Single cell and battery unit

The utility model discloses a single battery cell and a battery unit, and relates to the technical field of batteries. Comprising a naked battery cell, a shell, a positive pole and a negative pole, the naked battery cell is arranged in the shell, the positive pole and the negative pole are arranged at the two ends of the shell respectively, and the end face of the positive pole or the negative pole is further provided with a slot allowing the other pole to be inserted; and a plurality of the single battery cells are connected in series or in parallel to further form a battery unit. According to the single battery cell and the battery unit, the slots are formed in the end surfaces of the poles of the single battery cells, so that the single battery cells can be connected in an inserted manner through the poles, and further connected in series or in parallel to form the battery unit, so that the use of connectors among the single battery cells is reduced, and the energy density of a battery module is further im