Studies are continuing on advanced high-power systems for hybrid electric vehicles and high-energy systems for plug-in hybrid electric vehicles at the Argonne National Laboratory.
Speaking at the recent SAE 2009 Hybrid Vehicle Technology Symposium, Dr Khalil Amine, the senior scientist and manager of Argonne’s advanced lithium battery programme, highlighted a number of advancements that Argonne had made.
In particular, he pinpointed a new titanate system for hybrid electrics, which he said provides excellent power capability well beyond that of existing lithium-ion systems. This could make it possible for smaller batteries to be used that could in turn reduce the costs of producing hybrids.
The Mn-spinel cathode/carbon anode system has calendar life issues and question marks about how it can perform at high temperatures. Adding a small amount of manganese dissolution in the electrolyte can lead to significant capacity loss. However, Argonne has looked at replacing the carbon with lithium titanate material.
This offers a lower cost of production and outstanding safety as there is limited reactivity with the electrolyte. Peak power is almost 70kW – that’s three times more power.
In addition, Argonne is investigating improving the performance of conventional layered oxide cathodes. By using a metal fluoride coating, performance has been enhanced at a higher voltage.
