The study looked at the use of red lead in the manufacturing of valve regulated lead acid (VRLA) miners cap lamp (MCL) batteries that were made with either flat plate or tubular positive electrodes. A problem with using only grey oxide in the manufacture of thick flat plate or tubular electrodes is the poor conversion of the active material to the desired lead dioxide. | Available online at ELSEVIER Journal of Power Sources 155 2006 428-439 The addition of red lead to flat plate and tubular valve regulated miners cap lamp lead-acid batteries . Ferga P. Loysona A. Poorunb a Department of Chemistry Nelson Mandela Metropolitan University . Box 77000 Port Elizabeth 6031 South Africa b Willard Batteries . Box 1844 Port Elizabeth 6000 South Africa Received 30 August 2004 received in revised form 21 April 2005 accepted 26 April 2005 Available online 22 June 2005 Abstract The study looked at the use of red lead in the manufacturing of valve regulated lead acid VRLA miners cap lamp MCL batteries that were made with either flat plate or tubular positive electrodes. A problem with using only grey oxide in the manufacture of thick flat plate or tubular electrodes is the poor conversion of the active material to the desired lead dioxide. The addition of red lead to the initial starting material improves the formation efficiency but is considerably more expensive thereby increasing the cost of manufacturing. The study showed that by carefully controlling the formation conditions in terms of the voltage and temperature of a battery good capacity performance can be achieved for cells made with flat plate electrodes that contain up to 25 red lead. The small amount of red lead in the active cured material reduces the effect of electrode surface sulphate formation and allows the battery to achieve its rated capacity within the first few cycles. Batteries made with flat plate positive electrodes that contained more that 50 red lead showed good initial capacity but had poor structural active material bonding. The study showed that MCL batteries made with tubular positive electrodes that contained less than 75 red lead resulted in a poorly formed electrode with limited capacity utilization. Pickling and soaking times of the tubular electrodes should be kept at a minimum thereby allowing higher active material utilization .
