Lead acid batteries are still dominant in a variety of applications, including personal, commercial and utility automotives, industrial uses, and energy storage. However, they do suffer from limitations such as low energy density, short lifetime, and low charge acceptance, which caused the LAB market to lose some of its momentum.
On the other hand, Absorbent Glass Mat (AGM) technology is the norm for UPS batteries due to its lower cost and faster charge/discharge rates. To expand the field of application of stationary AGM batteries, the lifetime, which is about 500 cycles (50% DOD), can be extended.
Multi walled carbon nanotubes (MWCNT) with their high aspect ratio, high electrical and mechanical stability are considered as promising and effective negative active mass (NAM) additive towards improving the performance of lead acid batteries, including the lifespan.
It is well known that carbon nanotubes are a highly aggregable material due to the van der Waals forces that act between the particles. To achieve the full effect of MWCNTs, their particles must be dispersed. This is not possible if MWCNTs are directly added to batterie’s NAM without any pretreatment procedure.
In this work, we disperse MWCNTs in water to obtain a stabile aqueous dispersion of MWCNTs, used as a NAM’s additive.
Also, the effect of adding a MWCNT dispersion into the NAM of stationary AGM lead-acid batteries was investigated.
The batteries were subjected to several tests, such as cycle life at 50%DOD, Cycle Life (TUBITAK), Capacity (C0.25-C10), etc.
The positive effect of the MWCNTs utilization in the NAM of AGM lead acid batteries was clearly demonstrated. The Cycle Life was enhanced drastically, compared to the reference batteries.