Spiral-wound grids

The passivation layer that forms on pure-lead grids in spiral-wound cells can lead to a premature drop in capacity during the first few cycles [21]. The passive film completely covers the surface of the pure-lead grid. 

Highly corrosion-resistant, antimony-free, lead alloys have been used successfully in the positive electrode grids of both single-plate and spiral-wound cells. Spiral-wound cells almost exclusively feature binary lead-tin alloys [36,41] whereas flat-plate electrodes use either lead-calcium alloys, with or without silver additive [26], or lead-tin alloys [48]. Binary lead-tin is known to be highly corrosion-resistant, but rather soft, which is a handicap for plate stacking in prismatic cells. 

Lead—tin alloys with Sn content from 0.7 to 1.2 wt% Sn are used for casting grids for spirally wound and prismatic VRLA batteries for automotive, stationary and special purpose applications. Table 4.6 presents a summary of the mechanical properties of Pb—1.0 wt% Sn alloys with or without 0.06 wt% Ca [91]. 

FIGURE 6.13 Punched grid for spiral-wound battery. (Courtesy of Exide.)... 

FIGURE 6.14 Long punched grid for spiral-wound high-rate battery. 

Spirally Wound Cylindrical Cells. The spirally wound cell, illustrated in Fig. 14.40, is designed for high-current pulse applications as well as continuous high-rate operation. The lithium anode and the cathode (a thin, pasted electrode on a supporting grid structure) are... 

Pure lead is generally too soft to be used as a grid material. Exceptions that use pure lead plates are some special, very thick plate Plants or pasted-plate batteries, some small spiral wound batteries, some valve regulated cells and batteries (see Fig. 23.12c) and a cylindrical cell. The latter were developed by Bell Laboratories (now part of Lucent Technologies) (see Fig. 23.36). "... 

The latest designs of lithium-sulphur dioxide cells feature a cathode comprising Teflon bonded acetylene block laminated to an aluminium grid, an electrolyte comprising sulphur dioxide dissolved in acetonitrile and a microporous polypropylene separator. The cells are hermetically sealed, of spiral wound construction. 

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