Cross-linked poly(acrylic acid)-carboxymethyl cellulose and styrene-butadiene rubber as an efficient binder system and its physicochemical effects on a high energy density graphite anode for Li-ion batteries

Abstract

An increase in graphite anode thickness is an effective way to achieve a high-energy density lithium ion battery by designing a compact cell with a high mass loading and density. However, this may cause critical problems in Li+ diffusivity due to drastic increases in length and tortuosity of the ionic migration path. A mixture of cross-linked poly (acrylic acid) (PAA)–carboxymethyl cellulose hydrogels (CMC) was developed using styrene-butadiene rubber (SBR) as an efficient binder system to increase Li+ diffusivity and adhesion strength. Electrolyte permeability and adhesion strength of the electrode were enhanced by 2.5 and 2 times, respectively, compared to a conventional CMC–SBR system, which led to excellent electrochemical properties due to enhanced affinity with electrolytic and interpolymeric properties. Particularly, capacity retention was improved from 81 to 91% at a high 1 C rate.