| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a nonaqueous electrolyte secondary battery which allows the effect of adding a coating-film forming agent to be achieved preferably, and has both of durability and high-rate characteristic at high level.SOLUTION: The present invention provides a nonaqueous electrolyte secondary battery which comprises: a positive electrode; a negative electrode; and a nonaqueous electrolyte. The negative electrode has a negative electrode active material layer which contains amorphous carbon-coated graphite. As to the amorphous carbon coated graphite, the cumulative frequencyαof microparticles having a size of 3μm or smaller is 10% or more and 50% or less in a particle size distribution based on the number of the particles; and the particle size D(average particle size) corresponding to the cumulative frequency of 50 vol.% from the side of the microparticles smaller in particle size is 5μm or more and 20μm or less in a particle size distribution based on volume. Further, the nonaqueous electrolyte includes: 0.01 mol/L or more and 0.04 mol/L or less of an oxalatoborate-based compound; and 0.06 mol/L or more of a fluorine-containing phosphate compound at the time of constructing the battery at least before a step of charging.</p> |
