DE1771705C - Anhydrous electrolyte made from a solution of lithium perchlorate in tetrahydrofuran for galvanic elements - Google Patents

Description

of 50 mm, a width of 50 mm and a thickness only Tetrahydrofuian used «^ Jjjj ^^ ^u ^

of 1.8 mm for the four internal electrodes and a but ^'mmer ™ ^c _{Enereiespe} c} hervermögen per mass

Thickness of 1.2 mm for the two end electrodes and element A. uas , a & ^ ^ twice as large

Separators with a thickness of about 0.3 mm introduced, senemneit aes =. "= '-" Consideration of all

for example, from one opposite to the electrodes 5 such as that of the ^ Eleme «g» ^ ^ _opposite

insensitive felt made of cellulose or plastic ^Besta "J ^te i _n t _{h /} ke in the case of the element A by

fibers passed. These separators were between approximately uv WW _{electrolyte solvent} 250wh / kg

the electrodes of opposite polarity are used. Easily ChangingBleRtroiyi

The positive copper sulphide ^electrodes used with the ilK " ^l ? ^N \ f ¹ · _resistance d of 3 Ω discharged

were in accordance with the teaching of the French Pa- i ° Fur üas at a _{corresponding} to that for the

tentes 1 490 725 produced, with the addition of 2 to E again C was none ^ ^ _{immediatelyjgerl}

4% acetylene black to increase conductivity. Elements A eraeioar, _E , _{H d This} is a

The electrolyte of the element A consisted of a ^! "™ ^^ ₆ \ ^ Saer ρβα-irieninpfrdeii EntLösung from 110 to 115 g per liter of lithium perchlorate looking for de £ ^rn ° ™ ⁿ ^ _be [using the OF INVENTION-Tetrahydrofuian (that was about molar) and the i ₅ charging current the ma ^ *

However, the generators B and C from the glrichen solution at ^du ^ ^ ^sg LSI _n, t ° for elements among users, the tetrahydrofuran by a mixture ^Dl rfindun ^^ ^ n, ate electrolyte consequently much from _700/0 tetrahydrofuran and 30% dimethoxy - dung; d «« ^ W ™ ^^ _Eie inten. Ethane-1-2 was replaced. ^g w ^g ! c «“ Hnne can be the sitter at the same time

The elements A and B were re- _ao with ^the . ^E l ^. ^u ^ S _m sur be improved,

stood from 10 Q and the element C over a resistance ele ^ t ^ ta ^^ em ^ tu ^^ ^. ^

level of 3Ω discharged. , depending on the temperature

The voltage, in volts, was taken as the ordinate and the I * « ^A ^ ™ _cut H, as is the case with the

Discharge time, in hours, _{plotted as Abs ZI} sse. hch from 10 C notl ™ £ ° _{h drofuran} the case i, i.

It can be seen from the curves that the EIe-. a _S Losun ^ n with re mem ^

This electrolyte precipitates with that of the element A 3 °. according to the invention

comparable, where no very high concentration Furthermore M ^^ ™ * ™™ ^ ™ _not in

can be used so that when unloading ^^ Ä ^ SÄigU After 3 months

no. form insoluble salts. . ff ™ Sl s rlämHct only a loss of 5 to 10%

Even if the generator according to the invention was not found, it was only found to have a longer service life than element A, in which 35 was found.

1 sheet of drawings

Claims (7)

Geren polarization of the electrodes and thus to a patent claim: increasing the limit current of the polarization leads. The increase in the amount of dissolved lithium ions goes 1. Anhydrous electrolyte from a solution of lithium perchlorate with a better solubility Lithium perchloiate in tetrahydrofuran for galva- 5 hand in hand. This will interact too niche elements with negative lithium electrode, which improves the conductivity of the electrolyte. The characterized in that it works to the galvanic element accordingly under higher . Increase the solubility of lithium perchlorate voltage, and not just because its negative Contains dimethoxyethane. Electrode is less polarized, but additionally 2. Electrolyte according to claim 1, daduich gekenn- io also because its internal resistance is reduced. draws that the dimethoxyethane is a dimethoxy In the drawing, the invention is for example Ethane-1-1 is. shown, namely shows 3. Electrolyte according to claim 1, characterized. F i g. 1 a graphical representation of the maximum drawing, that the Dimethoxyäthan a Dime'thoxy- solubility curve of lithium perchlorate in one Ethane-1-2 i, i 15 Tetrahydrofuran (THF) -dimethoxyethane-1-2 mixture 4. Electrolyte according to claim 3, characterized at 25 ^J C, shows that the proportion of dimethoxyethane-1-2 in FIG. Fig. 2 is a graph of the same Solvent mixture is at most 60%. Curve for a tetrahydrofuran-dimethoxyethane-1- 5. Electrolyte according to claim 4, characterized by 1 mixture, records that the electrolyte is approximately 70% tetra-20 F i g. 3 is a graph of the conductivity of diofuran and 30% DimethJxyäthan-1-2 contains. speed curve of a mixture of 70% tetrahydrofuran 6. Electrolyte according to spoke 2, thereby marked and 30% dimethoxyethane-1-2 as a function of the drawn, that the electrolyte is about 54% tetra weight of the dissolved lithium perchlorate contains hydrofuran and 46% dimethoxyethane-1-1. and 7. Electrolyte according to one of the previous claims. 4 a graphical representation of the correspondences, characterized in that the charge curves of three galvanic elements,
thium perchlorate content between 100 and 250 g / l F i g. 1 and 2 show curves in which the ordinate is the electrolyte solution. the amount dissolved per liter of solvent mixture LiClO _{4 is} applied in grams. The percentage composition of the solvent is plotted as the abscissa. The curves increase with increasing proportion of dimethoxyethane The invention relates to an anhydrous electrolyte and a decreasing proportion of tetrahydrofuran ^ .n.
from a solution of lithium perchlorate in tetra- From these curves it follows that the LiClO ₄ hydrofuran for galvanic elements with a negative 35 is maximally soluble in the following mixtures:
Lithium electrode 70% tetrahydrofuran and 30% Oimethoxväthan-1-2 Electrolyte has already been proposed which (F ie D from a solution of lithium perchlorate in tetra- \, _ni %. _t . . - _ΑΑί - _Ο ι rv _m »* i" w ,, 3tho., 1 1 hydrofuran consists. 54% tetrahydrofuran and 46% dimethoxyathane-l-l With such an anhydrous electrolyte, 40 (F ¹ S- ² ) · in the case of small cells with only one positive elec- In practice, one advantageously uses one trode are equipped and an excess of free mixture based on dimethoxyethane-1-2 because Electrolyte have given good results. Do they show a higher concentration with the same perchlorate concentration Cells, however, more than one, in particular with a low conductivity, can be achieved. stood mutually arranged positive electrodes 45 F i g. 3 shows a curve from which the change in and only small electrolytes appear, the conductivity of a mixture of 70% tetrahydro- negative electrode has a polarization that functions on furan and 30% dimethoxyethane-1-2 insufficient transport of the lithium ions for the positive result from the mixture of the dissolved lithium perchlorate tive electrode is based. Additionally it decreases from about borrowed. The abscissa is the amount of material per liter 10 ° C the conductivity of the electrolyte with the temperature 50 mixed dissolved lithium perchlorate in grams and as temperature drops very quickly, while at the same time the lithium ordinate shows the conductivity in 10 ~ ³ Ω- ¹ er »- ¹ . perchlorate precipitates. gen. The maximum conductivity results from an un- The object of the invention is to avoid this approximately 250 g LiClO ₄ /! Solvent mixture, properties of the elec- F i g. 4 shows the discharge curves of three elements tiolyten, the solubility of lithium perchlorate to 55 A, B and C. An element A has an electrolyte raise. with pure tetrahydrofuran as solvent and is According to the invention, this task is thereby discharged via a resistance of 10 Ω. A EIelöst that the electrolyte additionally dimethoxyethane ment B hai an electrolyte with a solution contains. According to the invention, it can be a mixture of 70% tetrahydrofuran and 30% dimeth-dimethoxyethane-1-1 CH ₃ - CH - (OCH _a ) ₂ or around 60 oxyethane-1-2 and has a resistance of a dimethoxyethane-1 -2 10Ω discharged. One element corresponds to the egg η rn πι r » ru ment ß and is ent-CH ₃ -U-CH ₂ -CH ₂ -U-CH _{3 jaden Djese E} | via a resistance of 3 Ω _Elements were manufactured as follows: Act. In a parallelepipedic container made of plastic The anhydrous electrolyte, such as polyethylene or polypropylene, to which dimethoxyether was added, became five trolyt from a solution of lithium perchlorate in positive copper sulfide electrodes a length of Tetrahydrofuran has a vastly improved 50 mm, a width of 50 mm and a thickness of Solubility of lithium ions, wp.s to a small 1.5 mm, six negative Liihiumelectrodes one length