PowerGenix, the developer of high-performance, automotive Nickel-Zinc (NiZn) batteries, has entered into an innovation contract with PSA Peugeot Citroën Automobiles under which PSA will conduct a comprehensive evaluation of the use of PowerGenix’s NiZn batteries as a replacement for lead-acid in stop-start vehicles.
Start-stop systems shut off engines while the vehicle is at rest and restart it instantly and automatically upon re-engaging the gas pedal and are one of the most cost-effective and efficient means of optimizing fuel economy. Current estimates put stop-start efficiency improvements at around 5-8%, while next generation systems may achieve savings as high as 12-15%.
Stop-start technology has already been widely deployed in Europe, where 70% of all vehicles sold by 2017 are expected to carry the system as a standard feature. Lead-acid batteries, the most common battery choice, are low-cost, easily available and relatively safe. NiZn batteries with higher energy density and higher charge acceptance could be an alternative choice offering a sustained fuel economy improvement.
Nickel-zinc batteries are chemically similar to nickel-cadmium, but differ significantly in their voltage. The nickel-zinc cell delivers more than 0.4V of additional voltage both at open circuit and under load. With the additional 0.4V per cell, an inherent value of the nickel-zinc cell lies in the reduced cell count required for a multi-cell battery.
PowerGenix had first to solve the technical problems associated with the instability of the zinc electrode in a rechargeable cell. The cornerstone of this solution was found in a patented electrolyte formulation that reduces zinc solubility and prevents dendrite shorting problems. The capabilities of the cell were further enhanced with patented advancements in both the positive and negative electrode composition that are free of any heavy metal elements.
According to PowerGenix, replacing a lead-acid battery with NiZn results in up to 70% reduced battery weight and size, further increasing vehicle fuel efficiency.
As part of this innovation contract, PSA Peugeot Citroën Automobiles and PowerGenix will work closely together to verify several aspects of performance improvements, including high sustained charge acceptance, weight savings and service life improvements for use in stop-start vehicle applications. PSA and PowerGenix will also investigate battery sizing, cost projections, in-service life evaluation and safety analysis of the batteries, with tests performed under wide temperature ranges to validate NiZn’s performance at extreme temperatures.
At completion of the contract term, PowerGenix NiZn batteries are expected to be fully tailored for Peugeot and ready for successful integration into vehicles.
PSA Peugeot Citroën Automobiles is committed to reducing the ecological impact of our vehicles and maintaining our position as a leader in low emissions automobiles. 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 Automobiles’s interest in working closely with PowerGenix to validate the promise of NiZn technology.—Bernard Sahut, innovation team manager for PSA Peugeot Citroën
In June 2012, PowerGenix, China City Construction Corporation (CCCC) and Huainan City signed a three-party agreement to create the first commercial-scale Nickel-Zinc (NiZn) battery manufacturing center. The agreement provides a strategic framework for cooperation between the three parties as well as financial incentives for the joint venture, known as CCCC-PowerGenix Clean Energy Co., Ltd. (Earlier post.)
In December 2011, PowerGenix signed a joint venture agreement with CCCC to develop, manufacture and sell NiZn batteries for the automotive market—with an initial focus on start-stop applications—and other markets. (Earlier post.)