The anode-free design is a promising strategy to increase the energy density of aqueous Zn metal batteries (AZMBs). However, the scarcity of Zn-rich cathodes and the rapid loss of limited Zn greatly hinder their commercial applications. To address these issues, a novel anode-free Zn-iodine battery (AFZIB) was designed via a simple, low-cost and scalable approach. Iodine plays bifunctional roles in improving the AFZIB overall performance: enabling high-performance Zn-rich cathode and modulating Zn deposition behavior. On the cathode side, the ZnI2 serves as Zn-rich cathode material. The graphene/polyvinyl pyrrolidone heterostructure was employed as an efficient host for ZnI2 to enhance electron conductivity and suppress the shuttle effect of iodine species. On the anode side, trace I3− additive in the electrolyte creates surface reconstruction on the commercial Cu foil. The in situ formed zincophilic Cu nanocluster allows ultralow-overpotential and uniform Zn deposition and superior reversibility (average coulombic efficiency > 99.91% over 7,000 cycles). Based on such a configuration, AFZIB exhibits significantly increased energy density (162 Wh kg−1) and durable cycle stability (63.8% capacity retention after 200 cycles) under practical application conditions. Considering the low cost and simple preparation methods of the electrode materials, this work paves the way for the practical application of AZMBs.

No abstract

No abstract

Graphene is a potential candidate for achieving high-performance and multifunctional polypropylene (PP) composites. However, the complex manufacturing process and low dispersibility of graphene, as well as poor interfacial adhesion between graphene and polypropylene chains, stifle progress on large-scale production and applications of graphene/polypropylene composites. Here, we develop a strategy of maleic anhydride grafted polypropylene (MAPP) latex-assisted graphene exfoliation and melt blending to address the key challenges facing in industrial production. The surface property of the graphitic precursor is well-designed to achieve a high graphene exfoliation yield of ∼100% and induce abundant hydrogen bonding between the obtained mild-oxidized graphene (MOG) sheets and MAPP chains. Therefore, the MAPP-modified MOG can homogeneously disperse in the PP matrix and exhibits an excellent interfacial compatibility with the polymer. The addition of 5 wt % MOG results in simultaneous increase in the initial decomposition temperature, crystallization temperature, tensile strength, and Young′s modulus by 43.2, 11.4 °C, 21.5, and 50.7%, respectively, and the electrical conductivity increases to 0.02 S•m −1 . This work illustrates a practical solution to low-cost, eco-friendly, and feasible industrial production of graphene/PP composites through synchronous exfoliation and interfacial modification of graphene.