I have a "Xiaomi Redmi Note 8 Pro".
My phone is bricked beyond repair (as far as I can tell). I want to safely delete all data before I throw it away.
Can I drill a hole in somewhere? I do not what to risk my health by short-circuiting the battery or something like that.
Edit: My lock screen has 4 digits.
Unless you have a means to power the device on and wipe the data properly, you need to physically destroy it. The data lives inside an eMMC chip which is conceptually just a SD card soldered to the motherboard. It will not be damaged by salt water (suggested in another answer) or other means that do not physically break the chip into tiny bits. Unless you understand how it works well enough to judge what would destroy it, just assume most things don't.
Pry the phone open, remove the battery, then destroy the rest of the phone physically in a trash compactor or whatever.
Option 1) In case the phone still boots in recovery mode (usually hold Vol Up and Power-on) and you have root access you could run the command:
dd if=/dev/null of=/dev/block/by-name/userdata
This will put 0x00 to all your userdata.
As you said, the risk of drilling the battery with a drill is too high.
Option 2) If there is no power at all, you have to open the device to find the main board and destroy it. And it's a little complicated process because you have to put heat on the screen to unglue it from the back part. And then just remove the main board and put holes on every shield you find.
Option 3) I have seen many phones been destroyed by a professional company. What they did was to put the phone into salt water for about 30 minutes. It makes all boards completely unusable.
If you're just a regular user (not a public person) option 3 should be enough. But if you are really, really worried about your data getting in wrogn hands, I would say option 2 is better.
