Aqueous zinc‐ion batteries are largely restricted by the unsatisfactory performance of zinc (Zn) anodes, including their poor stability and irreversibility. In particular, the mechanism behind the electrochemical contrast caused by the surface crystal plane, which is a decisive factor of the electrochemical characteristics of the hostless Zn anode, is still relatively indistinct. Hence, new insight into a novel anode with a surface‐preferred (002) crystal plane is provided. The interfacial reaction and morphology evolution are revealed by theoretical analysis and post‐mortem/operando experimental techniques, indicating that Zn anodes with more exposed (002) basal planes exhibit free dendrites, no by‐products, and weak hydrogen evolution, in sharp contrast to the (100) plane. These features benefit the Zn (002) anode by enabling a long cyclic life of more than 500 h and a high average coulombic efficiency of 97.71% for symmetric batteries, along with delivering long cycling stability and reversibility with life spans of over 2000 cycles for full batteries. This work provides new insights into the design of high‐performance Zn anodes for large‐scale energy storage and can potentially be applied to other metal anodes suffering from instability and irreversibility.

Aqueous Zn–MnO2 batteries have received much attentions for large‐scale applications because of high safety and low cost. However, the energy storage mechanisms of Zn–MnO2 system are still in dispute. Herein, a cathode‐free Zn–MnO2 battery is provided with the coexistence of dual mechanisms in mild acidic environment, in which the decisive guiding effect of the pH value in electrolyte on the mechanism is deeply investigated. On this basis, acetic acid (HAc) is used as a buffering additive to effectively suppress the “fluctuation” phenomenon during the operation, hence achieving the “self‐adjust” mechanism. The assembled soft package battery possesses a long lifetime of 2000 cycles with the Coulombic efficiency of 99.6%, improved high‐loading performance and rate capability. A new idea is provided for the exploration of energy storage mechanism of Zn–MnO2 battery as well as a guidance on the optimization strategies especially the battery construction.

The Zn metal anode is considered one of the most promising anode choices for aqueous Zn-based batteries. Nevertheless, dendrites and intricate side reactions have hindered its usage. Herein, an elastic and anti-corrosive interlayer is introduced to address the problem. The idiosyncratic dielectric behavior of amorphous and nanostructured silicon nitride (Si 3 N 4 ) is utilized to manipulate the ion kinetics, by uniformly dispersing its particles in polyacrylonitrile (PAN) to fabricate an interlayer attached to Zn metal (PSN-Zn). PAN serves as an elastic constraint to inhibit drastic dendrite evolution and blocks H 2 O/O 2 corrosion, and Si 3 N 4 with a high dielectric constant can facilitate the ion kinetics and endow uniform Zn deposition. The electrochemical stability and deposition consistency of the Zn anodes are greatly improved, with an extended lifespan of over 800 h at 1 mA cm −2 . Even under draconian deep-discharging (DOD Zn = 60%) and high current density (10 mA cm −2 ), the PSN-Zn anode can still operate stably for over 250 h. The effect of the dielectric property is systematically discussed and verified by experiments and theoretical simulations. Moreover, full cells with vanadium-and manganesebased cathodes also deliver excellent performance, indicating the use of the multifunctional interlayer as an appealing approach for rechargeable aqueous zinc batteries.

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Aqueous Mn 2 + /MnO 2 -based batteries have attracted enormous attentions in aqueous energy storage fields, owing to their high working voltage and theoretical capacity (616 mAh g À 1 ) brought by the two-electron reaction (Mn 2 + /Mn 4 + ). However, there are currently several tricky challenges facing Mn 2 + /MnO 2 -based batteries: their complicated working mechanisms, existing issues, and optimization strategies. This Perspective aims to provide a mechanistic understanding and an overview of the insufficiency, optimization, and future development for Mn 2 + / MnO 2 -based batteries. The existing issues and deficiency in Mn 2 + /MnO 2 -based batteries have been systematically analyzed, and optimization strategies have also been rationally summarized and discussed with deep insights. Also, the often-overlooked optimized objects and aspects have been highlighted with unique perspectives. The proposals of testing methods and performance assessment are presented, containing different degradation mechanisms. Based on the above points, this Perspective will provide guidance and contribute to the further development of aqueous Mn 2 + /MnO 2 -based batteries.