Abstract: A bipolar lead-acid storage battery has both life performance to withstand long-term operation and high capacity performance. Positive electrode current collector plates include a lead alloy sheet, a mass loss per total surface area of a test piece is 100 mg/cm2 or less when measured after the test piece is placed in sulfuric acid at a concentration of 38 mass % maintained at a temperature of 60° C., and a continuous anodization performed at a constant potential of 1,350 mV on a reference electrode for 28 days. A thickness of the collector plate arranged on one surface of a substrate that covers both a side of a positive electrode and a side of a negative electrode of a cell member is between 0.10 mm and 0.50 mm, and a ratio of a volume of the current collector plate to a rated capacity of the battery is between 0.11 and 0.67.

Abstract: A bipolar storage battery includes cell members arranged with spacing in a stacked manner, each of the cell members including a positive electrode, a negative electrode, and an electrolyte layer interposed between the positive electrode and the negative electrode, and space-forming members forming a plurality of spaces individually accommodating the plurality of cell members. A value obtained by dividing the distance between a positive active material layer and a negative active material layer placed in a position facing the positive active material layer by the sum of the thickness of the positive active material layer and the thickness of the negative active material layer is 1.1 or more. The bipolar storage battery may suppress local use of active material during charging and discharging to achieve uniform use of active material in a cell.

Abstract: During welding for manufacturing a bipolar storage battery, it is possible to reduce heat accumulation inside an electrical conductor and heat conductivity to a periphery of a through-hole by connecting current collector plates on both surfaces of a substrate. In the battery in which a positive electrode current collector plate and a negative electrode current collector plate of cell members adjacent to each other are electrically connected to each other by an electrical conductor arranged in a through-hole and a plurality of cell members are electrically connected in series, an area of at least one of a connection surface of the electrical conductor with the positive electrode current conductor plate and a connection surface of the electrical conductor with the negative electrode current collector plate is smaller than a cross-sectional area of the electrical conductor parallel to the connection surface in a middle portion in a plate thickness direction.

Abstract: A bipolar storage battery includes cell members arranged with spacing in a stacked manner, each of the cell members including a positive electrode, a negative electrode, and separators interposed between the positive electrode and the negative electrode, space-forming members including a substrate that forms a plurality of spaces individually accommodating the plurality of cell members, and a frame body surrounding a side surface of the cell member. Each of the plurality of separators has a first surface and a second surface with different surface roughness, and a surface in contact with at least the positive active material layer is a surface having a smaller (finer) surface roughness than the first surface or the second surface. This configuration may suppress local use of active material during charging and discharging to achieve uniform use of active material in a cell.

Abstract: A positive electrode grid body for lead-acid battery includes frame rib including first and second lateral frame ribs and first and second longitudinal frame ribs, an inner rib including a plurality of lateral and longitudinal crosspieces, a plurality of opening portions, and a positive electrode current collection lug connected to the first lateral frame rib. In a region having a length of at least one opening portion or more in the lateral direction of the lateral crosspieces from the first longitudinal frame rib, a cross-sectional area of the plurality of lateral crosspieces located on at least the first lateral frame rib side becomes larger from the second longitudinal frame rib side toward a portion connected to the first longitudinal frame rib.

Abstract: A positive electrode grid body for lead-acid battery includes frame rib including first and second lateral frame ribs and first and second longitudinal frame ribs, an inner rib including a plurality of lateral and longitudinal crosspieces, a plurality of opening portions, and a positive electrode current collection lug connected to the first lateral frame rib. In a region having a length of at least one opening portion or more in the lateral direction of the lateral crosspieces from the first longitudinal frame rib, a cross-sectional area of the plurality of lateral crosspieces located on at least the first lateral frame rib side becomes larger from the second longitudinal frame rib side toward a portion connected to the first longitudinal frame rib.