You can take a battery charger for your cell phone or other devices on the airplane with you and should take it in your carry on luggage.
You can also use a battery bank that supplies power to your devices while on the plane or when you cannot find an outlet to plug the device into to charge it.
If you have any exposed terminals on spare lithium-ion batteries you need to cover and isolate those terminals to avoid them shorting out but your battery in your laptop is perfectly fine to carry on the airplane.