In order to meet the demands of present-day applications of lead‒acid batteries, the technology must provide higher levels of charge-acceptance to boost system efficiency and delay common failure mechanisms. In the past, the addition of various forms of carbon to the paste mix has been examined to address these challenges. Most, if not all, of these attempts have resulted, however, in changes in paste quality or production line equipment when the carbon is incorporated.
Molecular Rebar® is a novel form of carbon nanotubes which are discrete, predominantly free from impurities, and provided in a safe, easily-deployable mixture. The product is incorporated into either positive- or negative-active materials during the paste-mixing stage but, importantly, requires no changes to the paste recipe or production line. Density, penetration and other quality control factors are unaffected by the addition of Molecular Rebar®. Performance gains achieved from a 0.16 wt.% loading of Molecular Rebar® (with respect to lead oxide) include 100‒200% increases in charge-acceptance, >33%, >60% and >200% increases in 17.5% DoD, HRPSoC and SBA cycle-life tests (respectively), and augmentations to cold charge-acceptance. The most recent performance data, product development, and theories regarding the mechanism of Molecular Rebar® in lead‒acid batteries will be reported.
Black Diamond Structures
Director of Technology, Lead Acid Batteries
Biography: Dr Paul Everill earned his Ph.D. at Tufts University in Boston, Massachusetts, studying the surface chemistry of biological macromolecules with the goal of developing smarter, more targeted medicines. After three years of post-doctoral experience studying diabetes, cancer, and Alzheimer’s disease therapeutics, Dr Everill took his expertise in organic chemistry, surface chemistry, and molecule-molecule interactions and applied it to the growing field of nanotechnology. At Molecular Rebar Design, LLC, he was instrumental in formulating the functionalized carbon nanotubes known as Molecular Rebar® into a lead acid battery-compatible additive. He currently directs all product development and research-based activities for Molecular Rebar® Design’s lead acid battery initiatives.
Dr Everill published Molecular Rebar® Design’s research, together with Steven Swogger, Dr. Nanjan Sugumaran, and D. P. Dubey, in the Journal of Power Sources in 2014 and 2015. The first paper detailed the use of Molecular Rebar® (aka Discrete Carbon Nanotubes) in the negative electrode only (JoPS Vol. 261, September 1st, 2014, p55) and the second paper added to that work by discussing the addition to both electrodes (JoPS Vol. 279, April 1st, 2015, p281). Both articles are available free of charge.