Journal of Power Sources, Vol.209, 289-294, 2012
A universal way for gas-liquid flow control in the design of hermetical lead-acid batteries
The paper demonstrates the capabilities of our technique of implementation of the oxygen and hydrogen cycles in hermetically sealed lead-acid batteries with forced gas feed to the pores of the working electrodes. It is based on optimization of the porous structures of the separation materials and gas-absorbing electrodes, reducing free gaps in the interelectrode gap down to the large pores of the working electrodes. Such a structure of the interelectrode gap matrix provides a fine-jet gas flow (the filtration transfer mechanism is realized); the excessive pressure in the interelectrode gap (in the separator pores) exceeds the capillary pressure on the electrode pores, as a result, the gas displaces the electrolyte from some pores of the electrode and these pores get partially filled with the gas. The fine-jet gas flow is characteristic of fine-porous separators tightly fitting to the electrode surface. The authors offer methods to increase the rate of gas absorption on the working (lead and lead-dioxide) electrodes based on compulsory gas feed into the electrode pores, which are practically cost-free but allow designing of completely hermetical batteries. It is especially important now in the development of hermetical lead-acid batteries which should replace valve-regulated ones. (C) 2012 Elsevier B.V. All rights reserved.