Ultra-stable cycling of organic carboxylate molecule hydrogen bonded with inorganic Ti3C2Tx MXene with improved redox kinetics for sodium-ion batteries

Abstract

The application of small organic molecules for sodium-ion batteries is generally plagued by their high solubility, poor conductivity, and sluggish redox dynamics in organic electrolyte, thus developing efficient strategies to restrain solubilization while obtaining fast charge transfer becomes a challenge. Herein, a rational hybridization strategy through hydrogen bond between organic molecule and inorganic substrate has been proposed, employing the terminal –C═O of trisodium 1, 2, 4-benzenetricarboxylate (TBC) molecule and –OH groups of inorganic Ti₃C₂T_x MXene, respectively. In general, such a design evidently mitigates the aggregation of both TBC molecules and Ti₃C₂T_x MXene. Furthermore, the robust hydrogen bonding significantly mitigates the dissolution of TBC and guarantees the robust coupling between them, thus contributing to the integrity of electrode and modifying the electrochemical sodium storage in both half and full cells. Moreover, the systematic kinetic analysis and mechanism detection reveal improved charge transportation and robust two-electron electrochemical reversibility of the hybrid TBC/Ti₃C₂T_x. Taken together, this work demonstrates a potential novel strategy toward stable and practical organic battery chemistries through hydrogen bonding with inorganic compounds.