Abstract: An electrode assembly for use in an electrochemical cell for the production of ozone from water is provided, the electrode assembly comprising an electrode body formed from a polycrystalline diamond, the electrode body comprising first and second opposing contact surfaces, the first contact. surface for contacting a semi-permeable membrane; wherein the electrode assembly further comprises a first layer comprising an electrically conductive material, the first layer extending across at least a portion of the second contact surface of the electrode body. An electrochemical cell comprising the electrode assembly and its use in the production of ozone by the electrolysis of water is also provided.