Cylindrical battery and battery pack

A battery pack, comprising a plurality of cylindrical batteries, the plurality of cylindrical batteries being connected in series or in parallel;

• wherein each of the plurality of cylindrical batteries comprises:
• a housing having a receiving cavity;
• an electrode assembly disposed within the receiving cavity, wherein the electrode assembly comprises a positive electrode sheet, a separator, and a negative electrode sheet which are stacked and wound, and a positive electrode tab of the positive electrode sheet and a negative electrode tab of the negative electrode sheet are disposed at two ends of the electrode assembly, respectively;
• and
• a first insulating layer provided on a surface of the negative electrode sheet toward the separator and disposed at an end, away from the negative electrode tab, of the surface.