The Effect of Commercialized Binders on Silicon Oxide Anode Material for High Capacity Lithium ion Batteries

The lithium insertion/ extraction properties of silicon oxide (SiOx) composite electrode are investigated using polyvinylidene fluoride (PVDF), LA132 (which major copolymerization chain is polyacrylonitrile-polyacrylic acid (PAN-PAA)) and polyacrylic acid (PAA). Electrochemical cycling tests show that SiOx electrode with conventional binder PVDF results in rapid capacity fading, while aqueous binders LA132 and PAA remarkably improve the cycle performance of SiOx at a current density of 80 mA . g(-1). SiOx electrode with PAA delivers a reversible capacity up to 1090 mAh . g(-1) after 50 cycles. All of the electrodes after 10 cycles exhibiting a huge expansion of surface morphology, and some crevices are observed in SiOx-PVDF electrode. Results of Fourier Transform Infrared Spectroscopy (FTIR) and X-ray diffraction (XRD) show that amorphous or little crystalline grain structure and ester-like bonds are the key factors of adhesion property for binders in SiOx composite electrode. With cycling, impendence of the SiOx electrodes with different binders is increasing severely. In addition, the differential capacity plots are used to explain the capacity fading mechanism, the kinetics of electrode process of SiOx are not affected by applying different binders.