Composition for multi-layer ceramic battery case

Abstract

The present invention relates to a composition for a multi-layer ceramic battery case. The composition for a multi-layer ceramic battery case, according to an embodiment of the present invention, comprises oxides of Na, Ca, Zn, B, Si, and Bi.

Description

Composition for laminated ceramic battery case

[0001] The present invention relates to a composition for a case of a laminated ceramic battery.

[0002] Secondary batteries are used in a variety of fields, from IT devices such as mobile phones to electric vehicles and energy storage devices.

[0003] Lithium-ion batteries, which use liquid electrolytes, are the most widely used secondary batteries. However, liquid electrolytes pose a risk of leakage if the battery is subjected to external shocks, necessitating the use of additional components and devices to ensure safety.

[0004] Recently, active development has been underway on all-solid-state lithium-ion batteries, which use solid electrolytes to improve the safety of lithium-ion batteries. As a type of all-solid-state battery, a multi-layer ceramic battery is also being developed, applying conventional multi-layer ceramic capacitor technology.

[0005] While all-solid-state batteries offer greater stability than those using liquid electrolytes, they can still be vulnerable to moisture and external shocks. Therefore, a case is needed to protect the electrode and electrolyte layers that make up the all-solid-state battery.

[0006] Conventional battery cases are made of widely used materials such as insulating resin and metal. However, laminated ceramic batteries are manufactured in small sizes and require the case to be sintered integrally with the electrode and electrolyte layers. Therefore, conventional battery cases cannot be applied as-is, necessitating the development of new case materials.

[0007] The present invention is intended to solve the problems of the prior art described above, and its purpose is to provide a composition for a case that can increase the reliability and performance of a laminated ceramic battery.

[0008] A composition for a case of a laminated ceramic battery according to one embodiment of the present invention includes oxides of Na, Ca, Zn, B, Si, and Bi.

[0009] A composition for a case of a laminated ceramic battery according to one embodiment of the present invention may further include Al and Ce oxides.

[0010] A composition for a case of a laminated ceramic battery according to one embodiment of the present invention may include 8 to 15 mol% of Na2O, 6 to 11 mol% of CaO, 17 to 27 mol% of ZnO, 24 to 36 mol% of B2O3, 5 to 13 mol% of SiO2, and 17 to 28 mol% of Bi2O3. In addition, the composition for a case of a laminated ceramic battery may further include 2 mol% or less of Al2O3 and 1 mol% or less of CeO2.

[0011] A composition for a case of a laminated ceramic battery according to one embodiment of the present invention may include 9 to 11 mol% of Na2O, 7 to 9 mol% of CaO, 18 to 21 mol% of ZnO, 28 to 29 mol% of B2O3, 9 to 11 mol% of SiO2, and 21 to 27 mol% of Bi2O3. In addition, the composition for a case of a laminated ceramic battery may further include 2 mol% or less of Al2O3 and 1 mol% or less of CeO2.

[0012] A composition for a case of a laminated ceramic battery according to one embodiment of the present invention may have a transition temperature (Tg) and a crystallization temperature (Tc) of 585°C or less.

[0013] A composition for a case of a laminated ceramic battery according to one embodiment of the present invention has a thermal expansion coefficient of 100×10 -7 It can be m / m℃.

[0014] A laminated ceramic battery according to one embodiment of the present invention comprises a positive electrode layer, a negative electrode layer, a solid electrolyte layer disposed between the positive electrode layer and the negative electrode layer, an external electrode connected to each of the positive electrode layer and the negative electrode layer, and a case surrounding the positive electrode layer, the negative electrode layer, and the solid electrolyte layer. Here, the case is made of an oxide of Na, Ca, Zn, B, Si, and Bi.

[0015] In addition, the composition for a laminated ceramic battery and case according to the present invention may further include other additional components within a range that does not impair the technical idea of ​​the present invention.

[0016] According to one embodiment of the present invention, it is possible to integrally sinter the case of a laminated ceramic battery with a positive electrode layer, a negative electrode layer, and a solid electrolyte layer, thereby improving the reliability and performance of the laminated ceramic battery. Furthermore, it is possible to manufacture a case of a laminated ceramic battery with excellent properties, such as low water vapor permeability, low thermal characteristics, low electrical conductivity, and voltage stability.

[0017] Figure 1 is a perspective view schematically showing a laminated ceramic battery.

[0018] Figure 2 is a drawing schematically showing a cross-section of a laminated ceramic battery.

[0019] FIG. 3 is a graph showing the results of linear scanning voltage (LSV) for a composition according to one embodiment of the present invention.

[0020] FIG. 4 is a drawing showing the results of a high-temperature microscopy (HTM) analysis of a composition according to one embodiment of the present invention.

[0021] [Explanation of symbols]

[0022] 10: Stacked ceramic battery

[0023] 11: Bipolar layer

[0024] 12: Cathode layer

[0025] 13: Solid electrolyte layer

[0026] 14, 15: External electrode

[0027] 16: Case

[0028] Hereinafter, with reference to the attached drawings, a preferred embodiment of the present invention will be described in detail to a degree that a person having ordinary skill in the art to which the present invention pertains can easily practice the present invention.

[0029] To clearly explain the present invention, descriptions of parts irrelevant to the present invention have been omitted, and the same reference numerals are assigned to the same components throughout the specification. It should be understood that specific shapes, structures, and characteristics described in the specification may be modified and implemented from one embodiment to another without departing from the spirit and scope of the present invention, and that the location or arrangement of individual components may also be changed without departing from the spirit and scope of the present invention.

[0030] Accordingly, the detailed description set forth below is not intended to be limiting, and the scope of the present invention should be accepted as encompassing the scope claimed in the claims and all scopes equivalent thereto.

[0031] Fig. 1 is a perspective view schematically illustrating a laminated ceramic battery, and Fig. 2 is a drawing schematically illustrating a cross-section of the laminated ceramic battery. Referring to Figs. 1 and 2, the laminated ceramic battery (10) can be formed in the form of a small chip and can be used in small electronic devices such as wearable electronic devices.

[0032] According to one embodiment of the present invention, a laminated ceramic battery (10) includes a positive electrode layer (11), a negative electrode layer (12), and a solid electrolyte layer (13). The solid electrolyte layer (13) is disposed between the positive electrode layer (11) and the negative electrode layer (12), and can be in contact with the positive electrode layer (11) and the negative electrode layer (12), respectively. The positive electrode layer (11) and the negative electrode layer (12) can each have a current collector and an active material layer, and the active material layer of the electrode layer is formed by being applied to at least one surface of each current collector, and can be in contact with the solid electrolyte layer (13).

[0033] The positive electrode layer (11) and the negative electrode layer (12) of the laminated ceramic battery (10) can be connected to external electrodes (14, 15), respectively. The external electrodes (14, 15) can be connected to the exposed terminals of the current collectors of the positive electrode layer (11) and the negative electrode layer (12), thereby serving as positive and negative electrodes, respectively.

[0034] According to one embodiment of the present invention, a laminated ceramic battery (10) is configured such that a positive electrode layer (11), a negative electrode layer (12), and a solid electrolyte layer (13) are each formed of multiple layers and alternately laminated. In Fig. 1, the positive electrode layer (11) and the negative electrode layer (12) are alternately arranged and a solid electrolyte layer (13) is arranged between them. However, the arrangement of the positive electrode layer (11), the negative electrode layer (12), and the solid electrolyte layer (13) is not limited to what is illustrated.

[0035] According to one embodiment of the present invention, a laminated ceramic battery (10) includes a case (16) configured to surround a positive electrode layer (11), a negative electrode layer (12), and a solid electrolyte layer (13). In addition, external electrodes (14, 15) may be arranged at both ends of the case (16). In one embodiment, the case (16) may perform a function of protecting the internal components including the positive electrode layer (11), the negative electrode layer (12), and the solid electrolyte layer (13) from being exposed to the outside. The case (16) is required to have moisture permeability, heat resistance, insulation, etc. to protect the internal components from external moisture, heat, electricity, etc., and is also required to have high resistance to chemical corrosion along with long-term stability.

[0036] According to one embodiment of the present invention, a laminated ceramic battery (10) can be manufactured by stacking a cathode layer (11), a cathode layer (12), a solid electrolyte layer (13), a case (16), etc. and then sintering them integrally. In order to prevent the characteristics of each electrode layer, etc. from deteriorating during this sintering process, each component, including the case (16), must be sintered at a low temperature, for example, at a temperature of 600°C or lower.

[0037] That is, the case (16) of the laminated ceramic battery (10) is required to be capable of low-temperature sintering while also having moisture permeability and insulation properties.

[0038] The inventors of the present invention have devised a composition for a case that satisfies the characteristics of the case (16) of such a laminated ceramic battery (10) as follows.

[0039] A composition for a case of a laminated ceramic battery according to one embodiment of the present invention includes oxides of Na, Ca, Zn, B, Si, and Bi. For example, a composition according to one embodiment of the present invention may include Na2O, CaO, ZnO, B2O3, SiO2, and Bi2O3.

[0040] In the above composition, Na2O functions as a network modifier, which can break the bonds of the network forming agent and reduce the transition temperature and crystallization temperature. However, if the content of Na2O is too high, the softening temperature may increase to an undesirable level. Therefore, Na2O may preferably be included in an amount of 8 to 15 mol%.

[0041] CaO functions as a high-temperature network modifier, breaking the bonds of network-forming agents and reducing the transition temperature and crystallization temperature. Furthermore, CaO can improve the chemical durability and stability of glass. However, if the CaO content is too high, glass devitrification may occur during quenching. Therefore, CaO is preferably included in an amount of 6 to 11 mol%.

[0042] ZnO can function as an intermediate. That is, depending on its concentration in the glass, ZnO can function as a network former or network modifier. Furthermore, ZnO can contribute to achieving excellent CTE values. According to one embodiment of the present invention, ZnO may be preferably included in an amount of 17 to 27 mol%.

[0043] B2O3 can function as a medium-temperature network former. However, as the content of B2O3 increases, the transition temperature and softening temperature may slightly increase. According to one embodiment of the present invention, B2O3 may be preferably included in an amount of 24 to 36 mol%.

[0044] SiO2 can function as a high-temperature network former. Furthermore, SiO2 contributes to insulating properties, making it useful in battery cases where electrical insulation is crucial. However, increasing the SiO2 content can increase the transition temperature and softening temperature. Considering this, SiO2 is preferably included in an amount of 5 to 13 mol%.

[0045] Bi2O3 can function as a conditional network former. That is, Bi2O3 can function as a network former only when used together with other glass components. In addition, Bi2O3 can contribute to lowering the softening temperature as a low-temperature material. However, if the content is too high, multiple oxidation states of bismuth (Bi 3+ and Bi 5+ ) may deteriorate the electrical conductivity properties. Considering this, Bi2O3 may be preferably included in an amount of 17 to 28 mol%.

[0046] In one embodiment, the composition may further comprise Al and Ce oxides. For example, a composition for a case of a laminated ceramic battery may further comprise Al2O3 and CeO2.

[0047] In the above composition, Al2O3 can function as an intermediate. That is, Al2O3 can function as a network former or network modifier depending on its concentration in the composition. The addition of Al2O3 can improve the scratch, abrasion, and mechanical stress resistance of the glass, and thus, a small amount of Al2O3 can be included to improve the mechanical strength and hardness of the glass. However, as the content of Al2O3 increases, the sintering and softening characteristics may deteriorate. Therefore, Al2O3 can preferably be included in an amount of 2 mol% or less.

[0048] CeO2 can enhance chemical durability. Addition of CeO2 can enhance chemical durability against substances such as water, acids, and alkalis. In this embodiment, CeO2 may be preferably included in an amount of less than 1 mol%.

[0049]

[0050] A composition according to one embodiment of the present invention can be manufactured through the following process.

[0051] (1) Measure the weight of the raw materials and mix thoroughly.

[0052] (2) The mixture is melted using an alumina crucible at a temperature ranging from 1,100°C to 1,300°C for 30 minutes.

[0053] (3) Quenching is performed using twin rollers at room temperature.

[0054] (4) 1 mm thin ribbon glass is milled using a dry milling process.

[0055] (5) Finely powdered to an average particle size of 1 to 3 ㎛ through jet milling.

[0056]

[0057] A composition for a case of a laminated ceramic battery according to one embodiment of the present invention has a low transition temperature (Tg) and crystallization temperature (Tc), and can be sintered at a low temperature of 600°C or lower.

[0058] In addition, the composition for the case of the laminated ceramic battery obtained through the above process is sintered together with the positive electrode layer, the negative electrode layer, and the solid electrolyte layer to have a density of 0.005 g / (m 2 ·day) or less. Therefore, it can effectively prevent moisture from entering the case, thereby improving the reliability and performance of the laminated ceramic battery.

[0059] A composition according to one embodiment of the present invention comprises 100×10 -7 It has a coefficient of thermal expansion of m / m℃, which is compatible with the coefficient of thermal expansion (CTE) of the solid electrolyte material. This means that the case and the solid electrolyte layer can maintain a stable bond during heat treatment involving rapid heating and cooling.

[0060] The case of the laminated ceramic battery according to one embodiment of the present invention is 1×10 -11 It exhibits an electrical conductivity of less than S / cm. Therefore, the case of a laminated ceramic battery can maintain its integrity and ensure stability by preventing current leakage from the battery.

[0061]

[0062] Experimental example

[0063] The compositions of Examples 1 to 5 and Comparative Examples 1 to 5 were prepared by varying the ratio of each component. The composition of the solid electrolyte according to each Example and Comparative Example is as described in Table 1.

[0064] Composition (mol%)Na2OCaOZnOB2O3Al2O3SiO2Bi2O3CeO2Example 110.18.420.228.61.59.121.90.1Example 29.37.018.228.6-10.126.8-Example 39.57.018.234.2-11.419.7-Example 412.09.424.425.6-6.721.9-Example 513.09.525.625.5-7.518.9-Comparative Example 19.0-20.232.5-15.023.3-Comparative Example 214.89.2-31.17.87.030.1-Comparative Example 315.31.9-45.57.015.015.3-Comparative example 49.0-16.539.3--35.2-Comparative example 59.0-20.546.7-9.514.3-

[0065]

[0066] The transition temperature, sintering temperature, and softening point of the compositions according to the above examples and comparative examples were measured. The measurement results are as shown in Table 2.

[0067] Transition temperature (℃) Sintering temperature (℃) Softening point (℃) Example 1 394491563 Example 2 395491555 Example 3 401495563 Example 4 393490570 Example 5 392489572 Comparative example 1 379494558 Comparative example 2 380495575 Comparative example 3 381499582 Comparative example 4 401500557 Comparative example 5 405498561

[0068]

[0069] Referring to Table 2, Examples 1 to 5 and Comparative Examples 1 to 5 do not show a large difference in transition temperature and softening point, but the sintering temperature in Examples 1 to 5 is 489°C to 495°C, which is generally lower than the sintering temperature of 494°C to 500°C in Comparative Examples 1 to 5. Meanwhile, Comparative Examples 1, 4, and 5 are understood to exhibit high sintering temperatures because they do not contain CaO. In addition, Comparative Examples 2 and 3 exhibit excellent transition temperature characteristics but exhibit high sintering temperatures and softening points, which is understood to be due to the high Na2O content.

[0070] In addition to the temperature characteristics of the compositions according to the above examples and comparative examples, water vapor transmission rate, electrical conductivity, coefficient of thermal expansion (CTE), and linear scanning potential (LSV) measurements were performed. The measurement results are as shown in Table 3.

[0071]

[0072] Water vapor permeability (g / (m) 2· day))Electrical conductivity (S / cm)Coefficient of thermal expansion (×10 -7 m / m℃)LSV(0~5V)Example 10.0054.4×10 -11 1005 Example 20.0034.2×10 -11 1005 Example 30.0044.4×10 -11 1014 Example 40.0065.4×10 -10 995 Example 50.0064.9×10 -10 1025 Comparative Example 10.0107.5×10 -11 1005 Comparative Example 20.0073.1×10 -9 1124 Comparative Example 30.0084.7×10 -9 1025 Comparative Example 40.0094.4×10 -9 1104 Comparative Example 50.0044.4×10 -9 1025

[0073]

[0074] Referring to Table 3, Examples 1 to 5 had a content of 0.003 to 0.006 g / (m2 ·day) shows a water vapor transmission rate, which confirms that it has a relatively low water vapor transmission rate. That is, it can be seen that Examples 1 to 5 show superior water vapor transmission rates compared to the comparative examples. In the measurement results of electrical conductivity, Examples 1 to 5 also show a water vapor transmission rate of 4.2×10 -11 5.4×10 -10 It shows an electrical conductivity of S / cm, showing an overall lower electrical conductivity than the comparative examples. In particular, in the case of Examples 1 to 3, it is 10 -11 It is confirmed to have a low electrical conductivity in the order of S / cm.

[0075] Also, in Examples 1 to 5, 100×10 -7 It can be confirmed that it has good compatibility with solid electrolyte materials by showing a thermal expansion coefficient of about m / m℃. On the other hand, it is confirmed that Comparative Examples 2 and 4 show different thermal expansion coefficients of about 110×10-7 m / m℃.

[0076] FIG. 3 is a graph showing the results of linear scanning voltage (LSV) for a composition according to Example 1 of the present invention. Referring to FIG. 3, it can be seen that the composition according to Example 1 of the present invention maintains excellent electrical stability over the entire voltage range from 0 to 5 V.

[0077] FIG. 4 is a diagram showing the results of a high-temperature microscopy (HTM) analysis of a composition according to Example 1 of the present invention. Specifically, FIGS. 4 (a) to 4 (d) show the results of a high-temperature microscopy analysis of Example 1 at 22.9°C, 491°C, 563°C, and 585°C, respectively. Referring to FIG. 4 , it is confirmed that the composition according to Example 1 of the present invention begins to soften at a temperature of about 491°C and sinteres at a temperature of about 585°C.

[0078] In this way, the composition for a laminated ceramic battery case according to the present invention exhibits low water vapor permeability, low thermal characteristics, appropriate softening temperature, low electrical conductivity, and voltage stability, thereby satisfying the requirements for a case of a laminated ceramic battery.

[0079] In addition, the composition for a laminated ceramic battery case according to the present invention can be integrally sintered with a positive electrode layer, a negative electrode layer, and a solid electrolyte layer, thereby improving the reliability and performance of the laminated ceramic battery.

[0080] Although the present invention has been described above with specific details such as specific components and limited examples, the above examples are provided only to help a more general understanding of the present invention, and the present invention is not limited thereto, and those with ordinary knowledge in the technical field to which the present invention pertains can make various modifications and variations based on this description.

[0081] Therefore, the idea of ​​the present invention should not be limited to the embodiments described above, and all things that are modified equally or equivalently to the claims described below as well as the claims are considered to fall within the scope of the idea of ​​the present invention.

Claims

1. A composition for a case of a multi-layer ceramic battery, Containing oxides of Na, Ca, Zn, B, Si and Bi Composition.

2. In paragraph 1, Containing more Al and Ce oxides Composition.

3. In paragraph 2, Containing 8~15mol% Na2O, 6~11mol% CaO, 17~27mol% ZnO, 24~36mol% B2O3, 5~13mol% SiO2 and 17~28mol% Bi2O3. Composition.

4. In paragraph 3, Further comprising 2 mol% or less of Al2O3 and 1 mol% or less of CeO2 Composition.

5. In paragraph 3, Containing 9~11mol% Na2O, 7~9mol% CaO, 18~21mol% ZnO, 28~29mol% B2O3, 9~11mol% SiO2 and 21~27mol% Bi2O3. Composition.

6. In paragraph 5, Further comprising 2 mol% or less of Al2O3 and 1 mol% or less of CeO2 Composition.

7. In paragraph 1, Transition temperature (Tg) and crystallization temperature (Tc) are 585℃ or lower. Composition.

8. In paragraph 1, The coefficient of thermal expansion is 100×10 -7 m / m℃ Composition.

9. As a laminated ceramic battery, bipolar layer, cathode layer, A solid electrolyte layer disposed between the positive electrode layer and the negative electrode layer, External electrodes connected to the anode layer and the cathode layer, respectively; A case surrounding the anode layer, the cathode layer, and the solid electrolyte layer Including, The above case is a laminated ceramic battery made of oxides of Na, Ca, Zn, B, Si and Bi.

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