Electrochemical performance of natural graphite by surface modification using aluminum

We investigated electrochemical performance of natural graphite surface-tre ated with aluminum compared to that of untreated graphite. Aluminum trietho xide was used as the treatment source. In the treatment process, the drying temperature has critical influence on electrochemical performance of the t reated samples. The surface property of treated samples was investigated by scanning electron microscopy and Raman spectroscopy. The E-2g vibration mo de of the treated sample was sharpened and shifted upward, whereas no remar kable changes were found in A(1g) mode. The electrochemical performance imp roved markedly with Al treatment. The impedance measurement shows that the Al treated sample had much smaller charge-transfer resistance during cyclin g. (C) 2001 The Electrochemical Society.