PARIS (Reuters) - Total venture capital unit has acquired a stake in Ionic Materials, a privately held battery developer based in Massachusetts for an undisclosed amount, the French oil and gas company said on Wednesday.

Ionic Materials provides research and development services and focuses on developing advanced materials targeting high energy density batteries that it says are safer and cheaper than traditional ones.

"We have decided to invest in Ionic Materials in order to keep a closer look on this technology which may represent one of the most promising path for the development of solid-state batteries," Total said, declining to say how much shares of the company it has acquired.

Ionic Materials said in February it had secured $65 million in Series C funding from a group of financial and strategic investors.

"Total Energy Ventures (TEV) closely follows the energy storage sector and especially the emerging technologies for batteries," Total said.

TEV is its unit which has invested around $160 million in over 30 start-ups in the technology and energy sector.

Total said Ionic Materials' breakthrough technology could significantly improve battery safety, performance and cost.

"Solid-state batteries are considered as the next generation of batteries with various range of applications including the electric vehicles," it said.

Since 2013, Total has expanded its portfolio of assets in renewables energy as global energy consumption shifts towards cleaner and efficient use.

Total paid over $1 billion for French battery maker Saft in 2016.

(Reporting by Bate Felix; editing by Matthias Blamont and David Evans)

By Bate Felix