Conductive Polyacrylic Acid-Polyaniline as a Multifunctional Binder for Stable Organic Quinone Electrodes of Lithium-Ion Batteries.

Abstract

High solubility in aprotic organic electrolytes and poor electrical conductivity are the main restrictions of organic electrodes in practical application. Conductive binder contributes to the high-performance electrodes as it enables both mechanical and electronic integrity of the electrode, which have been scarcely explored for organic electrodes. Herein, a conductive interpenetrating polymeric network is synthesized through in situ polymerization of polyaniline with poly(acrylic acid) (denoted PAA-PANi), which served as a novel conductive binder for organic 2-aminoanthraquinone (AAQ) materials. The conductive PANi component enhances the electrical conductivity of the electrode. Meanwhile, the PAA component serves as the binding matrix to condense with the amino groups (-NH2) of AAQ, which therefore effectively inhibits their dissolution and maintains electrode integrity during cycling. As expected, the conductive binder exhibits both excellent electrical conductivity (10-3 S cm-1) and strong mechanical adhesion. The AAQ/reduced graphene oxide (AAQ@rGO) composite electrode prepared with the as-synthesized PAA-PANi binder delivers a high specific capacity of 126.1 mAh g-1 at 0.1 A g-1, superior rate capability (71.3 mAh g -1 at 3 A g-1), and outstanding cycling stability (2000 cycles at 1 A g-1), which greatly rivals polyvinylidene fluoride and PAA binder-based electrodes. Such a strategy points the way for the design and synthesis of conductive polymeric binders for organic electrodes, whose electrical conductivity and dissolution are massive issues.