JPH07302592A - Composition from which anode of alkaline metal or its alloy can be manufactured with thinning of film - Google Patents

Abstract

PURPOSE: To provide a composition capable of manufacturing a positive electrode of an alkali metal or its alloy by thin filming. CONSTITUTION: This composition includes a lubricant for thin filming containing at least one kind of solvent and a generally non-volatile additive, the additive is adopted to lithium and expressed by the following general formula L-Y-S (L is a hydrocarbon residue-useful as a lubricant segment, S is an oligomer segment useful as a solvation segment for a metallic salt, and Y shows a chemical bonding for bonding the hydrocarbon residue and an oligomer segment). When the additive is employed, rinsing a surface of thinly filmed lithium is not necessary following thinly filming.

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 a thin film of an alkali metal or an alloy thereof that can be used as an anode in an electrochemical cell that preferably uses a polymer electrolyte, and therefore contains the above-mentioned additive itself, or contains the additive. Related to the use of the composition. 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. Still for the purpose of reducing the thickness, the filim obtained by extrusion is then thinned between rolls made of hard material. 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 generator refers to the lithium / electrolyte interface of the battery described above. , A chemical reaction with lithium or the absence of a restricted chemical reaction that forms a passivating film that is not harmful in the electrochemical exchange.

Another object of the invention is not volatile,
Selected so that it can be retained on the surface of lithium after thinning without sacrificing the good performance of the lithium sheet (anode) when used by itself in an electrochemical cell, ie without prior cleaning. It resides in the chemical formulation of lubricants for use in thinning. 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 LY-S-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) over [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 provided that 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 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 may 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 comprising a lithium anode.

In another embodiment of the 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
It consists in the use of polyether glycol stearate, such as _{-CH 2 -O) n -OOC (CH} 2) 16 -CH 3 compound. Molecular weight of 200,400 and 6
A compound containing a polyether segment of 00 is commercially available from Polyscience, preferably as POE 400 Aldrik N ° 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'-L 'as L-Y.
Consists of.

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.
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 solvating and lubricating chains have been established and the choice of chemical bonds to be used can be 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 may be dehydrated in advance with, for example, a molecular sieve to obtain a water content of 10
Use less than 0 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 thin film formed into a thin film is immediately dried at the exit of the roll by a continuous operation using dry air, and then an inert plastic,
It is preferably wound with or without a separator thin film of 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 thin films of other alkali metals such as sodium and sodium-lead alloys.

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

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: Catalog number

[Table 1] Aldrich Commercial ICI US BRIJ

[Outer 1]

Other possible products are: Distearates (dilaurates, dipalmitates, dioleates) of: -POE (200,4000 molecular weight) -Polypropylene glycol (725,1000,2)
000,3000) -Pluronic [external 1] (OE-OP block
s) -polyoxytetramethylene (poly THF) (65
0,1000,2000) POE dihexadecyl ether (200-4000)
Molecular weight) POE dicholesterolyl carbonate (200-4
000) POE tristearate (laurate, palmitate, oleate), triol (200, 4000)
(DKS). Monostearate (laurate, palmitate, oleate) of the following: -BRIJ (35,58,78) -Igepal (CO-720, DM-970) Polymethacrylate 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%
P / P and less than 0.05% P / P.

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, the thinning additive becomes electrolyte conductive by diffusion of the lithium salt from the battery's electrolyte thin film.

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. A rapid change from toluene to hexane during operation resulted in an instantaneous increase in lithium thickness up to about 90 μm, resulting in a very poor intrinsic flatness of lithium.

The interest of the additive according to the invention is 143 m wide
m, 250 μm thick, by using extruded lithium. Pre-test equipment is distearate P
A hexane-toluene ratio 9: 1 solution containing OE200 (molecular weight) at a concentration of 0.2% P / P 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 / mi.
Obtained by a single pass at a thinning rate of n or higher. On top of that, this method, which is not yet optimal, results in a thickness of about 2
It was possible to produce rolls of thinned sheets with a length of 300 m or more, which is constant in μm. Subsequent productions are highly reproducible from one test to another, and the degree of process loss or process interference can be neglected; therefore, more important production is therefore relatively long rolls of extruded lithium. It can be started directly from the extruder, either from the feed to the thinning rolls.

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, the lithium shines without any coloring, and Dektak [external 1] (VEECO U.V.
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 consists of vanadium oxide and carbon black dispersed in a polymer electrolyte,
It 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 cell at 60 ° C was 15Ω, which was equal to or lower than that of the best commercially available lithium. 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
It is explained from the electrolyte conductivity caused by the presence of the POE solvating segment of the additive or from the chemical compatibility with the lithium of the battery. In another test, the electrolyte conductivity of this additive was 30 / salt content (CF ₃ SO ₂ ) ₂ NLi.
1 is about 1 × 10 ⁻⁵ S. cm. Is.

Example 3 In this example, the impedance of symmetrical cells Li ° / polymer electrolyte / Li ° made from thin film lithium 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 cell with an active surface area of 3.9 cm ² was given. 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.

Example 4 In this example, 250 μ to about 30 μ per pass.
The effects of various known thinning additives on the lubricating properties of lithium thinning efficiency were compared. For these comparisons, thinning was initiated under the same conditions as in Example 1 using POE200 distearate as an additive. When forming a thin film, change the composition of the solution to distearate P
It was changed by replacing the OE 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 an ethyl stearate solution at a concentration of 0.15% P / P, the lithium thickness suddenly increased from 40 to 90 μm, and the intrinsic flatness of the thinned lithium was lost. When changed to a thin film-forming solution based on the thin film-forming lubricant EPAL [external 1] 1012 (CO linear alcohol) of ethyl corporation,
The thickness of thinned lithium gradually increased over 65 μm, and the obtained lithium became tacky at the center of the roll, while the side surface became irregular (undulations).

When changing to a thinning solution based on POE5000 in toluene, the thinned lithium thickness rapidly increased to 90 μm with an inherent flatness loss. 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 though the electrolyte conductivity properties are appropriate in this case as shown in Example 3.

Example 5 In this example, other conditions were the same except that the POE stearate was replaced with another compound of the invention. The two compounds used are POE600 (molecular weight) dicholesterolyl carbonate and POE4000 dipalmitate. 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 6 In this example, the general formula L-Y-S-C (wherein C is a dissociative metal capable of imparting an ionic conductivity specific to the additive L-Y-S-C). Compounds according to the invention having an ionophore group according to (including salts) are described. This type of compound is important as a thinning additive when thin filmed lithium is to be used, for example, in batteries where the electrolyte contains a salt in which the anion is chemically bonded to the polymer chain. Is. In this case, the lithium salt should not disperse and the thinning additive should have an ionophore effect to prevent the formation of insulating deposits on the surface of the lithium.

BRIJ35 [external 1] type nonionic tension-activator, polyoxyethylene 23 lauryl ether C ₁₂ H ₂₅ (OCH ₂ CH ₂ ) ₂₃ OH is sulfonated by the following method: 12 g of BRIJ 35 [ Outside 1]
Was dried by azeotropic distillation with benzene and subsequent freeze-drying. After addition of 50 ml THF, the terminal OH groups were metallated with sodium hydride in the presence of 5 mg triphenylmethane. Stoichiometry was measured colorimetrically and the end of the reaction was indicated by the intense red color of the Φ ₃ C anion. Then 1.4 g of 1,4 butane sulfone was added. After evaporating the solvent, a powdered sulfonated oligomer was obtained. 15 g of 5 g product thus formed
The suspension, suspended in 1 l 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 1.2
g to the sodium salt of bis (trifluoromethanesulfonyl) methane. Filter and then add 1 to the reaction mixture.
Stirred in the presence of g of lithium phosphate Li ₃ PO ₄ . By filtering once more, a colorless solution which became a wax upon concentration could be separated. This material had the tenacity active properties of lubrication and ionic conduction. 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.

Substantial Example 7 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,
The diameter is 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 6
It was added on the sheet at a rate of 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, 0.2% P, represented by n in the formula is a polyether segment selected to have a molecular weight of 200)
/ P POE200 Distearate was added to the mixture.

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 sheet of lithium 3 work roll 5 work roll 7 arrow 9 arrow 11 thin film lubricant (or toluene) 13 injection tube 15 thin film of lithium 17 roll contact point 19 roll limit point 21 operation continued Point

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication location // C10N 50:02 (72) Inventor Paul-Emile Guerlain Québec Je8 Canada 3-8 cap -Dora Madeleine L'Latriille 109 (72) Inventor Michel Armand France Grenoble 38410 Saint-Marten D'Urger-Broad Les Corsions (no address)

Claims (32)

[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 additive is compatible with lithium and has the following general formula: LYS (where L serves as a lubricating segment. Represents a hydrocarbon residue having 8 or more carbon atoms; S is a heteroatom of O or N capable of solvating a metal salt and ensuring electrolyte conductivity in an additive. And Y represents a hydrocarbon residue L.
And at least one sequence represented by a bond or a chemical group that binds the oligomer segment S). 2. Composition according to claim 1, characterized in that the oligomeric segment S is attached to an end group C which has a low reactivity towards lithium. 3. The terminal group C has the formula Y'-L ', where Y'and L'are the same as Y and L and are the same or different from the latter.
The composition according to claim 2, which corresponds to 4. The composition according to claim 1, wherein L represents a linear or cyclic alkali or alkylene group which is saturated or unsaturated and has 8 or more carbon atoms. 5. S is ethylene oxide, propylene
Oxide or poly (N-methylene-ethylenediamine)
A composition according to claim 1, characterized in that it exhibits chains based on or a combination 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. A composition according to claim 2, characterized in that 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: CH₃-(CH₂)₁₆-(COO- (CH₂-CH₂−
O)_n-OOC (CH ₂)₁₆-CH₃ (However, n represents 3 to 100)
The composition according to claim 3, wherein 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. The composition according to claim 1, wherein 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 0.5 to 50 μm and coated with a thin film of an additive as defined in any one of claims 1 to 23. 25. A sheet having a thickness of 0.01 to 50 μm and in direct contact with a sheet containing carbon or a metal capable of chemically forming a lithium alloy or an insertion compound of lithium. A lithium-based anode manufactured from a lithium thin film coated with a thin film of the additive of. 26. A polymer electrolyte electrochemical cell comprising a lithium anode prepared according to claim 1, 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. 27. An electrochemical cell comprising a lithium anode made using the additive of claim 1, wherein the additive is soluble in the electrolyte. 28. Use of the additive or composition according to claim 1 for producing a thin film of an alkali metal or its alloy by thinning which can be used as anode in polymer electrolytes and electrochemical cells. A method of manufacturing a thin film, comprising: 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.