An electrochemical device comprising - a layer of solidified electrolyte, - at least one electrochemically active layer (105, 105a, 105b), wherein each electrochemically active layer comprises a polymer which is electrically conducting in at least one oxidation state, and which polymer is a polymer or copolymer of a 3,4-dialkoxythiophene in which said two alkoxy groups may be the same or different or together represent an optionally substituted oxy-alkylene-oxy bridge, and each one of said at least one active layer comprises a respective contact portion (140, 140a, 140b) in direct contact with said solidified electrolyte, wherein said solidified electrolyte covers each said contact portion (140, 140a, 140b), - a first electrode in electronic contact with a first region of one (105, 105a) of said at least one active layer, - a second electrode in electronic contact with a second region of one (105, 105b) of said at least one active layer, characterized in that - a first portion and second portion of said second electrode comprise corrosion resistant material, said corrosion resistant material being a conductive form of carbon, - said one of said at least one active layer (105, 105b) comprising the second region in electronic contact with the second electrode further comprises: a first covered portion which extends from said contact portion, and wherein said solidified electrolyte covers said first covered portion, - only said first portion of said first and second portions of said second electrode is in direct contact with said solidified electrolyte, and - said first portion of said second electrode is arranged between said first covered portion and said solidified electrolyte. - a layer of solidified electrolyte, - at least one electrochemically active layer (105, 105a, 105b), wherein each electrochemically active layer comprises a polymer which is electrically conducting in at least one oxidation state, and which polymer is a polymer or copolymer of a 3,4-dialkoxythiophene in which said two alkoxy groups may be the same or different or together represent an optionally substituted oxy-alkylene-oxy bridge, and each one of said at least one active layer comprises a respective contact portion (140, 140a, 140b) in direct contact with said solidified electrolyte, wherein said solidified electrolyte covers each said contact portion (140, 140a, 140b), - a first electrode in electronic contact with a first region of one (105, 105a) of said at least one active layer, - a second electrode in electronic contact with a second region of one (105, 105b) of said at least one active layer, characterized in that - a first portion and second portion of said second electrode comprise corrosion resistant material, said corrosion resistant material being a conductive form of carbon, - said one of said at least one active layer (105, 105b) comprising the second region in electronic contact with the second electrode further comprises: a first covered portion which extends from said contact portion, and wherein said solidified electrolyte covers said first covered portion, a first covered portion which extends from said contact portion, and wherein said solidified electrolyte covers said first covered portion, - only said first portion of said first and second portions of said second electrode is in direct contact with said solidified electrolyte, and - said first portion of said second electrode is arranged between said first covered portion and said solidified electrolyte.