The Thomas A. Edison Papers Digital Edition

Transcription

REPORT.
EXPERIMENTS WITH EDISON-LALANDE BATTERIES AT LOW TEMPERATURES.
TEST 1. Mr. Brodie, date March 27th to April 7th- 59 cells type [illegible text] were employed.
The conditions were varied in regard to make of soda, density, and glass or porcelain jars.
The kind of soda: [Solray?], Alheusen, and that employed in the Gordon cell.
The percentage of soda was varied from 18% to 25% (densities)
The temperature was lowered gradually to -20° and the last day reached -28°.
In this test the 20% soda and 21% soda plus salt showed the best results; greater and lesser percentages of soda froze and polarized more rapidly. The kind of soda used made very little difference, and while the glass jars gave slightly better results than the porcelain, still there was not sufficient differences to amount to anything.
TEST 2. Mr Brodie, date April 13th to April 28th.
The conditions were nearly the same as in the preceding test, the main difference being in dropping the temperature to -15° to 20° early in the test. The percentages of soda varied between 20% and 23%, with and without salt. 69 cells were employed. Glass and porcelain jars were used with the same results.
The 20% soda and 21% soda plus salt again showed up best. Mixtures of sodium and potassium hydroxides were tried, as well as plain potassium hydroxide with worse results than soda alone.
TEST 3. Mr Morse, date May 4 to May 16.
In this test 74 cells type "R" were used. They were made up as follows:-
12 cells 20% soda
12 cells 20% soda plus salt
12 cells 21% soda
22 cells 21% soda
6 cells 25% soda
A A 6 cells 21% soda
4 Gordon cells 20% soda
These were divided pretty evenly between glass and porcelain jars, and some were tried without oil. There was no marked difference between cells containing oil, and those without.
The temperature was again lowered immediately and kept around -18º and, though they all polarized with very few exceptions, still 20% soda and 21% soda plus salt showed best results.
TEST 4. Mr Morse Date May 17 to May 29th.
63 cells were employed. The object of the test was to see if the cells at different stages of their lives would act differently, hence-
9 cells with 0 ampere hrs taken out
9 " " 100 " " " "
9 " " 150 " " " "
9 " " 200 " " " "
9 " " 250 " " " "
9 " " 275 " " " and
9 " " 300 " " " "
were used. Of the nine in each set, 3 contained 205 soda, 3- 20% soda plus salt, and 3- 21% soda plus salt. As in the case of the first test the temperature was lowered gradually from 0" to -23" during the testing period. The results justified the expectation that those used the longest would be the first to polarize. The cells containing 21% soda plus salt averaged better than either the 20% soda plus salt or the 20% soda alone.
SUMMARY. 1. During the tests some cells containing hard pressed copper oxides, and some with soft oxides, as well as the loose oxide used by the Gordon people were compared and showed no marked difference in behavior. 2. Three makes of, visit;- Solvay, Alhusen and Gordon soda all giving similar results.
3. Porcelain and glass jars, with a slight advantage in favor of the glass.
4. Cells with oil, and no oil. No difference. and 3 cells containing 25% soda plain. The object of the latter being to add some salt as soon as they polarized, and see if it could be prevented; an objection to this being that they would have to be warned up to the ordinary temperature or the sale wouldn't mix with the solution- even the liquid, as was seen in the sixth test, sodium allicate (syrupy) settled upon the bottom and did not mix with the solution cold.
These cells behaved well, and gave great promise of an ultimate solution of the problem
Sodium phenolate
" acetate
" chlorate
" silicate
" tartrate
" bromide
were steady and never gave the least sign of polarization.
The others precipitated, chrystalized and polarized. Curves of the temperature changes and voltage changes accompany this report.
TEXT G. J. B. M. date July 26 to August 6 inclusive -
31 cells type "R" were used, contents 21% soda plus chemical, and 79% water, or the same conditions prevailed as in Test #4.
Amount used 6 lbs 5 oz water

                       1 lb 10 oz soda
                     30.5 grams.

The cells were made up as follows;-
4 cells sodium phenolate
4 " " acetate
5 " " silicate
4 " " tartrate
5 " " chlorate
2 " 20% soda plain
2 " 21% soda plain
The temperature in this test was run down immediately, and same in each The 21st% plain went out immediately. A set of curves showing the average of each set enclosed, also an average temperature curve. The box in which the test was made varies usually 3 to 5 degrees in temperature between the ends and middle. The ammonia coil runs through the middle of the box
[DRAWING OF BOX]
[illegible text] BOX [illegible text]
letters show where thermometers were placed.
SUMMARY . In test #5 with the "B" cells, there is but one zinc plate, and after the test the oxide plates were picked with a knife and showed much greater reduction to metallic cooper on the near side (side toward the zinc) This is the case in ordinary use, but, if the reduced copper occludes or absorbs the hydrogen gas evolved, it would form a positive membrane, and appose the cells' action occasioning polarization. The action, if a fact, must occur more easily during reduction, and at the low temperature employed, when it is naturally to be supposed that the oxide depolarized with less rapidity and efficiency An example tending to show this is found in the 3rd test; cells with 300 and 275 amp and even 250 amp hrs. taken out of them, were used and run the length of their life.
Now, if the form of cell "B" has any value, the large cell of "Y" type 300 amp hrs. may answer better than the "R" type- an explanation may be found in the fact that there is a larger oxide surface which ordinarily is not necessary, but in low temperature tests must be taken into account, especially if the action of the depolarizer become sluggish or the temperature falls.
The use of foreign salts was suggested for two reasons. 1 The salt would increase the density of the solution without increasing the percentage of soda- it being found that greater percentage of soda than 20 or 21 polarized more rapidly, and also chrystallised more quickly. Hence to prevent freezing and crystallization was the main object of the chemical. 2. The hydrogen was thought to be soluble, causing polarization. It is known that 100 volume of brine at 0° to -20° will [illegible text] [illegible text [values?] of hydrogen. The dissolving power of caustic soda is not known, but if it is a solvent for hydrogen it was hoped that the introduction of sodium phenolate, chlorate, etc would render it less so.
The trouble there is due to an inefficient depolarizer at the temperature required. The hydrogen may dissolve in the solution but it must necessarily stay around the copper oxide being positive and due to the fact that a current is passing through the oil in that direction whether the cell is polarized or not. If then, the hydrogen does not fill the pores of the reduced copper and is not occluded it must form a film around the outside of the oxide pole at all events. SUGGESTIONS- It would be interesting to try "Y" cells, also a larger percentage of sodium sillicate or chlorate, preferably the former, as it can't crystallize out- while it might increase local action internal resistance, and lower the life of the cell still it would keep the hydrogen right where it was liberated, at the oxide plate, and if the depolarizer will act, present the best conditions for such action. I don't know that it will increase local action, Na 4 Si04 is not a solvent for zinc. It doesn't increase the internal resistance in the amount heretofore employed. 1' course the "Y" type would increase internal resistance from the [form?] of cell.
J. B. M.