NOVELTY - A sealed lithium secondary battery comprises electrode component which is formed using positive electrode containing positive electrode active material, negative electrode containing negative electrode active material, electrolyte, and additive containing compound which generates gas when predetermined battery voltage is exceeded in battery case. The sealed lithium secondary battery is provided with electric current interruption mechanism which is operated when the pressure in the battery case is increased along with the generation of the gas.    USE - Sealed lithium secondary battery is used for assembled battery for vehicle (all claimed). Uses include but are not limited to personal computer, plug-in hybrid vehicle, hybrid vehicle, electric truck, bicycle with motor, electric wheel chair and portable terminal.    ADVANTAGE - The lightweight and compact sealed lithium secondary battery has high energy density, and excellent reliability and battery characteristics.    DETAILED DESCRIPTION - A sealed lithium secondary battery comprises electrode component which is formed using positive electrode containing positive electrode active material, negative electrode containing negative electrode active material, electrolyte, and additive containing compound which generates gas when predetermined battery voltage is exceeded in battery case. The sealed lithium secondary battery is provided with electric current interruption mechanism which is operated when the pressure in the battery case is increased along with the generation of the gas. The positive electrode active material is in particulate form containing primary particles including tungsten atom. The average tungsten concentration (Y in mol%) on the surface of the positive electrode active material particles is 1.5 nm or less along depth direction. The ratio of average tungsten concentration on the surface of the positive electrode active material particles to the tungsten concentration of the whole positive electrode active material particles is 0.25-0.72. The ratio of average particle diameter ( mu m) and specific surface area (m2/g) of the positive electrode active material particles is 13-26. INDEPENDENT CLAIMS are included for the following:    (1) manufacture of sealed lithium secondary battery; and    (2) assembled battery.