Electrochromic element

An electrochromic element comprising:

• a first substrate and a second substrate that are arranged to oppose each other;
• a first transparent electrode that is formed on a surface of the first substrate facing the second substrate;
• a second transparent electrode that is formed on a surface of the second substrate facing the first substrate;
• and
• a coloration layer that is arranged between the first transparent electrode and the second transparent electrode;
• wherein the coloration layer includes more than one electrochromic materials and an electrolyte;
• and
• wherein a concentration gradient of the electrochromic material is formed in at least a part of the coloration layer,
• wherein the coloration layer includes an oxidizing electrochromic material-containing layer that is formed to be in contact with the first transparent electrode and a reducing electrochromic material-containing layer that is formed to be in contact with the second transparent electrode,
• the concentration gradient of the electrochromic material is formed in at least a part of the oxidizing electrochromic material-containing layer, and
• the concentration gradient of the electrochromic material is formed in at least a part of the reducing electrochromic material-containing layer,
• wherein a concentration of the electrochromic material is uniform in a semicircle region of the oxidizing electrochromic material-containing layer, and the concentration gradient of the electrochromic material is formed in other semicircle region of the oxidizing electrochromic material-containing layer. and
• wherein a concentration of the electrochromic material is uniform in a semicircle region of the reducing electrochromic material-containing layer, and the concentration gradient of the electrochromic material is formed in other semicircle region of the reducing electrochromic material-containing layer.