The world's largest rechargeable battery maker Sanyo Electric is to produce lithium-ion batteries for plug-in hybrid cars in 2011.

It has plans for a production line able to turn out 300,000-400,000 cells a month, Sanyo said.

Sanyo has already said it will produce lithium-ion batteries for conventional hybrid cars by the end of this year in Japan and bring its monthly capacity to 1.1m cells in 2010.

In August, just-auto reported that Toyota was planning to buy lithium-ion batteries for its hybrids from Sanyo Electric. The move was part of an effort to widen supply sources of batteries for its increasingly popular hybrid models.

Earlier this year, Sanyo Electric said it planned to quadruple sales of battery cells to automakers to $1bn by 2015 as sales of hybrid vehicles increase. Mitsuru Honma, head of the company's rechargeable battery unit, said Sanyo may reverse its forecast for a sales decline at the unit this year to an increase as demand rises more than expected.