A system for generating electrical power includes an electrochemical cell including a cathode and an anode separated by an electrolyte, a cathode fluid flow path in operative fluid communication with the cathode including a cathode-side inlet and a cathode-side outlet, and an anode fluid flow path in operative fluid communication with the anode including an anode-side inlet and an anode-side outlet. The system also includes: a reactant source in operative fluid communication with the anode-side inlet; an oxygen generator in operative fluid communication with the cathode-side inlet, including a combustible composition comprising a fuel and a salt that thermally decomposes to release oxygen; and an electrical connection between the electrochemical cell and a power sink.