Thin tubular positive electrodes for lead-acid batteries and method of making same

A positive tubular electrode for a lead-acid battery, the said electrode including a grid structure comprising a top bar, a lug, and a plurality of spaced-apart lead alloy current carrying spines depending from the top bar, a plurality of tube members arranged around the spines such that one spine is enclosed by each tube member, active material portions comprising a lead oxide received in the tube members and the lower ends of the said tube members being closed by a bottom bar part, and wherein:

• (a) the ratio between a calculated weight of formed dry active material when filled into a tube member and the weight of the spine enclosed by the tube member;
• and
• (b) the ratio between the lateral cross-sectional area enclosed by the tube member to the lateral cross-sectional area of the spine enclosed by the tube member;
• are of sufficient value to produce spines sufficiently thick such that, during battery operation, the spines corrode to produce a high density zone of active material about the spine of about 4.8 gm/cm.sup.3 or higher while leaving a spine cross-sectional area sufficient to carry a predetermined battery current.

A positive tubular electrode for a lead-acid battery, the said electrode including a grid structure comprising a top bar, a lug, and a plurality of spaced-apart lead alloy current carrying spines depending from the top bar, a plurality of tube members received over the spines such that the length of each spine is substantially surrounded by a tube member, active material portions received in the tube members and the lower ends of the said tube members being closed by a bottom bar part, in which the ratio between a calculated weight of formed, dry active material received in each tube member to the weight of the spine surrounded by that tube member is restricted to a maximum value of 1.5:1, and the ratio between the lateral cross-sectional area enclosed by each tube member and the lateral cross-sectional area of the spine over which that tube member is received is restricted to a maximum value of 5.0:1 to provide spines of sufficient dimensions such that during battery operation, the spines may corrode to form a dense layer of active material about the remaining portions of the spine which substantially precludes further spine corrosion and wherein said dense layer contributes to the active material and wherein said corrosion is substantially terminated prior to the point at which the cross-sectional area of the spines are incapable of conducting the requisite battery current.