Aromatic organic molecular crystal with enhanced π–π stacking interaction for ultrafast Zn-ion storage†
Aqueous zinc batteries are promising in daily quick energy storage, but their commercialization is limited by the poor rate capability and low capacity of Zn-ion hosts, especially at practical-level mass loadings (>10 milligrams per square centimeter). This work reports a kind of aromatic organic molecular crystal, 3,4,9,10-perylenetetracarboxylic dianhydride, as an ultrahigh-rate host for Zn ions by enhancing the π–π stacking interaction to promote its ion transport kinetics. The interconnected layered structure with strong π–π stacking interaction enables fast electron transportation, and 1-D ion tunnels provide highways for rapid ion transportation. A zinc battery using such a host material displays high-rate capability (62.6% capacity remains from 1.6 C to 260.4 C), superior power density (14.8 kW kg−1) and excellent energy storage capacity reservation at high mass loading (83.6% capacity remains from 2.5 mg cm−2 to 12.3 mg cm−2), providing insight into host design for achieving ultrafast Zn-ion storage toward practical applications.