LONDONDETROIT, Jan 16 Reuters Volkswagen, whose drive to develop a solidstate electric car battery with U.S. startup QuantumScape has been dogged by delays, is casting its net wider in pursuit of the potentially gamechanging technology.

The German auto giant is holding talks with France39;s Blue Solutions, which already produces solidstate batteries for Daimler electric buses, about adapting the design for cars, a source with direct knowledge of the discussions told Reuters.

VW and Blue Solutions aim to reach a joint development agreement in the coming months, according to the source who asked not to be identified as the talks are private.

Volkswagen39;s move to widen its options in the field points to the array of technical hurdles holding back wider development of solidstate technology, seen by its backers as the holy grail of EV batteries, promising longer driving ranges and shorter charging times than traditional lithiumion packs.

VW said its venture with QuantumScape was on track and declined to comment when asked about any discussions with Blue Solutions.

A spokesperson for Blue Solutions, a unit of French conglomerate Bollore, confirmed that it was working on a battery for passenger cars and said it had signed development deals with BMW and another company, and was in talks with a third, but declined to identify the others.

VW, Toyota, BMW and other global automakers are vying to crack the conundrum of solidstate batteries, which remain technically elusive…