Electrode assembly, secondary battery, battery module, battery pack and electrical device

An electrode assembly comprising

• a positive electrode plate comprising a positive electrode current collector and a first positive electrode film layer and a second positive electrode film layer located on two opposite surfaces of the positive electrode current collector,
• a negative electrode plate comprising a negative electrode current collector and a first negative electrode film layer and a second negative electrode film layer located on two opposite surfaces of the negative electrode current collector;
• and
• a separator disposed between the positive electrode plate and the negative electrode plate, wherein the first positive electrode film layer is located on a side of the positive electrode current collector close to the separator and the second negative electrode film layer is located on a side of the negative electrode current collector near the separator, wherein
• the positive electrode plate satisfies 0<CAP1/CAP2<1, wherein CAP1 represents capacity of the first positive electrode film layer in Ah, CAP2 represents capacity of the second positive electrode film layer in Ah, and
• the negative electrode plate satisfies 0≤R4/R3≤30, the positive electrode plate satisfies 0<R2/R1≤20, the electrode assembly satisfies R4/R3−R2/R1≥0, wherein R1 represents resistance of the first positive electrode film layer in Ω, R2 represents resistance of the second positive electrode film layer in Ω, R3 represents resistance of the first negative electrode film layer in mΩ and R4 represents resistance of the second negative film layer in mΩ,
• the first positive electrode film layer comprises a first positive electrode base layer and at least one first positive electrode ceramic layer disposed on at least one of two opposite surfaces of the first positive electrode base layer, the first positive electrode ceramic layer comprises one or more of alumina ceramics, silicon nitride ceramics, silicon carbide ceramics, and boron nitride ceramics,
• the positive electrode plate satisfies R2<R1.