LAUSR

Dual-ion batteries (DIBs) with graphite as cathode material, show great superiority in sustainability, affordability and environmental impact over Li-ion batteries that rely on transition-metal based cathodes. However, graphite cathodes severely suffer from poor structural stability during anions storage at high potentials because of the co-intercalation and oxidative decomposition of electrolytes. This work presents an in-situ electrochemistry-driving route to create a bifunctional interphase via the implantation of diethylenetriaminepenta(methylene-phosphonic acid) (DTPMP) on the surface of graphite particles. The reaction mechanisms and functions of DTPMP are investigated both experimentally and theoretically. The DTPMP-derived interphase not only improves the antioxidative stability of electrolytes but also benefits the PF6- anions desolvation, which doubly protect the graphitic structure and give rise to fast-charge and ultralong cycling performance of graphite cathodes in DIBs.