Single-Ion-Conducting Hydrogel Electrolytes Based on Slide-Ring Pseudo-Polyrotaxane for Ultralong-Cycling Flexible Zinc-Ion Batteries.

Flexible zinc-ion batteries (ZIBs) with high capacity and long cycle stability are essential for wearable electronic devices. Hydrogel electrolytes have been developed to provide ion-transfer channels while maintaining the integrity of ZIBs under mechanical strain. However, hydrogel matrices are typically swollen with aqueous salt solutions to increase ionic conductivity, which can hinder intimate contact with electrodes and reduce mechanical properties. To address this, a single-Zn-ion-conducting hydrogel electrolyte (SIHE) is developed by integrating polyacrylamide network and pseudo-polyrotaxane structure. The SIHE exhibits a high Zn2+ transference number of 0.923 and a high ionic conductivity of 22.4 mS cm-1 at room temperature. Symmetric batteries with SIHE demonstrate stable Zn plating/stripping performance for over 160 h, with a homogenous and smooth Zn deposition layer. Full cells with La-V2 O5 cathodes exhibit a high capacity of 439 mA h g-1 at 0.1 A g-1 and excellent capacity retention of 90.2% after 3500 cycles at 5 A g-1 . Moreover, the flexible ZIBs display stable electrochemical performance under harsh conditions, such as bending, cutting, puncturing, and soaking. This work provides a simple design strategy for single-ion-conducting hydrogel electrolytes, which could pave the way for long-life aqueous batteries.

Xia H ，Xu G ，Cao X ，Miao C ，Zhang H ，Chen P ，Zhou Y ，Zhang W ，Sun Z ... -  《-》

Single-Ion Conducting Double-Network Hydrogel Electrolytes for Long Cycling Zinc-Ion Batteries.

Chan CY ，Wang Z ，Li Y ，Yu H ，Fei B ，Xin JH ... -  《-》

Stable Hydrogel Electrolytes for Flexible and Submarine-Use Zn-Ion Batteries.

Wang B ，Li J ，Hou C ，Zhang Q ，Li Y ，Wang H ... -  《-》

Polysaccharide hydrogel electrolytes with robust interfacial contact to electrodes for quasi-solid state flexible aqueous zinc ion batteries with efficient suppressing of dendrite growth.

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//V2O5 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.

Deng Y ，Wu Y ，Wang L ，Zhang K ，Wang Y ，Yan L ... -  《-》

An ionically cross-linked composite hydrogel electrolyte based on natural biomacromolecules for sustainable zinc-ion batteries.

Ge H ，Qin L ，Zhang B ，Jiang L ，Tang Y ，Lu B ，Tian S ，Zhou J ... -  《-》