Hydrogen-Bonded Interfacial Super-Assembly of Spherical Carbon Superstructures for High-Performance Zinc Hybrid Capacitors
Yang Qin, Chengmin Hu, Qi Huang, Yaokang Lv, Ziyang Song, Lihua Gan, Mingxian Liu
Abstract
Abstract Carbon superstructures with multiscale hierarchies and functional attributes represent an appealing cathode candidate for zinc hybrid capacitors, but their tailor-made design to optimize the capacitive activity remains a confusing topic. Here we develop a hydrogen-bond-oriented interfacial super-assembly strategy to custom-tailor nanosheet-intertwined spherical carbon superstructures (SCSs) for Zn-ion storage with double-high capacitive activity and durability. Tetrachlorobenzoquinone (H-bond acceptor) and dimethylbenzidine (H-bond donator) can interact to form organic nanosheet modules, which are sequentially assembled, orientally compacted and densified into well-orchestrated superstructures through multiple H-bonds (N–H···O). Featured with rich surface-active heterodiatomic motifs, more exposed nanoporous channels, and successive charge migration paths, SCSs cathode promises high accessibility of built-in zincophilic sites and rapid ion diffusion with low energy barriers (3.3 Ω s −0.5 ). Consequently, the assembled Zn||SCSs capacitor harvests all-round improvement in Zn-ion storage metrics, including high energy density (166 Wh kg −1 ), high-rate performance (172 mAh g −1 at 20 A g −1 ), and long-lasting cycling lifespan (95.5% capacity retention after 500,000 cycles). An opposite charge-carrier storage mechanism is rationalized for SCSs cathode to maximize spatial capacitive charge storage, involving high-kinetics physical Zn 2+ /CF 3 SO 3 − adsorption and chemical Zn 2+ redox with carbonyl/pyridine groups. This work gives insights into H-bond-guided interfacial super-assembly design of superstructural carbons toward advanced energy storage.