Featuring with low cost, exceptional inherent safety and decent electrochemical performance, rechargeable Znbased batteries (RZBs) have attracted increased attention and revived research efforts recently as a compelling alternative battery chemistry to Li-ion. However, some challenges still stand in the way of the development of these energy storage systems, such as low operation voltage, instability of cathode materials as well as dissolution of Zn electrode, etc. In this review, we present a comprehensive overview of recent progress in different RZBs systems including mild electrolyte RZBs, alkaline RZBs, hybrid RZBs, Zn-ion capacitors and Zn air batteries. The fundamental chemistry of various RZB systems, different cathode materials, optimization of Zn anode as well as various types of electrolytes and their influence on the battery performance are summarized. The major issues of different components along with respective strategies to alleviate them are discussed, aiming at providing a general guide for design and construction of high-performance RZBs. Additionally, the development of RZBs with different features in the last few years are summarized. Finally, we discuss the limitations and challenges that need to be overcome, providing potential future research directions in the field of next-generation RZBs.

A carbon nanostructured hybrid fiber is developed by integrating mesoporous carbon and graphene oxide into aligned carbon nanotubes. This hybrid fiber is used as a 1D cathode to fabricate a new cable-shaped lithium-sulfur battery. The fiber cathode exhibits a decent specific capacity and lifespan, which makes the cable-shaped lithium-sulfur battery rank far ahead of other fiber-shaped batteries.

Fiber-shaped dual-ion batteries (FSDIBs) are one of the promising flexible energy storage candidates for wearable electronics owing to their one-dimensional structure, good flexibility and high energy density. To the best of our knowledge, the fabrication of the FSDIBs has not been reported yet. One of the main challenges is to find the appropriate one-dimensional electrode with high capacity, high flexibility and good structure stability under different bending states and in reversible cycle processes. Herein, we report a proof of concept experiment on designing FSDIBs for the first time with high energy density, good reversibility and high cycle stability, which consists of the omnidirectional porous Al wire as the anode and the graphite on the Al wire as the cathode. The assembled battery shows high mass specific energy density of 173.33 Wh kg(-1) based on the total mass of the two electrodes (volumetric specific energy density of 10.4 mWh cm(-3)) and excellent flexibility under different bending states. The proposed mechanism is clearly revealed by the in-situ XRD measurements and in-situ Raman spectroscopy, showing that the PF6- anions are reversibly intercalated/de-intercalated into/from graphite interlayers in the charge/discharge processes to a large extent.

Rechargeable aqueous zinc-ion batteries are recently gaining incremental attention because of low cost and material abundance, but their development is plagued by limited choice of cathode materials with satisfactory cycling performance. Here, we report a porous V₂O₅ nanofibers cathode with high Znstorage performance in an aqueous Zn(CF₃SO₃)₂ electrolyte. We propose a reaction mechanism based on phase transition from orthorhombic V₂O₅ to zinc pyrovanadate on first discharging and reversible Zn²⁺ (de)intercalation in the open-structured hosts during subsequent cycling. This open and stable architecture enables a high reversible capacity of 319 mAh g^-1 at 20 mA g^-1 and a capacity retention of 81% over 500 cycles. The remarkable electrochemical performance makes V₂O₅ a promising cathode for aqueous zinc-ion batteries.

Aqueous zinc ion batteries (ZIBs) are truly promising contenders for the future large-scale electrical energy storage applications due to their cost-effectiveness, environmental friendliness, intrinsic safety, and competitive gravimetric energy density. In light of this, massive research efforts have been devoted to the design and development of high-performance aqueous ZIBs; however, there are still obstacles to overcome before realizing their full potentials. Here, the current advances, existing limitations, along with the possible solutions in the pursuit of cathode materials with high voltage, fast kinetics, and long cycling stability are comprehensively covered and evaluated, together with an analysis of their structures, electrochemical performance, and zinc ion storage mechanisms. Key issues and research directions related to the design of highly reversible zinc anodes, the exploration of electrolytes satisfying both low cost and good performance, as well as the selection of compatible current collectors are also discussed, to guide the future design of aqueous ZIBs with a combination of high gravimetric energy density, good reversibility, and a long cycle life.

Aqueous rechargeable zinc batteries (ZBs) have received considerable attention recently for large-scale energy storage systems in terms of rate performance, cost, and safety. Nevertheless, these ZBs still remain a subject for investigation, as researchers search for cathode materials enabling high performance. Among the various candidate cathode materials for ZBs, quinone compounds stand out as candidates because of their high specific capacity, sustainability, and low cost. Quinone-based cathodes, however, suffer from the critical limitation of undergoing dissolution during battery cycling, leading to a deterioration in battery life. To address this problem, we have introduced a redox-active triangular phenanthrenequinone-based macrocycle () with a rigid geometry and layered superstructure. Notably, we have confirmed that Zn ions, together with HO molecules, can be inserted into the organic cathode, and, as a consequence, the interfacial resistance between the cathode and electrolytes is decreased effectively. Density functional theory calculations have revealed that the low interfacial resistance can be attributed mainly to decreasing the desolvation energy penalty as a result of the insertion of hydrated Zn ions in the cathode. The combined effects of the insertion of hydrated Zn ions and the robust triangular structure of serve to achieve a large reversible capacity of 210 mAh g at a high current density of 150 mA g, along with an excellent cycle-life, that is, 99.9% retention after 500 cycles. These findings suggest that the utilization of electron-active organic macrocycles, combined with the low interfacial resistance associated with the solvation of divalent carrier ions, is essential for the overall performance of divalent battery systems.

High-performance flexible one-dimensional (1D) electrochemical energy storage devices are crucial for the applications of wearable electronics. Although much progress on various 1D energy storage devices has been made, challenges involving fabrication cost, scalability, and efficiency remain. Herein, a high-performance flexible all-fiber zinc-ion battery (ZIB) is fabricated using a low-cost, scalable, and efficient continuous wet-spinning method. Viscous composite inks containing cellulose nanofibers/carbon nanotubes (CNFs/CNTs) binary composite network and either manganese dioxide nanowires (MnO₂ NWs) or commercial Zn powders are utilized to spinning fiber cathodes and anodes, respectively. MnO₂ NWs and Zn powders are uniformly dispersed in the interpenetrated CNFs/CNTs fibrous network, leading to homogenous composite inks with an ideal shear-thinning property. The obtained fiber electrodes demonstrate favorable uniformity and flexibility. Benefiting from the well-designed electrodes, the assembled flexible fiber-shaped ZIB delivers a high specific capacity of 281.5 mAh g^-1 at 0.25 A g^-1 and displays excellent cycling stability over 400 cycles. Moreover, the wet-spun fiber-shaped ZIBs achieve ultrahigh gravimetric and volumetric energy densities of 47.3 Wh kg^-1 and 131.3 mWh cm^-3, respectively, based on both cathode and anode and maintain favorable stability even after 4000 bending cycles. This work offers a new concept design of 1D flexible ZIBs that can be potentially incorporated into commercial textiles for wearable and portable electronics.

Emerging research toward next-generation flexible and wearable electronics has stimulated the efforts to build highly wearable, durable, and deformable energy devices with excellent electrochemical performances. Here, we develop a high-performance, waterproof, tailorable, and stretchable yarn zinc ion battery (ZIB) using double-helix yarn electrodes and a cross-linked polyacrylamide (PAM) electrolyte. Due to the high ionic conductivity of the PAM electrolyte and helix structured electrodes, the yarn ZIB delivers a high specific capacity and volumetric energy density (302.1 mAh g and 53.8 mWh cm, respectively) as well as excellent cycling stability (98.5% capacity retention after 500 cycles). More importantly, the quasi-solid-state yarn ZIB also demonstrates superior knittability, good stretchability (up to 300% strain), and superior waterproof capability (high capacity retention of 96.5% after 12 h underwater operation). In addition, the long yarn ZIB can be tailored into short ones, and each part still functions well. Owing to its weavable and tailorable nature, a 1.1 m long yarn ZIB was cut into eight parts and woven into a textile that was used to power a long flexible belt embedded with 100 LEDs and a 100 cm flexible electroluminescent panel.

Several layer-structured vanadates of two-dimensional (2D) nanosheet morphologies have been investigated recently for flexible quasi-solid-state aqueous zinc-ion batteries (ZIBs), where one of the challenging issues is the poor electronic conductivity and mechanical stability especially in the cross-2D nanosheet direction, leading to insufficient rate capability and mechanical stability and shortened cycle life. Herein, we have devised a strategy of using one-dimensional (1D) carbon nanotubes (CNTs) to stitch zinc pyrovanadate (Zn(OH)VO·2HO, CNT-stitched ZVO) 2D nanosheets that are directly grown on oxidized CNT fiber (CNT-stitched ZVO NSs@OCNT fiber). With the CNT-stitched 2D nanosheet structure, the open frameworks of ZVO provide required spacing for reversible Zn (de)intercalation, and the stitching CNTs offer the desperately needed electronic conductivity and mechanical robustness across the ZVO 2D nanosheets. As a result, the fiber-shaped quasi-solid-state ZIB, assembled using the CNT-stitched ZVO NSs@OCNT as the cathode and Zn NSs@CNT fiber (electrodeposited zinc nanosheets on CNT fiber) as the anode, demonstrates an ultrahigh rate capability (69.7% retention after a 100-fold increase in current density), an impressively stack volumetric energy density of 71.6 mWh cm, together with a long-term stability (88.6% retention after 2000 cycles). The present work proves the proof-of-concept of developing 2D nanosheets purposely stitched together by 1D conducting nanotubes/nanowires as a class of advanced cathodes for quasi-solid-state ZIBs in future portable electronics.

Extensive efforts have been devoted to construct a fiber-shaped energy-storage device to fulfill the increasing demand for power consumption of textile-based wearable electronics. Despite the myriad of available material selections and device architectures, it is still fundamentally challenging to develop eco-friendly fiber-shaped aqueous rechargeable batteries (FARBs) on a single-fiber architecture with high energy density and long-term stability. Here, we demonstrate flexible and high-voltage coaxial-fiber aqueous rechargeable zinc-ion batteries (CARZIBs). By utilizing a novel spherical zinc hexacyanoferrate with prominent electrochemical performance as cathode material, the assembled CARZIB offers a large capacity of 100.2 mAh cm and a high energy density of 195.39 mWh cm, outperforming the state-of-the-art FARBs. Moreover, the resulting CARZIB delivers outstanding flexibility with the capacity retention of 93.2% after bending 3000 times. Last, high operating voltage and output current are achieved by the serial and parallel connection of CARZIBs woven into the flexible textile to power high-energy-consuming devices. Thus, this work provides proof-of-concept design for next-generation wearable energy-storage devices.

Wearable smart textiles are natural carriers to enable imperceptible and highly permeable sensing and response to environmental conditions via the system integration of multiple functional fibers. However, the existing massive interfaces between different functional fibers significantly increase the complexity and reduce the wearability of the textile system. Thus, it is significant yet challenging to achieve all-in-one multifunctional fibers for realizing miniaturized and lightweight smart textiles with high reliability. Herein, as bifunctional electrolyte additives, fluorescent carbon dots with abundant zincophilic functional groups are introduced into electrolytes to develop fluorescent fiber-shaped aqueous zinc-ion batteries (FFAZIBs). Originating from effective dendrite suppression of Zn anodes and multiple active sites of freestanding Prussian blue cathodes, high energy density (0.17 Wh·cm) and long-term cyclability (78.9% capacity retention after 1500 cycles) are achieved for FFAZIBs. More importantly, the one-dimensional structure ensures the same luminance in all directions of FFAZIBs, enabling the form of multicolor display-in-battery textiles.