PoundXI:
If I want to use battery as my power source, Should I avoid using lithium ion battery ?
If you want a rechargeable battery then NiMh cells or a lead-acid battery will have a much lower fire risk than a lithium battery.
However you probably already have several devices in your home (laptops, phones) that use lithium batteries without any problem. They just need to be managed properly to ensure they are safe.
If your project does not need much energy then you might also consider using non-rechargeable AA alkaline cells for their simplicity and convenience.
...R