Patent ID: 9070948
Filing Date: 2015-06-30
Classification: H01B,H01M,Y02E

Abstract:
1. A lithium secondary battery, which includes a cathode, an anode, a separator interposed between the cathode and the anode, and a non-aqueous electrolytic solution obtained by dissolving lithium salt to a non-aqueous solvent, wherein the separator includes: a porous substrate having pores; and a porous coating layer located on at least one surface of the porous substrate and having inorganic particles and a binder polymer, the inorganic particles being connected and fixed to each other by means of the binder polymer, the porous coating layer having pores therein formed by interstitial volumes among the inorganic particles, wherein the non-aqueous solvent is a high-viscous non-aqueous solvent having, a viscosity of 1.4 cP or above at 25° C, wherein the hinder polymer has a solubility parameter of 15 to 45 MPa wherein a weight ratio of the inorganic particles and the binder polymer in the porous coating layer is 50:50 to 99:1, wherein the porous substrate has a thickness of 1 to 100 μm, and the porous coating layer has a thickness of 0.01 to 20 μm, and wherein the high-viscous non-aqueous solvent includes γ-butyrolactone, fluoroethylene carbonate and their mixtures.