Nikola has filed patents covering a host of innovations and is working on a research project with the us department of energy, the truck start-ups head of hydrogen said, as the company begins a campaign to rebuild its credibility.

Claims that nikola passed off suppliers technology as its own are at the heart of fraud allegations that have rocked the business, leading to the collapse of its share price and the departure of founder trevor milton.

Jesse schneider, the companys executive vice-president of technology, hydrogen and fuel on thursday sought to clarify which parts of its vehicles nikola has directly developed, and which it purchased, in a presentation that named a handful of companies the group is working alongside.

We see where our strengths are, and we see where we need to collaborate with others, mr schneider told the virtual mission hydrogen conference on thursday.

His talk, including lists of pending patents and detailed truck diagrams, was in stark contrast to the style of mr milton, who often peppered his presentations with hyperbole.

Nikola has been battling questions over the true nature of its technology in the weeks since a short sellers report called the company an intricate fraud, and accused mr milton of deceiving investors.

Mr milton denies any deception but has since left the business.

Now the group is embarking on a drive to rebuild trust with investors, ahead of the end of a lock-up period in november that will allow shareholders who joined at or before its june listing to cash out of the business.

Mr schneiders presentation laid out nikolas various hydrogen projects including its trucks and fuelling stations, and talked about its role as a systems integrator, which involves packing all the components it buys into the confined space inside a truck.

Patents filed in the us include a heat shield that protects the hydrogen storage area in the event of a fire, and technology allowing the truck to communicate with devices around it.

Some patents, such as one for a cooling system, have been accepted in europe but are still pending in its home market, he added.

He also said the company is working with three universities on a $2m project with the us department of energy to develop a new membrane electrode assembly that is cheaper and more durable than current versions.

The companys pitch hinges on the idea that it can create a network of hydrogen fuelling stations so that buyers will be willing to purchase the trucks. the challenge is to do so before it begins generating the revenue that comes from selling those trucks.

Nikolas first vehicle, an electric model based on an iveco truck and built at a joint plant in germany, will not enter production until late next year, with a hydrogen version using bosch fuel cells coming the year after.

So far the company has built one station, at its headquarters in phoenix, arizona that can store about one ton of hydrogen. mr schneider described plans for stations along us highways that could store up to 10 tons on site, with hydrogen generated from renewable energy sources.

The plan for the fuelling stations relies on speeding up how fast drivers can refuel their vehicles. nikola is leading an industry group that includes toyota, hyundai and shell that is trying to shorten the time it takes to refuel from 45 minutes to 15 minutes. the group aims to increase the speed of fuelling five times the current rate to 300 grammes per second.

Mr schneider also said the company still intends to build its badger pick-up truck if discussions with general motors conclude.