NOVELTY - An active material comprises a core material comprising a compound capable of electrochemical oxidation/reduction; and a lithium ion conducting layer surrounding the core material. The lithium ion conducting layer comprises a compound from lithium ion conductors and/or lithium ion conductive polymers.    USE - The active material is used for a battery, e.g. manganese batteries, alkaline batteries, mercury batteries, silver oxide batteries, lead-acid storage batteries, nickel-metal hydride (Ni-MH) batteries, sealed nickel-cadmium batteries, lithium metal batteries, lithium ion batteries, lithium polymer batteries, or lithium-sulfur batteries. The active material is used in at least one of a positive electrode (12) and a negative electrode (13) of the battery. (All claimed)    ADVANTAGE - The active material has excellent lithium ion conductivity and suppresses the negative reaction of the core material with the electrolyte due to the lithium ion conductive layer surrounding the core material. The active material may complement thermal stability during charging and improve stability when the battery is allowed to stand at a high temperature after charging. When an overcurrent is applied to the battery cell, the active material including lithium ion conductors or lithium ion conductive polymers having low electron conductivity acts to insulate itself, thus increasing apparent voltage and protecting the positive electrode from safety problems due to lithium over-deintercalation at the positive electrode or delay the lithium over-deintercalation.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for:    (1) an electrode for a battery (10), comprising a current collector; and an active material layer disposed on the current collector, where the active material layer comprises the active material; and    (2) a battery, comprising the electrode.    DESCRIPTION OF DRAWING(S) - The drawing is a cross-sectional view of the battery.    Battery (10)    Electrode assembly (11)    Positive electrode (12)    Negative electrode (13)    Separator (14)