The uncontrolled zinc dendrite growth during plating leads to quick battery failure, which hinders the widespread applications of aqueous zinc-ion batteries. The growth of Zn dendrites is often promoted by the "tip effect". In this work, we propose a generate strategy to eliminate the "tip effect" by utilizing the electrostatic shielding effect, which is achieved by coating Zn anodes with magnetron sputtered Al-based alloy protective layers. The Al can form a surface insulating Al 2 O 3 layer and by manipulating the Al content of Zn−Al alloy films, we are able to control the strength of the electrostatic shield, therefore realizing a long lifespan of Zn anodes up to 3000 h at a practical operating condition of 1.0 mA cm −2 and 1.0 mAh cm −2 . In addition, the concept can be extended to other Al-based systems such as Ti−Al alloy and achieve enhanced stability of Zn anodes, demonstrating the generality and efficacy of our strategy.

Secondary aqueous zinc-ion batteries (ZIBs) are considered as one of the promising energy storage devices, but their widespread application is limited by the Zn dendrite issues. In this work, we propose a rational design of surface protective coatings to solve this problem. Specifically, a silver (Ag) nanoparticle embedded amorphous AlN matrix (AlN/Ag) protective layer is developed. The former would alloy in situ with Zn to form AgZn3 alloy sites, which subsequently induce the Zn deposition with preferred (002) facets. The latter can effectively alleviate the structural expansion during repeated Zn plating/stripping. Consequently, the delicately designed AlN/Ag@Zn anode delivers an enhanced stability with a long lifespan of more than 2600 h at 1 mA cm–2 and 1 mAh cm–2. Moreover, the AlN/Ag@Zn||Mn1.4V10O24·nH2O full batteries can be operated for over 8000 cycles under 5 A g–1. Our work not only suggests a promising Zn anode protective coating but also provides a general strategy for the rational design of surface protective layers for metal anodes.

CoS 2 and FeS 2 nanoparticles with mesoporous structures embedded in carbon polyhedrons are prepared by reasonable design of materials (CoS 2 -FeS 2 -NC), which are used as a modified cathode material. This composite material can limit the shuttling of polysulfides and catalyze and adsorb polysulfides. Further, electrochemical properties of Li−S batteries are enhanced. Li−S batteries using S/CoS 2 -FeS 2 -NC electrodes have the best cycle and rate performance. The S/CoS 2 -FeS 2 -NC cathode's initial discharge capacity at 0.2C is 938.9 mAh g −1 , while its reversible capacity remains 394.8 mAh g −1 after 200 cycles, with a 0.28% decline on average. S/CoS 2 -NC and bare sulfur cathodes have maximal discharging capacities of 82.3 and 63.8% of S/CoS 2 -FeS 2 -NC cathodes at 0.2C. The initial discharge capacity of S/CoS 2 -FeS 2 -NC at 0.5C is 795.6 mAh g −1 , and the capacity of 354.4 mAh g −1 is maintained after 200 cycles. So, S/CoS 2 -FeS 2 -NC has excellent electrochemical properties.

Alkaline Zn–MnO2 batteries feature high security, low cost, and environmental friendliness while suffering from severe electrochemical irreversibility for both the Zn anode and MnO2 cathode. Although neutral electrolytes are supposed to improve the reversibility of the Zn anode, the MnO2 cathode indeed experiences a capacity degradation caused by the Jahn–Teller effect of the Mn3+ ion, thus shortening the lifespan of the neutral Zn–MnO2 batteries. Theoretically, the MnO2 cathode undergoes a highly reversible two-electron redox reaction of the MnO2/Mn2+ couple in strongly acidic electrolytes. However, acidic electrolytes would inevitably accelerate the corrosion of the Zn anode, making long-lived acidic Zn–MnO2 batteries impossible. Herein, to overcome the challenges faced by Zn–MnO2 batteries, we propose a hybrid Zn–MnO2 battery (HZMB) by coupling the neutral Zn anode with the acidic MnO2 cathode, wherein the neutral anode and acidic cathode are separated by a proton-shuttle-shielding and hydrophobic-ion-conducting membrane. Benefiting from the optimized reaction conditions for both the MnO2 cathode and Zn anode as well as the well-designed membrane, the HZMB exhibits a high working voltage of 2.05 V and a long lifespan of 2275 h (2000 cycles), breaking through the limitations of Zn–MnO2 batteries in terms of voltage and cycle life.

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