Patent ID: 8637177
Filing Date: 2014-01-28
Classification: H01G,H01M,Y02E

Abstract:
1. An electrochemical device comprising a positive electrode, a negative electrode, a nonaqueous electrolyte, and a separator, wherein the separator comprises a porous layer (I) composed of a microporous film composed predominantly of a thermoplastic resin and a porous layer (II) containing a filler having a heat-resistant temperature of 150° C. or higher as the main component, the porous layer (II) has a thickness of 2 μm or more, the filler having a heat-resistant temperature of 150° C. or higher contained in the porous layer (II) makes up 70 vol % or more of a total volume of components of the porous layer (II), the negative electrode contains graphite having an R value of 0.1 to 0.5 and d a ratio of the graphite to the negative electrode active material is 30 mass % or more, a surface of a negative electrode mixture layer has an arithmetic mean roughness of 0.7 μm or more, and the nonaqueous electrolyte contains a dinitrile compound or acid anhydride.