Multifunctional binder on inhibiting dissolution of small-molecule organic electrode materials for Li-Ion batteries and Na-ion batteries

Abstract

Electrochemical utilization of organic electrode materials (OEMs) is highly dependent on their excess solubility in aprotic organic electrolytes leading to unsatisfactory cycling stability. In this study, a single-function conventional binder is substituted with the multifunctional one containing −SO32-, −COO−, −Ctriple bondN and −NHCO− groups, which serve as a binding matrix to maintain electrode integrity and suppress the dissolution of organic materials. The noncovalent interaction between the binder and organic electrodes is responsible for their remarkably low dissolution and maintain the stability of the electrode, enhancing the cyclic stability. The 3,4,9,10- perylenetetracarboxylic dianhydride (PTCDA) cathode with the poly(acrylic acid n-butyl ester-co-acrylamido-2-methylpropanesulfonic acid -co-acrylonitrile -co-acrylic acid)/P(BA-co-AMPS-co-AN-co-AA) (PBA) binder exhibits 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 30 C) and outstanding cycling stability (2000 cycles at 0.5 A g−1), which rival those of polyvinylidene fluoride (PVDF) and poly(acrylic acid) (PAA) binder-based electrodes. The concept of noncovalent interaction between the binder and organic electrodes is successfully proven by the preparation of feasible Li and Na battery cells containing perylene-3,4,9,10-tetracarboxydiimide (PTCDI). With the discovery of more sophisticated binder materials and OEMs, the proposed strategy will lead to further performance improvements at a cell level to compete with transition metal-containing Li and Na ion batteries.