The Department of Energy in the USA has released its 2008 Annual Progress Report on for the Energy Storage Research and Development Vehicle Technologies Program. In short: their view of the state of the art in battery technologies for cars.
They identify the challenges.
“The high-energy efforts are focused on overcoming the technical barriers associated with commercialization of PHEV batteries, namely:
- Cost – The current cost of Li-based batteries (the most promising chemistry) is approximately a factor of three-five too high on a kWh basis. The main cost drivers being addressed are the high cost of raw materials and materials processing, the cost of cell and module packaging, and manufacturing costs.
- Performance – The performance barriers include the need for much higher energy densities to meet the volume/weight requirements, especially for the 40-mile system, and to reduce the number of cells in the battery (thus reducing system cost).
- Abuse Tolerance – Many Li batteries are not intrinsically tolerant to abusive conditions such as a short circuit (including an internal short circuit), overcharge, over-discharge, crush, or exposure to fire and/or other high temperature environments. The use of Li chemistry in these larger (energy) batteries increases the urgency to address these issues.
- Life – The ability to attain a 15-year life, or 300,000 HEV cycles, or 5,000 EV cycles are unproven and are anticipated to be difficult. Specifically, the impact of combined EV/HEV cycling on battery life is unknown and extended time at high state of charge (SOC) is predicted to limit battery life.”
I just wonder if they have set the target at replacing a gasoline car without any compromise. Usually new technology is first driven to mimic and surpass old technology (which is very hard). But quite often you can witness a whole new disruptive approach in the next phase, where new technology suddenly is used differently.
I have a feeling this report is in phase 1.
