Coupling device for coupling two or more tab electric terminals, comprising: - a pair of jaws spaced apart from each other in a first direction (X-X), each jaw having a base with two end portions, the bases of the jaws delimiting in the first direction (X-X) a seat therebetween, the seat being adapted to receive therein two or more tab electric terminals, so that respective electrical contact surfaces of the terminals face each other in a second direction (Y-Y), transverse to the first direction (X-X), - at least one clamping element configured to clamp the jaws towards each other in the first direction (X-X), - side elements spaced apart from each other in the second direction (Y-Y) to delimit the seat in the second direction (Y-Y), each side element being an arm of a respective jaw, connected to an end portion of the base of the respective jaw, or each side element being distinct from the jaws and connected at least indirectly to a respective jaw so as to translate in the first direction (X-X) together with said jaw during the clamping of the jaws, - at least one electrically conductive spacing block, arranged in the seat so as to be placed between the terminals, when they are present in the seat, the spacing block having two opposite abutment surfaces, each arranged so as to face a respective contact surface of a respective terminal, when it is present in the seat, wherein at least one of the side elements has a wedge surface, that is inclined with respect to the first and the second direction (X-X, Y-Y), characterized in that said wedge surface is arranged and inclined so as to act on at least one terminal at a face of the terminal opposite the contact surface, and to convert a pressure in the first direction (X-X), exerted by clamping the pair of jaws, into a pressure for mutual approach of the terminals in the second direction (Y-Y), when they are present in the seat, so as to press in the second direction (Y-Y) the contact surfaces of the terminals against the respective abutment surfaces of the spacing block. - a pair of jaws spaced apart from each other in a first direction (X-X), each jaw having a base with two end portions, the bases of the jaws delimiting in the first direction (X-X) a seat therebetween, the seat being adapted to receive therein two or more tab electric terminals, so that respective electrical contact surfaces of the terminals face each other in a second direction (Y-Y), transverse to the first direction (X-X), - at least one clamping element configured to clamp the jaws towards each other in the first direction (X-X), - side elements spaced apart from each other in the second direction (Y-Y) to delimit the seat in the second direction (Y-Y), each side element being an arm of a respective jaw, connected to an end portion of the base of the respective jaw, or each side element being distinct from the jaws and connected at least indirectly to a respective jaw so as to translate in the first direction (X-X) together with said jaw during the clamping of the jaws, - at least one electrically conductive spacing block, arranged in the seat so as to be placed between the terminals, when they are present in the seat, the spacing block having two opposite abutment surfaces, each arranged so as to face a respective contact surface of a respective terminal, when it is present in the seat, wherein at least one of the side elements has a wedge surface, that is inclined with respect to the first and the second direction (X-X, Y-Y),