Search

[Display omitted] Aqueous zinc ion batteries (AZIBs) are receiving broad attention owing to their high safety and low cost. However, the high mechanical strength and irreversible growth of zinc dendrites limit the practical application of AZIBs. Herein, regular mesh-like gullies are built on the surface of zinc foil (M150 Zn) by using simple model pressing method and stainless steel mesh as a mold. Due to the charge-enrichment effect, zinc ion deposition and stripping will be preferentially carried out in the grooves to keep the outer surface flat. In addition, zinc is exposed to 002 crystal surface in the gully after being pressed, and the deposited zinc is more inclined to grow at a small angle, so that it has a sedimentary morphology parallel to the basement. Consequently, at a current density of 0.5 mA cm−2, the M150 zinc anode has a voltage hysteresis of only 35 mV and a cycle life of up to 400 h (relative to a zinc foil of 96 mV and 160 h). Even more imposing is that the full cell has a capacity retention of approximately 100% after 1000 cycles at 2 A g−1 and a specific capacity of almost 60 mAh g−1 when activated carbon is used as the cathode. It is a promising method to improve the stable cycle performance of AZIBs by using a simple method to realize the non-prominent dendrites on the surface of zinc electrode. [ABSTRACT FROM AUTHOR]

[Display omitted] Flexible aqueous zinc-ion batteries (AZIBs) require high conductive and adhesive hydrogel electrolytes. However, high adhesion tends to hinder ion conduction rate. Herein, we designed a water/glycerol binary solvent coordinating the hydrophilic polymers to reconstruct the water molecules' environment in the hydrogel. As a consequence, the interface adhesion strength between Zn and the hydrogel reached 3.0 kPa and the ionic conductivity was up to 16.8 mS cm−1. In addition, inspired by the slurry electrode preparation method, we developed a simple blade coating technique using a non-Newtonian polysaccharide liquid solution to construct an ultra-thin hydrogel electrolyte in situ on the cathode. The thickness of the obtained hydrogel reached 70 μm, and the ultrathin flexible AZIBs were easily constructed by pasting a Zn anode directly on the adhesive hydrogel, showing the potential of flexible AZIBs scalable assembly. In addition, the Zn//Zn symmetrical cells with the hydrogel electrolyte provided stable cycling performance for over 400 h at 0.1 mA cm−2 with suppressed dendrite growth. The assembled Zn//Polyaniline battery and Zn//V 2 O 5 battery also exhibited excellent capacity retention after cycles. This work has realized the hydrogel electrolyte with high adhesion and conductivity, which has good adaptability to metal electrodes and opened up a new practical way for large-scale assembly of flexible energy storage devices. [ABSTRACT FROM AUTHOR]

[Display omitted] Na 5 V 12 O 32 (NVO) is a potential cathode for aqueous zinc ion batteries (AZIBs). However, it suffers severe capacity decay due to the dissolution of the active material. The structural design may be an effective solution to the problem. Herein, we construct a typical two-dimensional hierarchical structure of Na 5 V 12 O 32 @graphene (NVO@G) via a facile molten salt method. The capacity fading problem is solved by the in-situ conversion of NVO@G to a more stable hierarchical system during cycling. The in-situ formed zinc pyrovanadate (Zn 3 V 2 O 7 (OH) 2 ·2H 2 O, ZVO) nanosheets on the surface of graphene exhibits excellent zinc-ion storage stability. The presence of graphene induces the growth of NVO nanobelts to construct the typical two-dimensional hierarchical structure. Additionally, the in-situ conversion makes the formed ZVO nanosheets contact with graphene better. Benefitting from the hierarchical nanostructure and in-situ phase conversion, the NVO@G electrode shows excellent long-term stability (96.4% retention after 340 cycles at 0.3 A g−1, 85.7% retention after 4400 cycles at 5 A g−1) and high zinc ion storage capacity (220 mAh g−1 at 0.3 A g−1), which is superior to those of most electrode materials previously reported. [ABSTRACT FROM AUTHOR]

Cationic surfactant type additive TMA 2 SO 4 is used to suppress zinc dendrites and improve the life time of zinc ion batteries. [Display omitted] Recently, zinc metal has been considered as a promising metal anode for aqueous rechargeable metal ion batteries due to its low electrochemical potential and high theoretical capacity. However, zinc metal suffers from hydrogen evolution reaction (HER) and dendrite growth during plating/stripping. Here, we propose a low-cost, effective and non-toxic electrolyte additive, tetramethylammonium sulfate hydrate (TMA 2 SO 4), as a simple cationic surfactant additive for zinc-ion batteries, to trigger the smooth Zn deposition during charging and discharging process. It is found that TMA 2 SO 4 enable the realization of the deposition of Zn ions along the surface of zinc foil laterally without stacking and thus dendrite growth and side reactions are greatly mitigated by the electrolyte additive of TMA 2 SO 4 even when the amount of the additive is as low as 0.25 mM. As a result, the TMA 2 SO 4 additive induces excellent cycling stability over 1800 h at the current density of 0.5 mA cm−2 with the limited capacity of 0.5 mAh cm−2 for the Zn-Zn symmetrical cell. Moreover, the electrolyte with TMA 2 SO 4 can well match with MnO 2 cathode, which achieves the high initial capacity of 181.3 mAh g−1 at 0.2 A g−1 and long-term cycling stability with the capacity retention of 98.72 % after 200 cycles for the Zn/MnO 2 full cell. This work provides a general electrolyte design strategy to suppress zinc dendrite growth and side reactions to achieve long-lifespan zinc metal anodes for aqueous zinc ion batteries by electrostatic shielding effect. [ABSTRACT FROM AUTHOR]

Sandwich-like V 2 O 5 /graphene composites with adjustable graphene content (denoted as V 2 O 5 /xG) were designed to demonstrate the effects of electrode structure and wetting characteristics on zinc storage properties. The V 2 O 5 /5G with 10.4% graphene content exhibits effective inhibition of vanadium dissolution, high capacity and excellent cycling stability. [Display omitted] Improving the stability of the layered structure and suppressing vanadium dissolution during repeated Zn2+ insertion/extraction processes are considered to be the key to promote the electrochemical stability of vanadium-based cathodes for ZIBs. In this work, a group of sandwich-like V 2 O 5 /graphene composites (V 2 O 5 /xG) were controllably fabricated by tuning the amount of hydrophobic graphene. With the increase of graphene content, the corresponding electrochemical properties show a parabolic trend that increase first and then decrease. A maximum capacity of 270 mAh g−1 after 100 cycles at 0.1 A g−1 and a superior cycle stability with 82.4% capacitance retention after 6000 cycles at 10 A g−1 are achieved when the amount of graphene is about 10.4% (that is V 2 O 5 /5G). The addition of graphene has been proven not only to act as an effective conductive network to promote charge transfer and enhance the pseudocapacitance effect on the electrode surface; but also to increase the electrode hydrophobicity, effectively inhibiting the dissolution of vanadium, and promoting the desolvation and diffusion kinetics of hydrated zinc ions. Moreover, the graphene layer, as a structural stabilizer, effectively prevents the structure of the active component V 2 O 5 from collapsing during cycling, contributing to the long-term cycle life. [ABSTRACT FROM AUTHOR]

[Display omitted] • Sodium lignosulfonate is used as the electrolyte additive of zinc-ion batteries. • The performances of Zn//MnO 2 battery are significantly improved by the additive. • The Zn//Zn cell with the modified electrolyte realizes excellent reversibility. • The Zn//Cu cell with the modified electrolyte exhibits uniform zinc striping/plating. • The additive can effectively suppress dendrite growth and byproduct formation. Thanks to high safety and low cost, rechargeable zinc-ion batteries (RZIBs) have become a promising candidate for grid-scale energy storage systems. However, zinc anodes suffer from severe dendrite growth and irreversible side reactions, leading to poor cyclability of RZIBs. In this work, low-cost sodium lignosulfonate (SL) is utilized as the electrolyte additive to solve this problem. The added amount of SL is optimized to be 0.02%, which enables the Zn//α-MnO 2 battery to deliver a large capacity of 146 mAh g−1 after 1000 cycles at 1 A g−1, corresponding to a high capacity retention of 83.5%. The Zn//Zn symmetric cell with the modified electrolyte also shows excellent cyclability even under a commercial level of areal specific capacity (4 mAh cm−2). Overall, the results of this study confirm that the SL additive can improve the ionic conductivity of electrolyte, restrict the two-dimensional planar diffusion of Zn2+ ions at the electrode/electrolyte interface, lower the nucleation overpotential of Zn2+ ions, prevent side reactions, and inhibit the corrosion of Zn metal. Therefore, the dendrite growth and byproduct formation can be effectively suppressed. This study provides new insights into protecting metal electrodes of electrochemical energy storage devices. [ABSTRACT FROM AUTHOR]

A novel egg waffle–like architecture consisting of double–shell ZnMn 2 O 4 hollow microspheres embedded in 2D carbon networks is designed and exhibits excellent electrochemical properties when used as a cathode electrode material in aqueous zinc ion batteries. Currently, aqueous zinc–ion batteries are receiving extraordinary attention because of their cheap price, superior energy density and great security. However, the inferior specific capacity and low rate capability significantly hamper their further widespread application. Herein, a novel egg waffle–like architecture consisting of double–shell ZnMn 2 O 4 hollow microspheres embedded in 2D carbon networks (ZnMn 2 O 4 @C) is designed and employed as a cathode material for aqueous zinc–ion batteries. Specifically, the ZnMn 2 O 4 @C electrode displays a capacity of 481 mAh g−1 at 0.2 A g−1 after 110 cycles with excellent cycling stability. The superior cycling stability of the ZnMn 2 O 4 @C electrode is ascribed to the synergistic effect of the double–shell ZnMn 2 O 4 hollow microspheres, which offer sufficient space to withstand volume expansion during Zn2+ intercalation/deintercalation process, as well as the 2D continuous conductive and interconnected carbon network, which facilitates rapid electronic transmission and guarantees good structural mechanical stability. This study offers a fascinating cathode material and extends the available choices for manganate based–materials in rechargeable aqueous zinc–ion batteries. [ABSTRACT FROM AUTHOR]