Secondary battery and battery pack

Abstract

Disclosed are a secondary battery and a battery pack. In the secondary battery, a negative active material layer is disposed on a current collector of a negative electrode sheet, the negative electrode active material layer comprises a negative active material, and the negative electrode sheet has a non-faradaic specific capacitance value of 50-250 nF/g, thereby ensuring the quantity of electrochemical active sites on the surface of the negative electrode sheet, facilitating the contact between the negative electrode sheet and an electrolyte, accelerating the ion-electron conduction rate, reducing the charge transfer resistance, effectively improving the charging rate capability of the secondary batteryimproving the current density of the negative electrode sheet, improving the energy density of the secondary battery, and realizing excellent dynamic performance and cycle performance of the secondary battery.

Dependencies are inferred from the claim text.