NOVELTY - The battery (100) has a folded C shape electrode assembly (110) comprising a positive electrode (112), a negative electrode (113) and a separator (114) between the positive electrode and the negative electrode. A cylindrical shape case (120) houses the electrode assembly, where the electrode assembly has an inner surface and an outer surface, and the outer surface includes a concave portion and a convex portion facing a direction. A support rod contacts the concave portion. An expansion space is defined by the concave surface of the outer surface.    USE - Rechargeable battery for use in a hybrid electric vehicle and a small portable electronic device e.g. mobile phone, laptop computer and camcorder.    ADVANTAGE - The expansion space is formed between the electrode assembly and the case, thus preventing stress to concentrate on the electrode assembly even when the electrode assembly expands, and preventing deterioration of the output of the battery, and hence extending the lifespan of the battery. The inner surface of the electrode assembly is transformed when the electrode assembly is folded and bent, so that the inner surface is prevented from wrinkling, thus improving the stability of the battery. The electrode assembly is relatively thin while reducing a distance between the inner surface and the outer surface to reduce temperature deviation between the inner surface and the outer surface, so that heat generated from an inner side of the battery during charging and discharging the battery can be easily discharged to an outer side to prevent an abnormal reaction from occurring at a high temperature. The battery can easily discharge internal heat to the outside, thus improving the performance and the lifespan of the battery.    DESCRIPTION OF DRAWING(S) - The drawing shows a cross-sectional view of a rechargeable battery.    Rechargeable battery (100)    Folded C shape electrode assembly (110)    Positive electrode (112)    Negative electrode (113)    Separator (114)    Cylindrical shape case (120)