| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a sodium secondary battery superior in charge discharge characteristics. <P>SOLUTION: The sodium secondary battery includes a first electrode, and a second electrode having a carbon material, and the carbon material has an R value (ID/IG) obtained by the following Raman spectroscopy of 1.07-3.<Raman spectroscopy> The Raman spectrum obtained by Raman spectroscopy of the carbon material has one peak in each of range of 1,300-1,400 cm<SP>-1</SP>of the abscissa axis and range of 1,570-1,620 cm<SP>-1</SP>of the abscissa axis, and in a fitting spectrum obtained by removing a base-line function from a fitting function obtained by conducting fitting by using two Lorentz functions and one base-line function, when the maximum value of an ordinate axis in the range of 1,300-1,400 cm<SP>-1</SP>of the abscissa axis is represented by ID and the maximum value of an ordinate axis in the range of 1,570-1,620 cm<SP>-1</SP>of the abscissa axis is represented by IG, R value (ID/IG) is obtained by dividing ID by IG. <P>COPYRIGHT: (C)2011,JPO&INPIT |
