A thermo-electro-chemical converter direct heat to electricity engine has a monolithic co-sintered ceramic structure or a monolithic fused polymer structure that contains a working fluid within a continuous closed flow loop. The co-sintered ceramic or fused polymer structure includes a conduit system containing a heat exchanger, a first high density electrochemical cell stack, and a second high density electrochemical cell stack.

A converter includes a working fluid, a housing, a heat sink, a heat source that is at an elevated temperature relative to the heat sink, a first electrochemical cell disposed within the housing, and a micro/nano porous media disposed within the housing. The first electrochemical cell includes a first membrane electrode assembly across which the working fluid is configured to flow. The first membrane electrode assembly includes a first porous electrode and a second porous electrode and at least one ion conductive membrane sandwiched between the first and second porous electrodes. The first electrochemical cell is arranged between the heat source and the heat sink. The working fluid is contained within the micro/nano porous media. The micro/nano porous media is thermally coupled between the heat source and the heat sink, and creates a pressure differential across the first electrochemical cell by transpiration pumping of the working fluid.

The invention discloses a bimetallic thermally regenerative ammonia-based battery system and using method for harvesting low-grade waste heat. In this battery, the electrodes are made of two different metals that can form ammine complexes, and the metal M.sub.1 that has a more negative redox potential of M.sub.1(NH.sub.3).sub.x1.sup.y1+/M.sub.1 is the negative electrode, and the metal M.sub.2 that has a more positive redox potential of M.sub.2.sup.y2+/M.sub.2 is the positive electrode, achieving high-voltage discharge and low-voltage charge at the same temperature. A closed-loop battery cycle consists of a discharge process, a charge process and two thermal regeneration processes. Deposition and corrosion reactions occur cyclically at the M.sub.1 and M.sub.2electrodes during successive charge and discharge processes. Thermal energy in waste heat is saved in the distilled ammonia, which is used to shift the redox couples for charging at lower voltage and stored in the battery as chemical energy.

A thermo-electro-chemical converter direct heat to electricity engine has a monolithic co-sintered ceramic structure or a monolithic fused polymer structure that contains a working fluid within a continuous closed flow loop. The co-sintered ceramic or fused polymer structure includes a conduit system containing a heat exchanger, a first high density electrochemical cell stack, and a second high density electrochemical cell stack.

A thermo-electro-chemical converter direct heat to electricity engine has a monolithic co-sintered ceramic structure or a monolithic fused polymer structure that contains a working fluid within a continuous closed flow loop. The co-sintered ceramic or fused polymer structure includes a conduit system containing a heat exchanger, a first high density electrochemical cell stack, and a second high density electrochemical cell stack.

A hydride heat engine produces electricity from a heat source, such as a solar heater. A plurality of metal hydride reservoirs are heated by the heating device and a working fluid comprises hydrogen is incrementally move from one metal hydride reservoir to a success metal hydride reservoir. The working fluid is passed, at a high pressure, from the last of the plurality of metal hydride reservoirs to an electro-chemical-expander. The electro-chemical-expander has an anode, a cathode, and an ionomer therebetween. The hydrogen is passed from the anode at high pressure to the cathode at lower pressure and electricity is generated. The solar heater may be a solar water heater and the hot water may heat the metal hydride reservoirs to move the hydrogen. The working fluid may move in a closed loop.

The present invention provides a method for suppressing generation of hydrogen gas at the time when an ion concentration gradient is generated by a temperature responsive electrolyte. An electrolytic solution contains a temperature responsive electrolyte and an oxidation-reduction active species. The temperature responsive electrolyte is an electrolyte whose pKa varies according to the temperature. A power generating device performs power generation by using the electrolytic solution. The power generating device includes a positive electrode, a negative electrode, a heating mechanism, and a cooling mechanism. The positive electrode and the negative electrode are immersed in the electrolytic solution. The heating mechanism heats the electrolytic solution that is present in the vicinity of one of the positive electrode and the negative electrode. The cooling mechanism cools the electrolytic solution that is present in the vicinity of the other one of the positive electrode and the negative electrode.

Thermally regenerative ammonia-based battery systems and methods of their use to produce electricity are provided according to aspects described herein in which ammonia is added into an anolyte to charge the battery, producing potential between the electrodes. At the anode, metal corrosion occurs in the ammonia solution to form an amine complex of the corresponding metal, while reduction of the same metal occurs at the cathode. After the discharge of electrical power produced, ammonia is separated from the anolyte which changes the former anolyte to catholyte, and previous anode to cathode by deposition of the metal. When ammonia is added to the former catholyte to make it as anolyte, the previous cathode becomes the anode. This alternating corrosion/deposition cycle allows the metal of the electrodes to be maintained in closed-loop cycles, and waste heat energy is converted to electricity by regeneration of ammonia, such as by distillation.

A direct thermoelectrochemical heat-to-electricity converter includes two electrochemical cells at hot and cold temperatures, each having a gas-impermeable, electron-blocking membrane capable of transporting an ion I, and a pair of electrodes on opposite sides of the membrane. Two closed-circuit chambers A and B each includes a working fluid, a pump, and a counter-flow heat exchanger. The chambers are connected to opposite sides of the electrochemical cells and carry their respective working fluids between the two cells. The working fluids are each capable of undergoing a reversible redox half-reaction of the general form R.fwdarw.O+I+e.sup., where R is a reduced form of an active species in a working fluid and O is the oxidized forms of the active species. One of the first pair of electrodes is electrically connected to one the second pair of electrodes via an electrical load to produce electricity. The device thereby operates such that the first electrochemical cell runs a forward redox reaction, gaining entropy, and the second electrochemical cell runs a reverse redox reaction, expelling entropy.

A electrochemical direct heat to electricity converter having a low temperature membrane electrode assembly array and a high temperature membrane electrode assembly array is provided. Additional cells are provided in the low temperature membrane electrode assembly array, which causes an additional amount of the working fluid, namely hydrogen, to be pumped to the high pressure side of the converter. The additional pumped hydrogen compensates for the molecular hydrogen diffusion that occurs through the membranes of the membrane electrode assembly arrays. The MEA cells may be actuated independently by a controller to compensate for hydrogen diffusion.