Ultralong-Life Zinc-Ion Hybrid Capacitors Enabled by Hydrogen-Bonding-Guided Nanosheet-Assembled Carbon Superstructures
Shreeti Jha, Yang Qin, Yumin Chen, Ziyang Song, Ling Miao, Yaokang Lv, Lihua Gan, Mingxian Liu
Abstract
Carbon superstructures with tailored morphology and multiscale hierarchy are beneficial in attaining excellent capacitive performance and sustained electrochemical performance during long-term cycling in Zn-ion hybrid capacitors, but their customized design is still unclear. Herein, we design a hydrogen-bond-guided nanosheet assembly approach to construct morphologically distinct origami fan-shaped carbon superstructures (FCS-8) for zinc-ion storage with concurrently high capacitive properties and durability. The process begins with the formation of nanosheets, driven by interaction between the –NH 2 groups of m-phenylenediamine (donor) and the carbonyl or carboxyl groups of pyromellitic dianhydride (acceptor). These nanosheets then stack and densify directionally, guided by sustained hydrogen bonding to form a superstructure. The well-ornate FCS-8, assembled from nanosheets that create interconnected open nanoporous channels, possesses multiscale hierarchy along with a remarkably large surface area (3143 m 2 g –1 ), providing continuous charge transport pathways for rapid Zn-ion diffusion with a minimal energy barrier (3.3 kJ mol –1 ), ensuring abundant zincophilic sites and collectively contributing to the superior zinc-ion storage metrics. Notably, FCS-8 demonstrates a substantial capacity of 264.7 mAh g –1, along with a high energy density of 168.9 Wh kg –1 and remarkable long-term durability with stability over 300,000 cycles at a current density of 20 A g –1 . The outstanding electrochemical performance is chiefly governed by a highly efficient charge storage mechanism, which involves the alternating adsorption of the Zn 2+ ion and CF 3 SO 3 – ions, together with a chemical redox reaction between Zn 2+ ions and pyridine and carbonyl functional groups at the numerous, well-exposed zincophilic sites embedded into robust, well-ornate superstructures featuring multiscale hierarchies. This work unlocks a new dimension for designing superstructural carbons toward advanced energy storage.