Effect of additives in compressed lead–acid batteries

The innovative solution proposed in this paper to improve both cycling life and performances of a very low cost lead–acid battery is the combination of the compression concept and the use of micro-porous additives added in the active mass. The influence of different rates of compression (10–100 kPa) applied on 2 V pre-industrial modules slightly modified has been studied in accelerated cycling test as well as the effect of different kinds of additives on 2 V lab cells performances in a compressed application. It appears that a pressure minimum of 10 kPa is necessary to stabilise the performances and multiply, by close to 10, the cycling life of the modules. Nevertheless, a 100 kPa pressure allows to perfectly maintain the electrode integrity during the cycling test and prevent effectively the shedding phenomenon. The idea of the insertion of porous additives into the active mass has been validated during this study since a significant improvement of the cell performances has been observed with two kind of additives tested: Zeolite and Carbon Graphite.