Patent ID: 7658775

Claim:
A method for making a negative electrode component used in a nonaqueous secondary battery comprising the step of polishing the surface of the negative electrode component by irradiating the surface with light to produce a negative electrode comprising a carbonaceous material in which the ratio RG=Gs/Gb of the degree of graphitization of Gs of the carbonaceous material, determined by a surface-enhanced Raman spectrum, to the degree of graphitization of Gb, determined by a Raman spectrum measured using argon laser light, is at least 4.5, based on the following conditions: Gb=Hbb/Hba; and Gs=Hsb/Hsa; wherein, Hba is the height of a peak lying in a range of 1,580 cm −1 to 1,620 cm −1 in a Raman spectrum which is measured using argon laser Raman spectrometer of a wavelength of 514.5 nm and a wavelength resolution of 4 cm −1 , Hbb is the height of a peak lying in a range of 1,350 cm −1 to 1,400 cm −1 in a Raman spectrum which is measured using an argon laser Raman spectrometer of a wavelength of 514.5 nm and a wavelength resolution of 4 cm −1 , Hsa is the height of a peak lying in a range of 1,580 cm −1 to 1,620 cm −1 in a surface enhanced Raman spectrum which is measured using an argon laser Raman spectrometer of a wavelength of 514.5 nm and a wavelength resolution of 4 cm −1 when silver having a thickness of 10 nm is deposited on the carbonaceous material, and Hsb is the height of a peak lying in a range of 1,350 cm −1 to 1,620 cm −1 a surface enhanced Raman spectrum which is measured using an argon laser Raman spectrometer of a wavelength of 514.5 nm and a wavelength resolution of 4 cm −1 when silver having a thickness of 10 nm is deposited on the carbonaceous material.