Date: Tuesday, June 2, 2015
Time: 11:00 am
Speaker: Gao Liu, LBNL
Title: Mesoscale Origin of the Enhanced Cycling-Stability of the Si-Functional Conductive Polymer Anode for Li-ion Batteries
Location: 67-3111 Chemla Room
Electrode used in lithium-ion battery is invariably a composite of multifunctional components. The performance of the electrode is controlled by the interactive function of all components at mesoscale. The functions of each component and its interaction in mesoscale will be discussed. Fundamental understanding of mesoscale phenomenon sets the basis for innovative designing of new materials. We will discuss the achievement and origin of a significant performance enhancement of electrode for lithium ion batteries based on Si nanoparticles wrapped with functional conductive polymer. The performance of the functional conductive polymer binder based electrode is in marked contrast with conventional non-conductive polymer electrode, which exhibit fast capacity fade. In-situ TEM unveils that the enhanced cycling stability of the conductive polymer-Si composite is associated with mesoscale concordant function of Si nanoparticles and the functional conductive polymer binder. Reversible accommodation of the volume changes of Si by the conductive polymer binder allows good electrical contact between all the particles during the cycling process. In contrast, the failure of the conventional Si-electrode is probed to be the inadequate electrical contact.