Disclosed is a lead acid battery including: a positive electrode; a negative electrode; a separator interposed between the positive electrode and the negative electrode; and an electrolyte containing sulfuric acid. The negative electrode includes a negative electrode active material, and a negative electrode grid that supports the negative electrode active material. The negative electrode grid contains tin in an amount of 0.1 mass % or more and 0.8 mass % or less. The electrolyte contains aluminum ions at a concentration of 1 mmol/L or more and less than 10 mmol L, and sodium ions at a concentration of 15 mmol/L or less.

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.

The present disclosure discloses a method for forming a lead-carbon compound interface layer on a lead-based substrate, wherein the lead-based substrate has a surface, and the method includes steps of: causing an acidic solution to contact with a carbon material and a lead-containing material to form a carbon-containing plumbate precursor having an ionic lead; and reducing the ionic lead in the carbon-containing plumbate precursor to form the lead-carbon compound interface layer on the surface.

A method for manufacturing a substrate for a lead acid battery includes manufacturing a powder mixture by mixing lead powder and carbon powder and manufacturing a substrate by compress-molding the powder mixture. 85 wt % to 95 wt % of the lead powder and 5 wt % to 15 wt % of the carbon powder are mixed, based on 100 wt % of the powder mixture.

A current collector assembly, such as for a bipolar lead acid battery, can include an electrically-conductive silicon substrate and a frame bonded to the electrically-conductive silicon substrate. The substrate can be treated or modified, such as to include one or more thin films which render a surface substrate electrically conductive and electrochemically stable in the presence of a lead acid electrolyte chemistry. An interface between the frame and the electrically-conductive silicon substrate can be hermetically sealed. In an example, the frame can provide an edge-seal ring configuration. In an example, a casing assembly can include a spacer bonded to the substrate, along with a casing segment and a thermally-conductive rib, the spacer isolating the thermally-conductive rib from the electrically-conductive silicon substrate electrically.

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.

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.

A positive electrode current collector plate, which is a current collector sheet for a lead-acid storage battery, includes a rolled sheet including a lead alloy in which a content ratio of tin (Sn) is between 1.0 mass % and 1.9 mass %, inclusive, a content ratio of calcium (Ca) is between 0.005 mass % and 0.028 mass %, inclusive, and a balance is lead (Pb) and inevitable impurities. A hole penetrating in a plate surface direction is not formed, and the number of crystal grains having a grain size of 10 m or more present in a range excluding top and bottom 10% in a thickness direction of the rolled sheet in an arbitrary cross section is between 25 and 55, inclusive, per area of 1 mm.sup.2 in the range.

The weight and size of a lead-acid battery is reduced and the energy density per mass by forming base members of components of the lead-acid battery is improved by using aluminum or aluminum alloy and forming multiple plating layers on a surface of each base member. In order to prevent formation of pinholes in the multiple plating layers, the surface of the base member 22 is subjected to flattening processing, a solder plating layer with a film thickness of 10 m or more is formed, or many layers of group 4 metals with similar chemical properties are laminated. Moreover, in a positive electrode plate and a negative electrode plate, an active material layer 24 is formed on the outermost lead plating layer by an electrolytic formation treatment to improve the charging and discharging efficiencies of the lead-acid battery and to greatly reduce fall-off the active material layer 24.

A lead alloy for an electrode grid comprises lead, 0.04 wt. %-0.08 wt. % calcium and 0.003 wt. %-0.025 wt. % of at least one rare earth metal. The at least one rare earth metal being yttrium. An electrode having an electrode framework formed at least partially of at least one of the lead alloys, a lead-acid accumulator having the electrode are also described.