Sony was scheduled to open a lithium-ion polymer battery plant in Singapore on Thursday, marking a milestone in the company's efforts to expand its production capacity for batteries.

The S$150 million (US$105 million) plant was designed to produce 8 million cell-phone batteries each month and employ 500 workers. It's housed inside an existing Sony factory in Singapore and is expected to reach full capacity in 2010.

Sony announced plans to build the Singapore battery plant in August 2007, citing fast-growing demand for lithium-ion polymer batteries. About half of these batteries end up in cell phones, while others end up in laptops, camcorders and other electronic devices.

Earlier this month, Sony announced plans to invest ¥40 billion (US$365 million) over the next two years to expand its lithium-ion battery production. That money, which does not include the funds invested in the Singapore battery plant, will be invested in new production lines and used to upgrade existing lines at its factories in Japan.

Alongside the new Singapore plant and plans to increase production at a factory in China, Sony expects the added production capacity in Japan to raise its total battery output from a current level of 41 million cells per month to 74 million cells by 2010.

The IDG News Service is a Network World affiliate.