The invention provides a secondary battery and an electronic device, the secondary battery comprises a positive
pole piece, a negative
pole piece and a diaphragm, a positive pole material layer comprises a first
oligomer, a negative pole material layer comprises a second
oligomer, and the diaphragm comprises a third
oligomer, the first oligomer, the second oligomer and the third oligomer have the same repeating unit, and the
thermal decomposition temperatures of the first oligomer, the second oligomer and the third oligomer are respectively and independently between 90 DEG C and 180 DEG C; in a
differential scanning calorimetry test
spectrogram of the positive
electrode material layer, a first
thermal decomposition peak exists between 90 DEG C and 180 DEG C, and the temperature of the first
thermal decomposition peak is TC; in a
differential scanning calorimetry test
spectrogram of the negative
electrode material layer, a second thermal
decomposition peak exists between 90 DEG C and 180 DEG C, and the temperature of the second thermal
decomposition peak is TA; in a
differential scanning calorimetry test
spectrogram of the diaphragm, a third thermal
decomposition peak exists between 90 DEG C and 180 DEG C, and the temperature of the third thermal decomposition peak is TS; 0 DEG C < = Max( TC, TA, TS)-Min (TC, TA, TS) < = 20 DEG C, and the interface problem and the cycle performance of the secondary battery in the charge-
discharge cycle process can be improved.