BIMONTHLY REPORT NO. 3 ON THE WATER ACTIVATED BATTERY

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP78-03424A000500040003-1
• Release Decision: RIPPUB
• Original Classification: C
• Document Page Count: 19
• Document Creation Date: December 22, 2016
• Document Release Date: April 10, 2012
• Sequence Number: 3
• Publication Date: October 22, 1959
• Content Type: REPORT

Declassified in Part - Sanitized Copy Approved for Release 2012/04/10: CIA-RDP78-03424A000500040003-1
Coy ii ENTIAL,
Period:
BIMONTHLY REPORT NO.
ON THE
WATER ACTIVATED BATTERY
22 October 1959 - 21 December 1959
M
ORIGINAL C'_ 7"' 3 592 9--
p ono
El 1) r--
EXT~ sS~ G
LI Declassified in Part - Sanitized Copy Approved for Release 2012/04/10: CIA-RDP78-03424A000500040003-1
 Declassified in Part - Sanitized Copy Approved for Release 2012/04/10: CIA-RDP78-03424A000500040003-1
W UUI HIULNI IHL IV
Page
I.
II.
III.
ABST
PURP
FACT
RA
OS
UA
CT ................................................ 1
E ................................................. 1
L DATA.... ......................................... 2
A.
Phase 2, Low Temperature Performance ................ 2
1.
Basic Approach .................................. 2
?
2.
Exploratory Test ................................ 4
3.
Small Scale Activation Tests .................... 5
4.
Evaluation of Results ........................... 8
B. Development of a New Cooling Method ................. 9
1. Basic Approach .................................. 9
2. The Effect of Boiling on Electrical output ...... 10
3. The Effectiveness of External Vaporization......13
0
C. Phase 2, High Temperature Performance ............... 15
IV. CONCLUSIONS .............................................16
V. FUTURE PLANS ............................................ 17
VI. PERSONNEL ............................................... 17
1 tL
~7'
Declassified in Part - Sanitized Copy Approved for Release 2012/04/10: CIA-RDP78-03424A000500040003-1
 Declassified in Part - Sanitized Copy Approved for Release 2012/04/10: CIA-RDP78-03424A000500040003-1
w ?
?
0
During the present period our efforts have been directed to
phase 2 of the program. A new and practical battery cooling technique
for improving high temperature performance has been developed.
Exploratory and incomplete tests indicate the feasibility of operating
the battery satisfactorily at both temperature extremes -40?C and +40?C.
Phase 1:
To demonstrate the feasibility of a large model, chemically
rechargeable, magnesium-silver chloride battery, activated by three per
cent salt solution at room temperature and delivering an average current
of 3 A at 12 V for at least 60 minutes. The voltage regulation at a
maximum load current of 5.3 A shall equal or surpass the stability ob-
tained previously.
Phase 2:
To demonstrate reasonably satisfactory performance of this
battery at environmental temperatures of -40?C and +40?C, using a variety
of electrolytes such as three per cent salt solution, tap water and
others. It is recognized, however, that such performance cannot be ex-
pected to match that at room temperature.
Declassified in Part - Sanitized Copy Approved for Release 2012/04/10: CIA-RDP78-03424A000500040003-1
 Declassified in Part - Sanitized Copy Approved for Release 2012/04/10: CIA-RDP78-03424A000500040003-1
w i
Phase 3:
To fabricate and deliver six battery cases and 30 complete sets
of chemical recharges for field testing purposes, including instructions
on the proper handling, activation, deactivation, disposal and temper-
ature control.
A. Phase 2, Low Temperature Performance
? 1. Basic Approach
Phase 1 being essentially completed, our attention shall
now be directed towards phase 2, a study of environmental temperature and
electrolytic variables. While satisfactory operation at room temperature
or higher is mainly determined by the adequacy of heat dissipation,
especially towards the end of the run, it is well-known that the low
temperature operation of a water-activated battery is primarily determined
by the activation process at the beginning of the run. Once activated,
the successful completion of the discharge is virtually assured by the
abundance of heat evolution, which is capable of maintaining the operating
temperature of the battery at a level substantially above the environmental
temperature. It has been found, for example, that a battery case, filled
with water and surrounded by a 1 1/2" layer of cotton heat insulation,
except for its open top surface, and with copper leads attached to its
terminals to simulate actual operating conditions, could be maintained at
Declassified in Part - Sanitized Copy Approved for Release 2012/04/10: CIA-RDP78-03424A000500040003-1
 Declassified in Part - Sanitized Copy Approved for Release 2012/04/10: CIA-RDP78-03424A000500040003-1
V ?
a battery temperature of 20?C with a supply of only 17 watts of heat,
although the environmental temperature was kept at -59?C. In fact, it
is questionable whether provisions for such good heat insulation should
be made at all since standard operation releases about 250 watts, which
is almost 15 times the minimum value required. Too much heat insulation
may therefore lead again to excessive operating temperatures towards the
end of the run.
It has also been found that adequate voltage regulation
is difficult to maintain at operating temperatures substantially below 0?C.
? Since activation must cover a much lower temperature region, it is recom-
mended that such activation be performed with the battery short-circuited
until standard operation is feasible. Depending on conditions this may
take from one to several minutes. During this shorted condition, the
maximum possible internal heat is generated at the highest rate, resulting
in a minimum sacrifice of battery capacity prior to standard operation.
In all the following low temperature tests, activation has been
accompanied by an initial period of shorting.
0
It is desirable to activate the battery by means of an
electrolyte, which is essentially in the liquid state prior to activation
with at least part of it remaining liquid at all times after activation.
While it has been possible to activate a battery with tap water frozen
solidly soon after adding it to the case, such activation is time consuming
and it is therefore not recommended. Since the battery case may be much
colder than the electrolyte, prior to activation, improved low temperature
Declassified in Part - Sanitized Copy Approved for Release 2012/04/10: CIA-RDP78-03424A000500040003-1
 Declassified in Part - Sanitized Copy Approved for Release 2012/04/10: CIA-RDP78-03424A000500040003-1
w .
activation can be attained by reducing the thermal capacity of the case
2. Exploratory Test
At the start of our low temperature studies it was
our intention to perform a small number of tests, using the large model
battery, described in Report No. 2. In implementing this, the paper heat
insulated battery case, provided with a 4-cell chemical charge, was
placed in a picnic cooler and its temperature was stabilized at -4o?C by
placing dry ice around it in the cooler, Ideally, activation should be
initiated with a liquid electrolyte also precooled to -40?C. A 50 per
cent alcohol solution is known to have its point of crystallization at
about this temperature. Such a solution was therefore selected as our
first low temperature electrolyte except for three per cent salt which
was added to enhance its electrical conductivity.
With all ingredients precooled to -40?C and the battery
terminals shorted by means of a 30 A DC ammeter, activation was initiated
? by adding half of the required amount of alcohol solution. During a 45
minute interval, the short-circuit current never exceeded 0.5 A, a value
too low for adequate internal heat generation. Consequently, the battery
temperature remained very low and no useful activation could be achieved.
Only after warming up the battery to about 0?C and adding standard three
per cent aqueous salt solution to fill the battery, did the short-circuit
Declassified in Part - Sanitized Copy Approved for Release 2012/04/10: CIA-RDP78-03424A000500040003-1
 Declassified in Part - Sanitized Copy Approved for Release 2012/04/10: CIA-RDP78-03424A000500040003-1
w a
current rise to 25 A. At this point a standard load was substituted for
the short, whereupon discharge proceeded normally with the battery temper-
ature rising very slowly.
This test leads one to conclude that the addition of
alcohol to the electrolyte has no beneficial effect on low temperature
activation, in spite of its lowering the freezing point substantially.
It was also concluded that such successful activation may require a much
larger number of tests than originally anticipated. Consequently it was
decided to continue our exploratory testing on much smaller samples.
This will be described in the next section.
3. Small Scale Activation Tests
In the interest of simplicity and speed it was decided
to use for these exploratory low temperature tests, a single cell arrange-
ment, developed during the previous contract and described on page 50 of
the Annual Report. This small case, embedded in "vermiculite" heat
insulation, is mounted inside a small beaker which, in turn, is surrounded
? by the low temperature environment of the cooler. The temperature of the
cell is measured by thermocouples., Activation is said to be completed as
soon as the short-circuit current reaches a value of 1 1/4 A, which is
about five times the equivalent maximum, standard load current (0.26 A)
for this size. As stated previously, this usually occurs at a battery
temperature of about 0?C. The sacrifice in battery capacity, resulting
from this type of activation, is less than 10 per cent as measured by the
reduction in thickness of the AgCl layer.
Declassified in Part - Sanitized Copy Approved for Release 2012/04/10: CIA-RDP78-03424A000500040003-1
 Declassified in Part - Sanitized Copy Approved for Release 2012/04/10: CIA-RDP78-03424A000500040003-1
w .
?
9
Our first activation tests with this cell were made,
asing brine (15 % NaCl) at its freezing point of -20?C. With the case
at -1+3?C activation starts normally at a short-circuit current in excess
of 0.5 A accompanied by a substantial increase in temperature. However,
as a result of the large salt concentration, polarization sets in within
one minute, preventing normal operation, even at room temperature. This
run illustrates the importance of the study of the electrochemical
behavior of any new system in addition to its low temperature performance.
Table I summarizes the results obtained with this type
of low temperature activation. Only chloride salt solutions have been
used so far. The magnesium chloride solutions in particular are part of
the Mg/AgCl electrochemical system. Runs 7, 11 and 12 approximate the
minimum freezing point conditions for the MgC12 and CaCl 2 electrolytes.
Run 12, a duplicate of No. 11, has been added to illustrate the effect of
CaCl 2 electrolyte aging on the activation time and on the polarization.
Unfortunately we have had no opportunity as yet to verify this hypothesis
on aging.
The list of potentially interesting low freezing point
electrolytes tested so far (see Table I) is by no means complete and should
be extended. Garrett and his co-workers have suggested a variety of
A.B. Garrett and co-authors: J. Phys. Chem., 53, 505 (1949).
*
"Some Fundamental Studies of Electrolytes and Electrochemical Couples
Over the Temperature Range 25?C to -75?C".
F. Rakowsky; A.B. Garrett, J. Electrochem. Soc., 101, 117 (195+),
"Low-Temperature Electrolytes".
Declassified in Part - Sanitized Copy Approved for Release 2012/04/10: CIA-RDP78-03424A000500040003-1
 Declassified in Part - Sanitized Copy Approved for Release 2012/04/10: CIA-RDP78-03424A000500040003-1
?
?
LOW TEMPERATURE ACTIVATION
(Single Mg/AgCl Cell 1.2 inch2)
1/2 minute
Run
%
Initial
Initial
Short-Circuit
Activation
No.
Electrolyte
Concen-
Electrolyte
Case
Current
Time
Remarks
tration
Temp. ?C
Temp. ?C
Ampere
3
NaCl
3
+23
-20
0.6
1 minute
-
4
3
+23
-38
0.85
1 1/2
-
5
3
-1.5
-1+0
0.35
2
-
15
11
-9
-40
0.8
1 1/2
Solution clear with to
viscosity at -9?C; no
polarization
9
MgC12.12H20
11
-15
-1+0
0.6
1 1/2
-
7
22
-31
-41
0.45
4 1/2
Solution cloudy and
viscous at -31?C; some
polarization
13
CaC12.6H2
15.5
-18
-1+0
0.55
2
No polarization
11
31
-42
-40
0.3
5
Solution is cloudy and
viscous, not as bad as
No. 7 however; some
polarization
12
31
-42
-41
0.2
1
Solution 2 days old;
polarization*
Conceivably caused by carbon dioxide pickup from atmosphere.
?
?
Declassified in Part - Sanitized Copy Approved for Release 2012/04/10: CIA-RDP78-03424A000500040003-1
 Declassified in Part - Sanitized Copy Approved for Release 2012/04/10: CIA-RDP78-03424A000500040003-1
w a
additional systems that can be profitably investigated. Some of these
?
Aqueous Eutectic
Solution
Minimum Freezing
Point ?C
CaC12
-55
CaBr2
-83
CaI2
-77
Fe2C16
ca. -55
LiBr - MgBr2
ca. -59
LiBr - CaBr
Below -60
2
4+. Evaluation of Results
?
Calcium chloride electrolytes of the type used in Run 11
(Table I) hold out considerable promise of fulfilling the low temperature
requirements stated in Section II. In this instance, both the electrolyte
and the case can be maintained at environmental temperatures of -40?C
prior to activation. Since the storage of the chemical charges at low
humidity probably requires the use of a dessicant and since calcium
chloride performs this function very well, it is suggested that such a
Declassified in Part - Sanitized Copy Approved for Release 2012/04/10: CIA-RDP78-03424A000500040003-1
 Declassified in Part - Sanitized Copy Approved for Release 2012/04/10: CIA-RDP78-03424A000500040003-1
w ?
?
?
dessicant can serve a dual purpose in case low electrolyte temperature
activation is desired. The amount of dessicant packaged with the charge
to be dissolved in 11 ounces of water prior to activation, can be de-
termined by such activation requirements.
However, since only 11 ounces of electrolyte are re-
quired for activation, the initial temperature requirements for the
electrolyte may not be as stringent as those applicable to the case.
The other data listed in Table I become equally significant if a higher
electrolyte temperature is permissible. In general, it can be seen that
higher electrolyte temperatures permit the use of lower salt concen-
trations as well as substantially reduced activation times. Even run
No. 5, using seawater at its freezing point, activates quite well.
In summary it can be said that the exploratory tests
reported here and supplemented by others still to follow will be very
helpful in narrowing down the choice for large battery testing, parti-
cularly if a clarification of the significance of the initial electrolyte
temperature can be obtained from the sponsor.
B. Development of a New Cooling Method
1. Basic Approach
The reasons for the development of additional battery
cooling, particularly in conjunction with high temperature operation,
have been adequately described in Report No. 2. At a meeting with the
Declassified in Part - Sanitized Copy Approved for Release 2012/04/10: CIA-RDP78-03424A000500040003-1
 Declassified in Part - Sanitized Copy Approved for Release 2012/04/10: CIA-RDP78-03424A000500040003-1
w ?
sponsor on 22 October 1959, it was stipulated that such additional cooling
should preferably not require the use of accessories such as sand or a
water bath. Neither should it lead to an increase in size or weight of
the battery case. This requirement seems to rule out the use of cooling
fins. In view of these new restrictions and remembering also that a high
operating temperature of our special water-activated battery is not in
itself detrimental to its functioning, it was felt that the additional
evaporation of water might provide us with a satisfactory solution to our
cooling problem. The cooling effect produced by the heating and vapori-
zation of one gram of water added to the battery can be calculated to be
equivalent to 41 watt minutes of heat. Thus the dissipation of 100 watts
of heat by this process for a 20 minute period would require an additional
supply of water of 2, 000/41 = 49 gms, which is only 15 per cent of the
water required to fill the battery.
2. The Effect of Boiling on Electrical Output
Since the battery electrolyte contains more than 300 cm3
? of water the question naturally arises whether or not a boiling of the
electrolyte has a detrimental effect on the satisfactory operation of the
battery. Since such boiling has been observed to create foaming action,
special provision was made for preventing such foam from spilling over
the battery walls. In order to be able to study the effect of boiling
for a longer period the battery case was pre-heated to 65?C by an oil
bath. Figure 1 illustrates the results obtained on a 4-cell run No. 51.
Declassified in Part - Sanitized Copy Approved for Release 2012/04/10: CIA-RDP78-03424A000500040003-1
 Declassified in Part - Sanitized Copy Approved for Release 2012/04/10: CIA-RDP78-03424A000500040003-1
z
H a
4.0 25
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48
TIME (MINUTES)
USED SOLN.
BOILING
ADDED
FRESH SOLN.
ADDED
00
V
I
\
/
t
I
RUN #
51
1
? CURRENT AT 1.1 .n.
I I
--CASE TEMPERATURE
?
Declassified in Part - Sanitized Copy Approved for Release 2012/04/10: CIA-RDP78-03424A000500040003-1
 Declassified in Part - Sanitized Copy Approved for Release 2012/04/10: CIA-RDP78-03424A000500040003-1
W is
Assisted by the preheating, the battery temperature-
rises rapidly during the early part of the run. At 19 minutes after
activation "boiling" becomes noticeable although the battery temperature
is still below 100?C. This "premature boiling" is the result of the
hydrogen formation, the bubbles of which begin to grow substantially in
size already at a water vapor pressure slightly below atmospheric. As a
result of the presence of these bubbles inside the cells the internal
resistance of the battery increases and the load current drops. The foam
formation, which extends beyond the cell boundaries, may also increase the
? internal leakage of the battery markedly, which in turn generates more
heat. There may be a slight tendency for a chain reaction to develop.
During boiling, electrolyte is removed from the battery. This excess
electrolyte has a chance to cool down on the bench. At 33 minutes this
liquid was returned to the battery; boiling stopped entirely for about
one minute and normal output was resumed. At 34 minutes a second boiling
cycle begins. Several such cycles have been identified in Figure 1.
?
Obviously the performance of a battery with a boiling
electrolyte is very unsatisfactory, as can be seen from Figure 1, and it
is therefore not recommended? The only other alternative, consistent
with our basic approach, is the external vaporization of water.
Declassified in Part - Sanitized Copy Approved for Release 2012/04/10: CIA-RDP78-03424A000500040003-1
 Declassified in Part - Sanitized Copy Approved for Release 2012/04/10: CIA-RDP78-03424A000500040003-1
w ?
?
?
. The Effectiveness of External Vaporization
The necessary requirements for effective external
vaporization are as follows:
a. The external water storage capacity must be
adequate for this purpose to make it practical.
b. The contact between water and circulating air
must yield adequate vaporization.
c. The conductance of heat from the battery to the
site of vaporization must be excellent.
Figure 2 shows an enlarged cross-sectional view of the
standard battery panels, each provided with 11 slots, which are filled
with a highly porous, water absorbent substance such as cotton or wool.
The outer surfaces of these water filled substances act as evaporators,
while the ribs in between serve the following purposes:
1. They support the absorbers mechanically.
2. They prevent the absorbed water from
draining downward.
They conduct the heat efficiently from
the battery interior to the evaporating
surfaces.
It was found that more than 100 grams of water could
The heat transfer measurements described in Report No. 2
are admirably suited to test the efficiency of this new cooling device.
Examination of Figure 4 of that report shows that a battery temperature
of 80?C is reached at a heating level of 80 W and 88?C at 120 W.
Declassified in Part - Sanitized Copy Approved for Release 2012/04/10: CIA-RDP78-03424A000500040003-1
 Declassified in Part - Sanitized Copy Approved for Release 2012/04/10: CIA-RDP78-03424A000500040003-1
w
?
?
-
CROSS-SECTIONAL VIEW OF A BATTERY SHOWING
EXTERNAL VAPORIZATION
Declassified in Part - Sanitized Copy Approved for Release 2012/04/10: CIA-RDP78-03424A000500040003-1
 Declassified in Part - Sanitized Copy Approved for Release 2012/04/10: CIA-RDP78-03424A000500040003-1
w -
With the new external cooling feature added and with the laboratory air
circulating freely along the two battery case panels by means of natural
convection only, the same temperatures were reached at heating levels of
180 W and 250 W respectively. This corresponds to a substantial improvement
in heat dissipation equivalent to 100 - 130 W at these temperatures. The
water could no longer be made to boil at 250 W. At this heating level it
was desirable to replenish the external water supply at 25 minute intervals.
C. Phase 2, High Temperature Performance
? While to date no actual high temperature battery tests,
incorporating this new external cooling feature, have been made, the heat
transfer measurements, described previously, have been extended to include
high temperature environments. By means of hot plates and infrared lamps
a high temperature environment was simulated on the laboratory bench,
creating an equilibrium temperature inside the battery case of about
47?C. At an internal heating rate of 250 W the water temperature inside
the battery was viratually unchanged (87-88?C), although the external water
? supply required replenishment now at a rate of 16-19 minute intervals.
Hence the cooling appears to be more efficient at higher temperatures.
To make sure that such excellent cooling performance is not
influenced by our bench type arrangement, the equipment was moved into a
steam tunnel. Cooling tests were repeated at tunnel temperatures of
38-39?C with the same results. Again the battery temperature could be
stabilized at 87-88?C. Although no such tests have been made, it is felt
Declassified in Part - Sanitized Copy Approved for Release 2012/04/10: CIA-RDP78-03424A000500040003-1
 Declassified in Part - Sanitized Copy Approved for Release 2012/04/10: CIA-RDP78-03424A000500040003-1
FB, yip t O"r
L ~j d AL
?
that variations in the relative humidity of the air are not likely to
affect the cooling efficiency to any appreciable extent.
Incomplete information on the low temperature activation of
the "water"-activated battery leads to the following tentative conclusions:
a. The activating electrolyte must be a liquid.
b. Calcium chloride solutions at -40?C do activate the battery.
c. If it is permissible to use electrolytes at a higher
activating temperature, much lower salt concentrations
can be used and activation may be completed in 1 to 2
minutes.
d. The sacrifice in capacity resulting from low temperature
activation is small.
e. Once activated, the discharge proceeds normally provided
a reasonable load level can be maintained.
?
A new efficient cooling technique for improving the high temper-
ature performance of the battery has been developed. It is based on the
external vaporization of water and it does not require any accessories or
increases in size or weight.
Although no full-scale battery tests on phase 2 have been made,
it is felt that most technical problems encountered during this program
have now been solved.
Declassified in Part - Sanitized Copy Approved for Release 2012/04/10: CIA-RDP78-03424A000500040003-1
 Declassified in Part - Sanitized Copy Approved for Release 2012/04/10: CIA-RDP78-03424A000500040003-1
~A4 H U~ TJAL
Proposals for the extension of the present contract are pending.
Since.they do affect the plans for the next reporting period, nothing
definite can be said about them at this time.
?
?
In case no program changes are contemplated it is recommended
a. The high temperature performance tests, including the new
external cooling feature, be completed.
b. The design of the battery case be finalized and work on
phase 3 be initiated.
c. Completion of the low temperature activation and performance
program be postponed until the period after next.
Declassified in Part - Sanitized Copy Approved for Release 2012/04/10: CIA-RDP78-03424A000500040003-1