Method for forming electrodes assemblies, in particular for producing electric energy storage devices, comprising the steps of: - feeding a first separator strip and a second separator strip, each strip being fed with a continuous feed motion, along paths converging in an operative section where said first strip and said second strip are superimposed on each other; - during said feeding step, inserting a number of electrodes with first polarity (A1, A2, A3,..., AN) between said two strips (S1, S2), one after the other at reciprocal distances (D1, D2,...) that progressively increase from the first electrode with first polarity to the last electrode with first polarity, whereby the distance between the first and second electrodes with first polarity (A1 and A2) is less than the distance between the second and third electrodes with first polarity (A2 and A3) which in turn is less than the distance between the third and fourth electrodes with first polarity (A3 and A4), and so on for all electrodes with first polarity; - during said feeding step, arranging a succession of electrodes with second polarity (C1, C2, C3,...), said second polarity being opposed to said first polarity, to form an arrangement of electrodes with second polarity (C1, C2, C3,...), in which the electrodes with second polarity (C1, C2, C3,...) are arranged alternately on an outer side of the first strip and on an outer side of the second strip so that an electrode with first polarity in an odd ordinal position (A1, A3,...) is superimposed on an electrode with second polarity (C1, C3,...) with the interposition of the first strip, and an electrode with first polarity in an even ordinal position (A2, A4,...) is superimposed on an electrode with second polarity (C2, C4,...) with the interposition of the second strip. - feeding a first separator strip and a second separator strip, each strip being fed with a continuous feed motion, along paths converging in an operative section where said first strip and said second strip are superimposed on each other; - during said feeding step, inserting a number of electrodes with first polarity (A1, A2, A3,..., AN) between said two strips (S1, S2), one after the other at reciprocal distances (D1, D2,...) that progressively increase from the first electrode with first polarity to the last electrode with first polarity, whereby the distance between the first and second electrodes with first polarity (A1 and A2) is less than the distance between the second and third electrodes with first polarity (A2 and A3) which in turn is less than the distance between the third and fourth electrodes with first polarity (A3 and A4), and so on for all electrodes with first polarity; - during said feeding step, arranging a succession of electrodes with second polarity (C1, C2, C3,...), said second polarity being opposed to said first polarity, to form an arrangement of electrodes with second polarity (C1, C2, C3,...), in which the electrodes with second polarity (C1, C2, C3,...) are arranged alternately on an outer side of the first strip and on an outer side of the second strip so that an electrode with first polarity in an odd ordinal position (A1, A3,...) is superimposed on an electrode with second polarity (C1, C3,...) with the interposition of the first strip, and an electrode with first polarity in an even ordinal position (A2, A4,...) is superimposed on an electrode with second polarity (C2, C4,...) with the interposition of the second strip.