Tesla has dominated the EV segment for years, but the automaker is about to face some stiff competition, as mainstream companies such as Volkswagen, Audi, and Mercedes-Benz are finally joining the EV bandwagon. However, according to Morgan Stanley analyst Adam Jonas, Tesla should be more worried about US start-up company Rivian Automotive.

Speaking to CNBC, Jonas believes that Tesla's dominance is "unsustainable" and that Rivian is "the next serious competition from a 'clean sheet' start-up with access to talent & capital focused on the fastest growing segments of pickup trucks & SUVs." He added: "We believe companies like Rivian will take elevated importance in investors' minds as EVs become the focus of OEM investment and strategy."

So far, Rivian has shown plenty of potential. At last year's LA Auto Show, the start-up presented two prototype EVs it intends to build with some very impressive specs. The first is the Rivian R1S, a seven-seat passenger SUV powered by four electric motors producing a combined 754 hp and 826 lb-ft of torque, and a range of 410 miles.

Whereas the R1S will be competing in a crowded market, Rivian attracted more attention with its all-electric pickup truck, the R1T, which will compete with Tesla's electric pickup as well as the forthcoming electric Ford F-150. Like the R1S, it has around 400 miles of range and four electric motors delivering a combined output of 754 hp and with 826 lb-ft of torque.

Both models will be built on a unique "skateboard" platform that packages the battery pack, suspension, and brakes below wheel height for better stability and lower center of gravity. However, Rivian doesn't have any models in production yet, so the start-up company still has a long way to go before it has a chance of crushing Tesla. It is, however, in talks with General Motors and Amazon to help make it happen.