Phenazine-based spiroborate complex with enhanced electrochemical stability for lithium storage

Abstract

Redox-active small organic molecules have, due to their ready availability and high capacity, been considered to constitute one of the most promising types of electrode materials. However, their facile dissolution into organic electrolytes deteriorates their cycle performance, thus limiting their applications as electrode materials. In this study, a novel redox-active molecule, lithium bis(2,3-dihydroxyphenazine)borate (LDPB), was synthesized effectively from 2,3-dihydroxyphenazine (DHP) using a spiroborate salification strategy. When used as a lithium storage material, LDPB showed better cycling stability, better rate performance, and higher capacity retention (84.6% after 250 cycles at 200 mA g⁻¹) than its DHP precursor. This spiroborate salification strategy could serve as an efficient approach for constructing novel organic electrode materials.