화학공학소재연구정보센터
Journal of Power Sources, Vol.261, 170-174, 2014
A novel polymer composite as cathode binder of lithium ion batteries with improved rate capability and cyclic stability
In this work, we have developed a novel polymer composite (MPVDF) by embedding maleic anhydridegrated-polyvinylidene fluoride (MA-g-PVDF) into polyvinylidene fluoride (PVDF) as binder of LiCoO2 cathode for lithium ion battery. The cathodes using MPVDF and PVDF as binder have been comparatively investigated with scanning electron microscope (SEM), X-ray diffraction (XRD) and electrochemical measurements. By using MPVDF as the binder for preparing LiCoO2 cathode, the rate capability and cyclic stability of the LiCoO2 cathode in LiCoO2/Artificial graphite battery are improved significantly. Compared to the cathode using PVDF alone, the discharge capacity of the battery increases by 38.5% at 2 C and the capacity retention of the battery is improved from 84.5% to 90.2% after 300 cycles at 0.5 C when the mass ratio of MA-g-PVDF to PVDF in MPVDF binder is 1:4. The improved performance is attributed to the low crystallinity of MPVDF, which allows larger electrolyte uptake. The electrolyte uptake is 43.5% for the LiCoO2 cathode using MPVDF but only 25.3% for the cathode using PVDF alone. (C) 2014 Elsevier B.V. All rights reserved.