Powering up esp8266

I am into a project using esp8266, I need to power up the board using a lithium ion 3.7v volt cell which has a max voltage of 4.2v through 3.3v pin of esp8266 directly. I have test out this method for 10 min and its working perfectly,without heating issues aswell. I would like to know whether this practice cause any problems for a long run of the project.

The data sheet for the esp8266 says input voltage in the range 3.0v to 3.6v
If you put a diode in series with it this would drop 4.2v down to 3.6v which may be worth experimenting with although of course once it got down to 3.6v this would drop below the 3.0v minimum.

Another options is using a power bank to boost the voltage up to 5v

why do you ask this in "Nano RP2040 Connect" category?

Thanks a lot, it works!

Your post was MOVED to its current location as it is more suitable.

For now... This is not a very good plan. ESP's are rather sensitive to the power they are provided with. That 3.6v is the absolute maximum. You should regulate the voltage properly, and from a LiPo, best would be to use something like a MT3608.