Secondary battery, battery pack, vehicle, and stationary power supply
摘要
說明書
The level of the flexibility of the separator can be determined by comparing the results of the above-described water-shielding test obtained on the test piece before the bending test with the results of the water-shielding test obtained on the test piece after the bending test. That is, if the difference between the electric conductivity Al of pure water obtained in the test piece before the bending test and the electric conductivity Al of pure water obtained in the test piece after the bending test is 500 μS/cm or less, it can be said that the separator is excellent in flexibility.
The porous self-supporting film can be impregnated with a nonaqueous electrolyte. The porous self-supporting film has a first main surface which is one main surface and a second main surface which is the other main surface. The solid electrolyte layer is carried on the first main surface. The first binder is carried on the second main surface.
The porous self-supporting film is, for example, a porous resin sheet or a nonwoven fabric. As the material of the porous resin sheet or nonwoven fabric, for example, polyethylene (PE), polypropylene (PP), cellulose, or polyvinylidene fluoride (PVdF) can be used. The porous self-supporting film is preferably a cellulose nonwoven fabric.
The thickness of the porous self-supporting film is, for example, 3 μm or more, preferably 5 μm or more. If the thickness of the porous self-supporting film is thick, the mechanical strength of the separator is increased, and internal short circuit of the secondary battery becomes hard to occur.
