Playing with the p-Doping Mechanism to Lower the Carbon Loading in n-Type Insertion Organic Electrodes: First Feasibility Study with Binder-Free Composite Electrodes

Abstract

Organic electrode materials should offer promising alternative to traditional inorganic compounds thanks to several attractive assets such as low-cost, low environmental footprint or the versatility in terms of cell assemblies (cationic and/or anionic shuttling). However, improvements are needed to push forward organic solid electrodes. In particular, decrease the quantity of conductive carbon in the composite electrode is important because it impedes the resulting energy density values. Herein, we present an innovative approach aiming at replacing most of the carbon conductive additive by an electron-conductive anion-inserting crystallized organic material, namely dilithium 2,5-(dianilino)terephthalate (Li2DAnT). Combined with an appropriate n-type lithiated organic electrode material, we demonstrate the beneficial effect of adding Li2DAnT (23 wt%)/carbon (10 wt%) compared to a typical conducting carbon loading of 33 wt% for powder-based composite electrodes made without binder by simple mixing and grinding with a pestle in a mortar. In fact, Li2DAnT provides an efficient percolating conductive network and contributes to the overall reversible capacity of the composite electrode through its own storage properties.