What is claimed is:
1. A metal air battery comprising:
a first battery cell module which generates electricity by oxidation of a metal and reduction of oxygen, wherein the first battery cell module comprises a plurality of battery cells;
a plurality of second battery cell modules in fluid-communication with the first battery cell module and which generates electricity by oxidation of a metal and reduction of oxygen, wherein each of the plurality of second battery cell modules comprises a plurality of battery cells; and
an air purifier in fluid-communication with the plurality of second battery cell modules,
wherein
the air purifier generates first purified air by purifying external air and supplies the first purified air to the plurality of second battery cell modules as reactant air of each of the battery cells of the plurality of second battery cell modules,
the battery cells of the plurality of second battery cell modules collectively generate second purified air using the first purified air by the oxidation of the metal and the reduction of the oxygen, and the plurality of second battery cell modules supplies the second purified air to the first battery cell module as reactant air of each of the battery cells of the first battery cell module such that the reactant air of the first battery cell module is different from the reactant air of the plurality of second battery cell modules, and
each of the plurality of second battery cell modules is replaceable, and
the plurality of second battery cell modules is disposed between the air purifier and the first battery cell module in parallel, and
fluid-communications between the plurality of second battery cell modules and the air purifier are controlled independently of each other and fluid-communications between the plurality of second battery cell modules and the first battery cell module are controlled independently of each other in a way such that the first battery cell module is allowed to operate during a replacement of one second battery cell module among the plurality of second battery cell modules and another second battery cell module among the plurality of second battery cell modules is allowed to operate during the replacement of the one second battery cell module.
2. The metal air battery of claim 1 , further comprising:
a moisture concentration measurer which measures a moisture concentration of the second purified air supplied to each of the battery cells of the first battery cell module.
3. The metal air battery of claim 2 , wherein the one second battery cell of the plurality of second battery cell modules is replaced when the moisture concentration of the second purified air thereof measured by the moisture concentration measurer is equal to or higher than a predetermined reference moisture concentration.
4. The metal air battery of claim 1 , further comprising:
a voltage measurer which measures a discharge voltage of the second battery cell module.
5. The metal air battery of claim 4 , wherein the one second battery cell of the plurality of second battery cell modules is replaced when the discharge voltage thereof measured by the voltage measurer is less than or equal to a predetermined reference discharge voltage.
6. The metal air battery of claim 1 , wherein a battery capacity of each of the second battery cell modules is less than a battery capacity of the first battery cell module.
7. The metal air battery of claim 1 , wherein
each of the plurality of second battery cell modules is in fluid-communication with the air purifier and the first battery cell module.
8. The metal air battery of claim 7 , further comprising:
a plurality of fluid regulators between the plurality of second battery cell modules and the air purifier and which regulates the fluid-communication between the plurality of second battery cell modules and the air purifier, respectively; and
a controller which controls operations of the plurality of fluid regulators.
9. The metal air battery of claim 8 , further comprising:
a moisture concentration measurer which measures a moisture concentration of the second purified air discharged from each of the plurality of second battery cell modules,
wherein the controller closes a corresponding fluid regulator of the plurality of fluid regulators when the moisture concentration of the first purified air measured by the moisture concentration measurer is equal to or greater than a predetermined reference moisture concentration.
10. The metal air battery of claim 8 , further comprising:
a voltage measurer which measures a discharge voltage of the plurality of second battery cell modules,
wherein the controller closes a corresponding fluid regulator of the plurality of fluid regulators when the discharge voltage measured by the voltage measurer is less than or equal to a predetermined reference discharge voltage.
11. The metal air battery of claim 1 , wherein the air purifier operates via at least one of a pressure swing adsorption method, a thermal swing adsorption method, a pressure thermal swing adsorption method, a vacuum swing adsorption method, and a selective separation method.
12. The metal air battery of claim 11 , wherein the air purifier comprises at least one of an adsorbent and a selective transmitting film.
13. The metal air battery of claim 12 , wherein the adsorbent comprises at least one selected from zeolite, alumina, silica gel, metal-organic framework, zeolitic imidazolate framework and activated carbon.
14. The metal air battery of claim 1 , wherein the metal air battery is a lithium air battery.
15. A method of operating the metal air battery of claim 1 , the method comprising:
removing a plurality of impurities from the external air using the air purifier; and
introducing the first purified air to the plurality of second battery cell modules; and
discharging the second purified air from the plurality of second battery cell modules.
16. The method of claim 15 , further comprising:
measuring a moisture concentration of the second purified air discharged from each of the plurality of second battery cell modules; and
replacing the one of the plurality of second battery cell modules when the measured moisture concentration thereof is equal to or greater than a predetermined reference moisture concentration.
17. The method of claim 15 , further comprising:
measuring a discharge voltage of each of the second battery cell modules; and
replacing the one second battery cell module of the plurality of second battery cell modules when the measured discharge voltage thereof is less than or equal to a predetermined reference discharge voltage.