Daimler struck a deal to buy lithium-ion battery cells from Farasis Energy in 2019 and the Chinese-American supplier had intended to build a factory in East Germany to help the Mercedes-Benz maker ramp up electric vehicle production.

But the plant has not yet been built and there were issues with the initial cell samples, Business Insider reported citing company sources, prompting a change of heart from Daimler Chief Executive Ola Kallenius.

Business Insider said it was unclear whether Daimler wants to manufacture the battery cells on its own or with a partner.

A spokesperson for Daimler declined to comment.

Last month, Daimler intensified its partnership with Chinese battery maker Contemporary Amperex Technology (CATL) as part of plans to speed up electrification.

(Writing by Caroline Copley; Editing by Riham Alkousaa and Louise Heavens)