Rechargeable zinc–air batteries show great potential in applications such as electric vehicles and wearable devices, especially for the flexible design. And the challenges and functional materials for each component are provided and discussed from air electrode, solid-state electrolyte to zinc anode, with perspectives of research directions.

Metal–organic frameworks have received increasing attention as promising electrode materials in supercapacitors. In this study, we have successfully synthesized a novel accordion-like Ni-MOF superstructure ([Ni₃(OH)₂(C₈H₄O₄)₂(H₂O)₄]·2H₂O), for the first time, and used it as an electrode material for supercapacitors. The supercapacitors with the novel electrode exhibited excellent electrochemical performance. For example, the accordion-like Ni-MOF electrode showed specific capacitances of 988 and 823 F g⁻¹ at current densities of 1.4 and 7.0 A g⁻¹, respectively, while maintaining outstanding cycling stability (capacitance retention of 96.5% after 5000 cycles at a current density of 1.4 A g⁻¹). More importantly, the accordion-like Ni-MOF and activated carbons were assembled into a high-performance flexible solid-state asymmetric supercapacitor with a specific capacitance of 230 mF cm⁻² at a current density of 1.0 mA cm⁻². The cycle test showed that the device can offer 92.8% capacity of the initial capacitance at 5.0 mA cm⁻² after 5000 cycles with little decay. The maximum energy density of the device can achieve 4.18 mW h cm⁻³ and the maximum power density can also achieve 231.2 mW cm⁻³.

As one of the most promising electrode materials, zinc oxide-based nanomaterials have attracted great attention in recent decades for remarkable features such as relatively low cost, relatively high reversible capacity and good physical and chemical stability. In this article, we aim to present a general review of synthetic methods of zinc oxide-based nanomaterials and related morphologies. In addition, recent advances in lithium storage batteries are summarized and discussed (lithium-ion and lithium–sulfur batteries). Tentative conclusions and assessments aim to promote the next generation of electrochemical lithium storage devices.