LITHIUM SECONDARY BATTERY

A disclosed lithium secondary battery includes a positive electrode (11), a negative electrode (12), a separator (50) disposed between the positive electrode (11) and the negative electrode (12), and a non-aqueous electrolyte having lithium ion conductivity. The negative electrode (12) is an electrode on which lithium metal is deposited during charging and from which the lithium metal dissolves during discharging. The separator (50) includes a substrate (51), a heat-resistant layer (52), and a spacer (53). The heat-resistant layer (52) is formed on at least one main surface selected from two main surfaces of the substrate (51). The spacer (53) is disposed on the negative electrode (12) side with respect to the substrate (51) and the heat-resistant layer (52). An average height of the spacer (53) is larger than a sum of an average thickness of the substrate and an average thickness of the heat-resistant layer.