A new family of electrochemical cells for decomposition of NO gas in the presence of excess oxygen were designed and investigated. It was shown that covering of the Pt cathode by a mixture of oxygen ionic conductor (YSZ) and electronic conductor (NiO) leads to enhancement of the properties of the electrochemical cell for nitrogen monoxide decomposition. The mechanism of the process of NO decomposition was proposed and the theoretical value of the current efficiency was calculated. A good numerical correlation between the calculated and measured characteristics of the electrochemical cell were observed. For the first time an electrochemical cell for NO decomposition with a value of current efficiency exactly equal to the theoretical value has been designed. The correlation between the microstructure of the working electrode and conversion rate of NO gas was studied. The phenomenon of self-organizing of the microstructure, of the NiO-YSZ working electrode during the process of cell operation was observed and investigated. It was shown that the specific microstructure of the NiO-YSZ mixed oxide enhanced the properties of the electrochemical cell for NO decomposition and increased the value of the current efficiency.