AllCell and International Copper Association develop more efficient Li-ion battery pack for hybrids using thermal management techniques
AllCell Technologies, LLC and the International Copper Association, Ltd., (ICA) have developed a new battery pack design for hybrid electric vehicles that promises to reduce battery size, weight, and cost while improving fuel economy. The design, which takes advantage of the high heat conductivity of copper integrated within AllCell’s proprietary passive thermal management system (earlier post), will be unveiled at The Battery Show 2011 in Novi, MI.
The 500 Wh lithium-ion battery pack can deliver 22 kW of peak power. AllCell’s patented phase change material (PCM) is the key to the improved performance and fuel efficiency. As the battery heats up during discharge, the PCM absorbs large amounts of heat while the graphite/copper matrix quickly conducts heat away from the lithium-ion cells, maintaining the cells within an acceptable temperature range. The result is a thermal management system primarily based on passive materials that require no energy to operate and have no moving parts.
The addition of PCM to the system acts as a thermal buffer to absorb the peak heat generation and allows it to be dissipated gradually while the addition of a highly conductive graphite/copper matrix allows even more power to be drawn from the battery while maintaining an acceptable battery temperature and temperature gradient.
The air, liquid, and direct refrigerant cooling systems found in current hybrid vehicle batteries are replaced with a small fan to provide auxiliary cooling when needed.
According to AllCell CEO Said Al-Hallaj, the project builds upon years of research and design work the firm has been leading with a number of large automotive OEMs.