JP3406683B2 - Composition capable of producing anode of alkali metal or alloy thereof by thinning - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to additives which can be used as or are part of a film-thinning lubricant. The present invention also relates to compositions containing these additives, which can be used in the thinning of sheets such as lithium to obtain thin films which, by themselves, can be used in the production of polymer electrolyte electrochemical cells. Furthermore, the present invention provides the thin film of an alkali metal or its alloy, which can be used as an anode in an electrochemical cell preferably using a polymer electrolyte, and therefore, the above-mentioned additive itself, or its additive Relates to the use of a composition containing The present invention also relates to a thin film forming method using the above additive or a composition containing the additive as a thin film forming lubricant.

[0002]

2. Description of the Prior Art Having a thickness of less than 75 μm, eg 5c
Producing a thin strip of lithium with a width of m or more and a length of a few tens of meters by a rapid and reliable method is due to the extreme physical and chemical properties of this metal: chemical reactivity, malleability, It encounters significant technical difficulties resulting from rapid self-adhesion by simple contact and strong adhesion to most solid materials such as ordinary metals. Such difficulties are
From a supplier of specialty metals and chemicals, having a suitable surface finish and chemical properties for use in lithium batteries,
With sufficient surface and length, thickness of 40 micrometers (μ
m) Confirmed by the difficulty of obtaining the following lithium thin films.

Currently, the cold extrusion method is used for continuous production of sheets of 75 μm and above. These thicknesses are
It is often applied to the manufacture of lithium batteries using liquid electrolytes. The film obtained by extrusion is then thinned between rolls made of hard material in order to reduce the thickness. These methods have been described for commercial production of finite quantities of 30-75 μm sheets and are in commercial use. In particular, the inventor
Reference may be made to U.S. Pat. No. 3,721,113 issued Mar. 20, 973. Depending on the current state of the technology, 40-
Multiple successive passes are required to obtain a 30 μm film.

Other approaches have been described for obtaining ultrathin film sheets used, for example, in the manufacture of polymer electrolyte batteries in the form of thin films. This is the case in the method of thinning between steel rolls protected by a thin film of hard plastic that is non-reactive with lithium, as described, for example, in US Pat. No. 3,721,113, Or the inventor of Entre Berlanger, 1989, 4
This is the case for the method based on the application of molten lithium on the metal of a plastic support as described in US Pat.

For the production of polymer electrolyte batteries
The difficulty in thinning lithium to a thickness varying between 5 μm is mainly due to the thinned metal and the components in contact with it: thinning roll, protective plastic thin film, reaction with thinning additives Property and adhesion, and poor physical properties of thin sheets. For example, thickness 20μm and width 1
A 0 cm lithium thin film cannot be released from the thinning roll if the thin film emerging from the thinning machine is pulled or the lithium adheres to the thinning machine to some extent. It breaks under a tensile force of 579.13 KPa or more. .
The methods commonly used for the widespread thinning or rolling of hard metals such as iron and nickel are based on the use of liquid thinning additives consisting of organic solvents which may also contain greases or lubricants. By way of example, fatty acids such as lauric acid or stearic acid or their derivatives,
And alcohols, such as linear mixture of primary alcohols of _C 10 _{-C 12,} there is a compound known under the trade name EPAL1012 ethyl Koporesoyon United States.

The use of such additives for lithium, and especially for lithium directed to electrochemical cells, presents two major difficulties. : 1) Chemical reactivity of lithium in contact with solvents or lubricants having reactive organic functional groups such as organic acids and alcohols. These functional groups react on the surface of lithium during and after thinning, creating a passivated thin film on the surface of the metal. This impairs the good operation of the latter, especially when trying to recharge electrochemical cells; 2) the difficulty of removing the lubricant or grease in contact with lithium after thinning. This is the case, for example, when a lubricant consisting mainly of hydrocarbon chains is used because it reacts very little with lithium. These compounds constitute electrically insulating materials which impair the good operation of the lithium electrodes made of sheet. Such lubricants are poorly soluble in polymer electrolytes and should therefore be removed from the surface of lithium by post-thinning washing.

In addition to the fact that cleaning the surface of lithium is a sensitive and expensive operation, this work also involves cleaning the surface of lithium, even if all precautions are taken to control the quality of the metal surface. It will be one of the causes of pollution. In fact, the latter reacts irreversibly, including water, with all impurities present in the wash solvent or resulting from accidental contamination.

It can be seen that the lithium obtained by the thin film treatment with the additive followed by the subsequent washing is generally more contaminated on the surface than the thin film lithium without the additive. This phenomenon can be observed by optical means, including simple visual inspection, or by controlling the impedance of an electrochemical cell made with a polymer electrolyte. On the other hand, thinning without solvent or lubricant means low production rate and new lithium tends to stick to the roll or the protective thin film of the roll; Many continuous thinnings are needed to achieve the desired thickness.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to thin or roll a lithium sheet to a thickness of between 40 and 5 μm, which can be used directly in thin film lithium batteries, for example polymer electrolyte batteries. To solve the problem.

It is also an object of the present invention to provide a lubricious additive that is chemically compatible with lithium and can be used in a thinning process without the need for subsequent cleaning of the thinned lithium surface.

Another object of the present invention is to provide a composition comprising a film-forming lubricant containing a suitable solvent and a dual-acting additive.

Another object of the present invention is to improve the method of thinning lithium in the presence of improved lubricants.

Another object of the invention is the extremely thin lithium,
For example, lithium with a thickness of 10 μm or less is 50 m / m
Surface properties at appreciable rates up to and above in. Excellent properties of uniform surface condition and low impedance of the inactive layer when the sheet thus produced is used in an electrochemical cell. The purpose is to provide a lubricious additive for thinning which can be controlled and produced in a single pass.

Another object of the present invention is to provide a film-thinning lubricant that includes an additive and a solvent selected for chemical application with lithium for electrochemical cells.

In the description and claims of the present invention, the chemical compatibility of a solvent or additive with lithium in an electrochemical cell is that it does not react with lithium or
Or react slightly, lithium in the above battery / electrolyte
A passivation thin film is formed at the interface, but for electrochemical exchange
It has no effect.

Another object of the present invention is to use it for thinning.
In the chemical formulation of the lubricant for This lubricant is
As-is, i.e. electrochemically without pre-cleaning
Lithium sheet ( anode ) when used in batteries
Of lithium after thinning the film without damaging the good operation of
It is selected so that it can be held on the surface . Another object of the present invention is to provide an excellent thin film forming method utilizing the additive according to the present invention.

[0017]

SUMMARY OF THE INVENTION The present invention is directed to at least two segments having different chemical properties: a solvate capable of ionic dissociation, at least in part, of a metal salt of, for example, a metal salt of lithium, such as a chain segment of ethylene polyoxide. Based on the selection of high molecular weight lubricious compounds having chains or chain segments with a lubricating action (L) made of hydrocarbon chains with chains (S), eg having at least 8 carbon atoms. The solvating segment present in the lubricating additive is selected to impart ionic conductivity to the lubricating additive. A preferred method of inducing the ionic conductivity of the lubricating additive is obtained when the thin film lithium contacts the battery electrolyte (solvated polymer lithium salt), but is not limited to this method. Next, the salt present in the electrolyte diffuses in the solvated portion of the additive to locally form a composite conductor (solvated chain salt).

The lubricant according to the invention contains at least one sequence: L-Y-S, where L is saturated or unsaturated, preferably alkyl, alkylene, straight-chain or cyclic having 8 or more carbon atoms or Represents a hydrocarbon residue such as aryl-alkyl,
And used as a lithium compatible lubricant segment; S represents an oligomer segment having a heteroatom such as O or N, which makes it possible to solvate salts such as lithium salts and to ensure electrolyte conductivity; Y represents a chemical bond or a chemical group that is at least divalent and bonds the chain or the chain segmets L and S. Solvation battery Segmet S
Can be attached to an end group C selected on the basis of its low reactivity with lithium to form the sequence LYS-C. C has, for example, a valence of 1 or more,
A Y'-L 'group which is the same as or different from the Y-L group, an alkyl group,
Alternatively, it represents an alkyl-aryl group. Alternatively, C is a polymerizable group that can be incorporated into at least one of the repeating units that make up the polymer electrolyte of the electrochemical cell. In another variation, C contains an ionophore group that can dissociate slightly and induce an intrinsic ionic conductivity in the additive. Examples of polymeric solvating chains are described in the following patents: Micelle by the inventor dated December 1, 1981
U.S. Pat. No. 4,303,748 to Armando et al. And U.S. Pat. No. 4,578,326 to Micelle Armando et al. Dated March 25, 1986. ethylene
Oxide _{- [CH 2 -CH 2 -O]} n -, propylene
Oxide _{- [CH 2 -CH 2 (CH} 3) -O] n or poly - (N-methyl - ethylene - imine) - _[CH 2 -C
Chains based on H ₂ —N (CH ₃ )] n or combinations thereof are generally preferred, but other solvating functional groups can also be used if they can induce ionic conductivity in the lubricating additive. . When the hydrocarbon segment originates from a fatty acid, the bond Y is an ester (L) -CO-O-
It is preferably composed of (S) or ether (L) -O- (S) groups. Y can also represent an amine or amide group.

In a preferred embodiment of the invention, the segment can correspond to a hydrocarbon chain of a fatty acid having at least 8, preferably 10 to 30 carbon atoms. For example, L may consist of a hydrocarbon chain of a fatty acid such as stearic acid, Y may be an ester or ether type chemical bond, or it may represent a carboxylate group resulting from a fatty acid ester. In another preferred embodiment of the invention, segment S may consist of a 150 molecular weight polyether or polyamine. In another preferred embodiment of the invention, the terminal group C can also comprise a chemical functional group capable of covalently fixing a metal salt, for example a lithium salt. In another preferred embodiment of the invention, the chemical bond C can comprise a lithium salt which is chemically grafted by anions or by one or more desaturations. The invention also resides in a lithium thin film having a thickness of 5 to 50 μm coated with a thin film of the above-defined additive.

Another aspect of the invention is prepared from a sheet of lithium coated with a thin film of the above-defined additive, having a thickness of between 5 and 50 μm, and chemically reacting the lithium alloy or the lithium insertion compound. It relates to a lithium-based anode in direct contact with a sheet having a metal or carbon that can be formed.

The present invention also forms the electrolyte conductor of the composite, produced as described above, by free diffusion of the lithium salt present in the electrolyte and by diffusion, together with the chain S of the additive which may be soluble in the electrolyte. A polymer electrolyte electrochemical cell with a lithium anode .

In another embodiment of the present invention, the use of an additive or composition as defined above for producing by thinning thin films of alkali metals or their alloys used as anodes in polymer electrolyte electrochemical cells. Regarding

Finally, the present invention obtains a thin film from the above-mentioned metal or its alloy sheet by passing a sheet of an alkali metal or its alloy together with a lubricant for thinning it between work rolls to thin the sheet into a thin film. In the thin film method described above, the lubricant contains an additive or composition as defined above. A particularly preferred additive is polyoxyethylene distearate with a solvating segment molecular weight corresponding to about 150-4000.

The composition according to the invention is preferably from 0.01 to
It contains 10% by weight, more preferably 0.2% of additives. The solvent is selected from saturated or partially saturated linear, cyclic or aromatic hydrocarbons such as heptane, benzene, toluene, cyclohexane or mixtures thereof. It is also selected from aprotic solvents compatible with lithium.
A particularly advantageous formulation is L-based on diesters of fatty acids.
Y-S-Y-L type compound system, for example, n is preferably 3
100 of _{CH 3 - (CH 2) 16} - (COO- (CH
_{2 -CH 2 -O) n - OC} (CH 2) 16 consists in the use of polyether glycol stearate, such as -CH ₃ compound. Compounds containing polyether segments having molecular weights of 200, 400 and 600 are preferably from POE Science, POE 400 Aldrik No. It is marketed as 30541-3. The stearate segment has excellent lubricating properties and its hydrocarbon chain is inert towards lithium: in this case,
The bond Y is secured by the carboxy group of the starting fatty acid. Moreover, the terminal group C has the same segment Y'as L-Y.
-L '.

The central polyether chain of the low molecular weight distearate POE200 is lubricated at ambient temperature when a lithium salt such as Li (CF ₃ SO ₂ ) ₂ NLi is added at a ratio of O / Li of 30/1. To compound 1 × 10
^-5 S.I. It has been observed to be sufficient to give an ionic conductivity in the order of cm. This value is sufficient to ensure ion exchange at the lithium / electrolyte interface of the electrochemical cell, taking into account the small thickness of the lubricant left over after thinning.

Such preferred formulations are given by the possible embodiments of the invention. Other lubricating and solvating functional groups L and S are used as well as the other bonds Y. The following references dealing with solvated chains are helpful, but not limiting. Polymer Electrolyte Review 1, Jay. R. Maccarlum & Sea. A. Vincent ed
s. Elsevier Applied Science London (1987); Polymer Electrolyte Review 2, Jay.
R. Maccarlum & Sea. A. Vincent e
ds. Elsevier Applied Science London (1989); Solid Polymer Electrolyte, F.M., Greybishich Publisher New York, Weinheim (1991); and Surface Active Ethylene Adducts,
Buoy, Shaw Enheld Topper Magon Press, (1
966).

The preparation of additives according to the invention is well known to the person skilled in the art and need not be discussed at length here. Once the solvation and lubrication chains are established and the choice of chemical bonds to be used is made, all skilled chemists will have no problem synthesizing the desired additives. During thinning, the lubricant according to the invention is compatible with lithium, preferably linear, saturated or partially saturated, or cyclic aromatic hydrocarbons such as heptane, benzene, toluene, cyclohexane or any other pre-dehydrated aprotic acid. It is generally preferred to dilute with one or more solvents which are organic organic solvents or mixtures thereof. This dilution makes it possible to reduce the required amount of lubricant to a minimum and to obtain an optimum quality of lithium for use in electrochemical cells. These solvents are dehydrated in advance with, for example, molecular sieves to obtain a water content of 100.
Reduce to less than ppm. The additive concentration can be up to about 10% by weight, for example 0.01 to 10% by weight, preferably 0.2% by weight. Addition of lubricant to the solution is done in a controlled manner just before thinning between rolls. The thinned film is immediately dried at the exit of the roll using dry air in a continuous operation and then wound with or without a separator thin film of an inert plastic, preferably propylene or polyethylene.

The present invention will be described with reference to the accompanying drawings, but the present invention is not limited thereto. A lithium sheet 1 having a thickness of about 250 μm wound around an unwinding drum (not shown) is passed between two work rolls made of polyacetal. Sufficient pressure to reduce the sheet thickness by about 90% is applied over the two rolls in the directions indicated by the marks 7 and 9. At the entrance of the sheet between the film-thinning rolls, a film-forming lubricant 11 such as toluene is injected into the injection pipe 13.
Pour from.

At the exit of the two thinning rolls, the lithium sheet is transformed into a thin film 15 about 25 μm thick. On the other hand, the thin film 15 is a roll 3 which forms an angle α of about 90 with the contact point 17 between the two rolls 3 and 5.
Remains adhered to the surface of the roll 3 over a predetermined limit point 19 on the circumference of. The membrane 15 is then wound on a take-up drum (not shown) with sufficient tensile force determined experimentally to move the membrane 15 on the one hand from point 19 to point 21 where operation is continued without any change. .
Typically, the angle β formed at point 21 is about 45 °, and this angle will vary depending on the circumference and the desired properties of the lithium film 15. An advantageous method of carrying out the invention is a co-application with which one between two rolls of hard plastic is
It is described in a patent application relating to a method of thinning a film in multiple passes. This method, which is preferably performed in a single pass, is based on adjusting the adhesion on one of the plastic rolls to pull the lithium through the preferred corners and adjusting its inherent flatness.

Other thinning methods using metal rolls can also be performed using these additives. Therefore,
The metal roll can be precoated with a lubricant to minimize adhesion. However, the concentration and chemistry of the additive according to the invention should be adjusted as a function of the intended production rate. These additives are also applicable to thin films of lithium-rich alloys such as lithium-boron or lithium-magnesium alloys or other alkali metals such as sodium and sodium-lead alloys.

The methods, compositions and additives according to the invention are
The lithium anode when the residual film is soluble in or electrolyte is conductive for use in a liquid electrolyte battery
It can be applied to the soil of the production. Similarly, the method and additives according to the invention can be used for chemically produced anodes based on lithium alloys or carbon-lithium.

The following chemicals can be advantageously used as additives according to the invention, but are not limited thereto. Molecular weight of solvation segment is 200,4
00, and 600 polyoxyethylene distearates, such as Aldrich 30541-3 distearate 400. Nonionic surfactant: from Aldrich
It is a commercially available product, and the catalog number of Aldrich Co. is 85,836-6 Brij (registered trademark) 35 23,599-7 Brij (registered trademark) 58 23,600-4 Brij (registered trademark) 78 23, 865-1 Igepal (registered trademark) CO-
720 23,896-4 Igepal (registered trademark) DM-
The product that is 970 .

Other possible products are: Distearates (dilaurates, dipalmitates, dioleates) of the following: POE (200,4000 molecular weight) Polypropylene glycol (725,1000,2)
000,3000) -Pluronic (registered trademark) (OE-OP bl
oxs) -polyoxytetramethylene (polyTHF (registered trademark
) ) (650, 1000, 2000) POE dihexadecyl ether (200-4000)
Molecular weight) POE dicholesterolyl carbonate (200-4
000) POE tristearate (laurate, palmitate, oleate), triol (200, 4000)
(DKS (registered trademark) ). The next thing of monostearate (laurate, palmitate, oleate) -Brij (registered trademark) 35, Brij (registered trademark)
58, Brij (registered trademark) 78-Igepal (registered trademark) CO-720, Igep
al DM-970 Poly-methacrylate of oligo-oxyethylene-monolauryl ether.

It is often preferable to use a lithium compatible solvent to dilute the lubricating additive. The latter are preferably linear hydrocarbons. Additive concentration is 10-20%
Also be less than (weight ratio) and 0.05% (by weight)
I can .

The lithium produced using the additives according to the invention is used by itself in polymer electrolyte batteries. Canadian Patent Application No. 2,068,290-6, filed May 8, 1992, describes one method of making a complete battery and various methods of providing electrical contacts on a sheet of lithium. Is listed. In these cases, power
By diffusion of lithium salt from the electrolyte thin film of the pond,
The thinning additive becomes ionic conductive .

In some cases, the residual layer remaining after lubrication is more or less dissolved or dispersed in the electrolyte, for example when the electrolyte is of low molecular weight or contains a liquid aprotic solvent.

[0037]

EXAMPLES The present invention will be described with reference to examples, but the present invention is not limited to these examples.

Example 1 In this example, the effect of the preferred additives according to the invention on thinning was carried out during a continuous operation in one pass in order to obtain a lithium thin film of less than 30 μm.
The apparatus used is that shown in FIG. 1 and thinning was carried out in an anhydrous atmosphere with a relative humidity of less than 1%. The roll is made of polyacetal and has a diameter of 20 mm; the starting lithium consists of extruded sheets 250 μm thick. If necessary, the solvent and the additives were also dehydrated in advance with a regular sieve so that the water concentration was less than 10 ppm.

As a first step, lithium having a width of 57 mm was continuously thinned to reduce its thickness to 25 μ per pass. If the lubricating liquid is not used during thinning, lithium will immediately adhere to the roll and cannot be properly processed; if hexane is added, thinning can be achieved unless the rate of reduction of the sheet thickness is significantly reduced. could not.
At best, it was treated so as to obtain 90 μm of lithium in one pass, but the flatness of the thin film was extremely poor in this case. Therefore, hexane, as used in the prior art, did not have sufficient lubricating properties to use it by itself to obtain less than 25 μm of lithium in a continuous process.

Lubricating liquid consisting of toluene 8 ml / min
When a thin film was formed by adding it onto an extruded sheet having a width of 57 mm at a speed of 5 mm, lithium could be thinned to 25 μm in a continuous operation, and a maximum speed of 5 m / min was obtained. As illustrated in FIG. 1 of the patent application, the thinned film was also adhered to a quarter of the height of the upper roll (45 ° angle). By this operation, the tension applied to the free thin film could be adjusted sufficiently, and lithium having excellent inherent flatness could be obtained. Therefore, a length of 10 to 20 m could be obtained by continuous operation. Suddenly change toluene to hexane during operation
This resulted in a momentary increase in lithium thickness up to about 90 μm , resulting in lithium of very poor intrinsic flatness.

The advantage of the additive according to the invention is that the width is 143 m.
m, 250 μm thick obtained by using extruded lithium. Pre-test equipment is distearate PO
A solution containing E200 (molecular weight) at a concentration of 0.2% (weight ratio) and a hexane to toluene ratio of 9: 1 was used. Excess lubrication solution was added onto the extruded sheet at a rate of 6 ml / min. Under these conditions, the lithium thin film 22μ having excellent intrinsic flatness has a thickness of 20 m / m2.
It was obtained by a single pass at a thinning rate of min or more.
Moreover, this sub-optimal method made it possible to produce rolls of thinned sheets with a length of 300 m or more and a constant thickness of about 2 μm. The following example is
Current resistance is high, the loss or interruption in the process to ignore
Wear. Also, more important production is from thin rolls of extruded lithium or directly from the extruder.
You can start with the supplied ones .

Example 2 22 μ of lithium produced using the additive of Example 1
m was used as the anode of a lithium battery operating at 60 ° C. The appearance of lithium is excellent, it shines without any coloration, and Dektak (registered trademark) (VEECO
U. S. A. The surface contour determined from the model 3030) of No. 3030) fluctuated within 3 μm. In this laboratory experiment, a lithium sheet was lightly placed under pressure on a thin nickel sheet to ensure current collection. The electrolyte used consisted of a copolymer of ethylene oxide and methyl glycidyl ether and a polymer electrolyte consisting of a lithium salt with an oxygen lithium ratio (O / Li) of 30/1, (CF ₃ SO ₂ ) ₂ NLi. . The composite cathode consisted of vanadium oxide and carbon black dispersed in a polymer electrolyte and had a capacitance of 5 C / cm ² . The active surface area of the battery thus constructed was 3.9 cm ² . The initial impedance of this battery at 60 ° C is 15Ω.
That is, it was equal to or lower than the best lithium on the market. The cycling characteristics of this cell using the lithium of Example 1 are excellent after 100 cycles, and the cell utilization is at least as good as a similar cell made from commercial lithium, or initially stabilized after 10 cycles. It was about 90% of the value. From this example it was determined that the presence of non-volatile POE distearate remaining on the surface of lithium did not harm the good functional groups of the battery. This result is explained by the electrolyte conductivity caused by the presence of the POE solvating segment of the additive or by the chemical compatibility with the lithium of the battery. In another test, the electrolyte conductivity of the additive was determined by salt content (CF ₃ SO ₂ ) ₂ NL.
If i is 30/1, then about 1 × 10 ⁻⁵ S.I. cm.

COMPARATIVE EXAMPLE 1 In this comparative example , the impedance of a symmetrical cell Li ° / polymer electrolyte / Li ° made from lithium thinned without additives and when coated with an excess of various possible lubricating materials. It was measured at 25 ° C. The amount of lubricant used per surface unit of lithium was 0.03 mg / cm ² . This value corresponds to an excess of lubricant compared to the amount required for thinning according to Example 1, but the intended purpose is to amplify and enhance the electrochemical effect of the various additives. The impedance value of the battery having an active surface area of 3.9 cm ² was measured . A battery was also manufactured by using the electrolyte of Example 1 under vacuum and hot pressing.

The results for the various materials used are as follows: Impedance 1) POE200 (molecular weight) distearate 113 Ω 2) POE600 (molecular weight) distearate 113 Ω 3) Pure stearic acid 840 Ω 4) Molecular weight 500 pure POE 139 Ω The measured values confirm the effect of the POE segment on the electrolyte conductivity of the additive and that stearic acid, which is often used as a conventional metal thinning lubricant for use in electrochemical cells, is lithium. It was concluded that was not compatible with.

Comparative Example 2 In this comparative example , 250 μ to about 30 μm per pass.
The effects of various known thinning additives on the lubricating properties of lithium thinning efficiency up to μ were compared. For these comparisons, thinning was initiated under the same conditions as in Example 1 using POE200 distearate as an additive. When thinning, the composition of the solution was changed by replacing the distearate POE with other additives. The effect of the addition was immediately known according to the thickness of the thinned lithium thin film, its inherent flatness and its appearance. When the solution containing distearate was replaced with the ethyl stearate solution at a concentration of 0.15% (weight ratio) , the thickness of lithium suddenly increased from 40 to 90 μm, and the intrinsic flatness of thinned lithium was lost. . Lubricant EPAL (registered trademark) 1012 (C
When changed to a thinning solution based on (O linear alcohol), the thickness of the thinned lithium gradually increases beyond 65 μm, and the obtained lithium becomes sticky at the center of the roll. , On the other hand, the side surface became irregular (undulations).

When the thinning solution of POE5000 in toluene was changed, the thinned lithium thickness rapidly increased to 90 μm with an inherent loss of flatness. These tests act as lubricants and demonstrate the importance of stearate-based formulations with functional groups such as POE-based solvating functional groups. Also preferred, but not exclusively, of these formulations are superior to pure POE-based additives from a thin filming standpoint, even if the electrolyte conductivity properties are appropriate in this case as shown in Comparative Example 1 .

Example 3 In this example, other conditions were the same except that the POE stearate was replaced with another compound of the present invention. The two compounds used are dicholesterolyl carbonate of POE 600 (molecular weight) and dipalmitate of POE 4000. In the two cases, the thinning rate can be maintained and the thinned lithium thickness is about the same. In these two cases, the inherent flatness of lithium is maintained. These examples confirm the generality of the formulations which combine solvation and lubrication.

EXAMPLE 4 In this example, the general formula L-Y-S-C (where C is an additive L-Y-S-C contains a dissociative metal salt that imparts an ionic conductivity specific to the additive L-Y-S-C). directed to compounds having the ionophore group)
And The thin film of lithium, for example, the electrolyte salt
The anion of this salt chemically binds to the polymer chain
Compounds of this type are important as thinning additives when intended for use in batteries . In this case, the lubricating additive should have an ionophore effect to prevent the formation of insulating deposits on the surface of the lithium, as the lithium salt is not likely to disperse.

BRIJ® Type 35 Nonionic Tension-Activator, Polyoxyethylene 23 Lauryl
The ether C ₁₂ H ₂₅ (OCH ₂ CH ₂ ) ₂₃ OH is sulfonated by the following method: 12 g BRIJ.
(Registered trademark) 35 was dried by azeotropic distillation using benzene and then freeze-dried. After addition of 50 ml THF, the terminal OH groups were metallated with sodium hydride in the presence of 5 mg triphenylmethane. Stoichiometry was determined by colorimetry, the end of the reaction _{(C 6 H 5) 3 C} - shown in intense red anion. Then 1.4 g of 1,4 butane sulfone was added. After evaporating the solvent, a powdered sulfonated oligomer was obtained. A suspension of 5 g of the product thus formed in 15 ml of acetonitrile was treated with 1 ml of thionyl chloride and 20 μl of dimethylformamide. A 20 mg sodium chloride precipitate was formed. From filtered, and the SOC ₂ solvent and excess evaporated under reduced pressure. The residue was solubilized with 30 ml pyridine and added to 1.2 g bis (trifluoromethanesulfonyl) methane sodium salt. After filtration, the reaction mixture was charged with 1 g of lithium phosphate Li ₃ P.
Stirred in the presence of O ₄ . By filtering once more, a colorless solution which became a wax upon concentration could be separated. This substance has a tension activity for lubrication and ion conduction.
ive) characteristics. When this substance was used under the conditions of Substantial Examples 1 and 5, it was possible to form a thin film of lithium under the same conditions. This embodiment is not limited only to this, and other equivalent substances having an ionic function capable of dissociating to some extent can be used.

Example 5 Extruded sheet 1 having a thickness of 250 μm and a width of 143 mm was used as a starting material. The latter was placed on the unwinding drum and passed between the work rolls 3 and 5 to wind the thin film on the winding drum. Sufficient pressure was applied to the work roll to thin the sheet. These rolls are made of polyacetal and have a diameter of 20 mm. The sheet was placed on the device between work rolls. The pressure on the roll was increased to reduce the sheet thickness by about 90%. Lubricant 11
Was added on the sheet at a rate of 6 ml / min. The lubricant and solvent, this solvent 9: 1 ratio of dry hexane and toluene and the following formula _{CH 3 - (CH 2) 16} - (COO-
_{(CH 2 -CH 2 O) n} -OOC (CH 2) 16 -CH
₃ (where n is a polyether segment is 20
Selected to have a molecular weight of 0) 0.2
% (Weight ratio) It consisted of a mixture with the addition of POE200 distearate.

The thin film was adhered to 1/4 of the height of the work roll to sufficiently control the tension applied on the work roll. The pressure applied to the roll is controlled and the thickness is 25 per pass.
A lithium thin film having a uniform thickness of 300 μm and a length of 300 μm was obtained. As a result, it is known that it can be operated in continuous mode without failure. This additive has a thinning rate of 20 m / min
Can be increased to obtain a good quality thin film of lithium.

[Brief description of drawings]

FIG. 1 is an explanatory view of a method for producing a thin film by thinning a sheet of retium in the present invention.

[Explanation of symbols] 1 Lithium sheet 3 work rolls 5 work rolls 7 arrows 9 arrows 11 Thin film lubricant (or toluene) 13 injection tube 15 Thin film of lithium 17 Roll contact point Limit point on the circle of 19 rolls 21 Point where operation is continued

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI // C10N 50:02 C10N 50:02 (72) Inventor Paul-Emile Guerlain Quebec Je8 Te 3 E 7 Coupe Canada La Madeleine Ryu La Triille 109 (72) Inventor Michel Armand Grenoble 38410 France San-Marten D'Urger Blodre Corzion (No address) (56) Reference JP-A-7-299504 (JP, A) Sho 63-241859 (JP, A) Special Table 1-503661 (JP, A) US Patent 3721113 (US, A) US Patent 4949566 (US, A) (58) Fields investigated (Int.Cl. ⁷ , DB) Name) H01M 4/12 H01M 4/04 H01M 4/40

Claims (32)

(57) [Claims] 1. A thinning lubricant containing at least one solvent and generally non-volatile additives.
In a composition capable of producing an anode of an alkali metal or its alloy by thinning, the above-mentioned additive is added.
The general formula is : LY-S, where L represents a hydrocarbon residue having 8 or more carbon atoms that can serve as a lubricating segment, S is capable of solvating a metal salt, and The additive represents an oligomer segment having a heteroatom of O or N capable of ensuring the electrolyte conductivity, and Y represents a bond or a chemical group that bonds the hydrocarbon residue L and the oligomer segment S.) A composition having at least one of the following sequences: 2. The oligomer segment S is electrochemically
At least one of the repeating units that make up the polymer electrolyte of the battery
A terminal group C which is a polymerizable group that can be incorporated into
The composition of claim 1, wherein the composition binds to 3. The oligomer segment S is linked to the terminal group C.
Combined, the terminal group C has the formula Y'-L '(where, L' lubrication Se
8 or more carbon atoms that can serve as
Represents a hydrocarbon residue having Y; Y'is a hydrocarbon residue L '
And a chemical group that connects the oligomer segment S with
The composition according to claim 1, wherein a shown). 4. The composition according to claim 1, wherein L represents a straight-chain or cyclic alkyl or alkylene group which is saturated or unsaturated and has 8 or more carbon atoms. 5. Composition according to claim 1, characterized in that S represents a chain based on ethylene oxide, propylene oxide or poly (N-methylene-ethylenediamine) or combinations thereof. 6. The composition according to claim 1, wherein Y represents a divalent chemical group. 7. The composition according to claim 6, wherein Y represents —COO— or —O—. 8. The composition according to claim 2, wherein C represents an ionophore group. 9. The composition according to claim 2, wherein C represents a polymerizable group or a group which can be incorporated into at least one of the repeating units constituting the polymer electrolyte. 10. The additive has the formula: CH ₃ — (CH ₂ ) ₁₆ — (COO— (CH ₂ —CH _{2
-O) n -OOC (CH 2)} 16 -CH 3 ( where, n is the composition according to claim 3, characterized by being represented by.) Indicating 3-100. 11. The composition according to claim 6, wherein Y comprises an ester, ether, amine or amide group. 12. A composition according to claim 1, wherein L corresponds to a hydrocarbon chain of a fatty acid having at least 14 carbon atoms. 13. L comprises a hydrocarbon chain of fatty acid, and Y
Represents a carboxylate group derived from a chemical bond of the ester or ether type or a fatty acid ester. 14. The composition according to claim 1, wherein S comprises a polyether or polyamine having a molecular weight of 150 or more. 15. The composition according to claim 1, comprising oxyethylene or oxypropylene. 16. Composition according to claim 2 or 3 , characterized in that the C group is alkoxy, alkyl, acryloyl or methacryloyl. 17. The composition of claim 3, wherein Y'-L 'is the same as Y-L. 18. The composition of claim 3, wherein C comprises a chemical functional group capable of covalently bonding to the anionic portion of the metal salt. 19. The composition according to claim 18, wherein the metal salt is a lithium salt. 20. The composition of claim 3, wherein the terminal group C comprises a lithium salt chemically bound through the anion of the lithium salt by one or more unsaturations. 21. The additive has a solvation segment of 150-150.
A composition according to claim 1, characterized in that it comprises a distearate of polyoxyethylene corresponding to a product having a molecular weight of 4000. 22. The composition of claim 1 containing about 0.01-10% by weight of additives. 23. A composition according to claim 22, which contains about 0.2% by weight of additives. 24. A lithium sheet having an anode thickness of 5 to 50 μm and coated with a thin film of the additive as defined in any one of claims 1 to 23. 25. Addition according to claim 1, which has a thickness of 5 to 50 μm and is in direct contact with a sheet containing carbon or a metal capable of chemically forming a lithium alloy or an insertion compound of lithium. Lithium, characterized by being manufactured from a lithium thin film coated with a thin film of agent
The anode . 26. The lithium ano prepared according to claim 25 , wherein a free lithium salt is present in the electrolyte so as to form a composite electrolyte conductor by diffusion with the S chains of the additive.
The electrochemical cell of the polymer electrolyte containing over de. 27. A lithium anoate produced using the additive of claim 1, wherein the additive is soluble in the electrolyte.
An electrochemical cell characterized by comprising a battery. 28. An electrochemical cell having a polymer electrolyte.
Which can be used as the anode of
A method for manufacturing a gold thin film by thinning,
A method for producing a thin film using the additive or composition according to item 1. 29. A sheet of alkali metal or its alloy is passed between work rolls together with a lubricant for thinning to thin the sheet to form a thin film. From the sheet of alkali metal or its alloy, the metal or its alloy is formed. A method for producing a thin film according to claim 1, wherein the lubricant contains the additive or the composition according to claim 1. 30. The composition according to claim 1, wherein the solvent is selected from linear saturated or partially unsaturated, cyclic or aromatic hydrocarbons. 31. The composition of claim 30, wherein the solvent is selected from heptane, benzene, toluene, cyclohexane or mixtures thereof. 32. The composition of claim 30, wherein the solvent is selected from lithium compatible aprotic solvents.