Carbon nanotubes create ‘spectacular’ improvement in lead batteries
Scientists at the university of Bar-llan in Israel and the nanotube company OCSiAl have announced “spectacular” results when they added single-walled carbon nanotubes (SWCNT) to the electrode pastes of lead-acid batteries.
Presenting at the world’s first nanoaugmented materials industry summit that was held in Novosibirsk, Russia, in November, Doron Auerbach, head of the chemistry department at Bar-llan University, said there had also been remarkable results with the addition of SWCNT to the electrodes of advanced lead batteries with gel electrolyte — an improvement he said had been completely unexpected.
“It was above all expectations,” said Auerbach. “SWCNT increased the mechanical strength of the active mass, the integrity of the active mass and the electric conductivity of the active mass.
“Even tiny amounts were very effective, which means with mass production the cost will not be a big issue because the amounts required are so tiny.”
Auerbach said that with just 0.001% of SWCNT added to the electrode paste of ordinary lead-acid batteries, the cycles of the cells increased by more than 600 and there was a five-fold increase in cycle life.
The rate capability increased more than five times with the addition of the nanotubes.
With advanced lead batteries it was even more remarkable because the results were unexpected, he said.
“In advanced lead acid batteries the electrolyte is now a gel, and we didn’t expect there to be much of a difference because the batteries are better, after all,” he said.
“But when the cells were polarized, they needed much lower voltage if they had SWCNT added to the gel.
“When we added our magic additive we could see the improvement in advanced lead batteries which was spectacular when compared with blank cells. There was a five-fold gain in cycle number.”
The addition of SWCNT also suppressed sulfation, Auerbach said.
The nanoaugmented materials summit was organized by OCSiAl, the Luxembourg-based firm that has developed its own brand of nanotubes, Tuball.
Tuball consists of more than 75% of single wall carbon nanotubes and is added to a wide range of materials which the firm says include touch screen panels, polymers, structural composites, rubber goods and batteries.
OCSiAl co-founder Yuri Koropachinoskiy said: “Commercial production of SWCNT is a fundamental achievement. This is the first material with fundamentally new properties which mankind has learned to produce commercially over the past 50 years.”