You’re not alone in looking for a higher-capacity battery! The good news is you might be able to upgrade a Tesla X 75D battery.
The bad news is Tesla doesn’t like to install bigger batteries in older models. You might have the option of unlocking more of your 75D battery’s capacity through a software update though, so ask your local Tesla dealership if that’s available.
If your battery doesn’t seem to be holding a charge effectively, it’s probably still under Tesla’s warranty. Tesla will replace a defective battery if it’s less than eight years old or has under 150,000 miles on it (whichever comes first).