A calcium-free lead alloy comprises lead and 0.003 wt %-0.025 wt % of at least two rare-earth metals. The rare-earth metals are at least a lanthanide and yttrium. Uses of the lead alloy include an electrode with an electrode structure, which is at least partly formed of the lead alloy and a lead-acid accumulator with the electrode.

A method for forming a connection such as an electrical connection, to a fibre material electrode element comprises moving a length of the fibre material relative to a pressure injection stage and pressure impregnating by a series of pressure injection pulses a lug material into a lug zone part of the fibre material to surround and/or penetrate fibres of the fibre material and form a lug strip in the lug zone. The fibre material may be a carbon fibre material and the lug material a metal such as Pb or a Pb alloy. Apparatus for forming an electrical connection to a fibre material electrode element is also disclosed.

A method for forming a connection such as an electrical connection, to a fibre material electrode element comprises moving a length of the fibre material relative to a pressure injection stage and pressure impregnating by a series of pressure injection pulses a lug material into a lug zone part of the fibre material to surround and/or penetrate fibres of the fibre material and form a lug strip in the lug zone. The fibre material may be a carbon fibre material and the lug material a metal such as Pb or a Pb alloy. Apparatus for forming an electrical connection to a fibre material electrode element is also disclosed.

Disclosed is a metal mixture composition containing lead and tin, and comprising by weight at least 10% tin and 45% lead, at least 90% of tin and lead together, more lead than tin, from 1-5000 ppm of copper, at least 0.42% antimony and at least 0.0001 % wt of sulphur, at most 0.1% of the total of chromium, manganese, vanadium, titanium and tungsten, and at most 0.1% of each one of aluminium, nickel, iron and zinc. Disclosed is also a process comprising a pre-treatment step for producing this metal mixture composition, followed by a vacuum distillation step wherein lead is removed by evaporation and a bottom stream is obtained comprising at least 0.6% wt of lead.

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/cm.sup.2 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.

A lead foil and a bipolar lead acid storage battery capable of preventing breakage of the lead foil due to growth deformation are described. The lead foil is for a current collector in a bipolar lead acid storage battery, in which at least one of a front surface or a back face has a maximum valley depth Rv of 4 m or less in a profile curve acquired, orthogonally to a rolling direction, by surface roughness measurement with a stylus.

A lead foil and a bipolar lead acid storage battery capable of preventing breakage of the lead foil due to growth deformation are described. The lead foil is for a current collector in a bipolar lead acid storage battery, in which at least one of a front surface or a back face has a maximum valley depth Rv of 4 m or less in a profile curve acquired, orthogonally to a rolling direction, by surface roughness measurement with a stylus.

A lead foil and a bipolar lead acid storage battery capable of suppressing a voltage drop in the battery due to peeling of the lead foil from a substrate are described. The lead foil is for a current collector in a bipolar lead acid storage battery. A back face of the lead foil opposed to a substrate of the bipolar lead acid storage battery has a contact length of between 150 m and 1800 m, inclusive, in a profile curve acquired, orthogonally to a rolling direction, by surface roughness measurement with a stylus, and with a scanning distance of 4 mm and a measurement interval of 0.5 m, the contact length is a sum total of respective absolute values of differences in height between adjacent measurement points.

A lead foil and a bipolar lead acid storage battery capable of suppressing a voltage drop in the battery due to peeling of the lead foil from a substrate are described. The lead foil is for a current collector in a bipolar lead acid storage battery. A back face of the lead foil opposed to a substrate of the bipolar lead acid storage battery has a contact length of between 150 m and 1800 m, inclusive, in a profile curve acquired, orthogonally to a rolling direction, by surface roughness measurement with a stylus, and with a scanning distance of 4 mm and a measurement interval of 0.5 m, the contact length is a sum total of respective absolute values of differences in height between adjacent measurement points.

A lead-acid battery includes a positive electrode plate, a negative electrode plate, and an electrolyte solution. The positive electrode plate includes a positive current collector and a positive electrode material. The negative electrode plate includes a negative current collector and a negative electrode material. The positive current collector contains a lead alloy containing Ca and Sn. The content of Ca in the positive current collector is 0.2% by mass or less, and the content of Sn is 0.5% by mass or more. The negative electrode material contains a first organic expander (excluding a lignin compound) containing at least one selected from the group consisting of a unit of a monocyclic aromatic compound and a unit of a bisphenol S compound.