Crosslinkable aqueous binders containing Arabic gum-grafted-poly (acrylic acid) and branched polyols for Si anode of lithium-ion batteries

Abstract

Arabic gum grafted poly (acrylic acid) (GA- g -PAA) is prepared through a free radical graft polymerization of acrylic acid onto Arabic gum. Crosslinkable aqueous binder is developed by combining GA-g-PAA and branched polyols (pentaerythrotol, PER; triethanolamine, TEOA) as crosslinking agent for Si anodes of lithium-ion batteries. The aqueous composite binder undergoes crosslinking at about 110 °C to form robust crosslinked networks, matching well with the processing temperature of the electrode sheet in industry. GA-g-PAA/PER binder displays higher adhesion strength than GA-g-PAA and GA-g-PAA/TEOA. The Si electrode with GA-g-PAA/PER exhibits a slightly better cycling stability at 0.2C for 100 cycles, better rate capability than GA-g-PAA and GA-g-PAA/TEOA. At a high rate of 1C, Si electrode with GA-g-PAA/P delivers a higher specific capacity of 1968.1 mAhg −1 with a better capacity retention of 57.5% when compared with those with GA-g-PAA and GA-g-PAA/T binder. • Crosslinkable aqueous binder (GA-g-PAA/PER) is designed for Si anodes in lithium-ion batteries. • Branched polyols as crosslinking agents can decrease the crosslinking temperature. • The binder can improve the adhesion strength and the distribution of Si anodes. • Si anodes with the crosslinkable aqueous binder show the excellent rate capability.