Battery cell and battery

The utility model provides a battery cell and a battery, the battery cell comprises a first pole piece, a diaphragm and a second pole piece which are laminated and wound, the polarity of the first pole piece is opposite to that of the second pole piece, the first pole piece comprises a first current collector and a first tab, the second pole piece comprises a second current collector and a second tab, the first current collector is a composite current collector, and the second current collector is a negative electrode. The second current collector is a metal current collector, the number of the first tabs is n, and the number of the second tabs is m; wherein n and m meet the condition that n is greater than m; and/or 2 * m-1 < = n < = 2 * m + 1. According to the arrangement, in the winding direction of the battery cell, one first tab is arranged on each half circle of the first pole piece, one second tab is arranged on each circle of the second pole piece, and the number of the first tabs of the first pole pi