Alkaline zinc–air batteries are promising energy storage technologies with the advantages of low cost, ecological friendliness, and high energy density. However, the rechargeable zinc–air battery has not been used on a commercial scale because the zinc electrode suffers from critical problems such as passivation, dendrite growth, and hydrogen evolution reaction, which limit the practical applications of zinc–air batteries. Herein, the Perspective summaries the solutions to minimize the negative effects of zinc electrodes on discharge performance, cycling life, and shelf life. The future direction of academic research based on current studies of the existing challenges is proposed.

With the low redox potential of −3.04 V (vs SHE) and ultrahigh theoretical capacity of 3862 mAh g −1 , lithium metal has been considered as promising anode material. However, lithium metal battery has ever suffered a trough in the past few decades due to its safety issues. Over the years, the limited energy density of the lithium-ion battery cannot meet the growing demands of the advanced energy storage devices. Therefore, lithium metal anodes receive renewed attention, which have the potential to achieve high-energy batteries. In this review, the history of the lithium anode is reviewed first. Then the failure mechanism of the lithium anode is analyzed, including dendrite, dead lithium, corrosion, and volume expansion of the lithium anode. Further, the strategies to alleviate the lithium anode issues in recent years are discussed emphatically. Eventually, remaining challenges of these strategies and possible research directions of lithium-anode modification are presented to inspire innovation of lithium anode.

The development of efficient and low-cost flexible metal electrodes is significant for flexible rechargeable zinc−air batteries (ZABs). Herein, we reported a new type of flexible metal (zinc and nickel) electrode fabricated via a two-step deposition method on polyurethane sponges (PUS) for flexible ZABs. Compared to conventional electrodes, the metal-coated PUS electrodes exhibited great flexibility, softness, and natural mechanical resilience. In addition, a flexible sandwich-structured ZAB was assembled with the metal-coated PUS electrodes and in situ cross-linked polyacrylic acid (PAA)−KOH hydrogel electrolyte. The flexible ZAB presented stable discharge/charge performance even under complex rolling and twisting deformations. Moreover, inspired by the kirigami-strategy for device-level stretchability, a 100% stretchable fence-shaped ZAB and a 160% stretchable serpentine-shaped ZAB were cut from the abovementioned flexible ZABs. The kirigami-inspired configuration enabled the battery performance to be stable during stretching, benefiting from the softness of the PUS@metal electrode. These flexible and stretchable ZABs would broaden the promising applications for portable and wearable energy storage devices.

Energy and environmental issues received widespread attentions due to the fast growth of world population and rapid development of social economy. As a transition metal dichalcogenide, tungsten disulfide (WS 2) nanomaterials make important research progress in the field of energy conversion and storage. In view of the versatile and rich microstructure of these materials, the modification and controllable synthesis of WS 2 nanomaterials also inspire a research interest. This review mainly focuses on WS 2-based nanomaterials in the application of energy conversion and storage as well as discusses some basic characteristics and modification strategies of them. Finally, the research progress of WS 2-based nanomaterials is reviewed and some prospects for future research directions are proposed. This review is expected to be beneficial to the future study of WS 2 nanomaterials used in the field of energy conversion and storage.

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