DE2257383C2 - Device for storing metal / oxygen cells - Google Patents

Description

The invention relates to a device for storing metal / oxygen cells with an im essential gas-impermeable container with at least one window made of a material containing hydrogen lets through, but prevents the passage of oxygen, carbon dioxide and water vapor, for implementation of the process according to DE-PS 21 08 847.

The main patent relates to a method of storage at least one metal / oxygen cell prior to use, placing the cell in a sealed container is arranged, which is designed so that on the one hand at least part of the container at least one passes such an amount of hydrogen that the container will not be damaged during the period of storage that but on the other hand oxygen and water. be prevented from passing through the container.

For most metal / oxygen cells, ζ. Β. Zinc / air cells, will be used during storage before use by corrosion of the zinc anode (negative electrode) with the electrolyte, e.g. B. potassium hydroxide, hydrogen developed. If the cell is not protected, the water in the electrolyte solution will tend to evaporate and reduces the life of the cell. Furthermore, it is advisable to prevent carbon dioxide from entering the cell as this will cause carbonization and reduce cell performance. It has found that oxygen, when it enters the cell through the air electrode (cathode = positive electrode) can occur, in the electrolyte is dissolved and tends to oxidize the zinc anode, the corrosion of the anode and thus continue to reduce the useful power of the cell.

In the case of galvanic primary elements, it is already known to design the envelope in such a way that gases can pass through However, hydrogen is retained to protect the cell from internal gas pressure or from To protect drying out (OE-PS 2 68 403, FR-PS 12 1.3 467, US-PS 27 29 693).

The object of the invention is to create a device with which metal / oxygen cells are stored without affecting the life and performance of the cells.

JO

■ 35 According to the invention, this passes to a device for storing metal / oxygen cells with a substantially gas-impermeable container having at least one window made of a material containing hydrogen, however, the passage of oxygen, carbon dioxide and water vapor prevents achieved in that the window consists of polyethylene and polypropylene laminate

Further features of the invention are the subject of the subclaims.

The invention is described below in conjunction with the figures on the basis of some exemplary embodiments explained The figures show:

F i g. 1 is a side sectional view of a container,

F i g. 2 is a graph of diffusion velocities of hydrogen in various laminates made of polyethylene and polypropylene,

F i g. 3 is a graph of diffusion rates of oxygen in various laminates made of polyethylene and polypropylene,

F i g. Figure 4 is a graph of diffusion rates of carbon dioxide in various laminates made of polyethylene and polypropylene,

Figure 5 is a graphical representation of water vapor transfer rates with various laminates made of polyethylene and polypropylene,

Figure 6 is a graph of the thicknesses of Polyethylene versus polypropylene, the different requirements for the diffusion rate for Storing an N-size metal / oxygen cell,

F i g. 7 and 8 representations similar to those of FIG. 6 for different containers to store 24 and 22 D-size metal / oxygen cells,

9 and 10 are graphical representations of memory test results for N-size cells which be stored at different temperatures, and

Figures 11 and 12 are graphical representations of memory test results for D-size cells which be stored at different temperatures.

In Fig. 1 shows a container for a metal / oxygen cell, which has a rigid top 11 made of Made of polyethylene or polystyrene. The pot 11 has a sufficiently large wall thickness that it is against gas is largely impermeable. A metal / oxygen cell (or metal / oxygen cells) is (are) in the pot arranged, and a closure 12 is provided as a lid over the pot 11. The end 12 made of laminate can be heat sealed to the pot 11 or glued to it.

The basic requirements for storing metal / oxygen cells are briefly as follows: Oxygen UnJ carbon dioxide should not reach the cells, any hydrogen that has occurred should escape and enter Transfer of water into or out of the electrolyte should not be permitted.

Practical requirements for storing an N-size cell in a container of FIG. 1 having an opening of 1.85 cm ² are given below.

Choice of materials
In a cell of N size:

Zinc weight = 2.2 g,

Electrolyte volume = 0.70 cm ^J.

3 4

The desired capacity loss per year is smaller (in cm ² ) that is available for diffusion than 10% at 20 ^o CT5 ° C. ie

hydrogen

/ 2.47X10 " ³ 3 _,.,. -,

(- cm m "tag 'atm

\ A

It is achievable the speed of the capacity water vapor

Loss due to hydrogen evolution to 5%

limit per year, pin value of 10% per year The allowable loss or gain of water from

however, it is allowed. From the reaction: io the electrolyte is chosen to be 0.05 g year-'

The diffusion rate must be less than
Zn + 2OH- + 2H ₂ O> Zn (OH) 4 ² ~ + H,

° ^'05 _E m ~ ³ Tae''

develop 65.3 g zinc 22400 cm ³ hydrogen, 0.22 g ^ xi0 " ⁴ x365 ^B '

Develop zinc 15

where A is the area of the surface of the container

22400X0.22 _cm3 _ ^ ^ ^ ₃ hydrogen closure (in cm ² ), which is used for diffusion to

65.3 ', d. H.

Assuming that the partial pressure of hydrogen is 20 / 1-37

inside the cell container is 0 (oxygen from the \ A

Cell used up), is the partial thickness of nitrogen

0.79 atmospheres and the partial thickness of hydrogen is carbon dioxide

0.21 atmospheres.

If one thus assumes a constant velocity r, one assumes that the electrolyte is 8M KOH (i.e. the hydrogen evolution, the hydrogen difference must be 448 g ltr- '), and that a one percent conversion to the fusion rate through the container closure Kabonar is permissible
be greater than:

-jy _ag -i

cm ³ m " ² day"'atm-'"> 1000 100

" ⁴

365X0.21 X / 1X10 "

converted from KOH to carbonate, d. H.

where A is the surface area of the 0.0031 g of KOH.

Closure (in cm ² ) is that for diffusion to the reaction:

Available is ü

The hydrogen diffusion rate must be greater than 2KOH + CO ₂ > K ₂ CO ₃ + H ₂ O

be greater than

₃ 112 g of KOH react with 22400 cm 'of CO ₂ . In order to

9.85X10 _cm - ³ _m ~ ² day'3tm ^! . ^{must the} volume of CO ₂ , which through the container

A 40 termination diffused, be smaller than:

Oxygen χ 0.0031 cm 'year' '

112 A capacity loss of less than 10% per year

is required, 5% per year is allowed for j-, d. H. <0.62 cm "'year'.

Hydrogen evolution, and therefore the loss must The partial pressure of CO ₂ = 4 x 10 ⁴ atm.

due to the oxidation of zinc to less than 5%. The diffusion speed must be less than

be reduced per year.

Zinc reacts with oxygen according to the reaction equation- ° ^ 6J, _2,,

chung ν. 365X4X10 ^J X / IX1O ^{4 g atm} '

2Zn + O ₂ + 4OH "+ 2 H ₂ O> 2Zn (OH) ₄ ² 'where A is the area of the surface of the jacket

(in cm ι is available for diffusion, 130 g of zinc react with 22,400 cm 'of oxygen d. Ii.

0.11 g zinc react with -, -,

4.25 XIO ⁴ ,., _T. , _,

22 400; ^{Lnl m} "< ^a £ ^atm ·

^X ° ' ^llcm ^ ¹⁸ - ^9cm ' · '

The following diffusion velocities must therefore

The partial pressure of oxygen outside the cell can be met by the sheathing material:
mantels is 0.21 atmospheres.

The rate of diffusion of oxygen through hydrogen> iJeSOMcn ^ m ^ Tag-'atm- ¹
the coat must be smaller than: Oxygen <2470 // 4cm ³ m- ² day- 'atm-'

Water vapor <1.37M gm - ² day - '

IN THE. _cm ' _m ² Tae' atm '* -, carbon dioxide <42500/4 cm ³ m ² day-' atm ¹

365X0.21 x Λ x. 1.0 '

For a surface of 0.85 cm ² the diffusion conditions are the following:

Hydrogen> 5319cm ^J m ² day 'atm' oxygen <I332cm ³ m ² day 'atm' water vapor <0.65 ^{gm 'day 1} carbon dioxide <23800cm' m ² day - 'atm -'

Around this relatively low water vapor transfer rate To achieve this, it seems appropriate to use a layering of polyethylene and to use another footage.

The diffusion velocities of different gases m through polypropylene and polyethylene, expressed in 0.025 mm material thickness, are shown below.

Assume that the diffusion rates for a laminate have the following relationship suffice:

I.
Pr

= V

Polyallene polypropylene

W.isv.-rstolT 18 800

Oxygen 8 4 (X)

kohlendmxyil 26 200

Water vapor 1.8

15 (K) O cm'm day

2 000 cm 'm ■ fag

7 5 (K) cm 'm' fag

2.0 g in lukewarm ^:

It is

Pi ^ - the diffusion rate of the laminate P ₁ = the diffusion rate of the / th component of the laminate.

Then the diffusion speed of the different gases through laminates can be different Thickness of polyethylene and polypropylene can be calculated and tabulated as follows:

al water streak / dilusion velocity cm ni lay ' atm

Thickness \ on pole \ .illnlen Tuesday cke from PoK propylene I in (l.l 125 πιπί) 1.0 1.5 2.0 In the O.o: . ■ "m πι ι Il 0.

(X) 30 (KKl :> 000 10,000 7 5 (X) 18 8 (X) 1 1 557 > '343 6 528 5 361 9 400 7 157 5 77 ') 4 345 4 172 6 267 5 184 4,420 3 853 3 414

hl Saucriloff diffusion speed cm m Tat; atm

IKke sop l'fi!; .. tlh>! En thickness of polypropylene (in 0.025 ninil 1 .n u. (I25 πίπι!

11 0.3 11.5

(l.ft

1.0

1.5

2.0

00 6 667 4 f XX) 3 333 2,000 1 333 1,000 8 400 3 717 2 "UO 2,386 1 615 1 150 894 4 20fi 2 577 2 04 ') 1 858 1 355 I 012 808 2S (X) 1 972 1 W " 1 522 I 167 903 737

The carbon dioxide diffusion sea velocity m 'm "Tasi aim

D ..; ■ • on PoK ;; lh ",! cn thickness \ ηπ Polypropylene (in 0.025 mm ι 1.0 1.5 2.0 ! ; n 05 m m ι 0 0.5

dl water vapor transfer rate g · ττΓ "day

00 15,000 7 500 5,000 3 750 26 200 9 539 5 830 4 199 3 280 13 100 6 993 4 770 3 619 2915 8 733 5 520 4035 3 180 2,624

Thickness of polyethylene Thickness of polypropylene (in 0.025 mmi (in 0.025 mm 1

0 0.1 0.2

0.4

0.5

1.0

1.5

2.0

00 20.00 10.00 6.667

18.00 9,474 6,429 4,865

3,600 3,051 2,647 2,338

5,000 4,000 2,000 1.333 1,000 3,913 3.2 ⁷ 3 1,800 1.241 0.947 2,093 1,895 1,286 0.973 0.783

continuation

Thickness of polyethylene thickness \ on l * ol> pr <ip> part (in 0.025 mim (in 0.025 mm)

0 0.1 0.2

(1.1

1.0

1.5

2.0

1,800 1,651 1,525 1.417

0.900 0.861 0.826 0.793

0.600 0.58.3 0.566 0.550

1,324 1.241 0.947 0.76 (i 0.643 0.763 0.735 0.621 0.537 0.474 0.536 0.522 0.462 0.414 0.375

From these tables it is possible to determine the diffusion rate of different gases across the thickness of polyethylene for different thicknesses of Apply polypropylene as shown in Figs. 2. 3. 4 and 5 for the diffusion rate of hydrogen. Oxygen, carbon dioxide and water vapor shown.

When using the F i g. 2. 3. 4 and 5 it is then possible to determine which .Laminates of polyethylene and polypropylene are required to meet the diffusion conditions for each gas shown above fulfill. E.g.

Hydrogen> 5319cm ^! m -'day 'atm ^!
Oxygen <I332cm'm -Tag 'atm'
Carbon dioxide <23800cm ³ m ~ ² day 'atm-'
Water vapor <0.65 gm ² day- '

and thus F i g. 6, which shows the laminates that meet the diffusion conditions.

(N. B. All laminates with> 0.0125 mm polypropylene meet the condition for carbon dioxide diffusion).

In Fig. 6 the line 13 means the condition for the Oxygen diffusion rate, where the area to the left defines that the oxygen diffusion rate is too high. Line 14 gives the condition for the hydrogen diffusion rate at. where the area above line 14 specifies that the hydrogen diffusion rate is too low is. Line 15 specifies the water vapor transition rate, with the area below the line 14 specifies that the water vapor transfer rate is too high. The area 16, which is defined by the lines 13. 14 and 15 is enclosed, indicates the material thickness. which together meet all the requirements for the specific examples chosen.

From Fig. 6 the following table can be seen, which shows the laminates of polyethylene and polypropylene which meet the requirements for a cladding for a cell of N-size, which has a surface area of 1.85 cm ² , which is available for diffusion.

Thick polyethylene Thickness is polypropylene (in mm ι (in mm) 0.0255 0.0493-0.0505 0.0280 0.0469-0.0483 O3O5 0.O437-O.O465 0.0330 0.0410-0.0445 0.0355 O.O385-O.O425 0.0380 0.O355-O.O4O5 0.0405 O.O33O-O.O388 0.0430 O.O3O3-O.O368 0.0455 0.0272-0.0348 0.0480 O.O268-O.O328 0.0505 0.0262-0.0308 0.0530 0.0255-0.0290 0.0555 0.0247-0.0268 0.0580 0.0242-0.024 ~

A sample of 0.0505 mm thick polyethylene and that of 0.0305 mm thick polypropylene were used was coated. and the following diffusion rates were obtained.

Laminate requirements

Hydrogen 5,439> 5,319

learn 'm ~~ day' atm ') oxygen 1 183 <1 332

(cm "m ~ ² day" ¹ atm ') carbon dioxide 3 564 <23 800

(cm * m ~ ² day " ¹ atm"') Water vapor 0.45 <O_65

(g m ~ ² day ')

this laminate is shown to give satisfactory storage of N-sized cells in a 1.85 cm ² pot available for diffusion.

N-sized cells were assigned for storage

different temperatures in pots with a laminate made of 0.0505 mm thick polyethylene and 0.0305 mm thick polypropylene was made to cover the pots and the following were made Results obtained after a discharge at a constant current of 40 mA:

At storage temperature

8.V »Utilization of the entire / inks ~ - 100" l.aclungshcihehiiltuni '.

Number of checked / rushed

Utilization of zinc ","" Charge heating retention " \

\ usiHii / ung von Zink ".-. Lailungsbeihehaltimg " ■ <

Utilization of / ink 'I charge accomodation " >

Utilization of zinc "· charge exposure" '■>

Utilization of zinc '"retention of charge " ■ <

Utilization of zinc '\, charge ho ibc ha I tu ng "n

Exploitation of Zinc ',. Charge retention \

Exploitation of zinc ^Λ .. charge retention '. »

Exploitation of zinc "· ό Ladungsheibchalt'.ing" .o

Exploitation of zinc \ charge retention ', «

Use of zinc.

79

82

P 102

79

S3 K) O

82 98

92

78 94

75 91

73 88

76 92 83 83 86 100 100 104

S3 SS

106

82
98

79
95

SO
96

77
93

75
91

80
96

82 9S

85

K) I 102

S3 85

102

81 97

80 96

79 95

75 91

80 96

S3 S3

10 (1 K) O

S.

S7

9 ~

79 95

82 S3

98 K) O

6 over

0 weeks

3 over 8 weeks

1 over

12 weeks

6 over 16 weeks

6 over 20 weeks

6 over 24 weeks

6 over 28 weeks

6 over 32 weeks

5 over

36 weeks

6 over

40 weeks

7 over

44 weeks

From the graphic representation of FIG. 9 that the reproduces the above results, it can be seen that the mean loss of capacity from a cell 10% per year when stored at 20 ± 5 "C.

^ 5

AuMiul / ung

40 -] ι

/ ink- - HXi Ludungsheihehaltune

Number ye Γ "lifter / rush

Zinc utilization% 83 85 Charge retention% 98 100

Utilizing zinc charge retention

79 83 93 98

Utilization of zinc% 80 82

Charge retention% 94 97

Utilization of zinc% 80 81

Charge retention % 94 96

3 over O weeks

3 over

4 weeks

3 over 8 weeks

3 over Ϊ2 weeks

storage ■ ^ temperature 85 'exploitation; λ η number 40 ± I ( of the entire audited / inks - 100 ". / rush Cargo heating reverberation

Utilization of zinc \ 81

Charge retention% 96

Zinc utilization% 80

Charge retention% 94

Exploitation of Zinc ". ■ 80

Charge retention% 94

Utilization of zinc% 78

Charge retention % 92

Zinc utilization% 67

Charge retention% 79

A usnutzung of zinc 70%

Charge retention% 82 9ö

81 3 over 96 14 weeks

81 96

77 90

3 over 16 weeks

81 3 about

96 18 weeks

84 3 over

99 20 weeks

78 3 over

92 22 weeks

3 over 24 weeks

continuation

Kl 'I (

X5 "^; . Λι · ΜΐιιΙΛΐιιμ
ties throughout
/ inks ΙΟΙ!

Λ η /; ihl

audited

/ ollen

hchiiltunj!

Utilization of zinc% 70 I over

Charge retention% 82 26 weeks

Utilization of zinc% 71 73 75 3 over
Charge retention% 83 86 88 28 weeks

Utilization of zinc% 62 71 74 3 over
I. Cage retention% 73 S3 87 30 weeks

From the graph of FIG. 10 showing the reproduces the above results, it can be seen that the mean loss of capacity from a cell 30% per year when the cell is at 40 ± I'C is saved.

These results show that the penetration of oxygen around carbon dioxide and the passage of Water vapor has been satisfactorily controlled and that hydrogen generated in the cell. can come off the pot. Another example of the present invention relates to storage of 24 D-size cells in one box:

The box dimensions are 33.4x12.8x8.9 cm ³ .

The box fits into a plastic container with a surface area available for diffusion of 34 × 10 cm ² = 340 cm ² , a zinc weight = 744 g, an electrolyte volume = 521 cm ¹ . and a target capacity loss per year of less than 10% at 20+ 5 ° C.

If one carries out calculations similar to those for the cell with N-size (see above), Establish the following requirements (carbon dioxide does not pose a problem):

Hydrogen 9800 cm ³ m- ² days' atmosphere ^;
Oxygen <2450cm ³ m- ² day- 'atm- '
Water vapor <1.98 gm- ² day- '

Using Figs. 2. 3. 4 and 5 then it is possible to apply Fig. 7, the layers of Shows polyethylene and polypropylene that meet all diffusion requirements.

From Fig. 7 can be found in the following table. which are the laminates of polyethylene and polypropylene shows the requirements for a casing for a battery in a box with 24 D-sized cells and with one for diffusion to the

Thick vim PoI) UtIn i

Uli 111 111 I.

You. kc vim l \>! \; ΐ | -ιιρ> lon
Im in in I.

0.020.10
0.02286
0.0254 (1
0.027 ¹ M
0.03048
0.03302

0.01575-0.0231
0.01524-0.02130
O.OI475-O.OI9O
0.0140 -0.017v /
0.0135 -0.01624
0.0130

A sample of 0.01524 mm thick polypropylene coated with 0.03048 mm thick Polyethylene obtained and the following diffusion rates were achieved:

Laminate

requirements

hydrogen Il 224 Jl . ^ • 9 8 (hi cm m Day ^! ι In Oxygen 2 163 <: 2 450 cm ' m ·' Day ' atm Steam I. <1.98 g m 'Day ^!

These values / inherent that the laminate has a satisfactory preservation of the case-mounted D-size 24 cell battery results.

In another example with a different box with 22 ½ inches of D-size, the box dimensions were 23 8 χ cm ³ .

The box fits into a plastic container with a surface area available for diffusion of 23 × 14 cm ² = 322 cm ² , the zinc weight = 682 g, the electrolyte volume = 374 cm ^! and the capacity loss per year at 20 ± 5 ⁵ C = <10%.

By making calculations similar to those for the N-size cell, the following can be obtained Define requirements:

Hydrogen 9450Cm ³ In -'Tag'atm '
Oxygen <2360 cm ³ m - -Ί ag 'atm'
Water vapor <1.90 gm - day '

Using the FIG. 2. 3, 4 and 5 it is then possible to apply Fig. 8, which shows the layers of polyethylene and polypropylene. welc ^: · meet all diffusion requirements.

The table below results from FIG which shows the laminates that meet the requirements for this boxed battery with one for the Fulfill the available area of 322 cm- 'for diffusion.

Available surface of 340 cm- meet. tin mm) "Thick \ on polyethylene
f ι ti m TTl \ Thickness of polypropylene Thickness of polyethylene Thickness of polypropylene UIlIH Π11 fill III Il If (in mm) 0.0254 -0.0393 0.02286-0.0370 0 0.0275 -0.0403 0 0.01955-0.0353 μ) 0.00255 0.0247 -0.03875 0.00255 0.01953-0.0330 0.00505 0.02155-0.03675 0.00505 Ο.Ο18ΟΟ-Ο.Ο313 0.00762 0.01955-0.03475 0.00762 .0.01750-0.0293 0.01010 0.01880-0.03275 0.01010 0.01675-0.0272 0.01270 0.01830-0.03075 0.01270 0.01625-0.0254 _B 5 0.01524 0.01750-0.0280 0.01524 0.01778 0.0170 -0.0264 0.0i 77S 0.02030 0.0165 -0.0244 0.02286 0.0 ί 60 -0.0223

22 57 13th Thickness of polypropy en 5 Cargo retention door! 80 80 383 14th I. 85 87 6 about storage is carried out at 20 ± 5 ° C. of total zinc = 100% number of cells tested 77 80 80 85 85 6 about (in mm) % 74 76 100 100 Storage of this battery is satisfactory 106 109 0 weeks Storage temperature 40 ± I C "80% utilization Charge retention 96 1 00 100 106 106 0 weeks continuation / o 93 95 83 83 Similar calculations to the above show that 85 88 6 about % 72 60 60 71 71 5 about 0.01550-0.0203 % 76 8 i 104 104 a laminate of 0.01524 mm thick polypropylene 106 110 4 weeks Exploitation of zinc % 90 75 75 89 89 4 weeks Thickness of polyethylene 0.01475-0.0183 95 101 77 78 and 0.03048 mm thick polyethylene also die 80 5 over Charge retention % 60 61 62 62 64 68 6 about (in mm) 0.01425-0.01625 10 % 66 74 96 98 Requirement for single D-size cells in one 100 8 weeks Exploitation of zinc % 75 76 77 77 80 85 8 weeks 0.0135 -0.0140 % 82 93 83 84 Container with one available for diffusion 84 87 6 about Charge retention % 60 71 71 72 73 74 6 about 0.02540 % 68 70 104 ! 05 standing surface area of 9.65 cm ² 105 109 12 weeks Exploitation of zinc % 75 89 89 90 91 93 12 weeks 0.02794 0.01524 mm thick polypropylene ^J / o 85 87 74 75 Single D-size cells were found at under 80 80 6 over Charge retention % 65 76 76 76 76 78 6 about 0.03048 ! en and 0.03048 mm thick polyethylene met again Storage temperature 20 ± 5 C 80% utilization of the % 70 74 93 94 different temperatures in pots with 0.01524 mm 100 100 16 weeks Exploitation of zinc % 81 95 95 95 95 98 16 weeks 0.03302 to meet these requirements and thus shows that he is responsible for the I. > / "87 93 82 thick polypropylene / 0.03048 mm thick polyethylene 3 over Charge retention % 76 Exploitation of zinc % 78 82 102 Laminate lid with a surface area of 9.65 cm ^: 20 weeks Exploitation of zinc % 95 The laminate from Charge retention / o 98 102 81 81 arranged and after a discharge at 1 A. 83 83 84 85 8 about Charge switching Exploitation of zinc 73 81 101 101 Constant current the following results were achieved: 104 104 105 106 24 weeks Charge retention '/ o 91 101 83 total zinc = 100% number of cells tested 3 over Exploitation of zinc % 76 77 104 28 weeks Charge retention / o 95 96 71 3 over Exploitation of zinc % 66 69 89 32 weeks Charge retention h 82 86 Representation according to FIG. 11, which shows the above results, shows that the average capacitance Exploitation of zinc loss of energy from a cell is 9% per year if c Charge retention Exploitation of zinc Charge retention Exploitation of zinc Charge retention Exploitation of zinc Charge retention Exploitation of zinc Charge retention Ausdergraphic

16

continuation

Storage temperature 40 ± 1 C

8 (1 "» utilization of the entire zinc = 100%
LaUungsbeibchaliung

Number of cells tested

Zinc utilization%
Charge retention%

Zinc utilization%
Charge retention%

Zinc utilization%
Charge retention%

From the graph of FIG. 11 showing the The above results show that the mean capacity loss from one cell is 9% per year, when stored at 20 ± 5 ° C.

From the graph according to FIG. 12 that the reproduces the above results, it can be seen that the mean capacity loss from a cell is 17% per Year if it is stored at 40 ± Γ C is made.

46 54 56 63 84 58 68 70 79 105 57 58 76 71 73 95 71 73 89 91

5 over
20 weeks

3 over
24 weeks

2 over
28 weeks

Another example of the present invention relates to the storage of a cell of A-A size. If calculations similar to the above are performed, a plastic container can be used with a surface area of 2 ^ 5 cm available for diffusion is used for storage will. The lid material again consists of 0.01524 mm thick polypropylene layered ml ·. 0.03048 mm thick polyethylene.

Here / u 8 Bkitt drawings

Claims (3)

Patent claims: 1. Device for storing metal / oxygen cells with a substantially gas-impermeable Containers with at least one window made of a material that allows hydrogen to pass through, however prevents the passage of oxygen, carbon dioxide and water vapor to carry out the Method according to DE-PS 2108 847, characterized in that the window is made of laminate made of polyethylene and polypropylene 2. Apparatus according to claim 1, characterized in that the window has a closure for the Represents container 3. Apparatus according to claim 1 or 2, characterized in that the container has the shape of a Rigid pot or box with a lid representing closure for the pot or box has, and that the closure made of polyethylene / polypropylene laminate consists