NOVELTY - The battery (100) has a battery case (110) whose inner side is filled with electrolyte and provided with an anode (121) and a cathode (122). An electrode assembly (160) comprises a porosity elastomer (140) i.e. foam rubber/vesicatory synthetic resin. A separation film (123) is laminated between the anode and the cathode. The electrolyte is supplied to the electrode assembly for pressurizing volume expansion of the electrode assembly. Size of a pore (150) of the porosity elastomer is 0.01-5000 micrometer. The foam rubber is made of natural rubber/synthetic rubber.    USE - Battery e.g. lithium ion battery, lithium ion polymer battery or lithium polymer battery, for a battery module of a battery pack of a power storage device i.e. mobile apparatus, and a vehicle e.g. electric vehicle, hybrid electric vehicle and plug-in hybrid electric vehicle (all claimed).    ADVANTAGE - The electrolyte is emitted between the cathode and the anode so as to reduce oxidation phenomenon of the electrolyte, improve electrochemical performance of the battery and prevent lifetime of the battery from being degraded when excess of electrolyte is injected between the electrode assembly and the battery.    DETAILED DESCRIPTION - The synthetic rubber comprises styrene-butadiene rubber, polychloroprene rubber, nitrile rubber, butyl rubber, butadiene rubber, isoprene rubber, ethylene free pylene rubber, polysulfide rubber, silicone rubber, fluoro rubber, urethane rubber and acryl rubber. The vesicatory synthetic resin comprises polyolefin, polyester, polyamide, polyacetal, polycarbonate, polyimide, polyether ketone, polyethersulfone, polyphenyleneoxide, polyphenylenesulfide, polyethylenenaphthalete, PTFE, polyvinylidene fluoride, polyethylene terephthalate, PVC, polyacrylo nitrile, nylon, polyparaphenylenebenzobisoxazole and polyurethane materials. The anode is made of lithium transition-metal oxide, magnesium, nickel, cobalt, iron, chromium, vanadium, titanium, copper, boron, calcium, zinc, zirconium, niobium, molybdenum, strontium, antimony, manganese, lungsten and bismuth materials. An INDEPENDENT CLAIM is also included for a power storage device.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of a battery.    Battery (100)    Battery case (110)    Anode (121)    Cathode (122)    Separation film (123)    Porosity elastomer (140)    Pore (150)    Electrode assembly (160)