SECONDARY BATTERY AND ELECTRIC DEVICE

The invention provides a secondary battery and an electric device. The secondary battery comprises a negative pole piece and electrolyte; the negative electrode plate comprises a negative electrode current collector and a negative electrode active layer located on at least one surface of the negative electrode current collector, the negative electrode active layer comprises graphite, and the surface density of the negative electrode active layer is smaller than or equal to 0.16 mg/mm < 2 >; the lithium ion conductivity of the electrolyte is less than or equal to 20mS/cm.