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Aqueous zinc‐ion batteries (ZIBs) have triggered a great deal of scientific research and become a promising alternative for large‐scale energy storage applications, owing to the unique merits of high volumetric energy density, abundance of zinc resources, eco‐friendliness, and safety. The pace of progress of ZIB development, however, is hindered by their poor reversibility and sluggish kinetics, derived from the dissolution of active materials in aqueous electrolytes and the strong electrostatic interactions between Zn2+ and the cathode lattice. Herein, a vanadium oxide (V2O5‐x)/polyaniline (PANI‐V) superlattice structure is demonstrated as a model of superlattice structural engineering to overcome these weaknesses. In this superlattice, the PANI layer not only plays the role of a spacer to expand the V2O5‐x interlayer spacing but also serves as a conductive capacity contributor. Moreover, the PANI layer servers as structural stabilizer to restrain the dissolution of V2O5‐x active materials in aqueous electrolytes. In addition, it introduces an interface effect to modulate the charge distribution of the V2O5‐x monolayer, promoting Zn‐ion diffusion into the structure. Correspondingly, weakening the electrostatic interactions and supressing the active materials dissolution synergistically boosts the electrochemical performance for Zn‐ion storage. This work paves the way for the development/improvement of cathodes for aqueous zinc‐ion batteries. [ABSTRACT FROM AUTHOR]

Hexacyanoferrate (Prussian blue, PB)/reduced graphene oxide (PB‐RGO) composites with a synergistic structure (graphene/PB/graphene) and a chemical bond are fabricated using a facile one‐step method that does not require any external chemical reducing agent. Here, Na4Fe(CN)6 is decomposed in an acidic solution to produce Fe2+ ions, which anchor onto the electronegative graphene oxide (GO) layers by electrostatic interaction and then reduce the GO. The formation of an FeOC chemical bond in the composite results in an excellent rate capability of the PB‐RGO composite at room temperature, delivering capacities of 78.1, 68.9, and 46.0 mAh g−1 even at the high rates of 10, 20, and 50 C, with a capacity retention of 70.2%, 63.4%, and 41.0%, respectively. The composite also shows an unprecedentedly outstanding cycling stability, retaining ≈90% of the initial capacity after 600 cycles. [ABSTRACT FROM AUTHOR]

Sodium ion batteries (SIBs) have recently attracted considerable attention and are considered as an alternative to lithium ion batteries (LIBs), owing to the cheap price and abundance of sodium resources. However, the commercialization of SIBs has so far been impeded by the low energy density and unstable cycle life of electrodes, especially as cathodes. Although some cathode candidates with a stable cycle life and high energy density have been developed using nanotechnologies, the commercial feasibility is seldom taken into account. This research news article provides an insight into the commercial prospects of existing cathode materials for SIBs in terms of environmental friendliness, manufacturing cost, synthesis methods and electrochemical performance. [ABSTRACT FROM AUTHOR]

Aqueous Zn‐ion batteries with mild acidic electrolytes are considered the promising energy storage solutions due to their outstanding merits of high energy density and cost‐effectiveness. However, the rampant dendrite growth and severe parasitic reactions caused by a series of factors such as irregular Zn2+ transport pathway and pH variation would result in poor cycling stability. Herein, a self‐regulated interface strategy implemented by ammonium persulfate ((NH4)2S2O8, denoted as APS) multifunctional additive is proposed to simultaneously address the above issues. The zincophilic NH4+ preferentially adsorbs on the Zn protuberance to exclude water molecules and shield the "tip effect," thus inhibiting side‐reactions and inducing uniform Zn deposition. Moreover, NH4+ and S2O82− can dynamically adjust H+ and OH− concentrations in a pH self‐buffer manner, thus effectively mitigating hydrogen evolution reaction and formation of by‐products. Consequently, with the existence of APS additive, Zn anode exhibits ultrahigh coulombic efficiency (CE) of 99.9% over 9000 cycles and ultra‐long lifespan of 4300 h at 5 mA cm−2. Furthermore, even under high NH4V4O10 mass loading (9.4 mg cm−2) and thin zinc foil (10 µm), the assembled NH4V4O10//Zn pouch cell with APS additive can still maintain stably over 210 cycles, demonstrating its excellent value for application. [ABSTRACT FROM AUTHOR]

Mn‐based hexacyanoferrate NaxMnFe(CN)6 (NMHFC) has been attracting more attention as a promising cathode material for sodium ion storage owing to its low cost, environmental friendliness, and its high voltage plateau of 3.6 V, which comes from the Mn2+/Mn3+ redox couple. In particular, the Na‐rich NMHFC (x > 1.40) with trigonal phase is considered an attractive candidate due to its large capacity of ≈130 mAh g−1, delivering high energy density. Its unstable cycle life, however, is holding back its practical application due to the dissolution of Mn2+ and the trigonal‐cubic phase transition during the charge–discharge process. Here, a novel hexacyanoferrate (Na1.60Mn0.833Fe0.167[Fe(CN)6], NMFHFC‐1) with Na‐rich cubic structure and dual‐metal active redox couples is developed for the first time. Through multiple structural modulation, the stress distortion is minimized by restraining Mn2+ dissolution and the trigonal‐cubic phase transition, which are common issues in manganese‐based hexacyanoferrate. Moreover, NMFHFC‐1 simultaneously retains an abundance of Na ions in the framework. As a result, Na1.60Mn0.833Fe0.167[Fe(CN)6] electrode delivers high energy density (436 Wh kg−1) and excellent cycle life (80.2% capacity retention over 300 cycles), paving the way for the development of novel commercial cathode materials for sodium ion storage. [ABSTRACT FROM AUTHOR]