ENHANCED PERFORMANCE OF STARTER LIGHTING IGNITION (SLI) TYPE LEAD-ACID BATTERIES WITH CARBON NANOTUBES AS AN ADDITIVE TO THE ACTIVE MASS

Even though, today, various battery systems are appeared in the global market with different advantages, the demands of lead-acid batteries are still in the peak position among the consumers, mainly because of cost-intensiveness and safety. The utility of lead-acid batteries in stationary load-leveling, house-hold UPS, SLI in automotive, renewable energy storage applications are unquestionable also in present days. The environmental issues of lead-poisoning, which are related to the battery manufacturing process and disposal, are appreciably tackled by recycling the battery materials up to about 99.99%. Mainly, the lead-acid battery technology is faced two limitations, such as low capacity and low operational life. Among various reasons of premature capacity loss of the batteries, the sulfation of active mass is prominent and well studied in literature. There are several mitigation pathways are highlighted, and among them addition of carbonaceous materials in active masses is most promising. There are several carbonaceous materials such as graphitic powder, carbon black, various activated carbons, and carbon-based nano materials like single-walled carbon nanotubes (SWCNT), multi-walled carbon nanotubes (MWCNT), graphenes could be used as an additive in active masses of battery plates. The carbon nanotubes are envisaged as most efficient materials, because of their ordered structures and consequently high intrinsic electrical conductivity.

In this study, we investigated the incorporation-effect of carbon nanotubes (CNT) to the positive and the negative active materials in lead-acid battery prototypes in a configuration of 2 V lead-acid flooded cells, as well as gelled cells. The cells were tested at 25% and 30% depth-of-discharge (DOD). The positive effect of the carbon nanotubes (CNT) utilization as additives to both positive and negative electrodes of lead-acid batteries was clearly demonstrated and is explained herein based on microscopic studies.