KR102255925B1 - Producing apparatus for lithium anode for lithium batteries and producding method for thereof - Google Patents

Abstract

A method for manufacturing a lithium negative electrode according to an embodiment of the present invention includes the steps of: providing a metal alloy foam wound on a first roller to a conveying means; providing a room temperature lithium foil wound around a second roller on the metal alloy foam by passing the metal alloy foam through the second roller according to the movement of the conveying means; and putting lithium into the metal alloy foam by pressing the lithium to the metal alloy foam at a first temperature below the melting temperature of the lithium using a press roller. The present invention enables easy mass-production.

Description

Lithium anode manufacturing apparatus and manufacturing method thereof {PRODUCING APPARATUS FOR LITHIUM ANODE FOR LITHIUM BATTERIES AND PRODUCDING METHOD FOR THEREOF}

The invention disclosed by the present application relates to an apparatus for manufacturing a lithium anode and a method for manufacturing the same, and specifically, to an apparatus for manufacturing a lithium anode and a method for manufacturing the same using a roll-to-roll process.

These days, lithium batteries are used in all equipment and devices in civil and military fields. In the case of civil affairs, research to develop a lithium battery that is light and can be used for a long time is mainstream, and in the military field, the demand for high-energy and high-power density lithium power sources that can be used in special environmental conditions for national defense is also rapidly increasing.

In accordance with the demands of the times, industry-academia-research centers are concentrating research on high-performance, high-energy lithium battery technology. Among them, the field in which the most research is being conducted is the negative electrode field that generates electricity by storing and supplying lithium. In theory, the use of pure lithium can show the highest specific energy (3,860 mAh/g, 13,900 Wh/kg), but if pure lithium is used, dendrite is caused by the unstable nature of lithium metal during the electrochemical reaction. By creating a short circuit or a side reaction with an electrolyte, the capacity is rapidly reduced. Carbon-based anodes that solve these problems and exhibit stable charging and discharging are currently in the mainstream, but carbon-based anodes exhibit a specific energy (372 mAh/g) of about 1/10 of that of pure lithium.

Meanwhile, a thermal battery, which is a representative lithium battery used in the military field, is a non-storage primary battery that is activated by melting a solid electrolyte within a few seconds by ignition of a heat source after being maintained in an inactive state at room temperature. Therefore, since there is almost no self-discharge during storage, it can be stored for more than 10 years without deteriorating performance. In addition, thermal cells are mainly used as power sources for guided weapons and space launch vehicles due to structural stability, reliability, etc. that can withstand vibration, shock, low temperature and high temperature.

In particular, in the case of a guided weapon, the average lifespan is 15 years or more, and since power is used only at the moment it is fired, self-discharging does not occur as an essential requirement of the power source. In addition, the power source of the guided weapon must meet the requirements that the weight must be light for flight. When the thermal cell is deactivated, the electrolyte is in a solid state, so self-discharge can be blocked, and thus can be used as a power source for an induction weapon.

As a negative electrode material of a thermal battery, a lithium-silicon (Li-Si) alloy and liquid lithium in which molten lithium and iron powder are mixed are used. However, the lithium-silicon (Li-Si) alloy is manufactured through the powder molding method and has a limitation in molding, and the open circuit voltage is 1.9V, which is 2.0V, which is the open circuit voltage of the liquid lithium electrode. It has a lower problem. On the other hand, the liquid lithium electrode has the advantage of using pure lithium with excellent theoretical capacity, but a decrease in specific capacity is inevitably caused by mixing and using an excessive amount of iron powder to prevent leakage of molten lithium at a high temperature, which is an operating condition of the thermal cell. .

Accordingly, in order to solve the above-described problems, studies on a negative electrode material for a thermal battery in another form capable of replacing the existing lithium-silicon (Li-Si) alloy and a liquid lithium electrode have been actively conducted.

Related prior documents include Korean Patent Nos. 10-2097077, 10-2050003, and 10-2151714 for impregnating molten lithium with lithium in a metal alloy foam, and Japanese Patent Laid-Open Patent No. 10-2151714 for impregnating lithium into a porous nickel substrate. 1996-078023 has been published.

A task according to an embodiment is an apparatus for manufacturing a lithium anode that can be easily mass-produced through a simplified process by sequentially and continuously performing a series of roll-to-roll processes targeting a metal alloy foam, and Is to provide a way.

The problem to be solved is not limited to the above-described problems, and the problems that are not mentioned will be clearly understood by those of ordinary skill in the art from the present specification and the accompanying drawings.

A method of manufacturing a lithium negative electrode according to an embodiment of the present invention comprises the steps of: providing a metal alloy foam wound around a first roller to a conveying means; Providing a room temperature lithium foil wound around the second roller on the metal alloy foam by passing the metal alloy foam through a second roller according to the movement of the conveying means; And charging lithium into the metal alloy foam by pressing lithium on the metal alloy foam at a first temperature equal to or lower than the melting temperature of lithium using a press roller.

In the step of charging the lithium, the first temperature may be 80 °C to 120 °C.

After the step of providing the lithium foil, the metal alloy foam passes through the first film roller according to the movement of the transfer means, and a protective film wound around the first film roller is provided on the metal alloy foam. It further includes, and the protective film may include a polymer that prevents the lithium from being deposited on the press roller.

In the step of charging lithium, the step of processing the lithium-loaded metal alloy foam to a predetermined thickness using the press roller.

In the step of charging lithium, when the first temperature is 70° C. to 80° C., the lithium may be charged under an argon (Ar) atmosphere.

It may further include; winding and recovering the lithium-loaded metal alloy foam using a third roller.

A method of manufacturing a lithium negative electrode according to an embodiment of the present invention includes the steps of providing a metal alloy foam to a conveying means in the form of a plate using a support roller; Providing a lithium foil at room temperature on the metal alloy foam in the form of a plate according to the movement of the transfer means; And charging the lithium into the metal alloy foam by pressing lithium on the metal alloy foam at a first temperature equal to or lower than the melting temperature of lithium using a press roller.

In the step of charging the lithium, the first temperature may be 80 °C to 120 °C.

After the step of providing the lithium foil in the form of a plate, the metal alloy foam passes through the first film roller according to the movement of the transfer means, and a protective film wound around the first film roller is provided on the metal alloy foam. Step; Including, the protective film may include a polymer that prevents the lithium from smearing on the press roller.

In the step of charging lithium, when the first temperature is 70° C. to 80° C., the lithium may be charged under an argon (Ar) atmosphere.

The apparatus for manufacturing a lithium anode according to an embodiment of the present invention includes: a first roller that unwinds a metal alloy foam wound as it rotates and supplies it to a conveying means; A second roller for providing the metal alloy foam with a lithium foil wound at room temperature according to the movement of the conveying means; And a press roller for charging lithium into the metal alloy foam by pressing lithium on the metal alloy foam at a first temperature equal to or lower than the melting temperature of lithium.

The press roller may be charged with the lithium under the condition that the first temperature is 80°C to 120°C.

The lithium anode manufacturing apparatus further includes a first film roller for providing a protective film wound according to the movement of the conveying means to the metal alloy foam, wherein the protective film prevents the lithium from being buried on the press roller. It may contain a polymer to prevent.

It may further include a; third roller for recovering by winding the lithium-loaded metal alloy foam.

At least one of the first roller, the second roller, the first film roller, and the press roller may have a diameter of 16 cm to 30 cm.

The rotation speed of at least one of the first roller and the second roller may be 0.02 m/min to 2 m/min.

The rotation speed of at least one of the first film roller and the press roller may be 0.1 m/min to 2 m/min.

According to embodiments of the present invention, by introducing a roll-to-roll process under conditions below the melting point of lithium, it is possible to mass-produce lithium anodes for high-capacity, high-power thermal cells, and to reduce process time and manufacturing cost.

The effects are not limited to the above-described effects, and effects not mentioned will be clearly understood by those of ordinary skill in the art from the present specification and the accompanying drawings.

1 is a cross-sectional view of a conventionally commercialized lithium negative electrode.
2 is a photograph of a metal alloy foam before and after lithium is charged according to an embodiment.
3 is an electron microscope photograph of a microstructure of a metal alloy foam before and after lithium is charged.
4 is a diagram of a lithium battery manufactured according to an exemplary embodiment and components thereof.
5 is a schematic diagram of an apparatus for manufacturing a lithium anode according to an embodiment of the present invention.
6 is a schematic diagram of a pressing part of the apparatus for manufacturing a lithium anode according to an embodiment of the present invention.
7 is a schematic diagram of an apparatus for manufacturing a lithium anode according to another embodiment of the present invention.
8 is a view showing a heat generation behavior generated when lithium is charged by a heated roller in an oxidized metal alloy foam and a result of nitridation of lithium accordingly.
9 is a flowchart illustrating a method of manufacturing a lithium anode according to an embodiment of the present invention.

Specific embodiments of the present invention will be described in detail with reference to the drawings. However, the spirit of the present invention is not limited to the presented embodiments, and those skilled in the art who understand the spirit of the present invention can add, change, or delete other elements within the scope of the same idea. Other embodiments included within the scope of the inventive concept may be easily proposed, but this will also be said to be included within the scope of the inventive concept.

In addition, components having the same function within the scope of the same idea shown in the drawings of each embodiment will be described using the same reference numerals.

The terms used in the embodiments have selected general terms that are currently widely used as possible while considering functions in the present invention, but this may vary according to the intention or precedent of a technician working in the art, the emergence of new technologies, and the like. In addition, in certain cases, there are terms arbitrarily selected by the applicant, and in this case, the meaning of the terms will be described in detail in the description of the corresponding invention. Therefore, the terms used in the present invention should be defined based on the meaning of the term and the overall contents of the present invention, not a simple name of the term.

When a part of the specification is said to "include" a certain component, it means that other components may be further included rather than excluding other components unless specifically stated to the contrary. In addition, terms such as "unit" and "module" described in the specification mean a unit that processes at least one function or operation, which may be implemented as hardware or software, or as a combination of hardware and software.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art may easily implement the present invention. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein.

1 is a cross-sectional view of a conventionally commercialized lithium negative electrode. Referring to FIG. 1, it can be seen that an electrode in which lithium 200 and iron powder 201 are mixed is contained in a nickel mesh 202 and a cup 203 made of nickel or iron.

The conventionally commercialized lithium negative electrode is manufactured through the process of dividing iron powder into molten lithium and making an ingot from lithium mixed with iron powder in a solidified state, pressing, rolling, and punching. It is manufactured to include a nickel mesh 202 and a nickel or iron cup 203 that can be accommodated therein.

The liquid lithium electrode undergoes a phase change from a solid to a liquid state at 400 to 500°C, which is an active temperature of a thermal cell. Liquid lithium has flowability, and if it flows to the positive electrode, a short circuit of the battery may occur.

In order to control the flow of lithium, the conventional lithium anode is manufactured by mixing a large amount of iron powder 201. The iron powder 201 may provide a holding force capable of maintaining the shape of the molten liquid lithium.

However, since the iron powder 201 is physically mixed, there may be a concern that the iron powder 201 or the lithium 200 may be unevenly distributed when the iron powder 201 is completed in an ingot shape. Therefore, the iron powder 201 is mixed in excess for stable operation, resulting in a reduction in lithium specific capacity.

On the other hand, it is common to assemble the battery under a pressurized environment in order to reduce contact resistance. However, when the lithium 200 and the iron powder 201 are partially unevenly mixed and the lithium 200 is melted by the operation of the thermal battery, deformation of the electrode inevitably occurs due to the pressing force applied during assembly of the thermal battery. When the electrode is deformed, the molten lithium 200 leaks out and moves to the positive electrode, thereby causing a short circuit of the battery.

Accordingly, a conventional lithium electrode is manufactured using a nickel mesh 202 and a cup 203 made of nickel or iron in order to prevent leakage of lithium due to such deformation.

However, since the weight of the nickel and iron cup 203 and the nickel mesh 202 occupies 30 to 40 wt% of the total weight of the negative electrode, a reduction in the specific capacity of lithium inevitably occurs. In addition, as a result of electrode analysis after discharge is over, it is observed that iron powder is aggregated more than before discharge, so there is a disadvantage that structural stability cannot be secured when discharged in a pressurized environment.

In order to solve these problems, the lithium anode according to the embodiments is manufactured through a process of impregnating lithium into a metal alloy foam manufactured according to a predetermined composition ratio. Accordingly, the method of manufacturing a lithium negative electrode according to the embodiments improved stability by lowering the reactivity of the metal alloy foam with respect to lithium, and improved wettability with respect to lithium. In addition, the lithium negative electrode does not use the cup 203 and the mesh 202, which have been essentially used in the past, and omits the surface treatment using a eutectic salt, whereby the lithium negative electrode has a higher lithium specific capacity than the conventional lithium negative electrode. Significant increase, simplification of the manufacturing process, and productivity improvement are shown.

Meanwhile, as mentioned in the background art, research and utilization of lithium batteries are being actively conducted in civil and military fields. Among the methods of using pure lithium so far, the most achievement is being impregnated or composited with pure lithium in a porous metal body or support, which is an attempt to melt lithium and put it in a porous metal body or support.

Unlike general metals that are commonly thought of, lithium has a density of about half compared to water and is very reactive, so it reacts with general metals. Above the melting temperature, lithium reacts rapidly with nitrogen in the air, showing a reactivity close to explosion. It is a material that is difficult to handle.

In addition, lithium does not exhibit the properties of a liquid generally considered in a molten state, because of the very high surface tension of lithium. It has higher surface energy than most metals, so it is formed like dewdrops on the metal surface and does not penetrate into the porous body or the support. In order to control such surface energy (wetability), a separate surface treatment and process are required, so the actual manufacturing process and unit cost are inevitably increased. Therefore, there is a need for a method of manufacturing a lithium negative electrode for a thermal battery below the melting temperature of lithium.

Hereinafter, the state of the metal alloy foam before and after charging of lithium will be described using Figs. 2 and 3 together. FIG. 2 is a photograph of a metal alloy foam before (a) and after (b) lithium is charged according to an embodiment, and FIG. 3 is before (a, b) and after (c, d) lithium is charged. It is a photograph taken by an electron microscope about the microstructure of the metal alloy foam.

Referring to FIG. 2A, the metal alloy foam before lithium is charged may exhibit a unique color of the alloy composition or may appear black due to the formation of a lithium-friendly oxide film on the surface thereof. According to an embodiment of the present invention, lithium in a solid state has flowability while passing through at least one roller rotating at a low speed (eg, about 0.2 to 2 m/min) heated to a first temperature below the melting point of lithium. It is charged into a plurality of pores of the metal alloy foam in a similar liquid state, and lithium penetrates and is accommodated. Referring to (b) of FIG. 2, it can be seen that lithium is charged into the plurality of pores to show a smooth surface having a metallic color.

Next, a microstructure is examined with reference to FIG. 3. 3A and 3B are photographs taken of a side view and a top view of the metal alloy foam before lithium charging, respectively, and FIGS. 3C and 3D are side views of the metal alloy foam after lithium charging, respectively This is a picture of the view and top view. Referring to FIGS. 3A and 3B before lithium is charged, the diameters of pores existing between the foams may be about 400 to 1200 μm. Referring to FIGS. 3C and 3D, it can be seen that after the lithium is completely charged, there are no pores unlike before the charging. Therefore, it can be confirmed that lithium is charged into the metal alloy foam without an empty space.

Lithium is introduced into the metal alloy foam manufactured according to a predetermined composition ratio, and the molten lithium is injected into the pores formed in the metal alloy foam. Accordingly, a lithium negative electrode in which lithium is charged in a metal alloy foam can be manufactured.

Compared to the existing lithium-silicon (Li-Si) alloy and liquid lithium electrode containing iron powder, the use of a metal alloy foam allows the amount of lithium charged to be controlled by adjusting the size of the pores (cells) in the foam. It is more free in designing the capacity than a liquid lithium electrode containing powder.

Reducing the time required to charge the liquid lithium in the solid state into the metal alloy foam is an important technical task because it directly leads to a reduction in process cost and productivity improvement. Through the composition design of the metal alloy foam, it is possible to find a composition ratio that maintains the pore shape well with mechanical strength so that lithium can be charged in a short time during rolling.

The metal alloy foam is formed with a pore that can accommodate lithium to be charged. At this time, the diameter of the pores may be about 250 to about 6000 ㎛, for example, may be about 400 to 1200 ㎛.

The metal alloy foam is a mixture of nickel (Ni), iron (Fe), chromium (Chrome; Cr), molybdenum (Mo), carbon (C), and vanadium according to a predetermined composition ratio. Vanadium; V), titanium (Ti), manganese (Mn) and aluminum (Aluminum; Al).

Nickel has a high reactivity with lithium, so it is difficult to use it alone at a high operating temperature of a battery. In addition, nickel is not suitable as an electrode structure for a thermal cell in a pressurized environment due to its low strength.

On the other hand, iron has low reactivity with lithium and has excellent mechanical strength, so it is good for charging lithium.

Therefore, the metal alloy foam according to an embodiment maintains mechanical strength by additionally including chromium and aluminum in addition to nickel and iron, and is easy for the charging process of lithium, and in the case of a battery operated at a high temperature, the reactivity with lithium is lowered. It makes it possible to greatly expand the scope of application of this technology.

The metal alloy foam mixed with chromium is excellent because of its low reactivity with lithium at high temperatures. Metal alloy foam mixed with chromium is the level of iron and has low reactivity with lithium at high temperatures. Therefore, the metal alloy foam mixed with chromium can secure stability at the operating temperature of the thermoelectric cell. In addition, the metal alloy foam mixed with chromium facilitates charging of lithium.

In the metal alloy foam mixed with aluminum, the surface of the metal alloy foam may react slightly with lithium, but it was observed that lithium does not penetrate into the inside of the surface of the metal alloy foam.

In other words, the metal alloy foam mixed with aluminum exhibits some reaction on the surface when it comes into contact with liquid lithium, but the reaction does not occur deeper than the surface of the metal alloy foam, so that the metal alloy foam can maintain its structure.

Therefore, the metal alloy foam mixed with aluminum can be used as a high-temperature lithium battery electrode structure by protecting it from reaction with lithium. In addition, the metal alloy foam mixed with aluminum improves wettability after lithium is charged to prevent lithium from leaking out. In addition, the metal alloy foam mixed with aluminum can prevent nitriding.

That is, the metal alloy foam mixed with chromium and aluminum facilitates charging of lithium.

In the conventional lithium anode manufacturing method, the metal alloy foam is an oxidative layer through oxidation, anodizing, plasma treatment, etc. in a high-temperature atmosphere in the air between about 500 to about 1100°C. ) Can be formed to charge lithium. In the case of lithium batteries operating at high temperatures, as lithium melts above about 182 ℃, which is the melting temperature of lithium, the excellent lithiophilic oxide film catches the molten lithium and prevents it from leaking out. There is an effect of preventing a short circuit due to leakage of lithium.

The first composition ratio of the metal alloy foam is 22 to 42 parts by weight of nickel, 9 to 29 parts by weight of iron, 21 to 41 parts by weight of chromium, and 9 to 29 parts by weight of aluminum, based on 100 parts by weight of the metal alloy foam.

The second composition ratio of the metal alloy foam is 26 to 46 parts by weight of nickel, 6 to 26 parts by weight of iron, 18 to 38 parts by weight of chromium, and 10 to 30 parts by weight of aluminum, based on 100 parts by weight of the metal alloy foam.

The metal alloy foam may further include an oxygen (O) element to facilitate the charging process of lithium and intimate interaction with lithium after charging through oxidation. At this time, the third composition ratio of the metal alloy foam is 10 to 30 parts by weight of nickel, 2 to 22 parts by weight of iron, 9 to 29 parts by weight of chromium, 2 to 22 parts by weight of aluminum, and oxygen based on 100 parts by weight of the metal alloy foam. It is 9 to 29 parts by weight of the element.

In addition, according to another embodiment, the metal alloy foam facilitates charging of lithium by additionally including chromium, molybdenum (Mo;), and silicon (Silicon; Si; silicon) in addition to nickel and iron. , It can prevent corrosion of metal alloy foam.

The conventional metal alloy foam composed of nickel and iron has a problem in that it melts due to reaction with molten lithium at the operating temperature of a high-temperature lithium battery (thermal cell). Due to this reaction, a decrease in the capacity of lithium may occur during the discharging of the thermal cell. In particular, a phenomenon in which the metal alloy foam melts due to reaction with lithium occurs at a discharge temperature of about 500 to 550° C., which is a discharge temperature of a high-temperature lithium battery. Therefore, the existing metal alloy foam composed of nickel and iron must be equipped with a mesh 202 and a cup 203 to prevent leakage of lithium.

However, when molybdenum is mixed with the metal alloy foam, the metal alloy foam does not react with molten lithium at the operating temperature of the thermal cell and is stable because it can maintain its shape. Accordingly, the metal alloy foam mixed with molybdenum can stably maintain the structure to prevent lithium leakage, and by removing the mesh 202 and the cup 203, which occupy about 30% of the total negative electrode weight, It is possible to increase the specific capacity of

The fourth composition ratio of the metal alloy foam containing molybdenum is 47 to 67 parts by weight of nickel, 13 to 33 parts by weight of chromium, and 1 to 14 parts by weight of molybdenum based on 100 parts by weight of the metal alloy foam.

The fifth composition ratio of the metal alloy foam containing molybdenum is 47 to 67 parts by weight of nickel, 13 to 33 parts by weight of chromium, 1 to 14 parts by weight of molybdenum, and 1 to 10 parts by weight of silicon based on 100 parts by weight of the metal alloy foam. It is a part by weight.

The metal alloy foam produced according to the predetermined composition ratio and oxidation treatment as described above has superior wettability to lithium as compared to a metal alloy foam in which simple nickel and iron are mixed. For example, molten lithium can be completely charged into the metal alloy foam within tens of seconds, and within a maximum of several minutes.

Meanwhile, in the past, attempts such as coating a eutectic salt on the nickel foam surface to improve the impregnation (wetting) of lithium, or depositing a material including silicon or gold on the nickel foam surface using CVD (Chemical Vapor Deposition) have been attempted. All of these processes must be performed by melting lithium at a melting temperature (about 182° C.) or higher (eg, the actual processing temperature is about 300 to about 550° C.). In addition, molten lithium can cause a fire through rapid nitration with lithium in the air, even if it is carried out in a dry room with very low moisture (relative humidity less than 2%). It is necessary to maintain very strict process control and conditions such as blackening by tens of ppm of oxygen or nitrogen in the glove box. In this case, the process cost and time may increase, which may lead to an increase in the production cost of the thermal cell.

Accordingly, the present invention aims to provide a method and apparatus for manufacturing a lithium negative electrode capable of improving wettability for molten lithium without performing additional surface pretreatment including eutectic salt on the surface of a metal alloy foam produced at a predetermined composition ratio. . Above all, since it does not need to melt lithium, it is possible to easily manufacture a high-performance lithium metal anode in a dry room environment, so it is for high-quality batteries by simply charging lithium into the metal alloy foam without the need for pre-processing such as eutectic salt coating or silicon deposition. Lithium negative electrodes can be prepared.

In addition, the metal alloy foam manufactured according to a predetermined composition ratio has a strength capable of withstanding a pressure of ^{about 1 to about 7 kg/cm 2 applied during the manufacturing process of the electrode.} Accordingly, the shape can be maintained without causing deformation in a pressurized environment, and lithium leakage does not occur. Accordingly, a unit cell of a thermoelectric battery can be configured without using the nickel and iron cup 203 and the nickel mesh 202 (refer to FIG. 1) that can prevent lithium from leaking.

4 is a diagram of a thermal cell manufactured according to an exemplary embodiment and components thereof. Referring to FIG. 4, the thermal cell may include at least one thermal cell 140. The thermoelectric cells 140 may be connected in series, and as the number of connected thermoelectric cells 140 increases, the output voltage of the battery increases.

The battery cell 140 includes a cathode 144, an electrolyte layer 145, a lithium anode 146, a heat source (not shown) when necessary for melting of the electrolyte layer 145, and a cathode current collector 142 And a negative electrode current collector 147. The negative electrode current collector 147 is disposed on one surface of the lithium negative electrode 146. The positive electrode 144 is disposed on the opposite side of the lithium negative electrode 146 based on the electrolyte layer 145. The positive electrode current collector 142 is disposed on the opposite side of the electrolyte layer 145 based on the positive electrode 144.

If necessary, a heat source (not shown) may be inserted and disposed between the positive electrode 144 and the current collector. At this time, for example, the anode 144, the electrolyte layer 145, the cathode 146, and a heat source (not shown) may be formed into disk-shaped pellets to facilitate stacking.

The positive electrode current collector 142 and the negative electrode current collector 147 serve as a support that allows the active material to exist in the thermal cell in the form of an electrode plate, and electrical energy generated by chemical substances of the positive electrode 144 and the negative electrode 146 It is responsible for transferring electrical energy so that it can be connected to a circuit. The positive electrode current collector 142 and the negative electrode current collector 147 may be made of, for example, a metal plate such as copper, stainless steel (SUS), and nickel (Ni) or a mesh.

At this time, the lithium negative electrode 146, due to the strength of the metal alloy foam, does not use the nickel and iron cup 203 and the nickel mesh 202 (refer to FIG. 1) commonly used in the existing lithium negative electrode, and the battery Alternatively, a unit cell 140 of a high-temperature battery (thermal cell) may be configured.

Thereafter, a negative electrode current collector 147 is disposed on one surface of the lithium negative electrode 146, and an electrolyte layer 145, a positive electrode 144, and a positive electrode current collector 142 are sequentially stacked on the other surface of the lithium negative electrode 146. A unit cell 140 of a thermal battery may be manufactured.

Hereinafter, an apparatus 1000 for manufacturing a lithium anode according to an exemplary embodiment will be described with reference to FIGS. 5 and 6. 5 is a schematic diagram of an apparatus 1000 for manufacturing a lithium anode according to an exemplary embodiment of the present invention, and FIG. 6 is a schematic diagram of a pressurizing portion of the apparatus for manufacturing a lithium anode according to an exemplary embodiment of the present invention.

Hereinafter, as a manufacturing apparatus 1000 and a manufacturing method for a lithium negative electrode for a thermal battery including a metal alloy foam, a roll-to-roll process is introduced to mass-produce a thermal battery negative electrode, and the process is simplified. The negative electrode manufacturing apparatus 1000 and manufacturing method will be described.

In general, the roll-to-roll process refers to a device that performs various types of processes using a flexible film wound in a roll form. Such a roll-to-roll processing device includes a film processing unit where various processes are performed on the film, and supplying the film to the film processing unit by unwinding the film wound in a roll form, or rewinding the processed film from the film processing unit in a roll form for recovery. It consists of a film transfer unit.

In the embodiments of the present invention, focusing on the fact that the metal alloy foam is thin and flexible like a film, by sequentially performing a series of roll-to-roll processes for the metal alloy foam, the process time and manufacturing cost can be drastically reduced.

The lithium anode manufacturing apparatus 1000 includes a conveying means 10, a first roller 100 that unwinds a metal alloy foam wound and supplies it to the conveying means 10, a second roller 200 that supplies lithium to be charged, A film roller 300 that supplies and removes a protective film that prevents lithium from getting on or contaminated on the roller during the rolling process, a press roller 400 that presses and processes a metal alloy foam impregnated with lithium, and a lithium-loaded metal alloy It may include a third roller 500 to recover and wind the foam.

First, the metal alloy foam wound around the first roller 100 may be provided to the conveying means 10. The metal alloy foam may be initially wound around the first roller 100. As the first roller 100 rotates, the metal alloy foam is released from the first roller 100 and supplied to the conveying means 10. For example, the metal alloy foam may have a rectangular shape, and the length of one side of the metal alloy foam may be about 30 cm, and the thickness may be about 0.2 to 5 mm, but is not limited thereto.

The diameter of the first roller 100 may be about 16 to about 30 cm. The rotational speed of the first roller 100 may be about 0.02 m/min to about 2 m/min. The moving distance of the metal alloy foam conveyed along the conveying means 10 by the rotation of the first roller 100 may be 0.1 to 1.9 m/min.

Thereafter, when the second roller 200 passes through the second roller 200 containing lithium to be charged with the metal alloy foam according to the movement of the transfer means 10, the lithium foil at room temperature can be provided to the metal alloy foam. have. The second roller 200 may accommodate lithium to be charged in the form of a foil. The width and thickness of the lithium foil can be calculated by converting the voids and thickness of the metal alloy foam to be charged into a volume.

The diameter of the second roller 200 may be about 16 to about 30 cm. The rotation speed of the second roller 200 may be about 0.02 m/min to about 2 m/min.

The film roller 300 may include a first film roller 310 and a second film roller 320 to be described later.

The first film roller 300 may supply a protective film that can be separated so that lithium does not adhere to the press roller 400 when lithium is charged by pressing by a press roller 400 to be described later. The first film roller 310 may provide a protective film wound up according to the movement of the transfer means 10 to the metal alloy foam. The bopo film may serve to prevent contamination of the press roller 400 so that sticky lithium does not adhere to the roller during the rolling process. To this end, the protective film may include a polymer material that is not melted or deformed at the operating temperature of the press roller 400.

The diameter of the first film roller 310 may be about 16 to about 30 cm. The rotational speed of the first film roller 310 may be about 0.02 m/min to about 2 m/min.

The press roller 400 may press lithium to the metal alloy foam at a first temperature equal to or lower than the melting temperature of lithium to charge the lithium into the metal alloy foam. The press roller 400 is heated to the first temperature to increase the fluidity of lithium when lithium is charged, so that lithium is completely charged into the metal alloy foam.

In this case, the first temperature is less than or equal to the melting temperature of lithium, and may be, for example, about 80° C. to about 120° C. Depending on the embodiment, the first temperature may be from about 70° C. to about 80° C., and in this case, a pressurization process of charging lithium in an argon (Ar) atmosphere may be performed. The first temperature control will be described in more detail with reference to FIG. 8 to be described later.

Here, using FIG. 6 together, the pressing unit 410 for charging lithium into the metal alloy foam through a pressing process using a pair of press rollers 400 will be described in more detail.

The gap (w) between the pair of press rollers 400 in which the metal alloy foam 600 is disposed may be, for example, about 0.2 to about 1.5 mm. The diameter of the press roller 400 may be about 16 to 30 cm, and the rotational speed of the press roller 400 may be about 0.1 m/min to about 2 m/min, for example.

In addition, it is possible to process the lithium-loaded metal alloy foam to a predetermined thickness by compressing the lithium-loaded metal alloy foam at the same time as lithium is charged using the press roller 400. Before passing through the press pole 400, the lithium foil 700 and the protective film 800 are sequentially provided in the metal alloy foam 600 may include pores 610 therein. As such, the relatively thick metal alloy foam 600 passes through the press roller 400 and is charged with lithium provided through the lithium foil 700 into the internal pores 610, and the processed metal alloy foam in which lithium is charged ( 900) is generated, and at this time, the processed metal alloy foam 900 may be processed to a target thickness. According to the embodiment, if the initial metal alloy foam 600 is provided with a target thickness, a press process of processing to a predetermined thickness may be omitted.

The second film roller 320 may be removed by winding the protective film 800 on the processed metal alloy foam 900 passing through the pressing portion 410.

The film rollers 310, 320; 300 may be provided as a disposable one-time, and the surface of the press roller 400 may be protected from lithium charged in the metal alloy foam by using the film roller 300. After the metal alloy foam has passed, the film roller 300 may be replaced with a new film roller 300, and contamination of the surface of the metal alloy foam 900 pressed by the press roller 400 may also be prevented through this.

Like the first film roller 310, the second film roller 320 may have a diameter of about 16 to about 30 cm, and its rotation speed may be about 0.02 m/min to about 2 m/min. It goes without saying that diameters and rotation speeds of the first and second film rollers 310 and 320 may be the same or different from each other within the numerical range.

Thereafter, the third roller 500 may be recovered by winding the processed metal alloy foam 900 loaded with lithium. The finally processed metal alloy foam 900 may be wound around a roller (third roller) again and stored in a completed form.

As shown in Fig. 5, the second roller 200, the film roller 300, and the press roller 400 are provided in a pair with a transfer means 10 provided with a metal alloy foam therebetween. I can.

7 is a schematic diagram of an apparatus 1000-1 for manufacturing a lithium anode according to another embodiment of the present invention. Hereinafter, the same contents may be applied to elements having the same reference numerals as in the above-described embodiments, and descriptions of overlapping contents may be simplified or omitted.

The lithium anode manufacturing apparatus 1000-1 may include a support roller 110, film rollers 310, 320; 300, and a press roller 400. The film rollers 310 and 320 may include a pair of first film rollers 310 and second film rollers 320 as in the above-described embodiment. In this embodiment, the support roller 110 may correspond to the first roller 100 (see FIG. 5) described above.

In the lithium anode manufacturing apparatus 1000-1 of the present embodiment, the metal alloy foam 600 may be supplied in the form of a sheet, not in the form of a roll wound around a roller, on the conveying means supported by the support roller 110. . In this case, the transfer means may be a lower protective film 810 supplied through the outermost first film roller 310.

In this way, a lower protective film 810 serving as a transport means is provided, and a laminate in which a metal alloy foam 600 and a lithium foil 700 are stacked is the lower protective film 810 which is a transport means. It can be provided upon movement. In this case, the laminate may be a laminate in which lithium foil 700 is disposed on both sides of the metal alloy foam 600, that is, upper and lower surfaces. That is, from a surface adjacent to the lower protective film 810, the lithium foil 700, the metal alloy foam 600, and the lithium foil 700 may be sequentially stacked. Thereafter, although not shown in the drawing, the upper protective film 820 is provided by the first film roller 310 in the middle, and the pressing process of the press roller 400 while passing through the pressing unit 410 with the surface protected Lithium is charged by, and the upper protective film 820 is removed again by the second film roller 320 in the middle, so that the processed metal alloy foam 900 may be manufactured in the form of a plate. Thereafter, the processed metal alloy foam 900 and the lower protective film 810 are separated through the second film roller 320 on the outermost side, and the metal alloy foam 900 in the form of a plate from which the protective film is finally removed will be manufactured. I can. That is, in this embodiment, the final metal alloy foam 900 loaded with lithium may be provided in the form of a plate through the transfer means 810.

At this time, when the laminate 60 passes through the pressing part 410, although not shown in this drawing, an upper protective film is provided to prevent contamination of the surfaces of the press roller 400 and the processed metal alloy foam 900. have. The laminate 60 is a structure in which a metal alloy foam 600, a lithium foil 700, and a protective film 800 are laminated, in detail, a metal alloy foam 600, a lithium foil 700 on the upper and lower portions thereof, and an upper protection It may mean a structure in which the film 820 is laminated.

Meanwhile, while passing through the second film roller 320, the protective film 800 on the surface (upper and lower surfaces) may be wound up and removed.

Hereinafter, a method of manufacturing a lithium anode by the lithium anode manufacturing apparatus 1000-1 according to the embodiment of FIG. 7 will be described. The method may include the steps described below. In the omitted description, the same contents as those of the above-described embodiment may be applied.

First, the metal alloy foam 600 may be provided to the conveying means in the form of a plate using the support roller 110. At this time, the conveying means may be a lower protective film 810 provided by the outermost first film roller 310 as described above. The support roller 110 may be a component corresponding to the first roller 100 described above.

Thereafter, the lithium foil 700 at room temperature may be provided in the form of a plate on the metal alloy foam 600 according to the movement of the lower protective film 810 operating as a conveying means. Before the metal alloy foam 600 is provided on the lower protective film 810 in the form of a plate, the lower lithium foil 700 is first provided, and after the metal alloy foam 600 is provided thereon, the upper lithium foil 700 is again provided. It can be provided in the form of this plate.

Thereafter, the lithium may be charged into the metal alloy foam 600 by pressing lithium on the metal alloy foam 600 at a first temperature equal to or lower than the melting temperature of lithium using a press roller 400. In this case, charging of lithium may be performed through a pressing process of the lithium foil 700 on the upper and/or lower portion of the metal alloy foam 600. The first temperature at which lithium is charged may be 80° C. to 120° C.

After the step of providing the lithium foil 700 in the form of a plate, the metal alloy foam 600 passes through the first film roller 310 in the middle according to the movement of the transfer means 810 and the metal alloy foam 600 A protective film 820 wound around the first film roller 310 in the middle may be provided. In this case, the metal alloy foam 600 is more specifically in a state in which a lithium foil 700 is stacked on an upper and/or lower portion, and the protective film may mean an upper protective film 820. The protective films 810 and 820 may include a polymer that prevents lithium from being adhered to the press roller 400.

In the step of charging lithium, when the first temperature is 70° C. to 80° C., the lithium may be charged under an argon (Ar) atmosphere.

Hereinafter, the control of the first temperature in the lithium charging step using the pressurization process of the present invention will be described with reference to FIG. 8. 8 is a view showing a heat generation behavior generated when lithium is charged by a heated roller in an oxidized metal alloy foam and a result of nitridation of lithium accordingly.

The first temperature is less than or equal to the melting temperature of lithium, and may be, for example, about 80° C. to about 120° C. Depending on the embodiment, the first temperature may be from about 70° C. to about 80° C., and it is as described above that an argon (Ar) atmosphere composition is required. At this time, the composition of the argon atmosphere may be necessary to prevent nitriding and damage to parts described later when performing the process of the present invention on the oxidized metal alloy foam. Depending on the embodiment, an oxidized metal alloy foam is used, but when lithium is charged at room temperature without preheating/heating the press roller 400 separately, an argon atmosphere may not be created.

8A is a photograph of a state in which lithium is charged by pressing the metal alloy foam subjected to oxidation treatment at a first temperature of about 70°C. When lithium is charged, the press roller 400 is preheated to increase the fluidity of lithium. However, when the oxidized metal alloy foam is preheated to a first temperature of about 70° C. to about 80° C., after charging of lithium An exothermic reaction such as the following [Chemical Formula 1] may occur.

[Formula 1]

2Li + NiO → Li ₂ O + Ni (-50.8 * 10 ⁹ * t (J/m ² )) (t is the thickness of the oxide film: mm)

When the reaction of [Chemical Formula 1] occurs, as shown in (d) of FIG. 8, if lithium is nitrided or heat generation is severe, damage to parts may occur. Figure 8 (b) shows the surface when the oxidized metal alloy foam of (a) passes through the preheated press roller 400 and then the lithium in the alloy foam generates heat according to the reaction of [Chemical Formula 1]. This is a picture taken with an infrared camera. FIG. 8(c) is a photograph taken with an infrared camera while covering the surface of the metal alloy foam with the metal foam not charged with lithium in the state of FIG. 8(b). In the case of directly photographing a metal alloy foam in a heating state as shown in (b), it may be difficult to confirm the heating pattern on an infrared photograph due to surface reflection or the like. Accordingly, as shown in (c), infrared photographing was performed by covering the metal foam before loading the metal as shown in FIG. 2(a).

(D) of FIG. 8 is a photograph of a state in which heat is generated for about 40 minutes in a lithium-loaded metal alloy foam, and at this time, the maximum temperature is about 140° C. It can be seen that the surface of the alloy foam is blackened.

Therefore, when the oxidized metal alloy foam is charged with lithium while the press roller 400 is heated to a first temperature of about 70° C. to 80° C., lithium charging may be performed under an argon atmosphere. The argon atmosphere may mean an environment in which argon is purged during the process of being sealed with an argon atmosphere or charging and cooling after charging. In the case of charging lithium using the press roller 400 preheated under an argon atmosphere, heat as shown in [Chemical Formula 1] may occur within about 30 minutes to about 1 hour after charging, and an argon atmosphere was created. The nitriding phenomenon as shown in (d) of FIG. 8 can be prevented. Through this exothermic process, lithium reacts with the oxidation-treated metal alloy foam, and lithium is densely charged into the pores and surfaces in the metal alloy foam.

9 is a flowchart illustrating a method of manufacturing a lithium anode according to an embodiment of the present invention. The method of manufacturing a lithium negative electrode of the present invention may include the steps described below. It will be described with reference to FIGS. 5 and 6 described above.

First, the metal alloy foam 600 wound around the first roller 100 may be provided to the transfer means 10 (S100).

Thereafter, the lithium foil 700 may be provided on the metal alloy foam 600 using the second roller 200 (S200). Specifically, as the transfer means 10 moves, the metal alloy foam 600 passes through the second roller 200 and is wound around the second roller 200 on the metal alloy foam 600 at room temperature. A lithium foil 700 may be provided (S200).

Thereafter, the protective film 800 may be provided on the metal alloy foam 600 provided with the lithium foil 700 using the first film roller 300. Specifically, the metal alloy foam 600 passes through the first film roller 310 according to the movement of the transfer means 10 to protect the metal alloy foam 600 wound around the first film roller 310 A film 800 may be provided. In this case, the protective film 800 may include a polymer to prevent lithium from being adhered to the press roller 400.

Then, lithium may be charged into the metal alloy foam 600 by pressing lithium on the metal alloy foam 600 at a first temperature equal to or lower than the melting temperature of lithium using the press roller 400 (S400). In this case, the first temperature may be 80 ℃ to 120 ℃. Depending on the embodiment, the first temperature may be 70 ℃ to 80 ℃, in this case, the metal alloy foam may be oxidized, and the step S400 may be performed under an argon (Ar) atmosphere.

In step S400, the metal alloy foam 900 loaded with lithium may be pressed using a press roller 400 to have a predetermined thickness.

Thereafter, the protective film 800 provided on the processed metal alloy foam 900 using the second film roller 320 may be wound and removed (S500).

Thereafter, the metal alloy foam 900 loaded with lithium may be wound and recovered using the third roller 500 (S600). In this way, the metal alloy foam into which lithium is finally charged may be wound on a roller again and stored in a finished form. However, as described in another embodiment of FIG. 7, the finally completed metal alloy foam may be manufactured and stored in the form of a plate.

The description of the presented embodiments is provided to enable any person skilled in the art to use or practice the present invention. Various modifications to these embodiments will be apparent to those of ordinary skill in the art, and general principles defined herein can be applied to other embodiments without departing from the scope of the present invention. Thus, the present invention is not to be limited to the embodiments presented herein, but is to be construed in the widest scope consistent with the principles and novel features presented herein.

1000, 1000-1: lithium anode manufacturing apparatus
100: first roller
200: second roller
300: film roller
310: first film roller
320: second film roller
400: press roller
410: pressurization part
500: third roller
140: battery cell
142: positive electrode current collector
144: anode
145: electrolyte layer
146: cathode
147: negative electrode current collector

Claims (17)

Providing the metal alloy foam wound around the first roller to the conveying means;
Providing a room temperature lithium foil wound around the second roller on the metal alloy foam by passing the metal alloy foam through a second roller according to the movement of the conveying means; And
Containing, lithium negative electrode manufacturing method comprising: pressing lithium into the metal alloy foam by pressing lithium at a first temperature equal to or less than the melting temperature of lithium using a press roller. The method of claim 1,
In the step of charging the lithium, the first temperature is 80° C. to 120° C., a method of manufacturing a lithium negative electrode. The method of claim 1,
After the step of providing the lithium foil,
In accordance with the movement of the conveying means, the metal alloy foam is passed through the first film roller to provide a protective film wound around the first film roller on the metal alloy foam.
The protective film includes a polymer that prevents the lithium from being deposited on the press roller, a method of manufacturing a lithium negative electrode. The method of claim 1,
In the step of charging the lithium,
Comprising the step of pressing the metal alloy foam charged with lithium using the press roller to a predetermined thickness; further comprising, a lithium anode manufacturing method. The method of claim 1,
In the step of charging lithium, when the first temperature is 70 to 80° C., the lithium is charged under an argon (Ar) atmosphere. The method of claim 1,
The method of manufacturing a lithium negative electrode further comprising; winding and recovering the lithium-loaded metal alloy foam using a third roller. Providing a metal alloy foam to the conveying means in the form of a plate using a support roller;
Providing a lithium foil at room temperature on the metal alloy foam in the form of a plate according to the movement of the transfer means; And
Containing, lithium negative electrode manufacturing method comprising: pressing lithium into the metal alloy foam by pressing lithium at a first temperature equal to or less than the melting temperature of lithium using a press roller. The method of claim 7,
In the step of charging the lithium, the first temperature is 80° C. to 120° C., a method of manufacturing a lithium negative electrode. The method of claim 7,
After the step of providing the lithium foil in the form of a plate,
In accordance with the movement of the conveying means, the metal alloy foam is passed through the first film roller to provide a protective film wound around the first film roller on the metal alloy foam.
The protective film includes a polymer that prevents the lithium from being deposited on the press roller, a method of manufacturing a lithium negative electrode. The method of claim 7,
In the step of charging lithium, when the first temperature is 70 to 80° C., the lithium is charged under an argon (Ar) atmosphere. A first roller that unwinds the metal alloy foam wound as it rotates and supplies it to the conveying means;
A second roller for providing the metal alloy foam with a lithium foil wound at room temperature according to the movement of the conveying means; And
Containing, a lithium negative electrode manufacturing apparatus comprising; a press roller for charging the lithium into the metal alloy foam by pressing lithium at a first temperature equal to or less than the melting temperature of lithium. The method of claim 11,
The press roller charges the lithium under the condition that the first temperature is 80° C. to 120° C., a lithium negative electrode manufacturing apparatus. The method of claim 11,
The lithium negative electrode manufacturing apparatus,
Further comprising a; a first film roller for providing the protective film wound in accordance with the movement of the transfer means to the metal alloy foam,
The protective film includes a polymer that prevents the lithium from being deposited on the press roller. The method of claim 11,
A third roller for recovering by winding the lithium-loaded metal alloy foam; further comprising, a lithium negative electrode manufacturing apparatus. The method of claim 13,
At least one of the first roller, the second roller, the first film roller, and the press roller has a diameter of 16 cm to 30 cm. The method of claim 13,
At least one of the first roller and the second roller has a rotational speed of 0.02 m/min to 2 m/min. The method of claim 13,
The rotation speed of at least one of the first film roller and the press roller is 0.1 m/min to 2 m/min.

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