Journal of Applied Electrochemistry, Vol.50, No.4, 431-438, 2020
Enhancement of the lithium titanium oxide anode performance by the copolymerization of conductive polypyrrole with poly(acrylonitrile/butyl acrylate) binder
An eco-friendly conductive water-dispersed polymer binder was used in lithium-ion batteries (LIBs) for the first time. A conductive polypyrrole (PPy) was copolymerized successfully into an adhesive poly(acrylonitrile/butyl acrylate) (PANBA) emulsified binder to impart two important properties to the PANBA-PPy binder system simultaneously: adhesion and electronic conduction. These two properties ultimately help the active materials of the LIB to exert better electrochemical performance. The copolymers were synthesized via two-step polymerization with different weights of pyrrole monomer. With the incorporation of PPy, the electrical resistance of the copolymer was reduced significantly, and the increase in PPy content of the binder system also decreased the resistance. The electrochemical performance of the conductive copolymers as a binder for the Li4Ti5O12 (LTO) anodes of lithium-ion batteries was superior to the non-conductive PANBA binder. At relatively low charge/discharge current densities, the more conductive PANBA-PPy4 binder was favorable to the cyclic performance of the LTO electrodes, whereas the PANBA-PPy2 sample has prominent high rate performance at a current density of 10 C because of its adhesive properties and conductive characteristics.
Keywords:Polypyrrole;Poly(acrylonitrile;butyl acrylate);Conductive polymer;Water-dispersed binder;Lithium titanium oxide anode;Lithium-ion battery