Bipolar plate for an electrochemical reactor including first and second opposing outer conductive faces, in which - first flow channels are formed on the first outer face, extending in the same direction; - first injection orifices are formed in the first outer face; - a first homogenization zone formed on the first outer face and including homogenization channels that: - each connect a first injection orifice to a plurality of said first flow channels, - each sub-divide into a plurality of branches extending from a first injection orifice to one of said flow channels, the bipolar plate being characterized in that the homogenization channels: - each include a first section into which one of said first injection orifices discharges and a second section including a plurality of branches discharging into the first flow channels, the branches in the second section being at an angle of at least 20° relative to the direction of the first flow channels and the homogenization channels in the first section are at an angle of at least 20° relative to the direction of the branches in the second section and at least 40° relative to the direction of the first flow channels. - first flow channels are formed on the first outer face, extending in the same direction; - first injection orifices are formed in the first outer face; - a first homogenization zone formed on the first outer face and including homogenization channels that: - each connect a first injection orifice to a plurality of said first flow channels, - each sub-divide into a plurality of branches extending from a first injection orifice to one of said flow channels, the bipolar plate being characterized in that the homogenization channels: - each include a first section into which one of said first injection orifices discharges and a second section including a plurality of branches discharging into the first flow channels, the branches in the second section being at an angle of at least 20° relative to the direction of the first flow channels and the homogenization channels in the first section are at an angle of at least 20° relative to the direction of the branches in the second section and at least 40° relative to the direction of the first flow channels. - each connect a first injection orifice to a plurality of said first flow channels, - each sub-divide into a plurality of branches extending from a first injection orifice to one of said flow channels, the bipolar plate being characterized in that the homogenization channels: - each include a first section into which one of said first injection orifices discharges and a second section including a plurality of branches discharging into the first flow channels, the branches in the second section being at an angle of at least 20° relative to the direction of the first flow channels and the homogenization channels in the first section are at an angle of at least 20° relative to the direction of the branches in the second section and at least 40° relative to the direction of the first flow channels. - each include a first section into which one of said first injection orifices discharges and a second section including a plurality of branches discharging into the first flow channels, the branches in the second section being at an angle of at least 20° relative to the direction of the first flow channels and the homogenization channels in the first section are at an angle of at least 20° relative to the direction of the branches in the second section and at least 40° relative to the direction of the first flow channels.