Lead Sulfate Accumulation During HRPSoC Duty

Mechanism of Lead Sulfate Accumulation During HRPSoC Duty 

Recent investigations conducted by CSIRO [7,8] have provided the following explanation for the mechanism of lead sulfate accumulation in negative plates during HRPSoC duty. 

During the initial stages of the discharge of a fully charged negative plate, eleetron transfer can take place at any location because the entire plate is conduetive. Accordingly, the discharge process (both dissolution and deposition steps) oeeurs both on the surfaces and in the interior of the plate. Nevertheless, the reaction in the 

The depth to which lead sulfate penetrates is dependent on the rate of discharge, as well as on the density and surface area of the plate. Paste density is the key factor in providing the macropores which are necessary for the transport of solution and ionic species to and from the reaction sites within the interior of the plate, while surface area provides sites for the current-generating electrochemical reaction. For the same paste density and surface area, the extent to which lead sulfate can penetrate is determined by the discharge rate. 

Accordingly, the lead sulfate develops evenly throughout the cross-section of the negative plate, as shown schematically in Fig. 17.6(a). 

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