Button batteries, as the name suggests, are batteries like buttons, also called coin batteries, about the same size as a $1 coin, and there are many types. The application is also relatively wide,
CR series: electronic scale, remote control, IC card, computer motherboard, calculator, Internet of Things, handwriting board, shoe lights, LED lights, electronic watch, etc..
CR wide temperature batteries -40+125 degrees: temperature and humidity sensors, electrical equipment, mobile police terminals, automobile tire pressure gauge, industrial control motherboards, etc..
LIR lithium-ion series: Bluetooth headset, medical equipment (blood glucose meter, gastroscope capsule, hearing aid), features: rechargeable.
AG series: toys, flashlights, hearing aids, calculators, electronic watches, anti-theft devices, watch movements, electronic calendars.
AA, AAA dry batteries, 23A, 27A: remote control, national defense, scientific research, drilling, telecommunications, navigation, aviation, medical, high-altitude meteorological and industrial and agricultural production of lighting, electronic computers, televisions, tape recorders, cameras, electronic clocks and electronic watches.
Soldering feet, welding wires, card battery: all of the above a processing of the battery, the range of applications can be.
I have a selection table here for your reference:
3V primary button battery selection table
3.7V rechargeable battery selection table
-40+125 degrees Celsius wide-temperature button battery selection table