Conductive Carbon Coatings for Electrode Materials

Doeff, Marca M. ; Kostecki, Robert ; Wilcox, James ; Lau, Grace

关键词: 25;    CARBON;    CATHODES;    COATINGS;    ELECTRODES;    ENERGY DENSITY;    INVENTIONS;    LITHIUM;    LITHIUM IONS;    MARKET;    MINIMIZATION;    SALES;   

DOI  :  10.2172/925590
RP-ID  :  LBNL--62837
PID  :  OSTI ID: 925590
Others  :  R&D Project: 500302
Others  :  Other: BnR: VT0301030
Others  :  TRN: US0802459

美国|英语

来源: SciTech Connect

【 摘 要 】

A simple method for optimizing the carbon coatings on non-conductive battery cathode material powders has been developed at Lawrence Berkeley National Laboratory. The enhancement of the electronic conductivity of carbon coating enables minimization of the amount of carbon in the composites, allowing improvements in battery rate capability without compromising energy density. The invention is applicable to LiFePO{sub 4} and other cathode materials used in lithium ion or lithium metal batteries for high power applications such as power tools and hybrid or plug-in hybrid electric vehicles. The market for lithium ion batteries in consumer applications is currently $5 billion/year. Additionally, lithium ion battery sales for vehicular applications are projected to capture 5% of the hybrid and electric vehicle market by 2010, and 36% by 2015 (http://www.greencarcongress.com). LiFePO{sub 4} suffers from low intrinsic rate capability, which has been ascribed to the low electronic conductivity (10{sup -9} S cm{sup -1}). One of the most promising approaches to overcome this problem is the addition of conductive carbon. Co-synthesis methods are generally the most practical route for carbon coating particles. At the relatively low temperatures (<800 C) required to make LiFePO{sub 4}, however, only poorly conductive disordered carbons are produced from organic precursors. Thus, the carbon content has to be high to produce the desired enhancement in rate capability, which decreases the cathode energy density.