| 摘要 |
PURPOSE:To improve collecting efficiency and the safety of a cell by coating the surface of graphite as negative electrode material with an amorphous coke layer. CONSTITUTION:A nonaqueous electrolyte secondary cell is composed of a positive electrode mainly made of a lithium-containing composite oxide, nonaqueous electrolyte, and a negative electrode. In the negative electrode, the surface of graphite, whose d002 value of a lattice plane, (002) plane, spacing by X-ray diffraction is 3.354A or more and the dimension of a crystal in a C axis is 200Angstrom or more, is coated by an amorphous cake layer, or the coke layer, whose d002 value of the lattice plane, (002) plane, spacing by the X-ray diffraction is 3.43Angstrom or more and the dimension of the crystal in the C axis is 200Angstrom or less. Thereby, it is possible to improve collecting efficiency, and suppress the increase of cell internal pressure accompanying gas generation resulting from electrolyte decomposition, and the like during the process of full charging, and the like. |
