| Abstract Title |
Nano-Silicon Anodes |
| Abstract Author(s) |
Alexandre Magasinski, Bogdan Zdyrko, Benjamin Hertzberg, Patrick Dixon, Frank Grant Jones, Thomas F. Fuller, Igor Luzinov and Gleb Yushin
School of Materials Science & Engineering, Georgia Institute of Technology, Department of Material Science, Clemson University, School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA USA |
| Abstract Presenter |
Gleb Yushin |
| Abstract |
Si anodes offer high Li storage capacity, but demonstrate low capacity retention with battery cycling due to large volume changes in Si during Li insertion and extraction. Conventional binders, developed decades ago for graphitic anodes, quickly become ineffective in holding the Si particles together and maintaining electrical conductivity within the anode. The desired characteristics of novel Si binders include good and stable adhesion to the Si electrode particles and Cu current collectors, chemical and electrochemical stability in conventional electrolytes. The binder should allow a uniform dispersion of Si particles and be able to withstand the large dimensional changes in the anode over a large number of cycles. In this study we systematically investigated the effects of the binder chemistry, its elastic properties, functional groups, swelling behavior, as well as anode density and Si, C and binder content on the electrochemical performance of the produced anodes. Morphology of the anodes before and after cycling has been analyzed using SEM. The interface between active particles and a binder has been studied using TEM. FTIR, AFM and tensile-tests were utilized to detect changes in the binder properties. Peel tests have been performed to monitor anode adhesion to Cu current collectors. Specific anode capacity in excess of 1400 mAh/g and stable performance has been achieved for selected nanoSi-nanoC-binder formulations. An additional effort has been made towards formation of nanoSi-C composite materials that do not exhibit volume changes during Li insertion and extraction. According to our approach Si nanoparticles or thin films are deposited on the walls of porous carbon. During the anode operation Si expands within the available pore volume and stable performance with specific capacity in excess of 1900 mAh/g can be achieved. |
|
