Effect of carbon source on electrochemical performance of carbon coated LiMnPO4 cathode

Abstract

Source materials for carbon coating on LiMnPO4 were examined to improve an electrochemical performance of LiMnPO4 Lascorbic acid, sucrose, polyethylene oxide (PEO), and carboxymethyl cellulose (CMC) were used as carbon sources for hydrothermal synthesis of carbon coated LiMnPO 4. Disordered (D) and graphite-like (G) carbons were detected by Raman spectroscopy for the prepared samples except for PEO-used one, and the highest G/D ratio was obtained for the sample prepared using CMC as carbon source. The electrochemical performance of the samples was evaluated by galvanostatic charge/discharge test. The carbon coated LiMnPO4 prepared with CMC carbon source showed the highest discharge capacity, 94 mA h g-1 at 0.01 C (corresponding to 55% of the theoretical capacity, 171 mA h g-1), indicating that the carbon sources greatly influenced on the electrochemical performance of the carbon coated LiMnPOa prepared by the hydrothermal synthesis. ©2009 The Ceramic Society of Japan. All rights reserved.