Disclosed is a lithium secondary battery provided with a separator, having improved thermal stability by including a micro-particle coating layer manufactured using Furan-based polymers, for example, polymers having polymer unit including furanyl or furoyl. The lithium secondary battery includes a cathode, an anode, an electrolyte, and a separator disposed between the cathode and the anode and including a coating layer including a micro-particle. The micro-particle includes the second polymer which may include cross-linked first polymer.