Tesla CEO Elon Musk said improvements to be unveiled at the electric-vehicle maker's Battery Day event today (22 September) would not reach "serious high-volume production" until 2022.
Reuters said analysts were expecting Musk to unveil at the event plans for Tesla to produce its own battery cell.
In a Twitter post ahead of the Tuesday event, cited by Reuters, Musk said: "This affects long term production, especially Semi, Cybertruck & Roadster, but what we announce will not reach serious high volume production until 2022."
Tesla expects significant shortages in 2022 and beyond, Musk cautioned, according to the report, adding it intended to increase cell purchases from Panasonic, LG Chem, CATL and possibly other partners.
"Battery firms believe it is not easy to mass produce batteries. It took them a lot of time … how can Tesla do it overnight?" a South Korean battery industry source told Reuters.
Tesla is working to produce new, bigger battery cells at its Fremont facility, two people familiar with the matter have told Reuters. The new cells will have a diameter of 42 mm, versus the 21 mm ones made at its joint battery factory with Panasonic that are used in Model 3 sedans, the sources said.
Tesla may have to partner with Panasonic to mass produce its own cells, Seoul based battery expert Park Chul-wan told the news agency.
Some battery industry officials are wary that Tesla's move to produce batteries in house could put pressure on prices.
"Tesla is sending signals to suppliers that they should further lower costs, and if not, Tesla would source more batteries in-house," a former LG Chem official told Reuters.
At the event, Tesla may also unveil its 'million mile' batteries, which it is developing with CATL and are expected to have much longer life: the equivalent of 1m miles or more, versus about 500,000 miles now, Reuters suggested.