Nickel-Zinc batteries for future Stop&Start PSA systems
PSA Peugeot Citroen is turning its attention to nickel-zinc (NiZn) battery specialist PowerGenix to help with its latest efforts at reducing emissions. The French OEM has agreed to evaluate NiZn batteries as a possible replacement for lead-acid batteries in stop-start (microhybrid) models.
Salil Soman, Director of Systems Engineering at PowerGenix, said that PSA had been interested in NiZn for some time. Early tests conducted by the OEM indicated that the swap to NiZn could provide additional reductions in both weight and CO2 emissions compared to lead-acid technology. This sort of promising preliminary results that encouraged PSA to take the next step. “This contract signifies that they are ready to move into a significant testing and validation phase,” Soman stated.
PowerGenix will now work with PSA to validate the results. In particular they will be looking at charge acceptance, weight savings and service life improvements over lead-acid technology. “The ultimate objective of this contract is to fully develop a NiZn battery that meets all of Peugeot’s technical specifications, and is ready for integration into their stop-start vehicles,” added Soman.
“NiZn holds the potential to provide an ideal replacement for lead-acid by reducing the weight and CO2 emissions of our stop-start engine vehicles. This study marks PSA Peugeot Citroen’s interest in working closely with PowerGenix to validate the promise of NiZn technology,” stated Bernard Sahut, innovation team manager for PSA Peugeot Citroen.
Stop-start technology is a cost-effective means of improving fuel economy. Representing a much-less expensive option than mild or full hybrid systems, stop-start can still bring in fuel economy improvements of between 5% and 8%. Next-generation systems could even see 12-15% improvements, believes Soman. At the moment, the stop-start market is dominated by lead-acid battery technology. However, PowerGenix believes that NiZn batteries offer a strong alternative, providing higher energy density and higher charge acceptance.
“NiZn’s primary challenge at this stage is the entrenchment of lead-acid in the automotive industry. Although OEMs recognize that lead is not an ideal solution to support stop-start systems, there is a bias in the industry towards proven technologies over newer, innovative solutions,” commented Soman.
Infrastructure plays a key role. Soman notes that the infrastructure surrounding the lead-acid battery industry has been building up for several decades, from the raw material supply chain to battery recycling. “That said, NiZn has already crossed the commercialization chasm with our cylindrical cell product line, which is a major asset. Automotive qualification cycles tend to be somewhat slower than some other battery markets; however, we are working with most major OEMs globally, and this contract with Peugeot indicates their strong interest in considering NiZn batteries as a replacement for lead-acid in stop-start applications.”
It seems that this battery pack has a higher power but lower energy than the classic lead-acid battery. It is therefore good for Stop&Start systems as the starter is demanding in terms of power. I guess that the lack of energy could be compensated by a smart alternator that charges the battery consequently. Do you think that this technology will raise and replace the lead-acid battery?