No, they claim MIT battery can actually be used for extracting CO2 from the atmosphere. It sucks CO2 from the air during charging and then relese concentrated CO2 during discharge.
265 Wh/kg is a practical energy density of Li-ion, theoretical is in the same range 1000 Wh/kg If I remember correctly.IMO it's more interesting because it might be more efficient than the Lithium-ion batteries currently used in electric cars.
From the paper:
Lithium-ion batteries are widely used as electrochemical energy storage systems for consumer electronics; [1] however, technologies with higher specific energy are needed for electrified transportation applications. [2] Therefore, beyond Li-ion battery chemistries such as rechargeable Li–O 2 batteries have recently garnered much attention due to their higher theoretical energy density. [3,4] Li–O 2 batteries generally have limited cyclability, though several studies have reported new concepts that have achieved long cycle life. [5,6] Although far less studied, the Li–CO 2 battery is another beyond Li-ion technology with a theoretical energy density of 1876 Wh kg −1 , [7,8] far exceeding that of Li-ion batteries (≈265 Wh kg −1 ).