Eaton's KW family of supercapacitors replace button cell batteries (and the battery holder) for real-time clock backup power, and provide ridethrough for battery operated devices to allow time for battery replacements. They are fully rated at industrial temperatures from -40 °C to +85 °C.
KR Coin cell supercapacitor | 5.5 V | 0.1 F to 1.5 F | Eaton
KR Supercapacitor