Battery roll core and cylindrical battery

The battery roll core is formed by winding a positive plate, a negative plate and a diaphragm between the positive plate and the negative plate, at least one surface of the positive plate is provided with a positive coating, at least one surface of the negative plate is provided with a negative coating, and the negative coating comprises a negative active material; the negative electrode active material at least comprises a silicon material and a carbon material, and the weight percentage of the silicon material in the negative electrode active material is Y%; the tortuosity of the diaphragm is X, the porosity is Z, and X is more than or equal to 0.15 Y < 0.5 + 1.8 > and less than or equal to 3-lnZ. The invention further provides a cylindrical battery. The cylindrical battery comprises the battery roll core, a cap and a steel shell, the battery roll core is accommodated in the steel shell, and the top is packaged by a cap. The tortuosity of the diaphragm is designed based on the proportion of the silicon-base