Boosting Spatial Charge Storage in Ion ‐Compatible Pores of Carbon Superstructures for Advanced Zinc‐Ion Capacitors

Flower-shaped heterodiatomic carbon superstructures with compatible pore dimensions for Zn(H2O)62+ ions are designed through the supramolecular self-assembly of 1,3,5-triazine-2,4,6-triamine and cyanuric acid via in-plane H-bonding and out-of-planeπ–π stacking. A high-kinetics anion −cation hybrid charge storage mechanism of carbon superstructures is proposed, contributing to excellent energy density, rate capacity, and cyclic life for Zn-ion capacitors. AbstractCapacitive carbon cathodes deliver great potential for zinc-ion hybrid capacitors (ZHCs) due to their resource abundance and structural versatility. However, the dimension mismatch between the micropores of carbons and hydrated Zn2+ ions often results in unsatisfactory charge storage capability. Here well-arranged heterodiatomic carbon superstructures are reported with compatible pore dimensions for activating Zn2+ ions, initiated by the supramolecular self-assembly of 1,3,5-triazine-2,4,6-triamine and cyanuric acid via in-plane hydrogen-bonds and out-of-planeπ–π interactions. Flower-shaped carbon superstructures expose more surface-active motifs, continuous charge-transport routes, and more importantly, well-developed pores. The primary subnanopores of 0.82  nm are size-exclusively accessible for solvated Zn2+ ions (0.86  nm) to maximize spatial charge storage, while rich mesopores (1–3 nm) allow for high-kinetics ion migration with a low activation energy. Such favorable superstructure cathodes contri...
Source: Small - Category: Nanotechnology Authors: Tags: Research Article Source Type: research