1. VOLTAGE
NiZn has a higher voltage than NiCd and NiMH : 1.65 V per cell versus 1.20 V (+ 37.5%).
So, NiZn delivers more energy per kilogram of nickel hydroxide; and cost per Wh is advantageously decreased for NiZn.
For a given Battery Voltage, 3 NiZn Cells replace 4 NiCd or NiMH Cells.

2. COLLECTORS
Ni cathodes and Zn anodes are plastic-bonded type electrodes, using metallic foams as current collectors :

• Nickel Foam for Ni cathodes
• Copper Foam for Zn anodes

For both Foam types, SCPS developed a new low cost and high quality patented production process. It is an exclusive process for making Cu Foams.

Cu Foams have two key advantages versus Ni collectors :

• Copper is 8 times more conductive than Ni,
• Copper is 7 times cheaper than Ni.

Copper can be used alone or as an alloy in negative electrodes of alkaline batteries.

3. Anodic active mass Zinc electrode is a low cost anode.
With the SCPS’ technology, cost of materials of the anodic active mass is one half of the cost of materials of the cathodic active mass (Zn is 12 times cheaper than Ni).

4. Separators
With the SCPS’ technology, there is no “dendritic” growth from the Zn anode.
That makes possible the use of only one layer of microporous membrane, and one layer of non-woven.

1 – Zinc anode is a combination of a very conductive collector network (copper foam) and of a conductive active mass (with metallic zinc as active material, and with a conductive ceramic powder such as TiN).

2 – SCPS’ NiZn battery has a low internal resistance, because it uses :

• only one layer of microporous separator,
• a concentrated alkaline electrolyte (as for NiCd and NiMH).

SCPS is presently realizing the adaptation of the NiZn system as high power battery for the Hybrid Electric Vehicle application, in collaboration with car makers.

NiZn is a member of the alkaline secondary batteries family, as well as NiCd and NiMH.
NiCd was, and NiMH is produced on a large industrial scale. Their production processes and equipment are well known.

As for upper quality NiCd, and for NiMH, collectors are metallic foams.
The only innovation here, with NiZn, is to use a copper foam (and not a nickel one) for the negative electrode.

Copper foam, with a much higher conductivity, can now be industrially produced at low cost, thanks to the new production process developed by SCPS (see Chapters “Copper foams Production” and “Copper Foam”).

Using these metallic foam collectors, electrodes are plastic-bonded type.
They are produced with similar processes and equipment than those used for making electrodes for NiCd and NiMH batteries, giving the same high level of characteristics reproducibility. The electrolyte is also a concentrated potash solution.

Assembling of cells and batteries is done as it is for other alkaline secondary systems.

Controls and initial formation are done according to the same procedures than for NiCd and NiMH.

Recycling of zinc, from primary batteries, is well established.

One of the most efficient processes is a thermal treatment (pyrometallurgical) which vaporizes zinc (recovered in the form of powder), and alloys iron and manganese.

The same process can be used for nickel-zinc secondary batteries : zinc is vaporized, and alloys of nickel and copper are recovered in the form of lingots.

There is no specific safety procedures required prior to the thermal treatment in the case of nickel-zinc batteries.

Other chemical processes can be used as well