To provide a separator for a lithium ion secondary battery, superior in electrolytic solution retention properties, adhesion and bondability to electrodes, and dimensional stability, having high and uniform ionic conductivity, reduced interfacial resistance to electrodes, and shutdown properties; and to provide a lithium ion secondary battery superior in capacity characteristics, charge and discharge characteristics, cycle characteristics, safety, reliability, and the like.
The separator for the lithium ion secondary battery has a porous layer, containing a vinylidene fluoride resin as a main component formed on at least one surface of a porous base material made of polyolefin, where the mean pore diameter of the porous layer is 0.1-5 μm on the outer surface of the layer and 0.5-10 μm in the inside of the layer, and the mean pore diameter is smaller on the outer surface than inside the layer. The lithium ion secondary battery of superior capacity characteristics, charge and discharge characteristics, cycle characteristics, safety, reliability, and the like can be provided by using the separator.
COPYRIGHT: (C)2004,JPO
Hiromi Totsuka
Shuji Mitani
Takanori Masanori
| JP2002240215A | ||||
| JP200359480A |
Tadashi Takahashi
Takashi Watanabe
Suzuki Mitsuyoshi
Kazuya Nishi
Yasuhiko Murayama