An active material is disclosed in the present invention. The active material includes a lithium active material and a complex shell which completely covers the lithium active material. The complex shell includes at least one protection covering and at least one structural stress covering. The protection covering is a kind of metal which may alloy with the lithium ion. The structural stress covering dose not alloy with the lithium active material. The complex shell efficiently blocks the lithium active material out of the moisture and the oxygen so that the lithium active material is able to be stored and operated in the general surroundings. The structural stress provided via the structural stress covering may keep the configuration of the active material unbroken after the repeating reactions.