and structural water within the framework afford high electronic/ionic conductivity, thus enabling enhanced Zn2+ intercalation/deintercalation kinetics in the layered phase. As a consequence, the cathode can deliver remarkable rate performance (103 mAh g−1 at 5000 mA g−1) and long-term cycling stability (95 mAh g−1 after 1000 cycles at 2000 mA g−1). The present study offers a totally new insight into the exploration of non-layered-structured vandium-based cathodes for high performance Zn-ion batteries.

Realizing high-performance Zn-ion batteries by a reduced graphene oxide block layer at room and low temperatures

Abstract Rechargeable aqueous Zn-ion batteries (ZIBs) have attracted great attention due to their cost-effectiveness, high safety, and environmental friendliness. However, some issues associated with poor structural instability of cathode materials and fast self-discharge hinder the further development of ZIBs. Herein, a new configuration is introduced by placing a reduced graphene oxide film as a block layer between the separator and the V2O5·nH2O cathode. This layer prevents the free diffusion of dissolved active materials to the anode and facilitates the transport of Zn ion and electrons, largely improving the cyclic stability and alleviating the self-discharge. Accordingly, the optimized battery delivers a remarkable capacity of 191 mAh g−1 after 500 cycles at 2 A g−1. Moreover, a high capacity of 106 mAh g−1 is achieved after 100 cycles at −20 °C. The strategy proposed is expected to be applicable to other electrode systems, thus offering a new approach to circumvent the critical challenges facing aqueous batteries.

Evaluating Flexibility and Wearability of Flexible Energy Storage Devices

Hongfei Li obtained his Bachelor’s degree from the School of Materials Science and Engineering, Central South University in 2009. After that, he received his Master’s degree from the School of Materials Science and Engineering, Tsinghua University in 2012. He joined Dr. Chunyi Zhi’s group as a PhD candidate in 2015 at City University of Hong Kong. His research focuses on flexible and wearable aqueous batteries and polymer electrolytes. Zijie Tang is a PhD student in the Department of Materials Science and Engineering, City University of Hong Kong. He received his Bachelor’s degree from the School of Materials Science and Engineering, Central South University. His research mainly focuses on high-performance Zn-ion battery electrodes and polymer electrolytes for wearable energy storage devices. Zhuoxin Liu completed his Bachelor’s degree in polymer science and engineering and Master’s degree in materials science at Sichuan University, China. He joined Dr. Chunyi Zhi’s group as a PhD candidate in 2016 at City University of Hong Kong, where he has started his research on flexible and wearable energy storage devices including supercapacitors and aqueous battery systems. Chunyi Zhi is currently an associate professor in the Department of Materials Science and Engineering, City University of Hong Kong. He received his PhD degree in physics from the Institute of Physics, Chinese Academy of Sciences. Then he moved to the National Institute for Materials Science (NIMS) in Japan as a post-doctoral fellow, followed by an ICYS research fellow, researcher (faculty), and senior researcher (permanent). His research focuses on wearable and flexible energy storage devices and aqueous electrolyte batteries.

Rational design of nano-architecture composite hydrogel electrode towards high performance Zn-ion hybrid cell.

In this paper, we developed a novel Zn-ion hybrid cell based on a graphene-conducting polymer composite hydrogel (capacitor-type) cathode and a zinc metal (battery-type) anode. The pseudocapacitive-type cathode materials can effectively boost the capacity of Zn-ion hybrid cell compared to that of electrical double layer cathode materials. In particular, the composite hydrogel with rational designed three-dimensional (3D) nano-architecture combining 3D porous nanostructure with hydrogel, can significantly enlarge the active interfaces between the electrode and electrolyte. According to our experiments, the 3D graphene@PANI composite hydrogel electrode exhibits a large capacity of 154 mA h g-1, a superior rate capability and excellent capacity retention of 80.5% after 6000 charge-discharge cycles in a Zn-ion hybrid cell. The outstanding electrochemical properties demonstrate that the 3D nanostructure composite hydrogel materials can effectively promote the material utilization, transport of charges, and reduce the degradation of conducting polymers, leading to a highly efficient, fast and stable electrochemical process. Based on our results, Zn-ion hybrid cells based on a composite hydrogel electrode could be an extremely promising candidate for next generation electrochemical energy storage devices.