Enhanced Desalination Capacity and Stability of Alkylamine-Modified Na0.71CoO2 for Capacitive Deionization-Min Luo

Simultaneously regulating the physical properties and chemical environment of interlayer is a critical need for enhancing the capacity and stability of layered electrode materials in energy and environmental applications. Herein, the intercalation of n-alkylamine with different alkyl chain lengths to the structure of layered Na0.71CoO2 (NCO) for application in capacitive deionization is reported. The amine intercalation via acid–base reaction routes allows the expansion of layer spacing of NCO, increase the active site of Na+ ions storage, reduce the diffusion energy barrier of Na+ ions, improve the electronic conductivity, and suppress the structural deformation of NCO upon the desodiation/sodiation processes. Benefiting from these features, the n-propylamine-intercalated NCO delivered a high capacity of 88.9 mg g–1 and a comparable energy consumption of 0.54 kW h kg–1. A combination of mechanism analyses and density functional theory calculations demonstrated that the synergistic effects of electrical and ionic conductivity account for the enhanced properties. Our work provides a strategy for engineering the interlayer to enable high capacity and cycling stability, which offers guidance for the design of preintercalated electrode materials.

文章链接： https://pubs.acs.org/doi/10.1021/acssuschemeng.0c09184

request for full text