A refuelable electrochemical battery (or cell) and methods of refueling a refuelable electrochemical battery are provided.
Primary and secondary types of batteries or cells have long been used as power sources. A primary battery is generally meant for one-time use, is not rechargeable, and may or may not be recycled. A secondary battery is rechargeable via a process in which the electrochemical process by which electrical energy was generated is reversed. For example, some lithium-ion and nickel-cadmium batteries can be recharged by applying an electrical current.
In addition, reconstructible metal/air batteries have been developed that take advantage of the high energy density of some metals (e.g., zinc), but which must be removed from the equipment they power in order to be refueled and refurbished. For example, Cooper (U.S. Pat. No. 5,434,020) provides a zinc/air battery that must be uninstalled and processed in order to replace the expended metal particles.
Other metal/air batteries, or fuel cells, are refillable via a process that relies upon gravity to ensure proper settling of the metal particles and formation of the metal electrode. For example, Gutierrez (U.S. Pat. No. 6,162,555) provides for feeding particles into cell cavities via flows shaped parallel to the cavities. However, these types of batteries are vulnerable to decreased efficiency resulting from clogging of valves, pores, and/or other conduits designed to allow circulation of the particles and/or an electrolyte. In particular, as some particles are expended, a sludge or paste tends to be formed that can prevent further or complete oxidation of the remaining particles. Attempts have been made to avoid this problem, but still rely upon gravity to combine the metal particles.
Existing metal/air batteries that rely upon gravity to feed metal particles into a cell are vulnerable to loss of power and/or decreased efficiency if they are disturbed or oriented such that gravity acts against the necessary flow of the particles or electrolyte.