Rechargeable aqueous metal-ion batteries are very promising because of their green and safe inherent features as alternative energy storage devices during the post-lithium-ion era. Aqueous zinc ion batteries (ZIBs) have...

Aqueous rechargeable Zn metal batteries have attracted widespread attention due to the intrinsic high volumetric capacity, low cost, and high safety. However, the low Coulombic efficiency and limited lifespan of Zn metal anodes resulting from uncontrollable growth of Zn dendrites impede their practical application. In this work, a 3D interconnected ZnF2 matrix is designed on the surface of Zn foil (Zn@ZnF2) through a simple and fast anodic growth method, serving as a multifunctional protective layer. The as‐fabricated Zn@ZnF2 electrode can not only redistribute the Zn2+ ion flux, but also reduce the desolvation active energy significantly, leading to stable and facile Zn deposition kinetics. The results reveal that the Zn@ZnF2 electrode can effectively inhibit dendrites growth, restrain the hydrogen evolution reactions, and endow excellent plating/stripping reversibility. Accordingly, the Zn@ZnF2 electrode exhibits a long cycle life of over 800 h at 1 mA cm−2 with a capacity of 1.0 mAh cm−2 in a symmetrical cell test, the feasibility of which is also convincing in Zn@ZnF2//MnO2 and Zn@ZnF2//V2O5 full batteries. Importantly, a hybrid zinc‐ion capacitor of the Zn@ZnF2//AC can work at an ultrahigh current density of ≈60 mA cm−2 for up to 5000 cycles with a high capacity retention of 92.8%.

Nowadays, energy generation and storage are two important topics. Unfortunately, conventional energy generators are not capable of responding to environmental changes, while traditional energy storage devices lack special functionalities apart from supplying electricity. Benefiting from exceptional physicochemical properties, graphene-based materials help to address the aforementioned issues. In this review, we highlight recent key advances in graphene-based smart energy generation and storage systems. In terms of smart energy generation, we focus on graphene-derived electric generators that can controllably produce electricity in response to external stimuli, such as moisture, flowing liquid, friction, pressure force, and heat. As for energy storage, smart batteries and supercapacitors with made-to-measure graphene materials are summarized to show impressive features of deformability, wearability, printability, stimuli response, self-healing, integration, and miniaturization. Beyond these, we also discuss the challenges ahead for these graphene-related smart energy generation/storage devices and their future development trend.

(1 of 30)additionally, it leads to reliable and manageable energy delivery. [2] Lithium-ion batteries (LIBs) have been the first choice for EES owing to their remarkable energy density, excellent cycle life, and small volume compared to other rechargeable batteries since they were successfully sold by SONY in 1991. [3] Nevertheless, their widespread applications have been limited due to sterile Li resources, high cost, toxic electrolytes, safety problems, and other disadvantages. [4] To date, environmentally friendly aqueous batteries using multi-valent charge carriers, such as Zn 2+ , Mg 2+ , and Al 3+ , have attracted attention because multiple electrons are involved in the redox reactions during intercalation, as well as higher capacity and energy density can be achieved. However, only a few cathode materials are available for Mg 2+ diffusion, and the passivation of Mg anode greatly restricts the further transport of Mg 2+ ions. Al battery anode also forms a protective oxide (Al 2 O 3 ) film in the aqueous electrolyte, which affects the battery performance. Hence, Mg and Al batteries are under investigation and are still a long way from practical application and commercialization. [5] ZIBs have attracted interest in grid-scale energy storage compared to other energy storage technologies owing to the following advantages: 1) ZIBs can be easily manufactured in an open-air environment, so the total cost of manufacturing ZIBs is much lower than other batteries (Li + /Na + /K + -ion) which require an inert environment for production. [6] 2) The price of Zn (0.5−1.5 $/lb) is much lower than that of Li (8−11 $/lb), and the reserves of Zn (79 ppm) are approximately four times than those of Li (17ppm). [7] 3) Zn as an anode exhibits a high theoretical volumetric (5855 mAh cm −3 ) and gravimetric capacity (820 mAh g −1 ), low electrochemical potential of −0.762 V versus the standard hydrogen electrode (SHE), and two-electron transfer during redox reaction, contributing to a high-energy density. [8] 4) ZIBs are highly safe, not only because Zn anode is non-toxic and stable in the general environment, but also because a majority of ZIBs electrolytes used are aqueous with higher ionic conductivity (10 −1 −6 S cm −1 ) than flammable and toxic organic solvents (10 −3 −10 −2 S cm −1 ). [9] Furthermore, the normal Zn salts (ZnSO 4

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