A flexible battery including at least one electrochemical cell for generating an electrical current, the battery including: a first substrate including a pair of opposed side portions (201A, 201B); a second substrate; a cathode collector layer provided on the first substrate between the pair of opposed side portions (201 A, 201 B) and being formed of a dried or cured ink; a cathode layer provided on the cathode collector layer and being formed of a dried or cured ink; an anode layer provided on the first substrate between the pair of opposed side portions (201 A, 201B), wherein the cathode and anode layers (21, 31) are disposed in a co-planar arrangement; an electrolyte layer including a liquid electrolyte in contact with both of the cathode layer and the anode layer, wherein the first substrate is connected and sealed to the second substrate to form an inner space containing the electrolyte, and also containing at least a major portion of the cathode layer and the anode layer within the inner space; a first electrode contact that is electrically coupled to the cathode collector layer and is disposed along one of the pair of opposed side portions (201A, 201B) of the first substrate, and a second electrode contact that is electrically coupled to the anode layer and is disposed along the other of the pair of opposed side portions (201A, 201B) of the first substrate, wherein the cathode collector layer includes a geometry having a height and a width such that the number of squares is 5 or less, wherein the number of squares is determined by dividing the cathode collector layer height extending in a direction between the pair of opposed side portions (201A, 201B) by the cathode collector layer width extending in a direction along one of the pair of opposed side portions (201A, 201B) of the first substrate, characterized in that an outer seal area formed around the perimeter of said at least one cell is provided, to seal the second substrate over the first substrate, and in that the cathode collector layer extends under a top side of the seal area and forms the positive contact. a first substrate including a pair of opposed side portions (201A, 201B); a second substrate; a cathode collector layer provided on the first substrate between the pair of opposed side portions (201 A, 201 B) and being formed of a dried or cured ink; a cathode layer provided on the cathode collector layer and being formed of a dried or cured ink; an anode layer provided on the first substrate between the pair of opposed side portions (201 A, 201B), wherein the cathode and anode layers (21, 31) are disposed in a co-planar arrangement; an electrolyte layer including a liquid electrolyte in contact with both of the cathode layer and the anode layer, wherein the first substrate is connected and sealed to the second substrate to form an inner space containing the electrolyte, and also containing at least a major portion of the cathode layer and the anode layer within the inner space; a first electrode contact that is electrically coupled to the cathode collector layer and is disposed along one of the pair of opposed side portions (201A, 201B) of the first substrate, and a second electrode contact that is electrically coupled to the anode layer and is disposed along the other of the pair of opposed side portions (201A, 201B) of the first substrate, wherein the cathode collector layer includes a geometry having a height and a width such that the number of squares is 5 or less, wherein the number of squares is determined by dividing the cathode collector layer height extending in a direction between the pair of opposed side portions (201A, 201B) by the cathode collector layer width extending in a direction along one of the pair of opposed side portions (201A, 201B) of the first substrate, characterized in that an outer seal area formed around the perimeter of said at least one cell is provided, to seal the second substrate over the first substrate, and in that the cathode collector layer extends under a top side of the seal area and forms the positive contact.