A zinc electrode for alkaline cells includes up to about ten percent by weight of Ba(OH)2.8H2O with about five percent being preferred. The zinc electrode may or may not be amalgamated with mercury

Nagle, W. J.

Sheibley, D. W.

Soltis, D. G.

English

NASA Technical Reports Server

United States Patent 4,418,130 
Soltis et al. [45] Nov. 29, 1983 
[54] ADDITIVE FOR ZINC ELECTRODES 
[75] Inventors: 
E731 Assignee: 
Daniel G. Soltis, Broadview Heights; 
Dean W. Sheibley, Sandusky; William 
J. Nagle, Sheffield Lake, all of Ohio 
The United States of America as 
represented by the Administrator of 
the National Aeronautics and Space 
Administration, Washington, D.C. 
[21] Appl. No.: 272,406 
[22] Filed: Jun. 10,1981 
[51] Int. C1.3 ........................ HOlM 6/04; HOlM 4/42 
[52] U.S. CI. .................................... 429/206; 429/229; 
252A82.1 
[58] Field of Search ............... 429/206, 229, 230, 232, 
429/231, 248, 223, 219; 252/182.1, 521; 
423/635 
1561 References Cited 
U.S. PATENT DOCUMENTS 
3,639,176 2/1972 Nordbloom et al. ............... 429/206 
3,970,477 7/1976 Ciliberti .............................. 429/206 
3,976,502 SA976 Sekido et al. ....................... 429/206 
4,039,729 SA977 Benczur-Urmossy .............. 429/206 
4,124,743 11/1978 Chireau et al. ..................... 429/248 
4,279,978 7/1981 Dodin et al. ........................ 429/248 
4,312,931 VI982 Witherspoon et al. ............. 429/231 
OTHER PUBLICATIONS 
Hackh’s Chemical Dictionary: Grant, Julius, Ed.; 1972, 
New York, St. Louis, San Francisco, etc: McGraw-Hill 
Book Company, p. 78 
Primary Examiner-Brian E. Hearn 
Assistant Examiner-Stephen J. Kalafut 
Attorney, Agent, or Firm-Norman T. Musial; John R. 
Manning; James A. Mackin 
1571 ABSTRACT 
An improved zinc electrode for alkaline cells includes 
up to about ten percent by weight of Ba(OH)2.8H20 
with about five percent being preferred. The zinc elec- 
trode may or may not be amalgamated with mercury. 
4 Claims, No Drawings 
https://ntrs.nasa.gov/search.jsp?R=19840006354 2020-03-22T07:47:22+00:00Z
4,418,130 
1 2 
silver electrode to be used in an alkaline-nickel or alka- 
line-silver accumulator. 
DISCLOSURE OF THE INVENTION 
In accordance with the present invention, Up to about 
10% by weight ofBa(OH)2*8H20 Powder is mixed with 
zinc powder and formed into an electrode for an alka- 
line cell as, for example, by pressing the mixture into a 
suitable electrode configuration. A suitable binder may 
lo also be added to the powdered mixture before the form- 
ing step. 
ADDITIVE FOR ZINC ELECTRODES 
ORIGIN OF THE INVENTION 
Government and may be manufactured or used by or 
for the Government without the payment of any royal. 
ties thereon or therefor. 
TECHNICAL FIELD 
This invention was made by employees of the U.S. 5 
This invention relates to secondary cells and is di- - .  
BEST MODE FOR CARRYING OUT THE 
INVENTION 
rected more particularly to alkaline- electrolyte cells 
having at least one zinc electrode. 
Because of pollution problems resulting from the 
various chemicals emitted by internal combhion auto- l 5  According to the invention, zinc powder and Ba- 
mobile and truck engines together with several criseses (OH)2.8H20 powder are mixed together, the Ba- 
in the abvailability of crude oil in recent years, there has (OH)2.8H20 comprising up to about 10% but prefers- 
been greatly increased interest in electric automobiles. bly 5% by weight of the total mixture. The mixture is 
Because electric automobiles are powered by batteries then formed into a desired shaped electrode by any of 
of electromotive force (EMF) cells, there has been a 2o the pressing techniques which are well-known in the 
parallel increase in research and development work on prior art of electrode forming. 
A number of zinc electrodes embodying the inven- the various aspects of EMF cells. 
powering electric automobiles and are currently in use cells having zinc electrodes with no additives and for various dollies and vehicles used, for example, to 25 against other cells in which carboxymethylcellulose 
which result from providing a sufficient number of 
lead-acid batteries to achieve a practical range of opera- 
tion for an electric automobile is presently too great to 
Lead-acid batteries have been used in the past for tion were installed in alkaline cells and tested against 
move stock in factories' The high weight and expense was incorporated into the electrodes. The results of 
these tests are shown in I 
The test conditions for the results indicated in Table 
make such vehicles acceptable to the general public. 30 I were: 6 hours (25 amperes) charge; 2 hours '(75 am- 
A desirable alternative to the lead-acid battery is the peres) discharge; and, 50% depth of discharge, 150 
nickel-zinc alkaline battery. There are, however, a num- ampere hours, cycling continuously. Three types of 
ber of problems with zinc electrodes. Among these cells were tested, the type 1 cells having no additives in 
problems are slumping of the electrode, the formation the zinc electrodes, the type 2 cells including 5% by 
of dendrites which eventually short out the separators 35 weight of carboxymethylcellulose, and the type 3 cells 
between the electrodes, densification, material loss, and includng approximately 5% by weight of the barium 
drying out. These deficiencies result in loss of capacity, hydroxide octohydrate. None of the cells tested in- 
shorting of the separators, inability to sustain a required cluded mercury in the zinc electrodes. However, the 
current output, and limitation of cycling capability. zinc electrodes embodying the invention can be amal- 
Some of the foregoing problems have been amelio- 40 gamated without any problem as is known in the prior 
rated by improved separators which reduce dendrite art, since mercury will not react with Ba(OH)2.8H20. 
formation and minimize slumping of the zinc electrode. To increase the accuracy of the results shown in 
Even with improved separators, nickel zinc cells were Table I, three cells of each type were constructed and 
still handicapped by loss of capacity, increased cell tested. One of the type 1 cells failed before completion 
operating temperatures and densification of the zinc 45 of 63 cycles. Further, two of the type 2 cells failed 
electrodes after relatively short periods of operation. before completing 63 cycles of testing. One of the type 
3 cells failed at 163 cycles. The average for the three 
type 3 cells, including the cell that failed, was 212 cy- 
,-les. 
TABLE I 
BACKGROUND ART 
U.S. Pat. No. 2,902,530 to Eisen and U.S. Pat. No. 
3,060,254 to Urry both disclose the use of carboxy- 50 
methylcellulose as a binder or adhesive for anode or 
cathode materials covering the surface of a fibrous elec- Exp. Cycles "C.Temp. Range AH1 AHD 
trode. Type 1 8 26-28 147.7 145.7 
U.S. Pat. No. 2,448,052 to Roberts discloses the use of Type2 8 27-29 147.3 145.7 
24-25 149.3 146.4 
27-30 
trodes, the cellulose material swelling when contacted Type 63 27-30 137.9 128.5 
by an alkaline electrolyte. Type 3 63 24-25 150 147.8 
146 117.0 
Moulton, and 2,870,234 to Moulton all disclose expan- Type 2 141 31-36 132 42.0 
der materials to be contained in electrodes and includ- 60 
ing pol yvinylalcohol, rubber and polyvinylpyrrolidone. 
U.S. Pat. No. 3,053,924 to Strauss discloses an elec- 
trode for an alkaline cell wherein cellulosic material is 
deposited within the pores of the electrode itself to limit 
dendrite formation or treeing. 
U.S. Pat. No. 3,184,340 to Andre teaches that crystal- 
line lithium hydroxide may be precipitated from a lith- 
ium hydroxide solution contained in pores of a nickel or 
143 144 cellulose materials as expanders for cadmium elec- 55 
Type 
Type 1 63 
U.S. Pat. Nos. 2,519,399 to Roberts, 2,727,080 to Type 1 141 30-34 
26-27 148 145 
28-29.5 148 121 Type  3 
From Table I, it will be seen that an alkaline cell 
utilizing a zinc electrode incorporating Ba(OH)2.8H20 
65 in accordance with the present invention has a greatly 
extended life. This makes silver zinc or nickel zinc cells 
much more acceptable in terms of useful life when com- 
pared to lead-acid batteries presently in general use. 
212 14' 
3 
4,418,130 
9 
It wilI be understood that changes and rnodifcatiuns 
may be made to the above-described invention by those 
skiHed in the art without departing from the spirit and 
scope of the invention as set forth in the cIaims ap- 5 
pended hereto. 
We c I k  
I. A zinc electrode for s cell having KOH or  NaQH 
electrolyte, said electrode containing from about 5% to la 
about IO% by weight of Ba(QH)2&H20. 
I5 
20 
25 
30 
35 
40 
45 
50 
4 
2. The electrode of claim 9 wherein Ba(OH)2.8&0 is 
contained in the amount of approximately 7% by 
weight. 
3. An W i n e  cell having a positive electrode of a 
metal selected from the group consisting of silver and 
nickel and a negative zinc electrode containing from 
about 5% up to about 10% by weight of Ba(Ogl2.8- 
H20. 
A The ceII of claim 3 wherein said zinc eIectrode 
contains about 7% by weight of Ba(OH)2.8H20. 
. e * * * *  
55 
60 
65 


Additive for zinc electrodes

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