Method for manufacturing electrode material for secondary battery

Abstract

The present invention relates to a method for manufacturing an electrode material for a secondary battery, wherein the surface of a thin metal plate made of a material selected from among nickel (Ni), a nickel-chromium alloy (Ni-Cr), a nickel-tin alloy (Ni-Sn), copper (Cu), and aluminum (Al), or a thin-plate porous metal body manufactured using said material to have a sponge structure, is sequentially plated with at least two metals selected from among nickel (Ni), zinc (Zn), tin (Sn), gold (Au), silver (Ag), copper (Cu), indium (In), bismuth (Bi), antimony (Sb), and an indium-antimony alloy (In-Sb), an alloy layer in which each of the plating metals is uniformly mixed is formed by a thermomigration treatment, an electromigration treatment, or a combination of the two treatments, and then the surface of the alloy layer is coated with a current collector made of a sulfur powder and a carbon powder (conductive material) or a sulfur powder, a carbon powder, and a metal powder (sulfur host).

Description

Method for manufacturing electrode materials for secondary batteries

[0001] The present invention relates to a method for manufacturing an electrode material for a secondary battery, which can more stably secure the battery capacity of a secondary battery that undergoes repeated charging and discharging, by sequentially plating two or more types of metals having a strong bonding force with polysulfide ions on the surface of a metal thin plate or a metal porous body for a cathode material, forming an alloy layer in which each plating film is uniformly mixed through thermomigration and / or electromigration treatment, and then coating a current collector of polysulfide ions on the surface of the alloy layer, thereby significantly improving the battery capacity, stability, and service life of a metal-sulfur secondary battery, and also allowing this method to be applied to some anode materials of a metal-sulfur secondary battery and a multivalent metal secondary battery that does not use sulfur.

[0002] In general, secondary batteries are batteries that can be used semi-permanently through charging, unlike primary batteries that are used once and thrown away. There are various types such as nickel-cadmium batteries, lithium-ion batteries, nickel-hydrogen batteries, and lithium polymer batteries. They are used as a core material for portable electronic devices such as laptop computers and smartphones as well as electric vehicles, and because they have very high added value, they are considered one of the three major electronic components of the 21st century, along with semiconductors and displays.

[0003] As shown in Fig. 1, the secondary battery (10) is installed by inserting a positive electrode material (1) and a negative electrode material (2) into a sealed container (7) with an electrolyte (6) and a separator (5) interposed therebetween. When charging, the electric energy is stored as + ions move from the positive electrode material (1) to the negative electrode material (2) through the electrolyte (6) and the separator (5), and when discharging, the electric energy is released as + ions move from the negative electrode material (2) to the positive electrode material (1). Since the separator (5) has high ionic conductivity and allows ions to pass through, but low electrical conductivity and prevents electrons from passing through, current (electricity) flows only through the conductor connected to the positive electrode terminal (3) and the negative electrode terminal (4).

[0004] Among the above secondary batteries, the lithium-ion battery (LIB) is the most widely used. It has been produced for nearly 30 years since its commercialization in 1991, and has been utilized for various purposes ranging from small electronic devices such as portable terminals to artificial satellites due to its high operating voltage and energy density and excellent cycle characteristics. However, existing lithium-ion batteries have encountered limitations in their use since they were developed to have a capacity close to 300 Wh / kg, which is close to the theoretical capacity.

[0005] Recently, secondary batteries with a capacity more than five times that of lithium-ion batteries have been required for use as power sources for electric vehicles as well as for storage of renewable energy sources such as solar and wind power. Metal-sulfur batteries developed in line with this trend use carbon materials (conductive materials) mixed with sulfur as cathode materials, and alkali metals (Li, Na, K), multivalent metals (Ca, Mg, Zn, Al) and alloys of these metals as cathode materials, while an electrolyte having electrical conductivity for metal ions is applied between the cathode and anode materials.

[0006] As described above, carbon materials used as conductive materials in metal-sulfur secondary batteries have relatively good electrical conductivity and a large surface area, and are therefore used as hosts for sulfur (sulfur) in various types of metal-sulfur batteries. They effectively accommodate sulfur during charging and discharging, and perform the function of rapidly promoting the exchange of electrons and ions. Sulfur applied to the positive electrode material generates polysulfide ions as shown in equations (1)-(5) below as charging and discharging are repeated.

[0007] S8+ 2e - → S8 2- --------- (1)

[0008] S8 4- → 2S4 2- --------- (2)

[0009] S8 2- → S6 2- + 1 / 4S8--------- (3)

[0010] S6 2- ↔ 2S3 2- --------- (4)

[0011] 2 S4 2- → 6 / 7 S8 2- + 8 / 7S1 2- --- (5)

[0012] However, since the carbon material used as a conductive material in metal-sulfur secondary batteries is a non-polar material, the interaction with negatively charged polysulfide ions becomes weak, and as a result, the polysulfide ions dissolve (leach out) into the electrolyte, not only does the viscosity of the electrolyte increase, but the polysulfide ions dissolved into the electrolyte move to the surface of the negative electrode material to form a passive film, and this passive film hinders the movement of metal ions through the electrolyte during charging and discharging, causing a problem of battery capacity reduction in a relatively short period of time.

[0013] In order to supplement the above problems, in order to suppress the movement of polysulfide ions from the positive electrode material to the negative electrode material, two or more types of metal powders, such as cobalt (Co) and nickel (Ni), which perform the host function of sulfur, are mixed with carbon powder as a conductive material and added to a solvent to first prepare a turbidity, and then the turbidity is applied to the surface of the positive electrode material and the solvent component is dried, thereby coating the surface of the positive electrode material with the carbon powder as a conductive material and the metal powder as a sulfur host as a current collector. This is described in Japanese Patent Application Laid-Open No. 2022-44986 (JP 2022-44986 A) (publication date: March 18, 2022).

[0014] However, even in the above-described conventional technology, as the battery is repeatedly charged and discharged, the difference in density between sulfur and metal-sulfur compounds causes expansion and contraction of the cathode material, and in severe cases, the ratio may exceed 50%, which not only causes a separation phenomenon between the cathode material and the current collector, but also causes the metal component that acts as a host for polysulfide to move and be biased toward the cathode material, making it impossible for it to fully exhibit its inherent function.

[0015] Due to the above factors, there were problems in which the capacity, stability and service life of metal-sulfur batteries were significantly reduced, and in the case of lithium-sulfur batteries, lithium ions (Li) were released during discharge. + ) is sulfur ion (S x 2- ) with Li2S x Sulfur compounds such as Li2S2 or Li2S x As larger compounds are formed, there is a problem that the capacity of the battery is further accelerated due to the dispersion and distribution of the host metal because these sulfur compounds are insulators with almost no electrical conductivity.

[0016] The present invention has been devised to solve the above-mentioned conventional problems, and by sequentially plating two or more types of metals having a strong bonding force with polysulfide ions on the surface of a metal thin plate used as a cathode material of a metal-sulfur secondary battery, preferably a metal porous body in the form of a thin plate manufactured to have a sponge structure, and forming an alloy layer in which each plating film is uniformly mixed through thermomigration and / or electromigration treatment, and then coating a current collector made of sulfur powder and carbon powder (conductive material) or sulfur powder, carbon powder, and metal powder (sulfur host) on the surface of the alloy layer, thereby preventing the occurrence of a separation phenomenon between the cathode material and the current collector by appropriately absorbing and buffering the expansion and contraction of the cathode material due to the difference in density of sulfur and the density of the metal-sulfur compound when using a metal-sulfur secondary battery by the sponge structure of the metal porous body, and at the same time maximizing the bonding force between the polysulfide ion and the cathode material by utilizing the large surface area of ​​the metal porous body, the capacity and stability of the metal-sulfur battery and its service life can be greatly improved. The main technical task of the present invention is to provide a method for manufacturing an electrode material for a secondary battery, which can double the performance of a metal-sulfur secondary battery and contribute to improving the performance of a multi-metal secondary battery by utilizing the method for manufacturing some negative electrode materials for a metal-sulfur secondary battery and a multi-metal secondary battery that does not use sulfur.

[0017] The present invention, as a means for solving the above technical problem, is a method for manufacturing an electrode material for a secondary battery, which comprises mixing carbon powder as a conductive material or carbon powder as a conductive material and metal powder as a sulfur host with sulfur powder on a metal thin plate used as a cathode material of a metal-sulfur secondary battery, and coating the mixed powder as a current collector, wherein the metal thin plate for the cathode material is made of a material selected from nickel, a nickel-chromium alloy, a nickel-tin alloy, copper, and aluminum, or is made of a thin plate-shaped metal porous body having a sponge structure using a material selected from nickel, a nickel-chromium alloy, a nickel-tin alloy, copper, and aluminum, and the method for manufacturing the electrode material comprises a plating film coating step of sequentially plating at least two kinds of metals selected from nickel, zinc, tin, gold, silver, copper, indium, bismuth, antimony, and an indium-antimony alloy on the surface of the metal thin plate for the cathode material or the metal porous body using an electroplating or electroless plating method, and a step of coating a metal film on the surface of the metal thin plate or the metal porous body after the plating film coating step. After that, it is characterized in that it comprises an alloy layer forming step of forming each plating film plated on the surface of a metal thin plate or a metal porous body for a cathode material into an alloy layer by using a thermomigration treatment or an electromigration treatment or a combination of the two treatment methods, and after the alloy layer forming step, a current collector coating step is performed of mixing carbon powder as a conductive material or carbon powder as a conductive material and metal powder as a sulfur host with sulfur powder and coating the mixed powder on the surface of the alloy layer of the metal thin plate or the metal porous body for a cathode material, and the metal-sulfur secondary battery is selected from a lithium-sulfur battery, a sodium-sulfur battery, a potassium-sulfur battery, a calcium-sulfur battery, a magnesium-sulfur battery, a zinc-sulfur battery, and an aluminum-sulfur battery, and the carbon powder as a conductive material is characterized in that at least one or more of graphite, graphene, carbon black, carbon nanotube, and fullerene is used.

[0018] In addition, the present invention is characterized in that, in the case of the negative electrode material of a metal-sulfur secondary battery or the negative electrode material of a multi-metal secondary battery in which sulfur is not applied to the positive electrode material, the negative electrode material is manufactured as a metal thin plate made of a material selected from magnesium, aluminum, and zinc, and then a plating film coating step and an alloy layer composition step are sequentially performed on the metal thin plate for the negative electrode material in the same manner as described above, and the thickness of each plating film plated in the plating film coating step is characterized in that it is in the range of 100 nm to 10 μm, and the thermomigration treatment in the alloy layer composition step is performed by setting the limit temperature of the low-temperature side to 100°C or higher and the limit temperature of the high-temperature side to 300°C or lower, and the electromigration treatment in the alloy layer composition step is performed at 1 kA / cm 2 ~50kA / cm 2 It is characterized in that it is performed within the current density range of, and the electromigration treatment in the alloy layer composition step is characterized in that it is performed under a temperature condition of 20 to 300°C, and the thermomigration treatment in the alloy layer composition step is performed alternately at least twice by alternating the metal thin plate or metal porous body portion and the plating film portion to the low temperature side and the high temperature side, and the electromigration treatment in the alloy layer composition step is also characterized in that it is performed alternately at least twice by alternating the metal thin plate or metal porous body portion and the plating film portion to the cathode side and the anode side.

[0019] According to the present invention as described above, when a metal-sulfur secondary battery is used, the expansion and contraction of the positive electrode material due to the difference in density of sulfur and the density of the metal-sulfur compound is appropriately absorbed and buffered by the sponge structure of the metal porous body, thereby preventing the occurrence of a separation phenomenon between the positive electrode material and the current collector, and by using a uniform alloy film over a large surface area of ​​the metal porous body, the movement and localization of the host metal and the resulting elution of polysulfide ions are blocked, and at the same time, the bonding force between the positive electrode material based on the current collector and the polysulfide ions is maximized, thereby providing the effect of significantly improving the capacity, stability, and service life of the metal-sulfur battery, and by utilizing the method for producing some negative electrode materials for metal-sulfur secondary batteries and multi-metal secondary batteries that do not use sulfur, thereby doubling the performance of the metal-sulfur secondary battery, and thereby contributing to the improvement of the performance of the multi-metal secondary battery, thereby providing very useful effects.

[0020] Figure 1 is a cross-sectional view showing the structure of a secondary battery.

[0021] Figure 2 is a schematic diagram of an electroplating method using copper plating as a representative example.

[0022] Figures 3 and 4 are schematic diagrams showing the alloy layer composition method by thermomigration treatment.

[0023] Figure 5 is a scanning electron microscope (SEM) photograph showing a cross-section of a metal porous body of a cathode material for a metal-sulfur secondary battery manufactured through Example 1.

[0024] Figure 6 is a scanning electron microscope (SEM) photograph showing a cross-section of a metal porous body of a cathode material for a metal-sulfur secondary battery manufactured through Example 2.

[0025] Figure 7 is a graph showing the results of X-ray diffraction (XRD) measurement on a cross-section of a metal porous body of a cathode material for a metal-sulfur secondary battery manufactured through Example 2.

[0026] Figure 8 is a scanning electron microscope (SEM) photograph showing a cross-section of a metal porous body of a cathode material for a metal-sulfur secondary battery manufactured through Example 3.

[0027] Figure 9 is a scanning electron microscope (SEM) photograph showing a cross-section of a metal porous body of a cathode material for a metal-sulfur secondary battery manufactured through Example 4.

[0028] Figure 10 is a scanning electron microscope (SEM) photograph showing a cross-section of a metal porous body of a cathode material for a metal-sulfur secondary battery manufactured through Example 5.

[0029] Hereinafter, the present invention for achieving the above purpose will be described in detail with reference to the attached drawings.

[0030] First, the main application field of the method for manufacturing an electrode material for a secondary battery according to the present invention is a cathode material of a metal-sulfur secondary battery as described above, and among these, lithium (Li)-sulfur batteries, sodium (Na)-sulfur batteries, and potassium (K)-sulfur batteries using alkali metals, and calcium (Ca)-sulfur batteries, magnesium (Mg)-sulfur batteries, zinc (Zn)-sulfur batteries, and aluminum (Al)-sulfur batteries using multivalent metals are representative application targets, and the cathode material is selected from among nickel (Ni), nickel-chromium alloy (Ni-Cr), nickel-tin alloy (Ni-Sn), copper (Cu), and aluminum (Al).

[0031] The reason why the five metals described above are limited to the types of cathode materials applied to the present invention is that, through various experiments in various fields, it has been recognized that these metals have the most suitable properties for metal-sulfur secondary batteries, and can also be easily manufactured into a metal porous body with a sponge (mesh) structure that can be optimized and used in the present invention. In addition, a general metal sheet form can also be applied instead of this metal porous body, and the metal porous body is a known product that has been manufactured and sold in various ways.

[0032] As a representative example of the above metal porous body, there is the CELMET (registered trademark) product of Sumitomo Electric Co., Ltd. of Japan, which is manufactured by forming a metal layer on the surface of a foamed resin skeleton as a base by a plating method, a deposition method, a sputtering method, a CVD method, etc., and then reducing the metal layer while simultaneously removing the foamed resin portion by firing. However, it should be noted that there are no restrictions on the manufacturing method and the product itself as long as it is manufactured as a sponge-structured porous body using a material selected from among the five metals mentioned above, and the thickness of the metal porous body is usually about 1 to 2 mm.

[0033] As described above, a cathode material manufactured in the form of a metal thin plate or metal porous body using a material selected from among nickel, nickel-chromium alloy, nickel-tin alloy, copper, and aluminum is first subjected to a plating film coating step in which at least two metals having excellent bonding strength with polysulfide ions are selected from among nickel (Ni), zinc (Zn), tin (Sn), gold (Au), silver (Ag), copper (Cu), indium (In), bismuth (Bi), antimony (Sb), and indium (In)-antimony (Sb) and the metals are sequentially plated on the surface of the metal thin plate or metal porous body using an electroplating or electroless plating method.

[0034] In the above plating film coating step, the plated material for each plating metal (nickel, zinc, tin, gold, silver, copper, indium, bismuth, antimony, indium-antimony alloy) is a metal sheet for an anode or a porous metal body itself, or a metal sheet or porous metal body on which at least one plating film is coated by a plating metal other than the metal to be plated, and as long as the plating films of the same metals do not overlap, one metal may be plated more than twice based on the entire plating layer by the plating film. This can be interpreted as a concept of arranging the necessary metals in the right places to increase the efficiency of the thermomigration treatment and / or the electromigration treatment to be described later.

[0035] In addition, the electroplating method applied in this step is a known technology that connects a cathode terminal (4) to a plated object to be plated, as shown in Fig. 2, connects a metal plate for plating to an anode terminal (3), immerses the plated object and the metal plate in an electrolyte (9a), and then connects the anode terminal (3) and the cathode terminal (4) to a power source (8), while applying a load (8a) between the cathode terminal (4) and the power source (8), thereby forming plating on the surface of the plated object according to the principle of oxidation and reduction.

[0036] In Fig. 2, the electroplating process of copper is shown as a representative example, and a metal porous body (11) is applied as a plated object, and the metal porous body (11) is connected to a negative terminal (4) by a connection plate (4a), and the plating metal plate connected to the positive terminal (3) will be a copper plate (9), and the metals to which electroplating is applied in this step are nickel, zinc, tin, gold, silver, and copper, and the indium, bismuth, antimony, and indium-antimony alloy are applied by an electroless plating method (chemical plating).

[0037] Since the above electroless plating method is also a known technology that adds a reducing agent to an aqueous solution of a metal salt to deposit a metal component on the surface of a material to be treated, a detailed description of the method itself will be omitted, and the plating method for each metal will be described in more detail below, and the material to be plated mentioned in the description means, as described above, a metal thin plate or metal porous body itself for an anode material, or a metal other than the metal to be plated on the surface of the metal thin plate or metal porous body at least once coated.

[0038] First, electroplating using nickel is performed by dissolving 240 to 260 g of nickel sulfate, 40 to 50 g of nickel chloride, and 30 to 40 g of boric acid in 1 L of ion-exchanged water, adjusting the pH to 4 to 5, and immersing the plated object connected to the negative terminal together with the nickel plate connected to the positive terminal, under temperature conditions of 45 to 55°C at 4 to 6 A / dm 2 It is performed by applying a current density of 4 to 6 A / dm, and electroplating using zinc is performed by dissolving 8 to 12 g of metallic zinc, 9 to 13 g of sodium cyanide, and 75 to 85 g of sodium hydroxide in 1 L of ion-exchanged water, and adjusting the pH to 13 to 14, and immersing the plated object connected to the negative terminal together with the zinc plate connected to the positive terminal under temperature conditions of 20 to 30°C. 2 It is performed by applying a current density of .

[0039] And, electroplating using tin is performed by dissolving 35 to 45 g of tin sulfate, 90 to 110 g of sulfuric acid, 35 to 45 g of potassium cresol sulfonate, 1.5 to 2.5 g of gelatin, and 0.5 to 1.5 g of β-naphthol in 1 L of ion-exchanged water, and immersing the plated object connected to the negative terminal together with the tin plate connected to the positive terminal, and applying 1 to 2 A / dm under temperature conditions of 20 to 30°C. 2It is performed by applying a current density of 0.4 to 0.6 A / dm, and electroplating using gold is performed by dissolving 10 to 14 g of potassium gold cyanide, 18 to 22 g of potassium cyanide, 18 to 22 g of potassium phosphate, and 18 to 22 g of potassium carbonate in 1 L of ion-exchanged water, and adjusting the pH to 11 to 13, and immersing the plated object connected to the negative terminal together with the gold plate connected to the positive terminal under temperature conditions of 65 to 75°C. 2 It is performed by applying a current density of .

[0040] In addition, electroplating using silver is performed by dissolving 35 to 45 g of potassium silver cyanide, 140 to 160 g of potassium pyrophosphate, and 4 to 6 g of EDTA 4 potassium salt in 1 L of ion-exchanged water, and then adjusting the pH to 8 to 10 using potassium pyrophosphate and potassium hydroxide, and immersing the plated object connected to the negative terminal together with the silver plate connected to the positive terminal, and applying 45 to 55 A / dm under temperature conditions of 45 to 55°C. 2 It is performed by applying a current density of 5 to 7 A / dm, and electroplating using copper is performed by immersing the plated object connected to the negative terminal together with the copper plate connected to the positive terminal in an electrolyte solution in which 90 to 110 g of copper sulfate pentahydrate, 90 to 110 g of sulfuric acid, and 45 to 55 mg of chloride ions are dissolved in 1 L of ion-exchanged water, and the current density is 5 to 7 A / dm under temperature conditions of 25 to 35°C. 2 It is performed by applying a current density of .

[0041] In addition, electroless plating using indium is performed by dissolving 75 to 85 g of trisodium citrate dihydrate, 35 to 45 g of nitrilotriacetic acid, 23 to 27 g of indium chloride tetrahydrate, and 5 to 7 g of titanium chloride in 1 L of ion-exchanged water, and then immersing the plated object in a plating solution in which the pH is adjusted to 9 to 11 using ammonia water, and depositing the indium layer at a temperature of 75 to 85°C. Electroless plating using bismuth is performed by dissolving 85 to 95 g of trisodium citrate dihydrate, 28 to 32 g of EDTA, 38 to 42 g of nitrilotriacetic acid, 24 to 26 g of boron chloride, and 7 to 9 g of tin chloride dihydrate in 1 L of ion-exchanged water, and then adjusting the pH to 8.6 to 9 using ammonia water. It is performed by immersing the plated material and depositing a bismuth layer under temperature conditions of 55 to 65°C.

[0042] Finally, electroless plating using antimony is performed by dissolving 16-20 g of antimony chloride, 92-96 g of trisodium citrate dihydrate, 28-32 g of disodium EDTA dihydrate, 18-20 g of nitrilostracetic acid, and 5-7 g of titanium trichloride in 1 L of ion-exchanged water, and then immersing the plated object in a plating solution whose pH is adjusted to 7-8 using a 28 wt% ammonia aqueous solution to deposit an antimony layer at a temperature of 18-22°C. Electroless plating using an indium-antimony alloy is performed by dissolving 16-20 g of indium chloride, 0.04-0.06 g of antimony chloride, 95-105 g of trisodium citrate dihydrate, 28-32 g of nitrilostracetic acid, and 5-7 g of titanium trichloride in 1 L of ion-exchanged water, respectively. It is performed by immersing the plated object in a plating solution in which the pH is adjusted to 7.6 to 8 using a 20 wt% sodium carbonate aqueous solution after being injected and melted, and depositing the indium-antimony layer under temperature conditions of 55 to 65°C.

[0043] As mentioned above, the components, their addition amounts, and plating conditions mentioned in the individual plating methods using each plating metal are optimal conditions for making the thickness of the plating film formed through the process within the range of 100 nm to 10 μm, and the reason for making the thickness of the plating film by each plating metal within the range of 100 nm to 10 μm is that if the thickness of each plating film is less than 100 nm, the thickness of the alloy layer formed by subsequent thermomigration and / or electromigration treatment also becomes very thin, so there is a concern that the bonding strength of the alloy layer with polysulfide ions may be reduced, and if the thickness of each plating film exceeds 10 μm, the work of forming the alloy layer through thermomigration treatment and / or electromigration treatment becomes very difficult.

[0044] As an additional matter, when plating each plating metal on the surface of a metal sheet or porous metal body for an anode, at least two plating films must be formed along the surface. Therefore, in order to ensure accuracy and convenience of each plating work, it is preferable that when the plating film coating step using one metal is completed, the metal sheet or porous metal body coated with the metal is subjected to a water washing treatment, and then the plating film coating step using another metal is performed in succession.

[0045] After the plating film coating process is performed in the above manner, an alloy layer forming step is performed in which each plating film plated on the surface of the metal sheet or metal porous body for the anode material is formed into an alloy layer by using thermomigration processing, electromigration processing, or a combination of these two processing methods. The thermomigration processing and electromigration processing applied in this step are also known technologies in themselves.

[0046] As shown in FIGS. 3 and 4, the above thermomigration treatment is performed by arranging a high-temperature side heater chip (14) and a low-temperature side heater chip (15) on a metal sheet or metal porous body (11) for an anode material on which at least two plating films (12) are formed, respectively, on the plating film (12) side and the metal sheet or metal porous body (11) side at the opposite position, thereby inducing heat transfer between the plated metal atoms and forming each plating film (12) into an alloy layer (13) between the plated metals. In the drawings, a process in which a first plating film (12a) made of copper and a second plating film (12b) made of tin are formed into an alloy layer (13) through thermomigration treatment is shown as a representative example.

[0047] To provide an additional explanation of the principle of thermomigration as described above, when two uniform phases A and B made of two metal components are in contact at different temperatures, there are cases where movement of atoms occurs between each phase. This phenomenon is called thermomigration, and the atomic flux and the driving force of thermomigration that diffuse due to thermomigration are calculated by Equations (6) and (7), respectively.

[0048] J TM =C(D / kT)Q* / T(-∂T / ∂x) ---------- (6)

[0049] F TM =-Q* / T(-∂T / ∂x) ---------- (7)

[0050] Here, Q* represents heat transport and has a unique value depending on the metal atom. If the value of Q* has a positive (+) value, atoms move from the high temperature side to the low temperature side, and if the value of Q* has a negative (-) value, atoms move from the low temperature side to the high temperature side. Among the metals used in the present invention, nickel (Ni), zinc (Zn), tin (Sn), gold (Au), silver (Ag), copper (Cu), indium (In), bismuth (Bi), antimony (Sb), and indium (In)-antimony (Sb), metals having negative values ​​of Q* are Sn and Au, Ag has a value of 0, and Zn, Cu, In, Sb, and Bi have positive values.

[0051] In the above equation (7), the driving force for the diffusion of atoms is determined by the heat flux Q* and the temperature gradient ∂T / ∂x, so it can be seen that the greater the temperature difference between two metals in contact with each other, the easier thermomigration occurs. Accordingly, in the present invention, when two or more types of metals are plated on the surface of a metal thin plate or a metal porous body and a temperature difference is applied to both sides in the manner shown in FIGS. 3 and 4, movement of metal atoms occurs, and when thermomigration is performed alternately on the high-temperature side and the low-temperature side, a more uniform alloy layer (13) is formed on the surface of the metal thin plate or the metal porous body (11).

[0052] In other words, if thermomigration is performed alternately at least twice with the high-temperature side heater chip (14) and the low-temperature side heater chip (15) on the metal porous body (11) portion and the plating film (12) portion based on FIGS. 3 and 4, the first plating film (12a) and the second plating film (12b) can be formed into a more uniform alloy layer (13), and since the melting point of indium is low at about 156.6°C, an excellent dispersion effect can be obtained through thermomigration.

[0053] As previously explained, the driving force of thermomigration is that the greater the temperature difference according to the distance between the low-temperature side and the high-temperature side, the more active the movement of atoms becomes. In the study for the present invention, the temperature difference per 1 cm was expressed numerically in the range of 1000°C / cm to 4000°C / cm (a temperature difference of 1000 to 4000 degrees occurs at a distance of 1 cm between the low-temperature side and the high-temperature side). As a result of conducting various experiments, it was obtained that the thermomigration treatment applied to the present invention is most efficient when the low-temperature side is set to 100°C and the high-temperature side to about 300°C.

[0054] In addition, it is acceptable to interpret that the above electromigration treatment is performed by using the low-temperature side heater chip (15) and the high-temperature side heater chip (14) applied to the thermomigration treatment as the cathode plate and the anode plate, respectively, and since the direction and speed of movement of metal atoms generated during the electromigration treatment also differ depending on the type of metal, it is preferable to alternately perform the metal thin plate or metal porous body (11) portion and the plating film (12) portion at least twice, alternating between the cathode side and the anode side, as in the preceding thermomigration treatment.

[0055] To provide an additional explanation of the principle of the above electromigration, when a high current density is applied to a thin film such as a metal, movement of material occurs, and this phenomenon is called electromigration. The atomic flux of atoms diffused by electromigration and the driving force of thermomigration are also calculated using equations (8) and (9) below.

[0056] J EM =C(D / kT)Z*eE

[0057] = C(D / kT)Z*eρj ---------- (8)

[0058] F EM =Z*eρj ---------- (9)

[0059] Here, C is the concentration of diffusing atoms, D is the diffusion coefficient of atoms, k is the Boltzmann constant, T is the absolute temperature, Z* is the effective charge of electromigration, and e is the charge of electrons (1.602176634 × 10 -19 C), E represents the electric field, ρ represents the resistivity, and j represents the current density, and the higher the current density, the easier it is for atoms to move.

[0060] In addition, if the above electromigration treatment is performed under a temperature condition of 20 to 300°C, an effect similar to that of performing electromigration treatment and thermomigration treatment simultaneously can be achieved, and since electromigration uses the principle that when current flows through a metal, electrons move into the metal and push out metal atoms, the greater the current density, the greater the electromigration occurs, but if the current density is too high, holes (damage) occur in the plating film, so taking this into account, the current density applied to the electromigration treatment of the present invention is 1 kA / cm 2 ~50kA / cm 2 It is desirable to do so within the scope of .

[0061] After performing the alloy layer composition step in the above manner, as mentioned in the prior art, carbon powder as a conductive material and metal powder as a sulfur host are mixed with sulfur powder, and a turbidity is first prepared by introducing the mixture as a solvent, and then the turbidity is applied to the surface of the alloy layer to dry the solvent component, thereby completing the electrode material manufacturing method according to the present invention. Through this, a cathode material for a metal-sulfur secondary battery is finally manufactured, in which carbon powder as a conductive material and metal powder as a sulfur host are coated as a current collector on the surface of the alloy layer.

[0062] In this step, it is preferable to use at least one of graphite, graphene, carbon black, carbon nanotube, and fullerene as the carbon powder, but various other types of carbon powders can be used, and if necessary, it is also possible to use carbon powder alone as a conductive material without using metal powder as a sulfur host. In this case, the mixing ratio of sulfur powder and carbon powder is preferably about 1 (sulfur):9 (carbon) to 8 (sulfur):2 (carbon), and when carbon powder and metal powder are mixed together with sulfur powder, the mixing ratio is preferably about 1 (sulfur):4 (carbon):5 (metal) to 8 (sulfur):1 (carbon):1 (metal).

[0063] In addition, as the metal powder as the sulfur host, as mentioned in the prior art, Mn, Fe, Co, Ni, Cu, Zn, Mo, W, V, Zr, Sn, Sb, In, Bi, Fe2O3, Fe3O4, Co3O4, CoO, NiO, MnO2, Mn3O4, MnO, VO2, V2O5, MoO2, ZnO, ZrO2, Co(NO3)2, Ni(NO3)2, Fe(NO3)3, CoCl2, NiCl2, FeCl3, Fe(SO4)3, Co(CH3COO)2, Ni(CH3COO)2, etc. can be applied, and it is to be noted that other metal powders can also be applied, and the solvent used for applying them and the application method can also be applied in a method other than the method mentioned in the prior art.

[0064] For example, a representative example is a method of mixing 5 to 10 wt% of mixed powder (sulfur + carbon or sulfur + carbon + metal) with 1 L of water (solvent), applying the turbidity on an alloy layer, heating and drying (solvent removal) at a temperature of 100 to 300 ° C. In addition to water, the solvent may also include alcohols (methanol, ethanol, 2-propanol, 1-butanol, 2-ethoxyethanol, 2-n-butoxyethanol, etc.) and ethers (tetrahydrofuran, diethyl ether, 1,4-dioxane, etc.), and N-methyl-2-pyrrolidone (NMP), acetone, acetaldehyde, cyclohexanone, etc., and depending on each solvent, the drying method of the turbidity may be performed in a different way, such as volatilization drying.

[0065] As mentioned in the introduction, the main application fields of the electrode material manufacturing method according to the present invention are positive electrode materials of lithium-sulfur batteries, sodium-sulfur batteries, and potassium-sulfur batteries using alkali metals, and calcium-sulfur batteries, magnesium-sulfur batteries, zinc-sulfur batteries, and aluminum-sulfur batteries using multivalent metals, but it can also be applied to negative electrode materials of metal-sulfur batteries that can perform plating film coating work using ion exchange water as a medium, and negative electrode materials of multivalent metal secondary batteries that do not use sulfur.

[0066] In other words, the anode materials of metal-sulfur batteries to which the present invention can be applied are magnesium-sulfur batteries, aluminum-sulfur batteries, and zinc-sulfur batteries, and among multi-metal secondary batteries that do not use sulfur, the present invention can be applied to magnesium anode materials, aluminum anode materials, and zinc anode materials. In order to apply the present invention to these anode materials, a metal sheet made of a material selected from among magnesium, aluminum, and zinc is used as a base, and only the plating film coating step and the alloy layer composition step are sequentially performed in the same manner as described above.

[0067] The present invention having the above-described configuration will be more clearly understood by the following examples, but this does not mean that the present invention is limited to the following examples, and it is to be understood that the process of selecting and combining at least two kinds of nickel, zinc, tin, gold, silver, copper, indium, bismuth, antimony, and indium-antimony alloy to perform plating film coating treatment, and forming each plating film into an alloy layer through thermomigration and / or electromigration treatment can be implemented in a wide variety of forms, not just the following examples.

[0068] Example 1: Zinc plating → tin plating → thermomigration / electromigration on nickel porous body

[0069] Dissolve 10g of metallic zinc, 11g of sodium cyanide, and 80g of sodium hydroxide in 1L of ion-exchanged water, and adjust the pH to 13.5. Add a 5cm x 5cm nickel porous body to the solution, use it as a cathode, and a zinc plate as an anode, and apply a current density of 5A / dm at 25℃. 2 As per the approval, 5 μm thick zinc plating was performed, and after washing, it was placed in an aqueous solution of 40 g of tin sulfate, 100 g of sulfuric acid, 40 g of potassium cresol sulfonate, 2 g of gelatin, and 1 g of β-naphthol dissolved in 1 L of ion-exchanged water, and the porous body was used as the cathode and the tin plate as the anode, and the current was applied at 25°C under 1.5 A / dm 2 As per the approval, 5 μm thick tin plating was performed.

[0070] After washing and drying the porous body, heater chips were attached to both sides of the porous body, and the temperature of the high-temperature side heater chip was set to 250°C and the temperature of the low-temperature side heater chip was set to 100°C, and thermomigration was maintained for 10 hours. After that, the high-temperature side was used as the cathode and the low-temperature side was used as the anode, and a current density of 5 x 10 3 A / cm 2Electromigration was performed for 50 hours, and then the temperatures of the high-temperature side and the low-temperature side attached to the heater chip were reversed to maintain thermomigration for 10 hours. Then, the temperatures of the high-temperature side and the low-temperature side attached to the heater chip were reversed again to maintain thermomigration for 10 hours. The results of scanning electron microscope (SEM) observation of the cross-section of the metal porous body that went through the process are shown in the photograph of Fig. 5.

[0071] Example 2: Copper plating → Indium plating → Tin plating → Silver plating → Tin plating → Thermomigration / Electromigration on a nickel porous body

[0072] A nickel porous body measuring 5 cm x 5 cm was placed in an aqueous solution containing 100 g of copper sulfate pentahydrate, 100 g of sulfuric acid, and 50 mg of chloride ion dissolved in 1 L of ion-exchanged water, and a copper plate was placed as an anode, and a current density of 6 A / dm was applied at 30°C. 2 Copper plating with a thickness of 1 μm was performed by applying the following: After washing, 80 g of sodium citrate dihydrate, 40 g of nitrilotriacetic acid, 25 g of indium chloride tetrahydrate, and 6 g of titanium chloride were added to 1 L of ion-exchanged water, and the solution was adjusted to pH 10 using ammonia water, and electroless indium plating with a thickness of 2 μm was performed at 80°C. After washing, 40 g of tin sulfate, 100 g of sulfuric acid, 40 g of potassium cresol sulfonate, 2 g of gelatin, and 1 g of β-naphthol were dissolved in 1 L of ion-exchanged water, and the solution was placed as a cathode and a tin plate as an anode, and a current of 1.5 A / dm was applied at 25°C. 2 As per the approval, 2 μm thick tin plating was performed, and after washing it, 40 g of potassium silver cyanide, 150 g of potassium pyrophosphate, and 5 g of EDTA tetrapotassium salt were dissolved in 1 L of ion-exchanged water, and then placed in an aqueous solution whose pH was adjusted to 9 with potassium pyrophosphate and potassium hydroxide, and used as a cathode and a silver plate as an anode, and the current was 50 A / dm at 50℃. 2As per the approval, silver plating with a thickness of 3 μm was performed, and after washing, it was placed in an aqueous solution of 40 g of tin sulfate, 100 g of sulfuric acid, 40 g of potassium cresol sulfonate, 2 g of gelatin, and 1 g of β-naphthol dissolved in 1 L of ion-exchanged water, and the solution was used as a cathode and a tin plate as an anode, and the current was applied at 25°C under 1.5 A / dm 2 As per the approval, 2 μm thick tin plating was performed.

[0073] After washing and drying the porous body, heater chips were attached to both sides of the porous body, and the temperature of the high-temperature side heater chip was set to 270°C and the temperature of the low-temperature side heater chip was set to 100°C, and thermomigration was maintained for 10 hours. After that, the high-temperature side was used as the cathode and the low-temperature side was used as the anode, and a current density of 5 x 10 3 A / cm 2 Electromigration was performed for 50 hours, and thermomigration was maintained for 10 hours by reversing the temperatures of the high-temperature side and the low-temperature side attached to the heater chip. After that, the temperatures of the high-temperature side and the low-temperature side attached to the heater chip were reversed again and thermomigration was maintained for 10 hours. The results of scanning electron microscope (SEM) observation of the cross-section of the metal porous body that went through the process and the results of X-ray diffraction (XRD) measurement of the cross-section are shown in the photograph of Fig. 6 and the graph of Fig. 7.

[0074] Example 3: Electroless plating of indium-antimony alloy on nickel-chromium porous body → tin plating

[0075] → Bismuth plating → Gold plating → Thermomigration / electromigration

[0076] In 1 L of ion-exchanged water, 18 g of indium chloride, 0.05 g of antimony chloride, 100 g of trisodium citrate dihydrate, 30 g of nitrilostracetic acid, and 6 g of titanium chloride were added, and the pH was adjusted to 7.8 with 20 wt% sodium carbonate aqueous solution. A nickel-chromium porous body measuring 5 cm x 5 cm was placed in the solution, and electroless indium-antimony alloy plating was performed at 60°C with a thickness of 1 μm. After washing the body, it was placed in an aqueous solution of 40 g of tin sulfate, 100 g of sulfuric acid, 40 g of potassium cresol sulfonate, 2 g of gelatin, and 1 g of β-naphthol dissolved in 1 L of ion-exchanged water, and the body was plated as a cathode and a tin plate as an anode, with a current of 1.5 A / dm at 25°C. 2 2 μm thick tin plating was performed by allowing the solution to be washed, and then 90 g of sodium citrate dihydrate, 30 g of EDTA, 40 g of nitrilotriacetic acid, 25 g of boron chloride, and 8 g of tin chloride dihydrate were dissolved in 1 L of ion-exchanged water, and the solution was placed in an aqueous solution adjusted to pH 8.8 using ammonia water, and electroless bismuth plating was performed at 60°C to a thickness of 1 μm. This was placed in an aqueous solution adjusted to pH 12 by dissolving 12 g of potassium gold cyanide, 20 g of potassium cyanide, 20 g of potassium phosphate, and 20 g of potassium carbonate in 1 L of ion-exchanged water, and used as a cathode and a gold plate as an anode, and the solution was electroplated at a current density of 0.5 A / dm at 70°C. 2 Gold plating of 0.5 μm thickness was performed by approving .

[0077] After washing and drying the porous body, heater chips were attached to both sides of the porous body, and the temperature of the high-temperature side heater chip was set to 250°C and the temperature of the low-temperature side heater chip was set to 100°C, and thermomigration was maintained for 10 hours. After that, the high-temperature side was used as the cathode and the low-temperature side was used as the anode, and a current density of 1 x 10 4 A / cm 2Electromigration was performed for 50 hours, and then the temperatures of the high-temperature side and the low-temperature side attached to the heater chip were reversed to maintain thermomigration for 10 hours. Then, the temperatures of the high-temperature side and the low-temperature side attached to the heater chip were reversed again to maintain thermomigration for 10 hours. The results of scanning electron microscope (SEM) observation of the cross-section of the metal porous body that went through the process are shown in the photograph of Fig. 8.

[0078] Example 4: Nickel plating → tin plating → indium plating → bismuth plating → thermomigration / electromigration on a copper porous body

[0079] Dissolve 250g of nickel sulfate, 45g of nickel chloride, and 35g of boric acid in 1L of ion-exchanged water, adjust the pH to 4.5, and add a 5cm x 5cm copper porous body to the solution as a cathode and a nickel plate as an anode. The current density is 5A / dm at 50℃. 2 Nickel plating with a thickness of 1 μm was performed by approving it, and after washing it, it was placed in an aqueous solution of 40 g of tin sulfate, 100 g of sulfuric acid, 40 g of potassium cresol sulfonate, 2 g of gelatin, and 1 g of β-naphthol dissolved in 1 L of ion-exchanged water, and the current density was 1.5 A / dm at 25℃ with a tin plate as the anode. 2 2 μm thick tin plating was performed by applying the following: After washing, 80 g of sodium citrate dihydrate, 40 g of nitrilotriacetic acid, 25 g of indium chloride tetrahydrate, and 6 g of titanium chloride were added to 1 L of ion-exchanged water, and the pH was adjusted to 10 using ammonia water. The resulting solution was placed in an aqueous solution, and 2 μm thick electroless indium plating was performed at 80°C. After washing, 90 g of sodium citrate dihydrate, 30 g of EDTA, 40 g of nitrilotriacetic acid, 25 g of boron chloride, and 8 g of tin chloride dihydrate were added to 1 L of ion-exchanged water, and the pH was adjusted to 8.8 using ammonia water. The resulting solution was placed in an aqueous solution, and 1 μm thick electroless bismuth plating was performed at 60°C.

[0080] After washing and drying the porous body, heater chips were attached to both sides of the porous body, and the temperature of the high-temperature side heater chip was set to 250°C and the temperature of the low-temperature side heater chip was set to 100°C, and thermomigration was maintained for 10 hours. After that, the high-temperature side was used as the cathode and the low-temperature side was used as the anode, and a current density of 5 x 10 5 A / cm 2 Electromigration was performed for 100 hours, and then the temperatures of the high-temperature side and the low-temperature side attached to the heater chip were reversed to maintain thermomigration for 10 hours. After that, the temperatures of the high-temperature side and the low-temperature side attached to the heater chip were reversed again to maintain thermomigration for 10 hours. The results of scanning electron microscope (SEM) observation of the cross-section of the metal porous body that went through the process are shown in the photograph of Fig. 9.

[0081] Example 5: Copper plating → Silver plating → Tin plating → Indium-antimony plating → Thermomigration / Electromigration on aluminum porous body

[0082] A 5 cm x 5 cm aluminum porous body was placed in an aqueous solution containing 100 g of copper sulfate pentahydrate, 100 g of sulfuric acid, and 50 mg of chloride ion dissolved in 1 L of ion-exchanged water, and a copper plate was placed as an anode, and a current density of 6 A / dm was applied at 30°C. 2 Copper plating with a thickness of 1 μm was performed by approving, and after washing, 40 g of potassium silver cyanide, 150 g of potassium pyrophosphate, and 5 g of EDTA tetrapotassium salt were dissolved in 1 L of ion-exchanged water, and then placed in an aqueous solution whose pH was adjusted to 9 with potassium pyrophosphate and potassium hydroxide, and used as a cathode and a silver plate as an anode, and a current density of 50 A / dm was applied at 50°C. 2 As per the approval, silver plating with a thickness of 1 μm was performed, and after washing, it was placed in an aqueous solution of 40 g of tin sulfate, 100 g of sulfuric acid, 40 g of potassium cresol sulfonate, 2 g of gelatin, and 1 g of β-naphthol dissolved in 1 L of ion-exchanged water, and a tin plate was used as the cathode and a current density of 1.5 A / dm was applied at 25°C. 2As a result, 2 μm thick tin plating was performed, and after washing, 18 g of indium chloride, 0.05 g of antimony chloride, 100 g of trisodium citrate dihydrate, 30 g of nitrilostracetic acid, and 6 g of titanium chloride were added to 1 L of ion-exchanged water, and the solution was placed in an aqueous solution whose pH was adjusted to 7.8 with a 20 wt% sodium carbonate aqueous solution, and 1 μm thick electroless indium-antimony plating was performed at 60°C.

[0083] After washing and drying the porous body, heater chips were attached to both sides of the porous body, and the temperature of the high-temperature side heater chip was set to 250°C and the temperature of the low-temperature side heater chip was set to 100°C, and thermomigration was maintained for 10 hours. After that, the high-temperature side was used as the cathode and the low-temperature side was used as the anode, and a current density of 1 x 10 4 A / cm 2 Electromigration was performed for 50 hours, and then the temperatures of the high-temperature side and the low-temperature side attached to the heater chip were reversed to maintain thermomigration for 10 hours. Then, the temperatures of the high-temperature side and the low-temperature side attached to the heater chip were reversed again to maintain thermomigration for 10 hours. The results of scanning electron microscope (SEM) observation of the cross-section of the metal porous body that went through the process are shown in the photograph of Fig. 10.

[0084] Example 6: Zinc plating → tin plating → thermomigration / electromigration on a magnesium metal sheet

[0085] Dissolve 10g of metallic zinc, 11g of sodium cyanide, and 80g of sodium hydroxide in 1L of ion-exchanged water, and adjust the pH to 13.5. Add a 5cm x 5cm magnesium metal plate to the solution, and use it as a cathode and a zinc plate as an anode. At 25℃, a current density of 5A / dm 2As per the approval, 5 μm thick zinc plating was performed, and after washing, it was placed in an aqueous solution of 40 g of tin sulfate, 100 g of sulfuric acid, 40 g of potassium cresol sulfonate, 2 g of gelatin, and 1 g of β-naphthol dissolved in 1 L of ion-exchanged water, and a current density of 1.5 A / dm was applied at 25°C with a metal foil as the cathode and a tin plate as the anode. 2 As per the approval, 5 μm thick tin plating was performed.

[0086] After washing and drying the metal sheet, heater chips were attached to both sides of the metal sheet, and the temperature of the high-temperature side heater chip was set to 250°C and the temperature of the low-temperature side heater chip was set to 100°C, and thermomigration was maintained for 10 hours. After that, the high-temperature side was used as the cathode and the low-temperature side was used as the anode, and a current density of 5 x 10 3 A / cm 2 Electromigration was performed for 50 hours, and then the temperatures of the high-temperature side and the low-temperature side attached to the heater chip were reversed and thermomigration was maintained for 10 hours. After that, the temperatures of the high-temperature side and the low-temperature side attached to the heater chip were reversed again and thermomigration was maintained for 10 hours.

[0087] According to the present invention having the above-described configuration, when a metal-sulfur secondary battery is used, the expansion and contraction of the positive electrode material due to the difference in density between sulfur and the density of the metal-sulfur compound is appropriately absorbed and buffered by the sponge structure of the metal porous body, thereby preventing a separation phenomenon between the positive electrode material and the current collector, and by using a uniform alloy film over a large surface area of ​​the metal porous body, the movement and localization of the host metal and the resulting elution of polysulfide ions are blocked, and at the same time, the bonding strength between the positive electrode material based on the current collector and the polysulfide ions can be maximized.

[0088] Through this, the capacity, stability, and service life of the metal-sulfur battery can be greatly improved compared to the conventional case where a carbon material (carbon powder) as a conductive material and a metal material (metal powder) as a sulfur host are mixed with sulfur powder and then simply coated on the surface of the cathode material. In addition, the method can be used to produce some cathode materials for metal-sulfur secondary batteries and multi-metal secondary batteries that do not use sulfur, thereby doubling the performance of metal-sulfur secondary batteries and contributing to the improvement of the performance of multi-metal secondary batteries.

[0089] The present invention relates to a method for manufacturing an electrode material for a secondary battery by sequentially plating two or more types of metals having a strong bonding force with polysulfide ions on the surface of a metal thin plate or metal porous body for a cathode material, forming an alloy layer in which each plating film is uniformly mixed through thermomigration and / or electromigration treatment, and then coating a polysulfide ion current collector on the surface of the alloy layer, and is an invention that can be applied industrially.

Claims

1. A method for manufacturing an electrode material for a secondary battery, wherein carbon powder as a conductive material or carbon powder as a conductive material and metal powder as a sulfur host are mixed with sulfur powder on a metal sheet used as a cathode material of a metal-sulfur secondary battery, and the mixed powder is coated as a current collector. The above metal sheet for the anode is made of a material selected from nickel, nickel-chromium alloy, nickel-tin alloy, copper, and aluminum, or is made of a thin metal porous body having a sponge structure using a material selected from nickel, nickel-chromium alloy, nickel-tin alloy, copper, and aluminum. The method for manufacturing the above electrode material comprises a plating film coating step of sequentially plating at least two kinds of metal selected from nickel, zinc, tin, gold, silver, copper, indium, bismuth, antimony, and an indium-antimony alloy on the surface of a metal sheet or metal porous body for the cathode material using an electroplating or electroless plating method, After the above plating film coating step, the method comprises an alloy layer forming step in which each plating film plated on the surface of the metal sheet or metal porous body for the anode material is formed into an alloy layer by using thermomigration treatment, electromigration treatment, or a combination of these two treatment methods. A method for manufacturing an electrode material for a secondary battery, characterized in that after the above alloy layer composition step, a current collector coating step is performed in which carbon powder as a conductive material or carbon powder as a conductive material and metal powder as a sulfur host are mixed with sulfur powder and the mixed powder is coated on the surface of the alloy layer of a metal thin plate or metal porous body for a cathode material.

2. A method for manufacturing an electrode material for a secondary battery, characterized in that in the first paragraph, the metal-sulfur secondary battery is selected from a lithium-sulfur battery, a sodium-sulfur battery, a potassium-sulfur battery, a calcium-sulfur battery, a magnesium-sulfur battery, a zinc-sulfur battery, and an aluminum-sulfur battery, and the carbon powder as the conductive material is at least one selected from graphite, graphene, carbon black, carbon nanotubes, and fullerene.

3. In a method for manufacturing an electrode material used as a negative electrode material of a metal-sulfur secondary battery or as a negative electrode material of a multi-metal secondary battery in which sulfur is not applied to the positive electrode material, The above cathode material is based on a metal sheet made of one of magnesium, aluminum, and zinc. The method for manufacturing the above electrode material comprises a plating film coating step of sequentially plating at least two kinds of metal selected from nickel, zinc, tin, gold, silver, copper, indium, bismuth, antimony, and an indium-antimony alloy on the surface of a metal sheet for a cathode material using an electroplating or electroless plating method, A method for manufacturing an electrode material for a secondary battery, characterized in that after the above-mentioned plating film coating step, an alloy layer forming step is performed to form each plating film plated on the surface of a metal sheet for a negative electrode material into an alloy layer by using thermomigration treatment, electromigration treatment, or a combination of these two treatment methods.

4. A method for manufacturing an electrode material for a secondary battery, characterized in that in any one of claims 1 to 3, the thickness of each plating film plated in the plating film coating step is within a range of 100 nm to 10 μm.

5. In any one of clauses 1 to 3, the thermomigration treatment in the alloy layer composition step is performed with the limit temperature on the low temperature side being 100°C or higher and the limit temperature on the high temperature side being 300°C or lower, and the electromigration treatment in the alloy layer composition step is performed with the limit temperature on the high temperature side being 300°C or lower. 2 ~50kA / cm 2 A method for manufacturing an electrode material for a secondary battery, characterized in that the method is performed within a current density range.

6. A method for manufacturing an electrode material for a secondary battery, characterized in that in the alloy layer composition step of paragraph 5, the electromigration treatment is performed under a temperature condition of 20 to 300°C.

7. A method for manufacturing an electrode material for a secondary battery, characterized in that in any one of claims 1 to 3, the thermomigration treatment in the alloy layer composition step is performed alternately at least twice between the metal thin plate or metal porous body portion and the plating film portion, alternately between the low-temperature side and the high-temperature side, and the electromigration treatment in the alloy layer composition step is also performed alternately between the metal thin plate or metal porous body portion and the plating film portion, alternately between the cathode side and the anode side, at least twice.

8. In any one of paragraphs 1 to 3, in the plating film coating step, the plated material for each plating metal is the anode metal sheet or porous metal sheet or cathode metal sheet itself, or at least one plating film is coated on the surface of the anode metal sheet or porous metal sheet or cathode metal sheet by a plating metal other than the metal to be plated. Nickel plating targeting the above-mentioned plated object is electroplated by dissolving 240 to 260 g of nickel sulfate, 40 to 50 g of nickel chloride, and 30 to 40 g of boric acid in 1 L of ion-exchange water, adjusting the pH to 4 to 5, and immersing the plated object connected to the cathode terminal together with the nickel plate connected to the anode terminal, and applying a current density of 4 to 6 A / dm2 under temperature conditions of 45 to 55°C. Zinc plating targeting the above-mentioned plated object is electroplating in which 8 to 12 g of metallic zinc, 9 to 13 g of sodium cyanide, and 75 to 85 g of sodium hydroxide are dissolved in 1 L of ion-exchange water, and the pH is adjusted to 13 to 14, and the plated object connected to the cathode terminal is immersed together with the zinc plate connected to the anode terminal, and a current density of 4 to 6 A / dm2 is applied under temperature conditions of 20 to 30°C. The tin plating for the above-mentioned plated object is an electroplating method in which the plated object connected to the cathode terminal is immersed in an electrolyte solution in which 35 to 45 g of tin sulfate, 90 to 110 g of sulfuric acid, 35 to 45 g of potassium cresol sulfonate, 1.5 to 2.5 g of gelatin, and 0.5 to 1.5 g of β-naphthol are dissolved in 1 L of ion-exchange water, and a current density of 1 to 2 A / dm2 is applied under a temperature condition of 20 to 30°C. Gold plating on the above-mentioned plated object is electroplating in which the plated object connected to the cathode terminal is immersed in an electrolyte in which 10 to 14 g of potassium gold cyanide, 18 to 22 g of potassium cyanide, 18 to 22 g of potassium phosphate, and 18 to 22 g of potassium carbonate are dissolved in 1 L of ion-exchange water, and the pH is adjusted to 11 to 13, and a current density of 0.4 to 0.6 A / dm2 is applied under a temperature condition of 65 to 75°C. The silver plating targeting the above-mentioned plated object is electroplated by dissolving 35 to 45 g of potassium silver cyanide, 140 to 160 g of potassium pyrophosphate, and 4 to 6 g of EDTA-4 potassium salt in 1 L of ion-exchange water, and then immersing the plated object connected to the cathode terminal together with the silver plate connected to the anode terminal in an electrolyte solution in which the pH is adjusted to 8 to 10 using potassium pyrophosphate and potassium hydroxide, and applying a current density of 45 to 55 A / dm2 under temperature conditions of 45 to 55°C. Copper plating targeting the above-mentioned plated object is electroplating in which the plated object connected to the cathode terminal is immersed in an electrolyte solution in which 90 to 110 g of copper sulfate pentahydrate, 90 to 110 g of sulfuric acid, and 45 to 55 mg of chloride ions are dissolved in 1 L of ion-exchange water, and a current density of 5 to 7 A / dm2 is applied under temperature conditions of 25 to 35°C. Indium plating for the above-mentioned plated object is an electroless plating method in which 75 to 85 g of sodium citrate dihydrate, 35 to 45 g of nitrilostramacetic acid, 23 to 27 g of indium chloride tetrahydrate, and 5 to 7 g of titanium chloride are dissolved in 1 L of ion-exchange water, and then the plated object is immersed in a plating solution whose pH is adjusted to 9 to 11 using ammonia water, and an indium layer is deposited at a temperature of 75 to 85°C. Bismuth plating for the above-mentioned plated object is an electroless plating method in which 85 to 95 g of sodium citrate dihydrate, 28 to 32 g of EDTA, 38 to 42 g of nitrilostramacetic acid, 24 to 26 g of boron chloride, and 7 to 9 g of tin chloride dihydrate are dissolved in 1 L of ion-exchange water, and then the plated object is immersed in a plating solution whose pH is adjusted to 8.6 to 9 using ammonia water, and a bismuth layer is deposited at a temperature of 55 to 65°C. Antimony plating for the above-mentioned plated object is an electroless plating method in which 16 to 20 g of antimony chloride, 92 to 96 g of trisodium citrate dihydrate, 28 to 32 g of disodium EDTA dihydrate, 18 to 20 g of nitrilostramacetic acid, and 5 to 7 g of titanium trichloride are dissolved in 1 L of ion-exchange water, and then the plated object is immersed in a plating solution whose pH is adjusted to 7 to 8 using a 28 wt% ammonia aqueous solution, and an antimony layer is deposited at a temperature of 18 to 22°C. A method for manufacturing an electrode material for a secondary battery, characterized in that the indium-antimony alloy plating targeting the above-mentioned plated product is an electroless plating method in which 16 to 20 g of indium chloride, 0.04 to 0.06 g of antimony chloride, 95 to 105 g of trisodium citrate dihydrate, 28 to 32 g of nitrilostramacetic acid, and 5 to 7 g of titanium chloride are dissolved in 1 L of ion-exchange water, and then the plated product is immersed in a plating solution in which the pH is adjusted to 7.6 to 8 using a 20 wt% sodium carbonate aqueous solution, and an indium-antimony layer is deposited at a temperature of 55 to 65°C.

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