On the back of news that Hyundai is now the world’s fifth biggest carmaker in terms of vehicle sales (when sales of its Kia subsidiary are included) comes the announcement that the South Korean carmaker will launch the world’s first hybrid vehicle powered by advanced lithium-polymer batteries and capable of running on liquefied petroleum gas (LPG).

Hyundai has confirmed the car will go on sale in July of next year, initially in South Korea but eventually global markets as well. The new hybrid will be based on the Elantra sedan (pictured), also known as the Avante in some markets.

Powered by a fuel-injected LPG Gamma engine displacing 1.6L, a 15kW electric motor and a continuously variable transmission, the Elantra hybrid will emit just 103g of carbon per km and will be able to recoup the extra price premium for the new technology in just two years through fuel savings (based on current LPG prices in South Korea).

It will be the first car in the world to use lithium polymer rechargeable batteries, which will be supplied by LG Chem – a leader in producing batteries. Lithium polymer batteries have significant advantages over lithium-ion batteries including higher energy density, lower manufacturing costs, being more robust to physical damage and they can also take more charge-discharge cycles before storage capacity begins to degrade.

As the Elantra hybrid is still in development, more detailed technical specifications will be released closer to the July 2009 launch date. By 2010, Hyundai hopes to expand its hybrid powertrain to even more models.