The fabrication of a superhydrophobic surface is demonstrated via a wet chemical route, and this method offers advantages of being cleanroom free, cost efficiency, and wide applicability. The preferable growth of ZnO crystalline forms a microstructured surface, and a variety of alkanoic acids were adopted to tune the surface wettability. Although all surfaces show an advancing contact angle greater than 150 degrees , they substantially differ in the wetting mechanisms. It is found that only when the length of alkanoic acid is greater than 16, the microstructured surface shows a stable superhydrophobicity, in which the Cassie state dominates. While for those moderate-length alkanoic acids (C8-C14), their corresponding surfaces have a tendency to fall into the Wenzel state and display a great contact angle hysteresis.

Photo‐assisted charging is considered an effective approach to reducing the overpotential in lithium–oxygen (Li–O2) batteries. However, the utilization of photoenergy during the discharge process in a Li–O2 system has been rarely reported, and the functional mechanism of such a process remains unclear. Herein, a novel bifunctional photo‐assisted Li–O2 system is established by employing a hierarchical TiO2–Fe2O3 heterojunction, in which the photo‐generated electrons and holes play key roles in reducing the overpotential in the discharging and charging processes, respectively. Moreover, the morphology of the discharge product (Li2O2) can be modified via the dense surface electrons of the cathode under illumination, resulting in promoted decomposition kinetics of Li2O2 during the charging progress. Accordingly, the output and input energies of the battery can be tuned by illumination, giving an ultralow overpotential of 0.19 V between the charge and discharge plateaus with excellent cyclic stability (retaining a round‐trip efficiency of ≈86% after 100 cycles). The investigation of the bifunctional photo‐assisted process presented here provides significant insight into the mechanism of the photo‐assisted Li–O2 battery and addresses the overpotential bottleneck in this system.

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Ameliorating the interfacial issues of the zinc anode, particularly dendrite growth and electrode corrosion, is imperative for rechargeable zinc metal batteries. Herein, an electrochemical-inert liquid gallium–indium alloy coating is designed toward the zinc anode, inspired by the gallium–indium–zinc phase diagram. This unique liquid coating prefers an inward-deposition of Zn underneath the liquid coating assisted by ultrafast mass/charge transport when charging. Moreover, the corrosion of the modified zinc anode is improved as well, depiciting a hydrogen-evolution reaction overpotential higher than that of the reference zinc anode. Consequently, it enables a polarization of 24 mV, the lowest to the best of our knowledge, at 0.25 mA cm–2 with a prolonged lifespan (2100 h), which further enables the corresponding MnO2 full cells with improved capacity retention and stage of charge above 96% after 48 h. This effective approach provides a universal idea for the future development of rechargeable metal batteries beyond zinc-storage systems.

Li-O 2) batteries with high theoretical energy densities offer considerable potential for a new generation of energy storage technology. [1] In 1996, the first nonaqueous Li-O 2 battery was introduced with a polymer organic electrolyte and a carbon-cobalt composite cathode by Abraham and Jiang. [2] This was followed by the verification of the rechargeability of Li-O 2 batteries with manganese dioxide-super S cathodes for over 50 cycles by Bruce and co-workers, [3] after which nonaqueous Li-O 2 batteries received substantial research attention worldwide. A typical nonaqueous Li-O 2 battery includes a Li metal anode, an aprotic electrolyte and an O 2 cathode. It operates according to the reaction 2Li + O 2 ↔ Li 2 O 2 (2.96 V vs Li/Li +), in which O 2 is reduced to form Li 2 O 2 on the cathode during discharging and Li 2 O 2 is decomposed to O 2 and Li + through a reversible charging process. In this way, the battery delivers exceptional theoretical energy density of ≈3600 Wh kg −1. [4] This report is centered on nonaqueous Li-O 2 batteries, and the use of the term "Li-O 2 batteries" mentioned below represents "nonaqueous Li-O 2 batteries." To date, enormous progress has been achieved in the understanding and application of high-performance Li-O 2 batteries, however, their low practical discharge capacity, poor rate capability, low round-trip efficiency, and inferior cycling stability have greatly blocked their practical applications. The current major scientific and technical challenges of Li-O 2 batteries can be summarized as follows. 1) The slow kinetics of formation and decomposition of the discharge products lead to poor rate capability and low round-trip efficiency. 2) Cathode corrosion and electrolyte decomposition due to the attack by the discharge intermediates such as superoxide species, giving rise to poor cycling stability. 3) Pore clogging on the cathode arising from the stacking of insulated, insoluble discharge products blocks the mass transfer and oxygen/Li + diffusion, limiting the capacity and degrading the cycling performance. 4) The inevitable side reactions between the highly reactive Li anode and the organic electrolyte, crossover O 2 , CO 2 , etc., and the redox mediators (RMs), give rise to premature battery death. [1a,5] 5) The unavoidable Li dendrites caused by uncontrollable deposition of lithium, as well as the risk of collapse of the lithium anode due to the volume change during iterative plating/stripping processes, increase the probability of safety problems. [6] Consequently, the slow kinetics of Li 2 O 2 Porous materials possessing high surface area, large pore volume, tunable pore structure, superior tailorability, and dimensional effect have been widely applied as components of lithium-oxygen (Li-O 2) batteries. Herein, the theoretical foundation of the porous materials applied in Li-O 2 batteries is provided, based on the present understanding of the battery mechanism and the challenges and advantageous qualities of porous materials. Furthermore, recent progress in porous material...