Elevated-temperature calendar

Lithium-ion [71-73] and lithium-ion polymer batteries [74] are commodity products in consumer applications, but are not yet ready for use in the harsh automotive environment. Although in an advanced state of development, the batteries are not expected to be ready for mass production for use in automotive applications in the near future. If limitations in calendar life at elevated temperature can be overcome and production costs can be lowered to an acceptable level, the lithium-ion battery may become a serious competitor to both AGM lead-acid and Ni-MH batteries, as the lithium-ion system combines the strengths of both these battery systems. 

The Bakelite Division of Union Carbide received US. Patent 2,462,331 on February 22, 1949, for the use of carboxylic acid esters or metal salts of carboxylic acids as additives to polyethylene, that improved the processing of polyethylene into film and sheets. The addition of 0.2-0.5 wt% of these compormds to polyethylene was reported to cause the ready release of the polyethylene film or sheet from hot milling and calendaring rolls at elevated temperatures (115-150°C) to provide films and sheets with good surface appearance. Examples of these releasing agents were calcium stearate, aluminum laurate and aluminum tristearate. 

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