RESEARCH

Lead-acid batteries are invented by the French physicist Raymond Gaston Plante in 1859, these batteries are made up of a spirally wounded pair of lead electrodes. Later sticky paste technology was developed on lead sheets, lead-alloy grids and commercialized successfully in the global community.
The fundamental electrochemistry of lead-acid batteries remains the same even after 160 years. However, the most successful applications are in telecommunications, automotive, uninterruptible power supplies, grid storage, and hybrid electric vehicles. The major failures in lead-acid batteries are irreversible sulfation, positive active material shedding, oxidative grid corrosion, low utilization of active material, and low specific energy. In the scientific community, research has been devoted to improving the energy density with lightweight substrates and the inclusion of suitable electrolyte and electrode additives with reduced cost.

Our group actively working on carbon nanotube (CNT)-based additives for advanced lead-acid batteries for commercial applications. Physical integration of CNT-based additives into a positive and negative paste to enhance the electrochemical activities of lead-acid batteries. These additives have outstanding properties like homogenous distribution throughout the plates and excellent electrical conductivities. CNT-based additives containing cells deliver a high specific capacity, improved cycle life, and excellent kinetics and mitigate the sulfation.
We showed the addition of properly oxidized CNTs in an amount above the percolation threshold to the active mass of the positive electrodes in lead-acid batteries lead to the formation of a stable conductive grid that enabled the delivery of current to all the active material. Further, we worked on a low loading level of SWCNT to lead-acid batteries cycled in a 25% and 50% depth-of-discharge (DOD) cycling, delivering the service life up to about 1700 and 1400 cycles for 25% and 50% DOD operations. We have successfully prolonged the cycle life of the practical batteries with the addition of CNTs to the positive and negative electrodes. The enhanced electrochemical performances due to the presence of CNT enable much better accessibility of the active mass to the electron transport processes during cycling, due to their physical properties as high aspect ratio, thin, flexible, robust, and stable electronically conducting agents. Some of our published results shown in below.