Tech billionaire Patrick Soon-Shiong claims to have broken the $100 per kWh barrier with a new rechargeable battery.

NantEnergy, formerly known as Fluidic Energy, has been working on the zinc-air battery six years.

Zinc-air batteries are thought to be a more ethical, less-dangerous alternative to the more widespread lithium-ion battery.

Since zinc-air batteries use regular air as the cathode-with zinc as the anode-manufacturing them doesn’t require as many rare or polluting materials.

Currently, the only types of batteries that are in the $100 per kWh range are lead-acid batteries, according to Ramkumar Krishnan, NantEnergy CTO. Lithium-ion batteries on average manage a cost of around $300 to $500 per kWh.

EV company Tesla has lithium-ion batteries that have gotten as low as $100 to $200 per kWh, but they have not yet achieved what NantEnergy has for zinc-air.

NantEnergy intends to have factories in California manufacturing the batteries in 2019.