Interpenetrating and cross-linking effects of commercial and biopolymer binders on silicon anode performance in lithium-ion batteries

Abstract

Lithium-ion batteries, which are energy storage systems, are gaining popularity due to their adaptability and benefits for a wide range of applications. Silicon (Si) is a potential anode material for high-energy LIBs, however its huge volume expansion (%300) during charging and discharging inhibits their industrialization. Polymer binders are crucial for minimizing this volume expansion and maintaining integrity of Si anodes, as reported by many studies. In this study, the effect of cross-linking chemistry and functionalities of polymers on Si-based anodes was investigated. For cross-linking, polyacrylic acid (PAA) and alginic acid were used as main polymers and polyvinyl alcohol (PVA) and poly(vinyl butyral-co-vinyl alcohol-co-vinyl acetate) (PBA) were used as counter polymers. These Si-anodes were further examined using cycle tests in half cells, as well as scanning electron microscopy (SEM), X-ray diffraction (XRD) analyses of the electrodes before and after cycling. All results suggested that as an anode for LIB, PAA-PVA exhibited high reversible capacity (2231 mAh/g at C/3) and good cycling performance (reversible capacity of 1422 mAh/g after 300 cycles at C/3).