Metal air battery, method of manufacturing the same, apparatus including the metal air battery, and system and method of controlling the metal air battery

A metal air battery apparatus comprising:

• a metal air battery comprising
• a first metal air cell comprising
• a first cathode layer comprising pores,
• a first anode layer facing the first cathode layer, and
• a solid electrolyte layer between the first cathode layer and the first anode layer, and
• a second cell at a location different from a location of the first metal air cell;
• and
• a controller configured to control at least one of a charge rate or a discharge rate of the first metal air cell based on a porosity of the first cathode layer.

A metal air cell comprising:

• a cathode layer comprising a mixed ionic electronic conductor;
• an anode layer facing the cathode layer;
• and
• a solid electrolyte layer between the cathode layer and the anode layer, wherein
• a porosity P1 of the cathode layer satisfies Equation 2
• (−0.122 ln(R)+0.3)≤P1≤(−0.122 ln(R)+0.5),
• wherein R is a charge rate or a discharge rate of the metal air cell and is in a range of about 0.01 C to about 2.3 C.

A method of operating a metal air cell, the method comprising:

• determining a porosity of a cathode layer of the metal air cell;
• determining a charge rate or a discharge rate of the metal air cell according to Equation 3
• e((P1−0.3)/−0.122)≤R≤e((P1−0.5)/−0.122),
• wherein P1 is the porosity of the cathode layer of the metal air cell and R is a charge rate or a discharge rate of the metal air cell;
• and
• controlling at least one of a charge rate or a discharge rate of the metal air cell such that at least one of a charge rate or a discharge rate of the metal air cell satisfies Equation 3.