Conductive Additive for Si/Mesoporous Carbon Anode for Li-Ion Batteries: Commercial Graphite vs Carbon Black C65

Monday, 25 May 2015: 09:00
Salon A-1 (Hilton Chicago)
A. Rezqita (Austrian Institute of Technology GmbH, Vienna University of Technology), R. Hamid (Austrian Institute of Technology GmbH), S. Schwarz, H. Kronberger (Vienna University of Technology), and A. Trifonova (Austrian Institute of Technology GmbH)
Silicon exhibits the highest theoretical capacity of 4200 mAh g-1, which is 10 times more than the capacity of graphite. Therefore, Si is a promising candidate for anode in lithium-ion batteries. However, Si has low electrical conductivity (theoretical: 6.7 x 10-4 S cm-1). To reach the high performance anode, the proper conductive additives are still needed in order to improve the electrical conductivity of Si-based anode. Here we investigated the effects of conductive nano-graphite and Carbon Black (CB65) on electrochemical performance of silicon-mesoporous carbon composite anode (Si/MC). The material has been synthesized by pyrolysis of polymer aerogel with embedded Si nanoparticles. The electrode was made by 75% active material, 15% conductive additive, and 10% polyacrylic acid (PAA) binder. The electrochemical characterization using impedance spectroscopy, voltammetry, and galvanostatic charge/discharge tests were conducted for both samples. Impedance spectroscopy showed that Si/MC anode with conductive graphite exhibited lower charge-transfer resistance (Rct 150 Ω), compared to those with carbon black (Rct 380 Ω). The collected results showed that the graphite additive improved significantly the electrochemical performance of Si/MC anode. In addition, the thermal and long cycling tests will be demonstrated.