Toyota said Tuesday it plans to unveil its latest fuel-cell concept car at the Tokyo Motor show, with an expected commercial rollout two years away.

The four-seater sedan has a range of 500 kilometres (310 miles) -- longer than previous versions -- and can be recharged in just three minutes through hydrogen gas tanks stored inside the vehicle, the Japanese auto giant said ahead of the exhibition later this month.

Toyota, the world's biggest automaker, said it would launch a commercial version of the mid-sized vehicle around 2015.

By that time, there were likely to be "hundreds" of hydrogen refuelling stations in Japan, Europe and the United States, it added.

Fuel cell vehicles are considered the holy grail of green cars because they emit nothing but water vapour from the tailpipe and can operate on renewable hydrogen gas.

Toyota's concept vehicle seeks to jump two key hurdles that analysts say have hindered consumer buying of so-called green cars, including electric vehicles -- range and re-fuelling infrastructure.

Relatively high prices have also dented purchasing of green vehicles.

However demand for lower-emission vehicles is forecast to grow, with further technological advances in the field seen as crucial due to toughening emissions standards.

Apart from Toyota, which is working on its fuel-cell concept car with Germany's BMW, others are eyeing a widespread commercial offering. They include a Honda joint venture with General Motors and Nissan's work with Ford and Daimler.

Honda already has a commercial fuel-cell car called the FCX Clarity but it has only been sold in limited markets on a very small scale.

At the Tokyo show, which runs from November 20 to December 1, Toyota is also planning to showcase a prototype taxi for the Japanese market that promises green technology while catering to the nation's rapidly ageing population.

The hybrid taxi has a sliding electric door to make entering and exiting the car easier for those wheelchair-bound or people with baby strollers, Toyota said. A screen fixed to the back of the front seats supplies information about routes and taxi fares.

The carmaker said it wanted to commercialise the vehicle ahead of an expected surge in demand when the Japanese capital hosts the 2020 Olympic games.

Toyota said it also planned to display a futuristic vehicle, dubbed Fun Vehicle 2, which allows standing drivers to change the vehicle's direction simply by shifting their weight, similar to the Segway although the car can move at faster speeds.

The car's pop-up windshield can turn oncoming objects a distinct colour to alert drivers to their presence.