The invention relates to a fuel cell stack (10) having a plurality of fuel cells (20) which have an inlet-side cathode port (22), anode port (24) and coolant port (26) and an outlet-side cathode port (23), anode port (25) and coolant port (27), wherein the fuel cell stack (10) also has: two end plates (30, 31) between which the plurality of fuel cells (20) are arranged, wherein at least one of the end plates (30, 31) has inlet openings (32, 34, 36) and outlet openings (33, 35, 37) for a cathode gas, an anode gas and a coolant, which are each fluidically connected to the inlet-side and outlet-side cathode ports (22, 23), anode ports (24, 25) and coolant ports (26, 27), and at least one sensor (50) which is guided through at least one additional opening (39) in at least one of the end plates (30, 31) into one of the inlet-side or outlet-side cathode ports (22, 23), anode ports (24, 25) or coolant ports (26, 27). The invention also relates to a method for producing the fuel cell stack (10).

A high temperature electrochemical cell includes a solid electrolyte separating a cathode and an anode, an anode flow field adjacent the anode, a cathode flow field, having an exhaust gas stream pathway, downstream from the cathode, and a thermal management system including a controller programmed to, in response to the exhaust gas stream temperature input, activate at least one component, configured to reduce temperature of the exhaust gas stream to a temperature within a threshold range corresponding to a temperature range promoting condensation of Cr-containing gas into solid, liquid, or aqueous Cr.sub.2O.sub.3 and H.sub.2CrO.sub.4, the high temperature electrochemical cell having an operating temperature of about 600-1000 C.