Conventional organic batteries suffer from rapid capacity fading. Organic compounds are inclined to dissolve in the electrolyte and limit the long-term cycling performance of lithium− organic batteries. Carbon skeletons show efficacy in confining the active materials of organic cathodes. In this study, we investigate the electrochemical performance of aqueous zinc-ion batteries with binder-free composite cathodes consisting of carbon nanotubes (CNTs) and naphthoquinone (NQ)-based organics. The quinones are trapped in the nanoporous structure of the CNT framework, and thus the dissolution was minimized. The composite cathodes show stable and high rate cyclability, owing to the high electrical conductivity and confinement of the CNT network. The NQ composite cathode exhibits an initial capacity of 333.5 mAh g −1 , close to the theoretical capacity of 339.0 mAh g −1 . Furthermore, it is uncovered that modifying NQ with functional groups significantly impacts the electrochemical behavior, including the redox potential and capacity retention. With the electronwithdrawing or electron-donating groups, dichlone and 2-((4-hydroxyphenyl) amino) naphthalene-1,4-dione (APh-NQ) show better performance than NQ with improved capacity retention from 41.0 to 70.9 and 68.3%, respectively, after 1000 cycles. The work promotes the development of binder-free organic cathodes for the aqueous Zn-ion batteries and sheds light on designing highperformance electrodes for low-cost energy storage systems.

The development of metal ion‐intercalated active materials for excellent electrochemical performance in rechargeable aqueous zinc‐ion batteries (AZIBs) is challenging. The structure instability and intrinsic electrostatic repulsion of the lattice framework cause structural breakdown and low‐rate performance. In response to these problems, yttrium vanadium oxide–poly(3,4‐ethylenedioxythiophene) (PEDOT@YVO) composite is reported as stable cathode material for AZIBs. The introduction of PEDOT in YVO nanorods improves the crystalline structure with an enlarged interplanar lattice spacing of 3.4 Å. The PEDOT@YVO composite electrode demonstrates effective electric conductivity and a higher initial specific capacity of 308.5 mAh g−1 than that (125.5 mAh g−1) of the pure YVO at 0.2 C rate. It also features a long‐term stable discharge–charge cycle performance of 4000 cycles with a capacity retention of 79.2% at 1C rate, better than YVO (29.4 mAh g−1). The oxygen vacancies and improved electrical conductivity of the composite account for the invigorated electrochemical performance. Consequently, this work reveals another avenue for constructing unique electrodes to enhance the electrochemical properties of AZIBs.

Aqueous zinc-ion batteries (AZIBs) lately garner a lot of interest and are viewed as a promising energy storage technology due to their low cost, eco-friendliness, and exceptional safety. Crystal metal oxide cathode research has advanced significantly in recent years, making AZIBs a viable choice for low-cost grid storage applications. However, the readily available (Mn-and V-based oxides) electrode materials suffer from instability and low conductivity. As a consequence, extensive study efforts are dedicated into the development and evaluation of high-performance cathode systems. Herein, advanced composite cathodes with modified structures are reviewed in an attempt to increase capacity and cycle life. The Mn-and V-based composite framework with polymer template, graphene, and MXene induces electric conductivity, improved lattice spacing, and tunable characteristics, as well as possible benefits for overcoming the redox kinetics and stability constraints for AZIBs. As a result, rational modification of the metal oxides as well as the production of composites shows promise in solving problems and improving cathode performance in high-performance AZIBs.