Matsushita Battery Industrial Co. Ltd. (Osaka, Japan), the manufacturer of Panasonic and National brand batteries, announced it has started mass-production of ultra-thin lithium-polymer batteries. Matsushita claims it is the first in the industry to commence mass production of the batteries, beginning this month with production capacity of 300,000 cells per month.The new batteries are 3.6mm thick, and are considered ideal for use in thinner and more compact mobile phones and other types of slim electronic products. The cells are comprised of a lithiated cobalt oxide film cathode and carbon film anode adhered with a stable polymer. The anode, cathode and separator are incorporated into monolithic fabrication (stack), with the thickness of one stack being 0.5-0.7mm. The addition/reduction of stacks enables the easy increase/decrease in the weight and capacity of the battery.According to Matsushita, gel electrolyte enables the use of a soft outer case for the first time. The prismatic-shaped battery is 35mm x 62mm x 3.6mm in dimension. Average electric capacity is 500mAh (charged at 4.2V), and weight is approximately 15g. Battery voltage is 3.7V.Additional features include volumetric energy density of 250Wh/L, gravimetric energy density of 120Wh/kg, and 500 or more charge-discharge cycles.