Constructing π–π Superposition Effect of Tetralithium Naphthalenetetracarboxylate with Electron Delocalization for Robust Dual‐Ion Batteries

Abstract

AbstractOrganics are gaining significance as electrode materials due to their merits of multi‐electron reaction sites, flexible rearrangeable structures and redox reversibility. However, organics encounter finite electronic conductivity and inferior durability especially in organic electrolytes. To circumvent above barriers, we propose a novel design strategy, constructing conductive network structures with extended π–π superposition effect by manipulating intermolecular interaction. Tetralithium 1,4,5,8‐naphthalenetetracarboxylate (LNTC) interwoven by carbon nanotubes (CNTs) forms LNTC@CNTs composite firstly for Li‐ion storage, where multiple conjugated carboxyls contribute sufficient Li‐ion storage sites, the unique network feature enables electrolyte and charge mobility conveniently combining electron delocalization in π‐conjugated system, and the enhanced π–π superposition effect between LNTC and CNTs endows laudable structural robustness. Accordingly, LNTC@CNTs maintain an excellent Li‐ion storage capacity retention of 96.4 % after 400 cycles. Electrochemical experiments and theoretical simulations elucidate the fast reaction kinetics and reversible Li‐ion storage stability owing to the electron delocalization and π–π superposition effect, while conjugated carboxyls are reversibly rearranged into enolates during charging/discharging. Consequently, a dual‐ion battery combining this composite anode and expanded graphite cathode exhibits a peak specific capacity of 122 mAh g−1 and long cycling life with a capacity retention of 84.2 % after 900 cycles.