The development of high-energy-density aqueous zinc-ion batteries requires the preparation of cathodes with a thick layer of active material. However, the insulating nature and dissolution of vanadium-based oxides lead to low areal capacity (0.1,1 mA h cm-2) during the charge/discharge cycle. Herein, V2O5 nanospheres are generated by anchoring onto the laser-induced graphene (LIG) conductive network through defect-induced adsorption, resulting in the formation of pomegranate-like V2O5@LIG composites. The unique and abundant defect structure in the honeycomb LIG can trigger the formation of uniform V2O5 nanospheres with high specific surface area and interact electronically with V2O5 to enhance the electrical conductivity of the cathode materials up to four orders of magnitude. In contrast to conventional carbon materials that can cause steric hindrance for ion transport, the micropores within LIG shorten the ion transport path through the cathode. Concurrently, the pomegranate-like encapsulated structure effectively prevents cathode material corrosion. Under a high-loading mass of 17.1 mg cm-2, the full cell is stably cycled for 200 cycles, possessing a 92.5% capacity retention, and achieving a high areal capacity of 6.05 mA h cm-2. Pomegranate-liked V2O5@LIG composites are formed by anchoring V2O5 nanospheres onto laser-induced graphene (LIG) networks via defects-triggered adsorption. The numerous defects and micropores of LIG endow the cathode material with enhanced electron conduction pathways and ionic conductivity, achieving 6.05 mA h cm-2 under high-loading mass (17.1 mg cm-2) and demonstrating a high-capacity contribution of vanadium (34.98 A h mol-1). image

Hybrid zinc-ion capacitors combine the energy storage capabilities of zinc-ion batteries with the high-power output of supercapacitors. However, the limited cycle life and narrow electrochemical window of hybrid zinc-ion capacitors currently restrict their potential applications. Herein, a hybrid zinc-ion capacitor is fabricated on laser-induced graphene (LIG) based on in situ electropolymerization of organic compound poly(8-amino-2-naphthol). The electropolymerized long-conjugated chain polymers on the 3D conductive framework of LIG can enhance reaction kinetics, suppress the dissolution of organic compounds, and boost capacity. Simultaneously, hydrogen bonds form between polymer chains, aiding in proton transport. The assembled Zn//carbon cloth/LIG/poly(8-amino-2-naphthol) hybrid zinc-ion capacitors possess a high specific capacity of 308 mAh g-1 at 0.1 mA cm-2, which is twice as much as that of the batteries without LIG. Additionally, these hybrid capacitors can stably endure 10 000 cycles at a current density of 5 mA cm-2. The hybrid zinc-ion capacitor, utilizing poly(8-amino-2-naphthol) on laser-induced graphene network presents a high specific capacity of 308 mAh g-1 at 0.1 mA cm-2, and demonstrates an exceptional cycling performance over 10 000 cycles with a retention rate of 99.98%. image

Side reactions on zinc metal (Zn) anodes are formidable issues that cause limited battery life of aqueous zinc‐ion batteries (AZIBs). Here, a facile and controllable layer‐by‐layer (LbL) self‐assembly technique is deployed to construct an ion‐conductive and mechanically robust electrolyte/anode interface for stabilizing the Zn anode. The LbL film consists of two natural and biodegradable bio‐macromolecules, chitosan (CS) and sodium alginate (SA). It is shown that such an LbL film tailors the solvation sheath of Zn ions and facilitates the oriented deposition of Zn. Symmetric cells with the four double layers of CS/SA ((CS/SA) 4 –Zn) exhibit stable cycles for over 6500 h. The (CS/SA) 4 –Zn||H 2 V 3 O 8 coin cell maintains a specific capacity of 125.5 mAh g −1 after 14 000 cycles. The pouch cell with an electrode area of 5 × 7 cm 2 also presents a capacity retention of 83% for over 500 cycles at 0.1 A g −1 . No obvious dendrites are observed after long cycles in both symmetric and full cells. Given the cost‐effective material and fabrication, and environmental friendliness of the LbL films, this Zn protection strategy may boost the industrial application of AZIBs.

The growth of dendrites and the hydrogen evolution reaction pose significant challenges to the development of Zn metal aqueous batteries as a promising solution for energy storage. Herein, trisodium nitrilotriacetate (Na3NTA) as an electrolyte additive is shown to improve the reversibility of the zinc plating-stripping process. NTA3- anions possess the potential not only to substitute water molecules in the solvation sheath of Zn2+ ions but also to construct a zincophilic electrolyte/Zn anode interface and suppress the activity of water molecules for stabilizing the Zn anode. The introduction of Na3NTA can effectively suppress side reactions arising from active water decomposition and simultaneously lead to the formation of a well-defined (002) texture structure. As a result, a Zn||Zn symmetric cell with a modified electrolyte demonstrates a lifespan of up to 3000 h at a cutoff capacity of 1 mA h cm-2. Furthermore, a Zn||V2O5 full cell exhibits an enhanced capacity retention of 83.2% even after undergoing 8000 cycles. No noticeable dendrites are observed even after long cycles in both symmetric and full cells. Due to the cost-effective material and ease of fabrication of the Na3NTA additive, this electrolyte strategy may promote the industrial application of aqueous zinc ion batteries. Trisodium nitrilotriacetate (Na3NTA), as an additive, can adsorb on the surface of the Zn anode and regulate the components within the inner Helmholtz plane. Moreover, the NTA3- has the ability to penetrate the primary solvation sheath of Zn2+ by displacing the coordinated water molecules. It effectively inhibits corrosion and hydrogen evolution reactions and produces a perfect (002) texture structure during adsorption, thus obviously extending the cycle life of the assembled cells.image

The development and application of rechargeable aqueous zinc‐ion batteries are seriously hindered by the problems of corrosion and dendrite growth on Zn metal anodes. Herein, a polyporous 3D zinc framework coupled with a zincophilic ZnSe overlayer (3D‐Zn@ZnSe) is synchronously obtained by one‐step electrochemical scanning, which precisely repairs intrinsic defects of the Zn foil surface and remodels the electrolyte/anode interface. The 3D‐Zn host formed by the pioneering electro‐oxidation significantly reduces the local current densities and facilitates adapting to the volume change during the plating/stripping. Meanwhile, the ZnSe overlayer obtained by electro‐deposition restrains the side reactions and promotes efficient desolvation, resulting in the acceleration of the deposition kinetics of Zn 2+ on the zinc anode. As a result, the anodes present an enhanced cycling stability of zinc plating/stripping for over 2000 h with low overpotential, and the assembled 3D‐Zn@ZnSe||V 2 O 5 cell retains 90.63% of its original capacity after 8500 cycles. The one‐step fabrication of polyporous interfaces with a zincophilic overlayer presents a promising strategy on improving the stability and reversibility of zinc anode for zinc‐based batteries.

The poor stability of the zinc-metal anode is a main bottleneck for practical application of aqueous zinc-ion batteries. Herein, a series of molecular sieves with various channel sizes are investigated as an electrolyte host to regulate the ionic environment of Zn2+ on the surface of the zinc anode and to realize separator-free batteries. Based on the ZSM-5 molecular sieve, a solid-liquid mixed electrolyte membrane is constructed to uniformize the transport of zinc ions and foster dendrite-free Zn deposition. Side reactions can also be suppressed through tailoring the solvation sheath and restraining the activity of water molecules in electrolyte. A V2 O5 ||ZSM-5||Zn full cell shows significantly enhanced performance compared to cells using glass fiber separator. Specifically, it exhibits a high specific capacity of 300 mAh g-1 , and a capacity retention of 98.67% after 1000 cycles and 82.67% after 3000 cycles at 1 A g-1 . It is attested that zeolites (ZSM-5, H-β, and Bate) with channel sizes of 5-7 Å result in best cycle stability. Given the low cost and recyclability of the ZSM and its potent function, this work may further lower the cost and boost the industrial application of AZIBs.