Toyota is aiming to develop a more advanced EV lithium-ion battery "in a few years" that will have around a 15% range improvement in current technology, according to reports.

Reuters reported the remarks of a leading Toyota R&D engineer at a media briefing in Tokyo.

"Lithium-ion battery is a key technology for electrifying cars, and there is a clear need, going forward, for improving this technology and its performance even more," Hisao Yamashige, a battery technology researcher at the company, told Reuters.

Improving the performance of lithium-ion battery technology is a pressing issue for traditional automakers such as Toyota and new entrants such as Tesla Motors Inc because of its limiting characteristics.

Other recent reports have said that Toyota  intends to start mass-producing electric vehicles by 2020 and will create a dedicated in-house team for planning and development as soon as the new year. Toyota will also seek cooperation from group companies to start production quickly.

Toyota aims to develop an EV that can run more than 300km on a single charge. The platform for models such as the Prius hybrid or Corolla sedan is being considered for use in building an electric sport utility vehicle, Nikkei reported.

The EV launch timetable for Toyota reportedly coincides with the 2020 Tokyo Olympics, but is also being driven by the need for EVs in markets pushing for their adoption.