A metal air flow battery includes an electrochemical reaction unit and an oxygen exchange unit. The electrochemical reaction unit includes an anode electrode, a cathode electrode, and an ionic conductive membrane between the anode and the cathode, an anode electrolyte, and a cathode electrolyte. The oxygen exchange unit contacts the cathode electrolyte with oxygen separate from the electrochemical reaction unit. At least one pump is provided for pumping cathode electrolyte between the electrochemical reaction unit and the oxygen exchange unit. A method for producing an electrical current is also disclosed.

A electrochemical storage device, referred to herein as a radical-ion battery, is described. The radical-ion battery includes an electrolyte, first free radicals, and second free radicals, wherein the first free radicals and the second free radicals are different chemical species. The radical-ion battery also includes a separator that allows select ions to pass therethrough, but separates the electrolyte from the second free radicals.

A solid-oxide cell includes a porous substrate and an element part. The porous substrate has a long shape in a longitudinal direction and includes a first main surface, a second main surface, a first side surface, a second side surface and a gas-flow passage. The second main surface faces the first main surface. The second side surface faces the first side surface. The first and the second side surfaces connect the first main surface to the second main surface. The gas-flow passage extends in the longitudinal direction. The element part is provided on the first main surface and includes a first electrode layer, a solid electrolyte layer and a second electrode layer. A thickness at an end portion in the longitudinal direction of the porous substrate is greater than a thickness at a center portion in the longitudinal direction of the porous substrate.

In an embodiment, a secondary ZnMnO.sub.2 battery comprises a battery housing, a MnO.sub.2 cathode, a Zn anode, and an electrolyte solution. The MnO.sub.2 cathode, the Zn anode, and the electrolyte solution are disposed within the battery housing, and the MnO.sub.2 cathode comprises a MnO.sub.2 cathode mixture and a current collector. The MnO.sub.2 cathode mixture is in electrical contact with at least a portion of an outer surface of the current collector, and the MnO.sub.2 cathode has a porosity of from about 5 vol. % to about 90 vol. %, based on the total volume of the MnO.sub.2 cathode mixture of the MnO.sub.2 cathode.

A metal air battery system having a rotating anode/cathode assembly. The assembly is mounted in a housing system that provides a mechanism for loading of fresh metal anodes for the purpose of mechanical recharge of the battery. The anode and cathode are able to rotate at high speed for the purposes of producing local high centrifugal (g) forces on their respective surfaces for the purpose of wiping clean liquid electrolyte from their surface to provide for almost instantaneous shutdown of chemical reactions producing hydrogen gas and electric current. The anode and cathode are also rotated at slower speeds for the purpose of providing an even corrosion of the metal anode surface and the cathode rides on the liquid electrolyte using a dynamic and or static liquid bearing design. This liquid bearing provides a constant distance and therefore electrical resistance in the battery.

An intermediate temperature sodium-halogen secondary cell that includes a negative electrode compartment housing a negative, molten sodium-based electrode and a positive electrode compartment housing a current collector disposed in a highly conductive molten positive electrolyte. A sodium halide (NaX) positive electrode is disposed in a molten positive electrolyte comprising one or more AlX.sub.3 salts, wherein X may be the same or different halogen selected from Cl, Br, and I, wherein the ratio of NaX to AlX.sub.3 is greater than or equal to one. A sodium ion conductive solid electrolyte membrane separates the molten sodium negative electrode from the molten positive electrolyte. The secondary cell operates at a temperature in the range from about 80 C. to 210 C.

A secondary battery in which convection in an electrolyte solution occurs easily is provided. A secondary battery whose electrolyte solution can be replaced is provided. A nonaqueous secondary battery includes a positive electrode, a negative electrode, a separator, and an electrolyte solution, and the separator includes grooves capable of making convection in the electrolyte solution occur easily. The nonaqueous secondary battery has at least one expected installation direction, and the grooves in the separator are preferably formed so as to be perpendicular to an expected installation surface. The exterior body includes a first opening for injection of an inert gas into the exterior body and a second opening for expelling or injection of an electrolyte solution from or into the exterior body. An electrolyte solution replacement apparatus has a function of injecting the inert gas through the first opening and expelling or injecting the electrolyte solution through the second opening.

A refuelable electrochemical battery is provided that features three phases of operation that repeat cyclically. In an intake phase a mixture of electrochemically active particles or pellets (e.g., aluminum pellets) and a suitable electrolyte (e.g., sodium hydroxide, potassium hydroxide) are fed into a cavity or chamber. In a power phase the resulting electrochemical reaction produces electrical energy. The particles are mechanically combined or collected to form one electrode, while a gas-diffusion membrane permeable by oxygen is another electrode. During the exhaust phase, a piston forces the residue of the reaction from the cavity in order to prepare for the next cycle of operation.

A redox flow battery 1 including: a battery cell (10) including a positive electrode (11), a negative electrode (12), and an ion exchange membrane (13); a positive electrode-side electrolyte tank (20); a negative electrode-side electrolyte tank (30); a positive electrode-side pipe connecting the battery cell (10) to the positive electrode-side electrolyte tank (20); and a negative electrode-side pipe connecting the battery cell (10) to the negative electrode-side electrolyte tank (30). The redox flow battery (1) performs charge and discharge by circulating respective electrolytes between the battery cell (10) and the positive electrode-side electrolyte tank (20) through the positive electrode-side pipe (21, 22) and between the battery cell (10) and the negative electrode-side electrolyte tank (30) through the negative electrode-side pipe (31, 32). A hydrogen gas amount decreasing means (40) having a hydrogen gas amount decreasing device (60) is provided on the negative electrode-side pipe (31, 32).

A zinc battery according to an embodiment includes a negative electrode and a positive electrode, an electrolytic solution, and a powder. The electrolytic solution is in contact with the negative electrode and the positive electrode. The powder includes zinc and is mixed in the electrolytic solution. A zinc flow battery according to an embodiment includes a reaction chamber and a stirrer. The reaction chamber includes the zinc battery. The stirrer stirs the electrolytic solution.