Zinc discharge curve

Eig. 11. Typical discharge curve comparison for zinc—mercuric oxide batteries (-) model 325, HgO, and (-... 

Figure 2. Schematic semi-ideal discharge curves of Mn02 in 9 mol L 1 and 5 mol L 1 NH4CI2 + 2 mol L l ZnCl2 solutions. IL, range of discharge capacity of commercial alkaline MnO, - Zn R2, range of discharge capacity of commercial Leclanche or zinc chloride cells.

Active carbon promoted with small amount of silver is used as catalyst in the air electrodes of these cells. In Figure 15 we presented the discharge curve of the zinc-air cell ZV3000 at constant current 1 A. 

Figure 15. Typical discharge curve of a zinc-air cell ZV3000.

Figure 1. Discharge curve of a primary button air - zinc cell PR-44 at the resistance 625 land at 293 K.

Button cells consist of cathode and anode cans (used as the terminals), powdered zinc anode, containing gelled electrolyte and the corrosion inhibitor, separator with electrolyte, thin (0.5 mm) carbon cathode with catalyst and PTFE, waterproof gas-permeable (teflon) layer and air distribution layer for the even air assess over the cathode surface. Parameters of battery depend on the air transfer rate, which is determined by quantity and diameters of air access holes or porosity of the gas-diffusion membrane. Air-zinc batteries at low rate (J=0,002-0,01C at the idle drain and J= 0,02-0,04C at the peak continuous current) have flat discharge curves (typical curve is shown by Figure 1). 

Fig. 3.31 Continuous discharge curve through 2 Cl load of a 750 Ah zinc-air cell. Such cells have a 5A intermittent pulse capability and good capacity retention. (By courtesy of SAFT (UK) Ltd.)...

The lithium-copper oxide cell is voltage compatible (OCV = 1.5 V), i.e. it may be used as a direct replacement for conventional Leclanche or alkaline zinc cells. CuO has a particularly high volumetric capacity (4.2 Ah/cm3) so that cells are characterized by high specific energy -300 Wh/kg (700 Wh/dm3). The discharge curve shows a single step which may be attributed to the simple displacement reaction ... 

Fig. 4. 25 Comparison of discharge curves at ambient temperature of voltage-compatible lithium-copper oxide button cells and conventional aqueous cells (a) lithium-copper oxide (b) alkaline manganese (c) zinc-silver oxide. Load = 75 k i...

Zinc-Manganese Dioxide Batteries. The combination of a zinc anode and manganese dioxide cathode, which is the dominant chemistry in large cylindrical alkaline cells, is used in some miniature alkaline cells as well. Overall, this type of cell does not account for a huge share of the miniature cell market. It is used in cases where an economical power source is wanted and where the devices can tolerate the sloping discharge curve shown in Figure 2. 

Fig. 1 Typical discharge curves of D size alkaline and carbon-zinc cells at high rate (500mA). (From Ref. l) (View this art in color at www.dekker.com.)...

Fig. 15. Relative discharge curves for (-) zinc—silver oxide, and (—) zinc—mercuric oxide batteries. Cells are of equal volume (21).

Fig. 12. Silver—zinc cell discharge curves at rates of A, 10 min B, 1 h and C, 10 h.

Figure 3.2. Typical battery discharge curves. 1— Steep discharge curve typical, for example, for Leclanche cells 2— flat discharge curve typical, for example, for mercury-zinc cells 3—discharge curve with initial dip typical, for example, for thionyl chloride-hthium cells.

The prepared PVA/KOH/H2O SPE was employed for both Ni/MH and Zn/air batteries. Fig. 4 shows typical charge and discharge curves of all solid-state Ni/MH battery. The results exhibited the advantage of flat plateau discharge curve and the battery had average 82% current efficiency after ten cycles [33]. In addition, the PVA/KOH SPE was successfully assembled into Zn/air battery with a high zinc utilization of 83%. 

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