Nonaqueous electrolyte secondary battery having a negative electrode containing carbon fibers and carbon flakes

A nonaqueous electrolyte secondary battery comprising

• an electrode composite and a nonaqueous electrolyte solution, the electrode composite comprising a positive-electrode comprising a positive-electrode active material and a negative electrode comprising a particulate negative-electrode active material, the positive electrode and the negative electrode being wound by several turns together with a separator disposed therebetween;
• wherein the negative electrode further comprises carbon fibers and carbon flakes disposed in the interstices between the particulate negative electrode active material;
• wherein the ratio by weight of the carbon fibers to the carbon flakes in the negative electrode is in a range of 0.2 to 100;
• wherein the carbon fibers are produced by vapor phase deposition;
• wherein the carbon flakes have a (002) interplanar spacing of less than 0.3360 nm by X-ray diffractometry and a thickness of (002) c-axis crystallites of 100 nm or more and the bulk density of the carbon flakes, as measured by Japanese Industrial Standard K-1469, is 0.4 g/cm3 or less, and the maximum particle size of the carbon flakes, as measured by laser diffraction, is 50 μm or less;
• wherein the content of the carbon fibers in the negative electrode is in a range of 00.2 percent by weight to 5 percent by weight;
• wherein the positive-electrode active material comprises a Li compound oxide and the negative-electrode active material comprises one of a Li compound oxide, an amorphous metal oxide, and a carbonaceous material;
• and
• wherein the Li compound oxide of the positive-electrode active material is LiMxOy one selected from the group consisting of Co, Ni, Mn, Fe, Al, V, and Ti, and the negative-electrode active material comprises the carbonaceous material.