LONDON, Sept 1 (Reuters) - Chinese battery maker Gotion High Tech is buying a 25% stake in Slovak battery maker Inobat and will provide supply chain and technology support as the startup scales up production of electric vehicle batteries, the companies said on Thursday.

The companies did not disclose terms for the investment or what it means for Inobat's valuation.

The move by Gotion, partly owned by Volkswagen, is the first investment by a Chinese battery maker in a European startup and comes after the two companies announced earlier this year that they would explore joint venture opportunities to develop batteries for EVs and energy storage.

Inobat said the investment will provide it access to Gotion's research and development, as well as to the Chinese battery maker's raw materials including lithium, and to cell production and recycling capabilities. This will accelerate the Slovak startup's path to mass production.

"Through our joint efforts, we aim to develop and manufacture batteries that will find their way into countless households in Europe," Gotion CEO Li Zhen said in a statement.

Europe's efforts to build out its own EV battery industry and reduce reliance on dominant Asian battery makers have seen only a few companies draw continued investment as funding for startups has dried up amid high interest rates and economic uncertainty.

Last week Swedish lithium-ion battery producer Northvolt - whose customers include Volkswagen and Volvo Cars - told Reuters it had raised $1.2 billion from investors including BlackRock and several Canadian pension plans as it prepares to build new factories in Europe and North America.

Others have struggled, including UK startup Britishvolt, which failed earlier this year.

Gotion said last year that it plans to locate one third of its production capacity outside China by 2025 to meet growing demand from EV makers and energy storage clients.

The Chinese battery maker is building a $2.36 billion plant in Michigan and is looking at setting up an EV battery plant in Morocco with a potential investment of up to $6.3 billion.

Inobat has signed declarations of intent with the governments of Spain and Serbia to build EV battery plants, though those agreements are not final. (Reporting By Nick Carey; Editing by Simon Cameron-Moore)