Here we can see probably the first photo of the inside of the pack of the Model S Plaid, shared by Redditor u/rpunx.
The refreshed Model S/Model X still utilizes the 1865-type cylindrical battery cells supplied by Panasonic from Japan, unlike the Model 3/Model Y, which have bigger 2170-type cylindrical cells (aside from the upcoming 4680-type that is in the pipeline) or prismatic LFP cells (SR versions, produced in China).
Tesla said in early 2021 that the new battery system and an improved powertrain improved the energy efficiency and allows to increase the number of high-speed quarter-mile runs by 5-times, compared to the prior architecture. We know also that the peak charging power increased to 250 kW.
The battery capacity is probably slightly below 100 kWh (the manufacturer does not communicate the numbers).
And here is a quick look at the Tesla Model 3's 2170 battery, shown by Sandy Munro and analyzed by George Bower in 2019.
Probably soon we will know more about the new Tesla battery as Munro Live already awaits its Tesla Model S Plaid and intends to conduct an extensive teardown.