Lead-Acid Dominates Automotive Energy Storage – Lithium-Ion Coming On Strong
Lead-acid batteries have been highly popular for over 150 years and it seems that their domination will not be interrupted in automotive applications.
“Lead-based batteries are currently the only available mass-market technology for SLI applications in conventional vehicles, including those with start-stop and basic micro-hybrid systems, due to their excellent cold cranking performance, reliability and low cost. Starter batteries of 12V are standardised globally. The handling and behaviour of these batteries is well understood in all EU countries.”
Of course, lithium-ion batteries are the type that allow manufacturers to produce contemporary electric cars, but 12 V lead-acid batteries are and will be in the foreseeable future common in all cars, regardless of drivetrain type (ICE, hybrid, plug-in hybrid or pure electric). In EVs and PHEVs, lead-acids will be used as auxiliary batteries, because they work and are cost effective.
However, according to a study from European, Japanese and Korean automotive associations (ACEA, JAMA and KAMA), the Association of European Automotive and Industrial Battery Manufacturers (EUROBAT ) and the International Lead Association (ILA), lithium-ion batteries are/will be essential in all applications where high energy density is needed.
“Lithium-ion rechargeable battery systems entered the mass market of small-sized consumer applications in the early 1990s. Their up-front cost is at present significantly higher than corresponding battery technologies based on other chemistries. Therefore, larger-sized lithium-ion batteries are currently found in segments such as military and space applications, where their high energy and power density as well as their superior cycling ability create value. The high capacity of the active materials and a single cell voltage of up to 4.2V (depending on active material used) give lithium-ion the highest energy density of all rechargeable systems operating at room temperature.”
“In automotive applications, they are the product of choice for plug-in HEVs and full EVs, in which both these criteria are important. For hybrid vehicles, lithium-ion systems have started to compete with NiMH batteries and are now used at an industrial level in several hybrid cars on the market. For use in SLI, start-stop and micro-hybrid applications, lithium-ion batteries still require improvements in cold-cranking ability and economic packaging (including cost level) to be considered a viable mass-market alternative to lead-based batteries. Their strengths and limitations in these applications are under continual evaluation from European OEMs.”
“Research is also ongoing on the possible use of lithium-ion batteries in new segments of micro-hybrid application such as dual-battery systems (together with a 12V lead-based battery). In such combinations they provide benefits including good cycling ability and high energy yield. High levels of research and development are ongoing to raise their performance for electric vehicle applications, improve safety, and reduce costs, with strong developments projected in the next 10 years and beyond.”
NiMH chemistry probably will be stuck in standard hybrid applications, as lead-acid takes about 50% share of micro hybrids (start-stop systems) and lithium-ions grab some part of full hybrid systems.
Here is the summary for the next six years to 2020: