Elon Musk hints at batteries with 50 percent higher energy density

This year Tesla shareholders have been in for quite a ride. Tesla shares were trading for just over $400 at the start of the year and are currently exchanging hands for close to $2,000 per share. This meteoric rise has made Elon Musk's car firm one of the largest companies in the world (in terms of market cap) as investors are betting on a very bright future for the company.

Tesla is hosting a Battery Day event on September 22, which will be the company's most interesting event since the introduction of the Cybertruck on November 23, 2019. A new tweet from Musk sparks speculation that a major battery announcement will be made at the September event.

In his tweet, Musk indicates that mass production of batteries that offer 400Wh/kg is just 3 to 4 years away. The batteries used by Tesla's Model 3 have an estimated energy density of 260Wh/kg so this would be an improvement of over 50 percent!

Reuters writes Tesla may have achieved a breakthrough with silicon nanowire anode. This technology wouldn't only enhance energy density but also boost battery life:

South Korean battery expert Park Chul-wan said the image may hint at “silicon nanowire anode,” a breakthrough technology which can potentially increase both battery energy density and battery life sharply.

400 Wh/kg *with* high cycle life, produced in volume (not just a lab) is not far. Probably 3 to 4 years.

— Elon Musk (@elonmusk) August 24, 2020