Battery and battery module

The invention discloses a battery and a battery module. The battery comprises a battery shell; a laminated battery pole group is arranged in the battery shell; the laminated battery pole group comprises a positive plate, an isolating membrane and a negative plate which are sequentially stacked, the isolating membrane is arranged between the positive plate and the negative plate; the positive plate comprises a positive current collector and a positive active material coating arranged on the surface of the positive current collector; the negative plate comprises a negative current collector and a negative active material coating arranged on the surface of the negative current collector; the positive plate comprises a positive plate body and an optional first corner part, the positive plate body is rectangular after being connected with the first corner part, and the positive plate body is non-rectangular; and/or the negative plate comprises a negative plate body and an optional second corner part, the negative