| 摘要 |
PROBLEM TO BE SOLVED: To provide a positive electrode foil for a lithium ion secondary battery capable of improving rapid charge/discharge characteristics while an increase in cost and deterioration in strength of the positive electrode foil are suppressed.SOLUTION: A positive electrode collector foil is used for a lithium ion secondary battery including a positive electrode 1 having a positive electrode collector 1a and a positive electrode active material 1c and a negative electrode having a negative electrode collector and a negative electrode mixture layer, and has a surface on which pits 1d accommodating the particulate positive electrode active material 1c are formed. Further preferably, in the positive electrode collector foil, the pits having a diameter of 0.3-3 μm are present at a density of 10pits/mmor more and 10pits/mmor less, and a density of the pits having a diameter exceeding 3 μm is 10 pits/mmor less. |
