Zinc mechanically rechargeable

The second and the third papers of this chapter were contributed by Bulgaria s National Academy of Sciences distinguished developers, Dr. A. Kaisheva and Professor I. Iliev. The two papers address magnesium-air and zinc-air chemistries, respectively. Concepts of mechanical recharging, new non-KOH based electrolytes, and the role of carbon materials in cell design have been thoroughly studied. Authors have reduced to practice their many developments. Systems created work(ed) in many specialty applications. 

Zinc is commonly used as an anode in metal-air batteries. Zinc-air batteries are commercially available and used as power supply for navigation buoys, communication systems, hearing aids, and etc. [2], Mechanically rechargeable Zn-air batteries are developed recently for traction [3],... 

Iliev I., Kaisheva A., Stoynov Z. Pauling H.J, Mechanically rechargeable Zinc-air cells, Proceedings of the 3th International Battery Recycling Congress, July 2 - 4, 1997, Noordwijk Aan Zee, the Netherlands. 

In Fig. 17 we have presented the current-voltage and the power characteristics of 12-cells battery from the cells type ZV300. It must be reminded that, when the zinc anode in the primary zinc-air cells is discharged, the cell is out of operation. By this, the air electrodes, which in principle can operate for a long time, are lost. In order to avoid this inconvenience, mechanically rechargeable zinc-air cells were developed [14]. The essential feature of the mechanically rechargeable zinc-air cell is that the air electrodes are used many times. 

Once the mechanically rechargeable zinc-air cell is discharged, the spend (oxidized) zinc electrode is removed from the cell together with the electrolyte and new zinc electrode and fresh electrolyte are introduced by which the cell is operational again. 

Several types of mechanically rechargeable zinc-air cells are developed in this laboratory, operating at nominal current 20A + 40 A with capacity ca.300 Ah. 

A variety of primary zinc-air cell and batteries are designed with capacity ranging from 100 Ah to 3300 Ah, operating at nominal currents from 2 to 40A at temperatures in the range +40 -t- -40°C. Mechanically rechargeable zinc-air cell are also developed and tested in experimental electric cars and scooters. 

The cell uses a replaceable anode cassette made up of a slurry of elec-trochemically generated zinc particles in a potassium hydroxide solution with a collection frame and a separator envelope with two sides of oxygen reduction cathodes that extract oxygen from the air for the zinc-oxidation reaction. The discharged zinc-air module is refueled or mechanically recharged by exchanging spent cassettes with fresh cassettes. 

Mechanically Rechargeable Zinc—Air Battery , ECOM 3086 (1969) 11) C.L. Mantell, Bat-... 

Fig. 3.30 Cross-section of the electrode assembly of an early 500 Ah mechanically rechargeable zinc-air wet cell used for railway signalling applications...

Fig. 9.19 Schematic diagram of a filling station for electric vehicles powered by mechanically rechargeable zinc-air batteries. (By permission of Edison.)...

Mechanically Rechargeable Batteries. To avoid the time required for electric recharge, the problems of in silu electric recharge, or to utilize anodes that are not electrically rechargeable in aqueous electrolytes, mechanically rechargeable batteries have been studied. These systems arc metal-air couples. Ihe anodes that have received attention arc zinc, lithium, and aluminum. 

In the mechanically rechargeable zinc-air batteries, each cell has its own zinc hopper. The electrochemical process continues until the hoppers are empty, at which point the cells are completely discharged and must be refilled. An important aspect of these systems is that the... 

Mechanically rechargeable, zinc-air batteries have been tested in Europe in postal trucks... 

In the 1970s, a mechanically rechargeable 35 kWh zinc/air battery was demonstrated by General Motors in a 1350 Kg test bed vehicle, but the development was not continued to commercialisation [17]. 

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