Module of storage cells (A1-A4), comprising: - at least two metal-ion electrochemical storage cells (A1, A2) aligned according to their longitudinal axis and each comprising a hollow mandrel; - a mechanical interface and electrical insulation part, arranged between the two metal-ion electrochemical storage cells (A1, A2) aligned according to their longitudinal axis, to provide the mechanical interface and the insulation between the two storage cells, each of the two storage cells comprising a casing with a bottom and a cover through which emerges a bushing (5, 50) forming an output terminal of the storage cell, the part being made of electrically insulating material and consisting of a flange ring comprising: • a flat base designed to be pressed against the cover of one of the two storage cells, the flat base being pierced with a through opening whose diameter is matched to that of a part of the output terminal of the storage cell which comes to be housed therein; • an annular wall encircling the flat base and conformed to delimit, on the one hand, an annular groove of a form complementing that of the top of a casing of one of the storage cells, including the form of the cover, so as to be able to fitted therein and, on the other hand, a bearing surface with the bottom of the casing of the other of the storage cells; • the flange ring being conformed so as to leave an empty volume between the flat base which is pressed against the cover of the casing of one of the two storage cells and the bottom of the casing of the other of the storage cells; - an electronic module supported by the flat base in the empty volume or incorporated in the thickness of the flat base, the electronic module being adapted to monitor the electrical characteristics of one or the other of the storage cells (A1, A2). - at least two metal-ion electrochemical storage cells (A1, A2) aligned according to their longitudinal axis and each comprising a hollow mandrel; - a mechanical interface and electrical insulation part, arranged between the two metal-ion electrochemical storage cells (A1, A2) aligned according to their longitudinal axis, to provide the mechanical interface and the insulation between the two storage cells, each of the two storage cells comprising a casing with a bottom and a cover through which emerges a bushing (5, 50) forming an output terminal of the storage cell, the part being made of electrically insulating material and consisting of a flange ring comprising: • a flat base designed to be pressed against the cover of one of the two storage cells, the flat base being pierced with a through opening whose diameter is matched to that of a part of the output terminal of the storage cell which comes to be housed therein; • an annular wall encircling the flat base and conformed to delimit, on the one hand, an annular groove of a form complementing that of the top of a casing of one of the storage cells, including the form of the cover, so as to be able to fitted therein and, on the other hand, a bearing surface with the bottom of the casing of the other of the storage cells; • the flange ring being conformed so as to leave an empty volume between the flat base which is pressed against the cover of the casing of one of the two storage cells and the bottom of the casing of the other of the storage cells; • a flat base designed to be pressed against the cover of one of the two storage cells, the flat base being pierced with a through opening whose diameter is matched to that of a part of the output terminal of the storage cell which comes to be housed therein; • an annular wall encircling the flat base and conformed to delimit, on the one hand, an annular groove of a form complementing that of the top of a casing of one of the storage cells, including the form of the cover, so as to be able to fitted therein and, on the other hand, a bearing surface with the bottom of the casing of the other of the storage cells; • the flange ring being conformed so as to leave an empty volume between the flat base which is pressed against the cover of the casing of one of the two storage cells and the bottom of the casing of the other of the storage cells; - an electronic module supported by the flat base in the empty volume or incorporated in the thickness of the flat base, the electronic module being adapted to monitor the electrical characteristics of one or the other of the storage cells (A1, A2).