Tesla has recently announced a global shift to LFP lithium-ion battery chemistry for all its standard range cars. The company already uses CATL's LFP cells on a mass scale at Tesla Giga Shanghai (see the Tesla Model 3's LFP battery here).
Assuming that a single battery pack is 55 kWh (Model 3) or 60 kWh (Model Y), the 45 GWh would be enough to produce 750,000-818,000 electric cars.
It's not clear at this point whether the 45 GWh is for annual production or total, but considering Tesla's scale (probably towards 1.5 million annually in 2022/2023), it could be an annual volume.
According to the report, the two companies are in talks to increase the volume even further.
"The sources also said that apart from the 45GWh order, Tesla is going to order more. “Both parties are in talks about that,” the people said. CATL declined to comment about the report."
We must remember that Tesla would like to use LFP battery chemistry also for energy storage systems so part of the deal might be related to this branch of the business.
The cobalt-free LFP chemistry is one of the most affordable, as well as being long-lasting and safe. However, it does not match the energy density of the other types like NCM or NCA. This is why the main approach is to utilize LFP in base range vehicles, heavy vehicles or energy storage systems. To improve energy density, manufacturers try the cell-to-pack and structural battery approach.