Ni (Ⅱ) Coordination Supramolecular Grids for Aqueous Nickel-Zinc Battery Cathodes

摘要

Aqueous rechargeable nickel-zinc batteries (NZBs) have the advantages of economical cost and reliable safety. Despite reports of success in achieving high-utilization and stable Zn anodes, the practical application of NZBs has been plagued by the restrictive capacity density and degradation of the Ni-based cathode. Herein, it is reported that nickel-ligand coordination grids (NCGs) with a high theoretical capacity of 128.12 mAh g(-1) offer a fast faradic reaction while maintaining good reversibility due to the abundant open metal sites and flexible network structures. In situ and ex situ characterizations demonstrate that the graphene nanosheet (GN) modification of NCGs supramolecular substantially boosts surface charge and reducing the work function of supramolecular compounds. A Ni//Zn battery using such a graphene organic-inorganic material (G-NCGs) achieve a high gravimetric capacity of 113.8 mAh g(-1) at 0.5 A g(-1) with 50% of its initial capacitance retained after 2000 cycles and an exceptional rate capacity of 43.3 mAh g(-1) even at the current density of 5.0 A g(-1).