Aluminum-air battery

The aluminum-air battery is an electrically non-rechargeable primary cell , the voltage of which is 1.2 V per cell  and is created by a chemical reaction of oxygen in the air with aluminum . The aluminum-air battery has a high energy density of 1300  Wh / kg. Due to the comparatively high operating costs, the aluminum-air battery is, however, only less popular than other electrical storage systems. There are applications in the military sector for driving electrically powered vehicles. Electric vehicles with aluminum-air batteries as energy stores achieve, under otherwise identical conditions and the same weight, a range that is approx. 8 times greater than that of lithium-ion batteries .

Since the aluminum-air battery cannot be electrically charged, the used aluminum anode and the electrolyte must be physically replaced when re-used. The battery also has a high self-discharge , which is why in some applications the electrolyte is only inserted into the cell shortly before or during operation. The additional technical equipment required for this is the primary reason for the comparatively low distribution and the high operating costs.

Reaction equations

The oxidation occurring on the aluminum anode during discharge is:

${\displaystyle \mathrm {Al+3OH^{-}\rightarrow \ Al(OH)_{3}+3e^{-}} }$

At the of carbon existing cathode following reduction occurs:

${\displaystyle \mathrm {O_{2}+2H_{2}O+4e^{-}\rightarrow \ 4OH^{-}} }$

The redox reaction is:

${\displaystyle \mathrm {4Al+3O_{2}+6H_{2}O\rightarrow \ 4Al(OH)_{3}} }$

The terminal voltage of 1.2 V is achieved when using potassium hydroxide as the electrolyte.

Individual evidence

1. ↑ ^{a b} Shaohua Yang, Harold Knickle: Design and analysis of aluminum / air battery system for electric vehicles . In: Journal of Power Sources . tape 112 , no. 1 , 2002, p. 162-173 , doi : 10.1016 / S0378-7753 (02) 00370-1 .
2. ↑ N. Fitzpatrick, F. Smith, P. Jeffrey: The Aluminum-Air Battery . In: SAE Technical Paper 830290 . 1983, doi : 10.4271 / 830290 .