Water‐Soluble Conductive Composite Binder Containing PEDOT:PSS as Conduction Promoting Agent for Si Anode of Lithium‐Ion Batteries

Abstract A novel water‐soluble conductive composite binder consisting of carboxymethyl cellulose (CMC) as binder and aqueous poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) as conduction‐promoting agent is reported for the Si anode of Li‐ion batteries. The introduction of conductive PEDOT:PSS into a water‐soluble binder facilitates the formation of homogenous and continuous conducting bridges throughout the electrode and increases the compaction density of the electrode by reducing the content of the commonly used conducting agent of acetylene black. Galvanostatic testing, cyclic voltammetry and electrochemical impedance spectroscopy measurements show that the electrodes using the composite binder exhibit higher initial Coulombic efficiencies, better cycling and rate performance, and more favorable electrochemical kinetics compared with the electrodes using CMC binder with acetylene black conducting agent.