Cell and battery

A battery, comprising:

• a housing;
• and
• the battery cell, the battery cell comprises a positive electrode tab, a negative electrode tab, and a packaging bag, wherein the packaging bag has a sealing region;
• the sealing region comprises a first sealing segment, two second sealing segments, and a third sealing segment;
• the positive electrode tab and the negative electrode tab are arranged side by side in a width direction of the battery cell, and both extend beyond the packaging bag through the first sealing segment;
• the first sealing segment is arranged at an included angle with each of the two second sealing segments;
• the third sealing segment is connected between the first sealing segment and the each second sealing segment;
• and the third sealing segment has a curved outer edge;
• and
• the third sealing segment has an orthographic projection area S in a thickness direction of the battery cell;
• the third sealing segment comprises a first corner-cutting segment disposed on a side of the positive electrode tab far away from the negative electrode tab than the positive electrode tab in the width direction of the battery cell and a second corner-cutting segment disposed on a side of the negative electrode tab far away from the positive electrode tab than the negative electrode tab in the width direction of the battery cell;
• and S comprises an orthographic projection area S1 of the first corner-cutting segment in the thickness direction of the battery cell and an orthographic projection area S2 of the second corner-cutting segment in the thickness direction of the battery cell, wherein 0.75≤S1/S2≤0.99.