Storage battery manufacturing method which uses a polar plate having a foamed-metal electrode substrate and joins a current collector to the electrode substrate, and storage battery obtained through the manufacturing method

A method of manufacturing a storage battery, comprising the steps of:

• (a) forming an electrode assembly by positioning a positive electrode and a negative electrode opposite from each other with a separator sandwiched therebetween,
• wherein each of the electrodes includes an electrode substrate, and has an active material unfilled portion, which is unfilled with an active material, within the electrode substrate along an edge thereof lying perpendicular to a width direction of the electrode substrate,
• the electrode substrate of at least one of the electrodes is made of foamed metal, and
• the active material unfilled portion of the at least one electrode projects outward from an edge of the separator;
• (b) forming a tab portion by applying compression to the active material unfilled portion of the at least one electrode from a direction opposite to the projection while maintaining relative positions of the electrodes to the separator within the electrode assembly, the compressed active material unfilled portion being the tab portion, part of the tab portion located at a periphery of the electrode assembly being plastically bent inward in a facing direction of the electrodes;
• and
• (c) joining a platy current collector to the tab portion in abutting contact with the current collector.