Secondary battery, battery pack, vehicle, and stationary power supply
摘要
說(shuō)明書
The thickness of the separator is preferably 100 μm or less, and more preferably 70 μm or less from the viewpoint of raising the energy density of the secondary battery. Since this separator has a two-layer structure of a porous self-supporting film and a solid electrolyte layer, even if the thickness of the separator is reduced, both water shielding property and sufficient strength can be achieved. From the viewpoint of raising the mechanical strength, the thickness of the separator is preferably 50 μm or more.
The separator preferably has water shielding property. The level of the water shielding property of the separator depends on the type of the solid electrolyte particles included in the solid electrolyte layer, denseness of the solid electrolyte layer, and the like. The water shielding property of the separator can be measured, for example, by the following method.
First, the secondary battery is disassembled, and the separator is extracted. Next, a portion of the separator is cut to obtain a test piece. The test piece has, for example, a square plate shape whose side is 2 cm long. Next, an H-type cell is prepared. The H-type cell includes a pair of glass cells. Each glass cell has a columnar glass container body having a first opening and a tube portion vertically connected to the side surface of the glass container body and having a second opening. The pair of glass cells constitutes a connecting portion such that the second openings of the tube portions of the pair of glass cells face each other. Next, the test piece is fixed to the tube portion of one of the glass cells so that an interior space of the connecting portion is separated by the test piece.
