Electrode plate of an electrochemical battery and electrochemical battery comprising such electrode plate

An electrode plate of an electrochemical battery, the electrode plate comprising:

• a frame and a substantially planar grid connected to the frame, the frame having at least a top frame member with a contact lug, and the grid having a plurality of grid wires arranged in a grid pattern and a plurality of window-like open areas between the plurality of grid wires;
• at least one of the plurality of grid wires and the open areas occupied by an active mass, with the active mass having opposing surfaces;
• grooves extend diagonally along each opposing surface from a position proximate to the top frame member to a position distal from the top frame member and arranged in a groove pattern on each opposing surface, the groove pattern comprises a groove first group and a groove second group, the groove first group intersecting the groove second group to provide for the pattern, the groove pattern further comprising a plurality of intersections between the first group and the second group;
• and
• a two-dimensional arrangement of the grid pattern differs from a two-dimensional arrangement of the pattern of grooves, when looking on an outer surface of the active mass of the electrode plate where the pattern of grooves is formed in.