Electrode assembly, secondary battery, and electric device

The invention provides an electrode assembly, a secondary battery and an electric device, and aims to consider that the corresponding NP value of the electrode assembly changes along with the increase of the number of cycles or the number of storage days. Therefore, the NP value design corresponding to the condition that the current capacity retention ratio of the electrode assembly is not lower than m is considered, when the NP value is designed, values can be obtained according to different weight percentages of the silicon-containing active material on the negative plate, for example, 1.035-0.158 X serves as the lower limit value of the NP value, and 1.206-0.184 X serves as the upper limit value of the NP value. As the value of NP takes X as a subtraction item of the upper and lower limit values, the total consumption of the negative electrode material is reduced, the expansion force of the secondary battery in circulation is reduced, the circulation diving risk of the secondary battery caused by overlarge expansion force is improved, and the long service life is realized. In addition, the total use amount of the negative electrode material is reduced, and more space is saved to further improve the energy density under the condition of ensuring that the endurance mileage in the life cycle is not influenced.