La(2-x)Sr(x)Co(0.5)Ni(0.5)O(4 +/-delta) (LSCN) is presented as a novel electrode for both solid oxide fuel cells (SOFCs) and solid oxide electrolysis cells (SOECs). LSCN/10Sc1CeSZ (scandia and ceria stabilised zirconia)/LSCN symmetrical cells were fabricated and characterised by AC impedance spectroscopy under different oxygen partial pressures at temperatures of up to 900 C. At 850 degrees C polarisation resistances of 5.15 and 5.74 Omega cm(2) were found applying air and oxygen, respectively. Electrolysis and fuel cell j-V experiments were also performed at temperatures between 700 and 850 degrees C using a LSCN/10Sc1CeSZ/Ni-YSZ. Electrochemical results showed that the cell performs equally in both SOFC and SOEC modes. Detailed results in terms of performance are presented and discussed. LSCN is presented as a good candidate for both SOFC and SOEC. The similar performance obtained for j-V (current density-voltage) curves in electrolysis and fuel cell operation mode is thought to be related to the flexible oxygen non-stoichiometry of the LSCN (K(2)NiF(4)-type structure).