| 摘要 |
<P>PROBLEM TO BE SOLVED: To enhance the battery characteristics of a bipolar lithium ion secondary battery that uses stainless foil as a collector. <P>SOLUTION: The bipolar lithium ion secondary battery includes bipolar electrodes stacked with electrolyte layers between them, each of the bipolar electrodes comprising a stainless foil collector with a positive active material layer formed on one side and a negative active material layer formed on the other side, the stainless foil collector having spherical pits thoroughly formed by alternating electrolytic etching in aqueous ferric chloride solution, and having a roughened surface whose surface roughness is from 0.1 to 2.0 μm inclusive when the surface area of a rectangle with one side measuring 50 μm is measured with a scanning confocal laser microscope having a resolution of 0.01 μm, the ratio of its ridge interval to the surface roughness being 5 or less. <P>COPYRIGHT: (C)2010,JPO&INPIT |
