Mercury-free primary alkaline cell

Details Mercury-free primary alkaline cell Mercury-free primary alkaline cell

1997-04-18

2001-03-13

Nuzzollilo, Maria (Department: 1745)

Chemistry: electrical current producing apparatus, product, and

Sealed cell having gas prevention or elimation means

Prevention or elimination means is one of the cell...

C429S057000, C429S224000, C429S229000, C429S231600

Reexamination Certificate

active

06200699

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to galvanic cells, and, in particular, to galvanic cells that comprise (a) an anode gel comprising mercury-free zinc powder, (b) an alkaline electrolyte, and (c) a cathode material that is separated from the anode gel by a separator and comprises manganese dioxide.
2. Description of the Related Art
Batteries of the abovementioned type are known as alkaline manganese primary cells. Because, on the grounds of protection of the environment, mercury is no longer being added to zinc powder, the anode material of cells of the abovementioned type is subject to increased corrosion which manifests itself in a higher self-discharge and a corresponding gassing rate. Numerous earlier attempts have been made to avoid these negative effects. For example, the zinc used as zinc powder has been alloyed with the metals bismuth, indium, lead, aluminum, and calcium (see U.S. Pat. No. 5,209,995). It is also known for the anode gel to be admixed with inorganic gassing inhibitors such as barium hydroxide (see U.S. Pat. No. 4,418,130). EP-A 582293 additionally discloses the addition of an indium salt to the electrolyte.
A further reduction of the gassing rate is desirable on the grounds of cost and with a view to improving the discharge behavior and increasing the capacity of the cells.
It is an object of the invention to provide a solution to the abovementioned problems.
Further aspects and advantages of this invention will become apparent from the detailed description which follows.
SUMMARY OF THE INVENTION
The object is achieved according to the invention in that the cathode material of cells of the abovementioned type comprises salt-like calcium compounds in solid form.
The present invention is directed to a galvanic cell, comprising (a) an anode gel comprising mercury-free zinc powder; (b) an alkaline electrolyte; and (c) a cathode material, separated from the anode gel by a separator and comprising manganese dioxide, wherein the cathode material further comprises salt-like calcium compounds in solid form.


REFERENCES:
patent: 4418130 (1983-11-01), Soltis et al.
patent: 4913898 (1990-04-01), Langan
patent: 5128222 (1992-07-01), Yoshizawa et al.
patent: 5164274 (1992-11-01), Kordesch et al.
patent: 5209995 (1993-05-01), Tada et al.
patent: 5464709 (1995-11-01), Getz et al.
patent: 5532085 (1996-07-01), Davis et al.
patent: 5626988 (1997-05-01), Daniel-Ivad et al.

Affiliated with

Also associated with

Rating

Mercury-free primary alkaline cell does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Mercury-free primary alkaline cell, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Mercury-free primary alkaline cell will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2465722