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

1. An electrode plate of an electrochemical battery, the electrode plate comprising a frame and a generally flat grid connected to the frame, the frame comprising at least a top frame member having a contact lug, wherein the grid comprises a plurality of grid wires arranged in a pattern and a plurality of window-like open areas between the grid wires, further comprising an active mass within the open areas and/or on the grid wires, wherein the electrode plate comprises on one outer surface or on both opposing outer surfaces of the active mass a pattern of grooves, wherein the grooves extend diagonally from a position closer to the top frame member to a position further away from the top frame member, wherein the pattern of grooves comprises a first group of diagonally extending grooves and a second group of diagonally extending grooves, wherein the grooves of the first group of grooves intersect with the grooves of the second group of grooves, wherein the pattern of grooves forms a plurality of crossing points between the grooves of the first group of grooves and the grooves of the second group of grooves, wherein a two-dimensional arrangement of the pattern of the grid wires differs from a two-dimensional arrangement of the pattern of grooves when looking on the one outer surface of the active mass of the electrode plate where the pattern of grooves is formed, and wherein the pattern of the grid wires is only partially covered by the pattern of grooves.

2. The electrode plate of claim 1 , wherein the grooves extend diagonally in a monotonic manner further away from the top frame member.

3. The electrode plate of claim 1 , wherein the grooves extend diagonally in a strictly monotonic manner further away from the top frame member.

4. The electrode plate of claim 1 , wherein the plurality of crossing grooves defines a waffle pattern on the surface of the active mass.

5. The electrode plate of claim 1 , wherein one, several or all of the grooves extend in a linear way diagonally over the surface of the active mass.

6. The electrode plate of claim 5 , wherein the linear grooves extend diagonally at an angle with respect to the top frame member in the area of 30° to 60°.

7. The electrode plate of claim 1 , wherein a layer of mass holding material is located on the outer surface of the active mass, wherein the layer of mass holding material comprises the pattern of grooves.

8. The electrode plate of claim 1 , wherein the grooves have a depth in the area of 0.1 mm to 1.0 mm.

9. The electrode plate of claim 1 , wherein the distance between neighbouring grooves which do not intersect is in the range of 3 mm to 15 mm.

10. The electrode plate of claim 1 , wherein the pattern of grooves is a regular pattern.

11. The electrode plate of claim 1 , wherein the grid is a stamped or punched grid.

12. The electrode plate of claim 1 , wherein the electrode plate is a positive electrode plate.

13. The electrode plate of claim 1 , wherein the frame comprises the top frame member, a bottom frame member and a left side frame member and a right side frame member, wherein the top frame member is connected to the bottom frame member via the left side frame member and the right side frame member, wherein the grid is located with the frame.

14. The electrode plate of claim 1 , wherein the active mass is covered with a liquid absorbing material which is arranged for absorbing a liquid electrolyte of the electrochemical battery.

15. An electrochemical battery comprising at least one electrode plate according to claim 1 .

16. The electrochemical battery of claim 15 , wherein the electrochemical battery comprises a liquid electrolyte which is absorbed within a liquid absorbing material covering the active mass of at least one electrode plate.

17. The electrochemical battery of claim 15 , wherein the electrochemical battery is an AGM battery.

18. A method for producing an electrode plate of an electrochemical battery comprising the steps of:

a) producing a grid arrangement comprising a frame and a generally flat grid connected to the frame, the frame comprising at least a top frame member having a contact lug, wherein the grid comprises a plurality of grid wires and a plurality of window-like open areas between the grid wires, wherein the plurality of grid wires is arranged in a pattern,

b) applying active mass into the open areas and/or on the grid wires of the grid arrangement,

c) pressing a pattern of grooves in the outer surface of the active mass on one side of the electrode plate or on both opposing sides, wherein the pattern of grooves comprises a first group of diagonally extending grooves and a second group of diagonally extending grooves, wherein the grooves of the first group of grooves intersect with the grooves of the second group of grooves, and wherein the pattern of grooves forms a plurality of crossing points between the grooves of the first group of grooves and the grooves of the second group of grooves, wherein a two-dimensional arrangement of the pattern of the grid wires differs from a two-dimensional arrangement of the pattern of grooves when looking on the one outer surface of the active mass of the electrode plate where the pattern of grooves is formed, and wherein the pattern of the grid wires is only partially covered by the pattern of grooves.

19. The electrode plate of claim 1 , wherein the grooves have a depth in the area of 0.2 mm to 0.3 mm.

20. The electrode plate of claim 1 , wherein the linear grooves extend diagonally at an angle with respect to the top frame member in the area of 40° to 50°.

21. The electrode plate of claim 1 , wherein the distance between neighbouring grooves which do not intersect is in the range of 6 mm to 10 mm.