All-solid-state battery

Abstract

The disclosed all-solid-state battery comprises: a laminated body, comprising a first surface and a second surface which are opposite to each other in a first direction, a third surface and a fourth surface which are opposite to each other in a second direction and are connected with the first surface and the second surface, and a fifth surface and a sixth surface which are opposite to each other in a third direction and are connected with the first surface and the second surface, the positive electrode layer and the negative electrode layer are alternately stacked in the third direction, and the solid electrolyte layer is arranged between the positive electrode layer and the negative electrode layer; a first external electrode connected to the positive electrode layer and disposed outside the laminate; and a second external electrode connected to the negative electrode layer and disposed outside the laminate. The positive electrode layer may include a positive electrode current collector including an aluminum foil, the negative electrode layer may include a negative electrode active material including graphite, and the positive electrode current collector may be connected to the first external electrode on the first surface, the third surface, and the fourth surface of the laminate.

Description

Technical Field

[0001] This disclosure relates to an all-solid-state battery. Background Technology

[0002] Recently, due to the need for miniaturization and long-term use of portable electronic devices, high-capacity batteries are required, and with the increasing popularity of wearable electronic devices, it is necessary to ensure battery safety.

[0003] Currently, lithium-ion batteries on the market use electrolytes containing flammable organic solvents, which pose a risk of overheating and fire in the event of a short circuit. Therefore, all-solid-state batteries using solid electrolytes instead of electrolyte solutions have been proposed.

[0004] Because all-solid-state batteries do not use flammable organic solvents, the possibility of fire or explosion in the event of a short circuit is greatly reduced. Therefore, compared with lithium-ion batteries that use electrolyte solutions, all-solid-state batteries offer significantly improved safety.

[0005] Because high-temperature sintering is required to form the positive electrode layer of oxide-based all-solid-state batteries, graphite is often used instead of metal as the positive electrode current collector. Graphite current collectors suffer from low electronic conductivity. Summary of the Invention

[0006] Solution to the problem One aspect of the embodiments is to provide an all-solid-state battery with a positive electrode current collector having high electronic conductivity.

[0007] However, the purpose of this disclosure is not limited to the foregoing purposes and may be extended in various ways within the spirit and scope of this disclosure.

[0008] An embodiment provides an all-solid-state battery, comprising: a laminate including a first surface and a second surface opposite to each other in a first direction, a third surface and a fourth surface opposite to each other and connecting the first surface and the second surface in a second direction, and a fifth surface and a sixth surface opposite to each other and connecting the first surface and the second surface in a third direction; the laminate including a solid electrolyte layer and a positive electrode layer and a negative electrode layer alternately stacked in the third direction, wherein the solid electrolyte layer is located between the positive electrode layer and the negative electrode layer; a first external electrode connected to the positive electrode layer and disposed outside the laminate; and a second external electrode connected to the negative electrode layer and disposed outside the laminate, wherein the positive electrode layer may include a positive electrode current collector comprising aluminum foil, the negative electrode layer may include a negative electrode active material comprising graphite, and the positive electrode layer may be connected to the first external electrode on the first surface, the third surface, and the fourth surface of the laminate.

[0009] Additionally, the positive current collector may include a first surface and a second outer surface that are opposite to each other in the third direction, and the positive active material may be disposed on at least one of the first outer surface and the second outer surface.

[0010] In addition, the positive electrode active material can be disposed on the first outer surface and the second outer surface, respectively.

[0011] In addition, the positive electrode active material may be disposed on only one of the first outer surface and the second outer surface.

[0012] Additionally, when viewed along the third direction, the positive current collector may include: a body having a rectangular shape, the body including a first side and a second side opposite to each other in the first direction and a third side and a fourth side opposite to each other in the second direction; a first extension protruding from the third side of the body toward the third surface of the laminate; and a second extension protruding from the fourth side of the body toward the fourth surface of the laminate, wherein the first side of the body may contact the first surface of the laminate, and the second side of the body may be spaced apart from the second surface of the laminate.

[0013] Additionally, the first extension may contact the first surface and the third surface of the laminate, and the second extension may contact the first surface and the fourth surface of the laminate.

[0014] In addition, the all-solid-state battery may also include a first edge portion disposed between the second surface of the laminate and the positive electrode layer.

[0015] In addition, the first edge portion may include at least one of a solid electrolyte and an insulating material.

[0016] In addition, the solid electrolyte included in the first edge portion may be the same as the solid electrolyte included in the solid electrolyte layer.

[0017] Furthermore, the solid electrolyte included in the first edge portion may be different from the solid electrolyte included in the solid electrolyte layer.

[0018] Additionally, the negative electrode layer may be connected to the second external electrode on the second surface of the laminate.

[0019] In addition, the all-solid-state battery may also include a second edge portion disposed between the first surface of the laminate and the negative electrode layer.

[0020] Additionally, the second edge portion may include at least one of a solid electrolyte and an insulating material.

[0021] In addition, the solid electrolyte included in the second edge portion may be the same as the solid electrolyte included in the solid electrolyte layer.

[0022] Furthermore, the solid electrolyte included in the second edge portion may be different from the solid electrolyte included in the solid electrolyte layer.

[0023] In addition, the positive electrode layer may have a shape different from that of the negative electrode layer.

[0024] According to the all-solid-state battery of the embodiment, the positive electrode current collector has high electronic conductivity, thus achieving high positive electrode characteristics. Attached Figure Description

[0025] Figure 1 A schematic perspective view of an all-solid-state battery according to an embodiment is shown.

[0026] Figure 2 It shows along Figure 1 The cross-sectional view taken from line II-II'.

[0027] Figure 3 It shows along Figure 2 The cross-sectional view taken from line III-III'.

[0028] Figure 4 It shows along Figure 2 The cross-sectional view taken from line IV-IV'.

[0029] Figures 5A to 5D This is a diagram schematically illustrating a method for manufacturing a stack of all-solid-state batteries according to Example 1.

[0030] Figure 6 This is a schematic diagram illustrating the stacked body according to Example 1.

[0031] Figure 7 This is a schematic diagram illustrating a laminate manufactured according to Example 2.

[0032] Figure 8 This is a schematic diagram showing a laminate manufactured according to a comparative example.

[0033] Figure 9 The graphs showing the capacity ratio versus charge-discharge rate of all-solid-state batteries manufactured according to Example 1, Example 2 and Comparative Example are shown. Detailed Implementation

[0034] The present disclosure will be described more fully below with reference to the accompanying drawings, in which embodiments of the disclosure are illustrated. The drawings and description are to be considered illustrative rather than restrictive in nature. Throughout the specification, the same reference numerals denote the same elements. Additionally, some constituent elements are shown enlarged, omitted, or simplified in the drawings, and the dimensions of the corresponding constituent elements do not reflect their true dimensions.

[0035] The accompanying drawings are provided only to facilitate understanding of the embodiments disclosed in this specification and are not to be construed as limiting the spirit of the disclosure. It should be understood that this disclosure includes all variations, equivalents and alternatives without departing from the scope and spirit of the disclosure.

[0036] Ordinal terms such as "first," "second," etc., will be used only to describe the various constituent elements and will not be construed as limiting these constituent elements. These terms are used only to distinguish one constituent element from others.

[0037] It will be understood that when an element such as a layer, film, region, area, or substrate is referred to as being "on" or "above" another element, the element may be directly on the other element, or there may be an intermediate element present. In contrast, when an element is referred to as being "directly on" another element, there is no intermediate element present. Furthermore, in the specification, the terms "on" or "above" mean disposed on or below the target portion, and do not necessarily mean disposed on the upper side of the target portion based on the direction of gravity.

[0038] Throughout this specification, it should be understood that the terms "comprising," "including," "having," or "construction" indicate the presence of the features, quantities, steps, operations, constituent elements, components, or combinations thereof described in the specification, but do not preclude the possibility of the presence or addition of one or more other features, quantities, steps, operations, constituent elements, components, or combinations thereof. Unless explicitly stated otherwise, the word "comprising" and variations such as "including" or "having" will be understood to imply the inclusion of the stated elements but not the exclusion of any other elements.

[0039] Furthermore, throughout the specification, the phrase "in a plan view" or "on a plane" indicates the target portion as viewed from the top, and the phrase "in a cross-sectional view" or "on a cross-section" indicates the cross-section formed by vertically cutting the target portion as viewed from the side.

[0040] Furthermore, throughout the specification, “connection” not only refers to when two or more elements are directly connected, but also to when two or more elements are indirectly connected through other elements, and to when two or more elements are physically or electrically connected. In addition, it may be referred to by different names depending on location or function, and may also refer to the situation where the various components that are basically integrated are connected to each other.

[0041] Figure 1 A schematic perspective view of an all-solid-state battery according to an embodiment is shown. Figure 2 It shows along Figure 1 A cross-sectional view taken from line II-II'. Figure 3 It shows along Figure 2 The cross-sectional view taken from line III-III', and Figure 4 It shows along Figure 2 The cross-sectional view taken from line IV-IV'.

[0042] Reference Figure 1 , Figure 2 , Figure 3 and Figure 4 The all-solid-state battery 1000 according to this embodiment includes a laminate 100, a first external electrode 200 and a second external electrode 300.

[0043] First, for the purpose of clearly describing this embodiment, the orientation is defined. The L-axis, W-axis and T-axis shown in the figure represent the axes representing the length, width and thickness of the all-solid-state battery 1000, respectively.

[0044] The thickness direction (T-axis direction) can be a direction perpendicular to the wide surface (main surface) of the sheet component. For example, the thickness direction (T-axis direction) can be used as the same concept as the direction in which the components of the laminate 100 are stacked.

[0045] The length direction (L-axis direction) is parallel to the wide surface (main surface) of the sheet assembly and can be a direction that intersects (or is perpendicular to) the thickness direction (T-axis direction). For example, the length direction (L-axis direction) can be the direction in which the first external electrode 200 and the second external electrode 300 are opposite to each other.

[0046] The width direction (W-axis direction) is parallel to the wide surface (main surface) of the sheet component, and can be a direction that intersects (or is perpendicular to) both the thickness direction (T-axis direction) and the length direction (L-axis direction).

[0047] The laminate 100 may have a generally hexahedral shape, but this embodiment is not limited to this. Due to shrinkage during sintering, the laminate 100 may have a generally hexahedral shape, rather than a perfect hexahedral shape. For example, the laminate 100 may have a generally cubic shape, but the corners or vertices may have a rounded shape.

[0048] In this embodiment, for ease of description, surfaces that are opposite to each other in the length direction (L-axis direction) are defined as the first surface S1 and the second surface S2, surfaces that are opposite to each other in the width direction (W-axis direction) and connect the first surface S1 and the second surface S2 are defined as the third surface S3 and the fourth surface S4, and surfaces that are opposite to each other in the thickness direction (T-axis direction) and connect the first surface S1 and the second surface S2 are defined as the fifth surface S5 and the sixth surface S6.

[0049] Therefore, the first direction in which the first surface S1 and the second surface S2 are opposite to each other can be the length direction (L-axis direction), and the second and third directions that are perpendicular to the first direction and perpendicular to each other can be the thickness direction (T-axis direction) and the width direction (W-axis direction), or they can be the width direction (W-axis direction) and the thickness direction (T-axis direction), respectively.

[0050] Based on an optical microscope or scanning electron microscope (SEM) photograph of a cross-section of the laminate 100 located at its center in the width direction (W-axis direction) and along the length direction (L-axis direction) and thickness direction (T-axis direction), the length of the laminate 100 can be defined as the maximum length of a plurality of line segments connecting the two outermost boundary lines of the laminate 100 shown in the cross-sectional photograph that are opposite each other in the length direction (L-axis direction) and parallel to the length direction (L-axis direction). Alternatively, the length of the laminate 100 can be defined as the minimum length of a plurality of line segments connecting the two outermost boundary lines of the laminate 100 shown in the cross-sectional photograph that are opposite each other in the length direction (L-axis direction) and parallel to the length direction (L-axis direction). On the other hand, the length of the laminate 100 can be defined as the arithmetic mean of the lengths of at least two of the plurality of line segments connecting the two outermost boundary lines of the laminate 100 shown in the cross-sectional photograph that are opposite each other in the length direction (L-axis direction) and parallel to the length direction (L-axis direction).

[0051] Based on an optical microscope or scanning electron microscope (SEM) photograph of a cross-section of the laminate 100 located at its center in the width direction (W-axis direction) and along the length direction (L-axis direction) and thickness direction (T-axis direction), the thickness of the laminate 100 can be defined as the maximum length of a plurality of line segments connecting the two outermost boundary lines of the laminate 100 shown in the cross-sectional photograph that are opposite each other in the thickness direction (T-axis direction) and parallel to the thickness direction (T-axis direction). Furthermore, the thickness of the laminate 100 can be defined as the minimum length of a plurality of line segments connecting the two outermost boundary lines of the laminate 100 shown in the cross-sectional photograph that are opposite each other in the thickness direction (T-axis direction) and parallel to the thickness direction (T-axis direction). On the other hand, the thickness of the laminate 100 can be defined as the arithmetic mean of the lengths of at least two of the plurality of line segments connecting the two outermost boundary lines of the laminate 100 shown in the cross-sectional photograph that are opposite each other in the thickness direction (T-axis direction) and parallel to the thickness direction (T-axis direction).

[0052] Based on an optical microscope or scanning electron microscope (SEM) photograph of a cross-section of the laminate 100 located at its center in the thickness direction (T-axis direction) and along its length direction (L-axis direction) and width direction (W-axis direction), the width of the laminate 100 can be defined as the maximum length of a plurality of line segments connecting the two outermost boundary lines of the laminate 100 shown in the cross-sectional photograph that are opposite each other in the width direction (W-axis direction) and parallel to the width direction (W-axis direction). Alternatively, the width of the laminate 100 can be defined as the minimum length of a plurality of line segments connecting the two outermost boundary lines of the laminate 100 shown in the cross-sectional photograph that are opposite each other in the width direction (W-axis direction) and parallel to the width direction (W-axis direction). On the other hand, the width of the laminate 100 can be defined as the arithmetic mean of the lengths of at least two of the plurality of line segments connecting the two outermost boundary lines of the laminate 100 shown in the cross-sectional photograph that are opposite each other in the width direction (W-axis direction) and parallel to the width direction (W-axis direction).

[0053] The laminate 100 may include a solid electrolyte layer 110, a positive electrode layer 130, a negative electrode layer 150, and an edge portion 170.

[0054] There are multiple solid electrolyte layers 110, positive electrode layers 130 and negative electrode layers 150, and the positive electrode layers 130 and negative electrode layers 150 can be stacked alternately in the thickness direction (T-axis direction) with the solid electrolyte layer 110 located between the positive electrode layer 130 and the negative electrode layer 150.

[0055] The positive electrode layer 130 may be disposed on one surface of the solid electrolyte layer 110, and the negative electrode layer 150 may be disposed on the other surface of the solid electrolyte layer 110.

[0056] The solid electrolyte layer 110 includes a solid electrolyte. The solid electrolyte can be used as a channel for lithium (Li) ions.

[0057] The solid electrolyte contained in the solid electrolyte layer 110 may include a glass-ceramic-based electrolyte containing lithium halides (such as halogens like LiX, where X is F, Br, Cl, or I). Glass-ceramics (or microcrystalline glass) refer to a mixture of crystalline and amorphous materials that exhibit peaks and bulges in X-ray diffraction, electron diffraction, etc., and are crystallographically consistent. Therefore, glass-ceramic-based electrolytes are electrolytes that undergo partial crystallization through sintering and contain a mixture of amorphous and crystalline materials.

[0058] Glass-ceramic based electrolytes can be mixtures of amorphous materials and two or more types of crystalline materials. Furthermore, the crystalline materials contained in glass-ceramic based electrolytes can include lithium compound crystalline phases containing lithium.

[0059] When glass-ceramic-based electrolytes are included, sufficient densification is achieved after sintering, thereby enabling high ionic conductivity.

[0060] Glass-ceramic based electrolytes may include lithium (Li) oxide, boron (B) oxide, silicon (Si) oxide, aluminum (Al) oxide, gallium (Ga) oxide, phosphorus (P) oxide, germanium (Ge) oxide, magnesium (Mg) oxide, and lithium chloride (LiCl). As a specific example, a glass-ceramic based electrolyte may comprise Li₂O-B₂O₃-SiO₂-P₂O₅-GeO₂-LiCl.

[0061] On the other hand, the solid electrolyte contained in the solid electrolyte layer 110 may include a lithium borosilicate-based electrolyte (hereinafter also referred to as LBSO-based electrolyte). LBSO-based electrolyte is a glassy electrolyte, and glass refers to a crystallographically amorphous material with bulging peaks observed in X-ray diffraction, electron diffraction, etc.

[0062] When LBSO-based electrolytes are included, the amorphous state can be maintained during sintering while lowering the sintering temperature. Therefore, it offers the advantages of achieving high ionic conductivity and low ionic conductivity with low reactivity to the electrode. LBSO-based electrolytes may include lithium (Li), boron (B), silicon (Si), aluminum (Al), phosphorus (P), germanium (Ge), and sulfur (S).

[0063] Optionally, the solid electrolyte contained in the solid electrolyte layer 110 may be one or more types selected from the group consisting of garnet, Nasicon, LISICON, perovskite and LiPON.

[0064] Garnet-type solid electrolytes can refer to those composed of Lia La b Zr c O 12 Lithium lanthanum zirconate (LLZO) represented by (such as Li7La3Zr2O 12 ) and the Nasicon-type solid electrolyte may refer to lithium aluminum titanium phosphate (LATP) (Li 1+x Al x M 2-x (PO4)3) (where 0 < x < 2 and M is Zr, Ti or Ge) formed by introducing Ti into the compound of the type LAMP (Li 1+x Al x Ti 2-x (PO4)3 (where 0 < x < 1)) and lithium germanium aluminum phosphate (LAGP) and / or lithium zirconium phosphate (LZP) (LiZr2(PO4)3) represented by Li 1+x Al x Ge 2-x (PO4)3 (where 0 < x < 1) (such as Li 1.3 Al 0.3 [[ID=*31]]Ge 1.7 (PO4)3).

[0065] In addition, the LISICON-type solid electrolyte may refer to a solid solution oxide represented by xLi3AO4-(1-x)Li4BO4 (where A is P, As, V, etc. and B is Si, Ge, Ti, etc.), such as Li4Zn(GeO4)4, Li 10 GeP2O 12 (LGPO), Li 3.5 Si 0.5 P 0.5 O4, Li<*code 10.42 Si(Ge) 1.5 P 1.5 Cl 0.08 O 11.92 etc., and a solid solution sulfide represented by Li 4-x M 1-y M' y S4 (where M is Si or Ge and M' is P, Al, Zn or Ga), such as Li2S-P2S5, Li2S-SiS2, Li2S-SiS2-P2S5, Li2S-GeS2, etc.

[0066] In addition, the perovskite-type solid electrolyte may refer to Li 3x La 2 / 3-x □ 1 / 3-2x TiO3 (where 0 < x < 0.16 and □ is the assumed vacancy content) (such as Li 1 / 8 La Note: There seems to be an error in the original text where 'Li 10.42 ' is incomplete. I've marked it as '*code000002*' in the translation for clarity. Also, there is an asterisk added to 'Ge' in the translation to indicate a possible error in the original text where it might be a different character or there could be a missing part. Please check the original text for accuracy.5 / 8 Lithium lanthanum titanate (LLTO) is represented by TiO3, and LiPON-type solid electrolytes can refer to nitrides such as lithium phosphorus oxides, such as Li 2.8 PO 3.3 N 0.46 wait.

[0067] The positive electrode layer 130 may be exposed on the first surface S1, the third surface S3 and the fourth surface S4 of the laminate 100 and may be connected to the first external electrode 200.

[0068] The positive electrode layer 130 may include a positive electrode current collector 133 and a positive electrode active material layer 135.

[0069] The positive current collector 133 can be made of aluminum (Al) foil. The positive current collector 133 can be a porous component, for example, having a network or mesh structure.

[0070] Because the surface of the aluminum foil is oxidized, the oxide film does not increase even when sintered in air at temperatures below 600°C. Aluminum has high electronic conductivity. Therefore, when aluminum foil is used as the positive electrode current collector in all-solid-state batteries, it can improve the positive electrode characteristics.

[0071] On the other hand, high-temperature sintering is required to form the positive electrode of oxide-based all-solid-state batteries, so graphite is sometimes used as the positive electrode current collector. Graphite has the following problems: it is thick and has low electronic conductivity (or ionic conductivity). To solve this problem, metallic conductive materials can be used instead of graphite, but metals other than aluminum may have reduced electronic conductivity due to surface oxidation.

[0072] Reference Figure 3 The positive current collector 133 may include a main body 133a, a first extension 133b, and a second extension 133c.

[0073] The main body 133a has a generally rectangular shape, and one of its two opposing sides in the length direction (L-axis direction) contacts the first surface S1 of the laminate 100 while the other side is spaced apart from the second surface S2. On the two opposing sides of the main body 133a in the width direction (W-axis direction), the portions other than those provided with the first extension 133b and the second extension 133c are spaced apart from the third surface S3 and the fourth surface S4 of the laminate 100, respectively.

[0074] The first extension 133b is a portion that protrudes from the main body 133a toward the third surface S3 of the laminate 100, and the first extension 133b has a generally rectangular shape. The first extension 133b contacts the first surface S1 and the third surface S3 of the laminate 100. The first extension 133b is connected to the first external electrode 200 on the first surface S1 and the third surface S3 of the laminate 100.

[0075] The second extension 133c is a portion protruding from the main body 133a toward the fourth surface S4 of the laminate 100, and the second extension 133c has a generally rectangular shape. The second extension 133c contacts the first surface S1 and the fourth surface S4 of the laminate 100. The second extension 133c is connected to the first external electrode 200 on the first surface S1 and the fourth surface S4 of the laminate 100.

[0076] As described above, the positive current collector 133 can be connected to the first external electrode 200 on three surfaces of the laminate 100. Specifically, the main body 133a is connected to the first external electrode 200 on the first surface S1 of the laminate 100, the first extension 133b is connected to the first external electrode 200 on the first surface S1 and the third surface S3, and the second extension 133c is connected to the first external electrode 200 on the first surface S1 and the fourth surface S4. Because the positive current collector 133 is connected to the first external electrode 200 on three surfaces of the laminate 100, the contact area between the first external electrode 200 and the positive current collector 133 is increased. Therefore, electron transfer between the first external electrode 200 and the positive electrode layer 130 can be improved, and the punching area can be reduced, thereby improving the processing efficiency of the aluminum foil.

[0077] The positive electrode active material layer 135 may include a positive electrode active material and may be disposed on the surface of the positive electrode current collector 133. The positive electrode active material layer 135 may be formed by printing the positive electrode active material on one or both surfaces of the positive electrode current collector 133, but the method of forming the positive electrode active material layer is not limited thereto.

[0078] The positive electrode active material included in the positive electrode active material layer 135 can be a material containing lithium (Li) ions. The positive electrode active material can reversibly insert and extract lithium ions. In other words, the positive electrode active material can include lithium ions and is used to provide lithium ions to the negative electrode during charging of the all-solid-state battery. The positive electrode active material can affect the capacity and output of the all-solid-state battery.

[0079] The positive electrode active material can be, for example, a compound represented by the following chemical formula: Li a A 1-b M b D2 (where 0.90≤a≤1.8 and 0≤b≤0.5); Li a E 1-b M b O 2-c D c (Where, 0.90≤a≤1.8, and 0≤b≤0.5, 0≤c≤0.05); LiE 2-b M b O 4-c Dc (Where, 0 ≤ b ≤ 0.5, and 0 ≤ c ≤ 0.05); Li a Ni 1-b-c Co b M c D α (Where, 0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05, and 0<α≤2); Li a Ni 1-b-c Co b M c O 2-α X α (Where, 0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05, and 0<α<2); Li a Ni 1-b-c Co b M c O 2-α X2 (where 0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05, and 0<α<2); Li a Ni 1-b-c Mn b M c D α (Where, 0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05, and 0<α≤2); Li a Ni 1-b-c Mn b M c O 2-α X α (Where, 0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05, and 0<α<2); Li a Ni 1-b-c Mn b M c O 2-α X2 (where 0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05, and 0<α<2); Li a Ni b E c G d O2 (where 0.90≤a≤1.8, 0≤b≤0.9, 0≤c≤0.5, and 0.001≤d≤0.1); Li a Ni b Co c Mn d G e O2 (where 0.90≤a≤1.8, 0≤b≤0.9, 0≤c≤0.5, 0≤d≤0.5, and 0.001≤e≤0.1); Li aNiG b O2 (where 0.90 ≤ a ≤ 1.8 and 0.001 ≤ b ≤ 0.1); Li a CoG b O2 (where 0.90 ≤ a ≤ 1.8 and 0.001 ≤ b ≤ 0.1); Li a MnG b O2 (where 0.90 ≤ a ≤ 1.8 and 0.001 ≤ b ≤ 0.1); Li a Mn2G b O4 (where 0.90≤a≤1.8 and 0.001≤b≤0.1); QO2; QS2; LiQS2; V2O5; LiV2O2; LiRO2; LiNiVO4; Li (3-f) J2(PO4)3 (0≤f≤2); Li (3-f) Fe2(PO4)3 (where 0≤f≤2) and LiFePO4, in the above chemical formulas, A is Ni, Co or Mn; M is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V or rare earth element; D is O, F, S or P; E is Co or Mn; X is F, S or P; G is Al, Cr, Mn, Fe, Mg, La, Ce, Sr or V; Q is Ti, Mo or Mn; R is Cr, V, Fe, Sc or Y; and J is V, Cr, Mn, Co, Ni or Cu.

[0080] The positive electrode active material can also be LiCoO2 or LiMn. x O 2x (where x is 1 or 2), LiNi 1-x Mn x O 2x (where 0) <x<1)、LiNi 1-x-y Co x Mn y O2 (where 0 ≤ x ≤ 0.5 and 0 ≤ y ≤ 0.5), LiFePO4, TiS2, FeS2, TiS3 or FeS3, but not limited to these.

[0081] Positive electrode active materials may selectively include conductive materials and binders.

[0082] There are no particular restrictions on the conductive materials, as long as they are conductive without causing chemical changes in the all-solid-state battery 1000. For example, the following materials can be used: graphite, such as natural or artificial graphite; carbon-based materials, such as carbon black (acetylene black, Ketjen black, channel black, furnace black, lamp black, and pyrolysis black); conductive fibers, such as carbon fibers, metal fibers, etc.; fluorides; metallic components (such as lithium (Li), tin (Sn), aluminum (Al), nickel (Ni), and copper (Cu)) and oxides, nitrides, or fluorides of metallic components; conductive whiskers, such as zinc oxide and potassium titanate; conductive metal oxides, such as titanium oxide; conductive materials such as polyphenylene derivatives, etc.

[0083] Adhesives can be used to improve the bonding strength of active materials, conductive materials, etc. Examples of adhesives may include, but are not limited to, polyvinylidene fluoride, polyvinyl alcohol, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, polytetrafluoroethylene, polyethylene, polypropylene, ethylene propylene diene monomer (EPDM), sulfonated EPDM, styrene-butadiene rubber, fluororubber, and various copolymers.

[0084] Furthermore, the positive electrode layer 130 may also include a solid electrolyte component. The solid electrolyte component may include one or more of the components described above and can serve as an ion conduction channel within the positive electrode layer. This method can reduce the interfacial resistance.

[0085] The negative electrode layer 150 may be exposed from the second surface S2 of the laminate 100 and may be connected to the second external electrode 300.

[0086] The negative electrode layer 150 may include a negative electrode current collector 153 and a negative electrode active material layer 155. Alternatively, the negative electrode layer 150 may not include a negative electrode current collector.

[0087] Reference Figure 4 The negative electrode current collector 153 can be made using, for example, a plate-like member or a thin member. As another example, the negative electrode current collector 153 can be made using a porous member having a network-like or mesh-like structure.

[0088] The negative electrode current collector 153 may be, for example, a porous metal plate made of stainless steel, nickel (Ni), copper (Cu), tin (Sn), aluminum (Al) or alloys thereof, but is not limited thereto.

[0089] In addition, the negative electrode current collector 153 may be coated with an anti-oxidation metal film or alloy film to prevent oxidation.

[0090] The negative electrode active material layer 155 may include a negative electrode active material and may be provided on the surface of the negative electrode current collector 153. The negative electrode active material layer 155 may be formed by printing the negative electrode active material on one surface or both surfaces of the negative electrode current collector 153, but the method of forming the negative electrode active material layer is not limited thereto.

[0091] The negative electrode active material included in the negative electrode active material layer 155 may store lithium ions migrating from the positive electrode during charging of the all-solid-state battery and release lithium ions during discharging of the all-solid-state battery to generate electric energy. As the negative electrode active material, a carbon-based material, silicon, silicon oxide, silicon-based alloy, silicon-carbon-based material composite, tin, tin-based alloy, tin-carbon composite, metal oxide, or a combination thereof may be used, and the negative electrode active material may include lithium metal and / or a lithium metal alloy.

[0092] The lithium metal alloy may include lithium and a metal / metalloid that can be alloyed with lithium. For example, the metal / metalloid that can be alloyed with lithium may be Si, Sn, Al, Ge, Pb, Bi, Sb, Si-AM alloy (where AM is an alkali metal, alkaline earth metal, element in Groups 13 to 16, transition metal, rare earth element, or a combination thereof, and does not include Si), Sn-AM alloy (where AM is an alkali metal, alkaline earth metal, element in Groups 13 to 16, transition metal, transition metal oxide such as lithium titanate (Li4Ti5O 12 ), rare earth element, or a combination thereof, and does not include Sn), and MnO x (where 0 < x ≤ 2), etc.

[0093] The element AM may be Mg, Ca, Sr, Ba, Ra, Sc, Y, Ti, Zr, Hf, Rf, V, Nb, Ta, Db, Cr, Mo, W, Sg, Tc, Re, Bh, Fe, Pb, Ru, Os, Hs, Rh, Ir, Pd, Pt, Cu, Ag, Au, Zn, Cd, B, Al, Ga, Sn, In, Tl, Ge, P, As, Bi, S, Se, Te, Po, or a combination thereof.

[0094] In addition, the oxide of the metal / metalloid that can be alloyed with lithium may be lithium titanate, vanadium oxide, lithium vanadium oxide, SnO2, SiO x (where 0 < x < 2), etc. For example, the negative electrode active material may include one or more elements selected from the group consisting of elements in Groups 13 to 16 of the periodic table. For example, the negative electrode active material may include one or more elements selected from the group consisting of Si, Ge, and Sn.

[0095] The carbon-based material can be crystalline carbon, amorphous carbon, or a mixture thereof. The crystalline carbon can be graphite, such as natural graphite or artificial graphite which can be amorphous, plate-like, flaky, spherical, or fibrous. Additionally, the amorphous carbon can be soft carbon (low-temperature calcined carbon) or hard carbon, mesophase pitch carbide, calcined coke, graphene, carbon black, fullerene soot, carbon nanotubes, carbon fibers, etc., but is not limited thereto.

[0096] Silicon can be optionally selected from the group consisting of Si, SiO x (where 0 < x < 2, for example, 0.5 to 1.5), Sn, SnO2, silicon-containing metal alloys, and mixtures thereof. The silicon-containing metal alloy can include, for example, one or more of Al, Sn, Ag, Fe, Bi, Mg, Zn, In, Ge, Pb, and Ti and silicon.

[0097] The negative electrode active material can optionally include a conductive material and a binder.

[0098] There is no particular limitation on the conductive material as long as it has conductivity without causing chemical changes in the all-solid-state battery 1000. For example, the following materials can be used: graphite, such as natural graphite or artificial graphite; carbon-based materials, such as carbon black (acetylene black, Ketjen black, channel black, furnace black, lamp black, and pyrolytic carbon black); conductive fibers, such as carbon fibers, metal fibers, etc.; carbon fluorides; metal components (such as lithium (Li), tin (Sn), aluminum (Al), nickel (Ni), and copper (Cu)) and oxides of metal components, nitrides of metal components, or fluorides of metal components; conductive whiskers, such as zinc oxide and potassium titanate; conductive metal oxides, such as titanium oxide; conductive materials such as polyphenylene derivatives, etc.

[0099] The binder can be used to improve the binding strength of the active material, conductive material, etc. Examples of the binder can include polyvinylidene fluoride, polyvinyl alcohol, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, polytetrafluoroethylene, polyethylene, polypropylene, ethylene propylene diene monomer (EPDM), sulfonated EPDM, styrene butadiene rubber, fluororubber, and various copolymers, but is not limited thereto.

[0100] For example, the edge portion 170 fills the portion other than the positive electrode layer 130 and the negative electrode layer 150 within the surface on which the positive electrode layer 130 or the negative electrode layer 150 is provided.

[0101] The edge portion 170 can be provided on the outer surface of the laminate 100 to prevent moisture penetration and can be used to prevent damage caused by physical stress and chemical stress.

[0102] Refer to Figure 3The edge portion 170 may form a portion of the second surface S2, the third surface S3, and the fourth surface S4 of the laminate 100. (Refer to...) Figure 4 The edge portion 170 may form a portion of the first surface S1, the second surface S2, the third surface S3, and the fourth surface S4 of the laminate 100.

[0103] The edge portion 170 can be configured to resolve the step difference between the solid electrolyte layer 110 and the positive electrode layer 130, and between the solid electrolyte layer 110 and the negative electrode layer 150. For example, the edge portion 170 can be located on the same plane as the plane of the positive electrode layer 130 and the same plane as the plane of the negative electrode layer 150. The edge portion 170 resolves the step difference between the solid electrolyte layer 110 and the positive electrode layer 130, or between the solid electrolyte layer 110 and the negative electrode layer 150. This increases the density between the solid electrolyte layer 110 and the electrode layers, preventing delamination or bending due to sintering during the manufacturing process of all-solid-state batteries.

[0104] The edge portion 170 may be made of an insulating material (i.e., a material that does not have electronic (ionic) conductivity).

[0105] The edge portion 170 may include a ceramic material, such as alumina (Al2O3), aluminum nitride (AlN), beryllium oxide (BeO), boron nitride (BN), silicon (Si), silicon carbide (SiC), silicon dioxide (SiO2), silicon nitride (Si3N4), gallium arsenide (GaAs), gallium nitride (GaN), barium titanate (BaTiO3), zirconium dioxide (ZrO2), mixtures thereof (oxides and / or nitrides in these materials), or any other suitable ceramic material, but is not limited thereto.

[0106] Furthermore, the edge portion 170 may selectively include the aforementioned solid electrolyte, and may include one or more types of solid electrolytes, but is not limited thereto.

[0107] Additionally, the edge portion 170 may contain a material with low ionic conductivity and low electronic conductivity (i.e., an insulating material), or a material with ionic conductivity (or electronic conductivity) approximating that of the solid electrolyte. For example, when a material with ionic conductivity (or electronic conductivity) approximating that of the solid electrolyte is present in the edge portion, this material may be the same as the solid electrolyte in other regions, or it may be a different material from the solid electrolyte in other regions. As another example, an insulating material and a material with ionic conductivity (or electronic conductivity) approximating that of the solid electrolyte may coexist in the edge portion.

[0108] The first external electrode 200 and the second external electrode 300 are disposed outside the laminate 100 and connected to the laminate 100.

[0109] The first external electrode 200 is connected to the positive electrode layer 130 on the first surface S1, the third surface S3, and the fourth surface S4 of the laminate 100. Alternatively, the first external electrode 200 may be disposed on the first surface S1, the third surface S3, the fourth surface S4, the fifth surface S5, and the sixth surface S6 of the laminate 100.

[0110] The second external electrode 300 is connected to the negative electrode layer 150 on the second surface S2 of the laminate 100. Furthermore, the second external electrode 300 may be disposed on the second surface S2, third surface S3, fourth surface S4, fifth surface S5, and sixth surface S6 of the laminate 100.

[0111] In another embodiment, the first external electrode 200 may be disposed on the first surface S1, the third surface S3, the fourth surface S4, and the fifth surface S5 of the laminate 100, or it may be disposed on the first surface S1, the third surface S3, the fourth surface S4, and the sixth surface S6 of the laminate 100. The second external electrode 300 may be disposed on the second surface S2, the third surface S3, the fourth surface S4, and the fifth surface S5, or it may be disposed on the second surface S2, the third surface S3, the fourth surface S4, and the sixth surface S6.

[0112] For example, the first external electrode 200 and the second external electrode 300 can be formed by coating a paste containing a conductive metal onto the first surface S1 and the second surface S2 of the laminate 100, respectively, or by transferring a dry film of a dried conductive paste onto the laminate 100 and then sintering it. However, the method of forming the first external electrode 200 and the second external electrode 300 is not limited to these methods. Furthermore, the conductive metal can be one or more of, but is not limited to, copper (Cu), nickel (Ni), tin (Sn), palladium (Pd), platinum (Pt), gold (Au), silver (Ag), tungsten (W), titanium (Ti), lead (Pb), and alloys thereof.

[0113] Both the first external electrode 200 and the second external electrode 300 may be covered with a plating layer (not shown). The plating layer may include, but is not limited to, at least one selected from the group consisting of copper (Cu), nickel (Ni), tin (Sn), palladium (Pd), platinum (Pt), gold (Au), silver (Ag), tungsten (W), titanium (Ti), lead (Pb), and alloys thereof. The plating layer may include one or more layers.

[0114] In the following text, reference will be made to Figures 5A to 5D A method for manufacturing a stack of all-solid-state batteries according to an embodiment is described. Figures 5A to 5DThis is a diagram schematically illustrating a method for manufacturing a stack of all-solid-state batteries according to an embodiment.

[0115] A positive electrode active material layer 135 and an edge portion 170 are printed on two surfaces of a sheet made of aluminum foil for the positive electrode current collector 133. The sheet is then punched to form openings 137 around the three side surfaces of the positive electrode active material layer 135 to form a first sheet 210.

[0116] The second sheet 220 is formed by printing a negative electrode active material layer 155 and an edge portion 170 on a solid electrolyte layer (green sheet) 110.

[0117] The third sheet 230 is formed by printing an edge portion 170 on the solid electrolyte layer (green sheet) 110. Here, the edge portion 170 has a shape corresponding to the opening 137 of the first sheet 210.

[0118] The green sheet is formed by repeating the following process: a third sheet 230 is stacked on the second sheet 220, and then a first sheet 210 is stacked on the third sheet 230. The green sheet is cut to form a laminate 100, and sintered in air at 400°C to 550°C.

[0119] Figure 6 This is a schematic diagram illustrating the stacked body according to Example 1.

[0120] Reference Figure 6 The positive electrode layer 130 of the laminate 100 includes a positive electrode current collector 133 made of aluminum foil and positive electrode active material layers 135 disposed on two surfaces of the positive electrode current collector 133 in the thickness direction (T-axis direction). The sum of the thicknesses of the two positive electrode active material layers 135 is 80 μm, and the thickness of the positive electrode current collector 133 is 10 μm. The negative electrode layer 150 includes a negative electrode active material layer 155 containing graphite. The thickness of the negative electrode layer 150 is 95 μm. A solid electrolyte layer 110 is disposed between the positive electrode layer 130 and the negative electrode layer 150.

[0121] Figure 7 This is a schematic diagram illustrating the stacked body according to Example 2.

[0122] Reference Figure 7The positive electrode active material layer 135 is disposed on only one surface of the positive electrode current collector 133 made of aluminum foil in the thickness direction (T-axis direction). An insulating layer 180 is disposed on the outer surface of the positive electrode current collector 133. The thickness of the positive electrode active material layer 135 is 70 μm, and the thickness of the positive electrode current collector 133 is 10 μm. The thickness of the negative electrode layer 150 is 80 μm. Another insulating layer 180 is disposed on the outer surface of the negative electrode layer 150. The remaining components, except for the components described above, are the same as those of the laminate according to Example 1. Furthermore, in another embodiment, a solid electrolyte layer may be disposed on the outer surface of both the positive electrode current collector 133 and the negative electrode layer 150. In another embodiment, a material layer containing a mixture of solid electrolyte and insulating material may be disposed on the outer surface of both the positive electrode current collector 133 and the negative electrode layer 150.

[0123] Figure 8 This is a schematic diagram illustrating the laminate according to the comparative example.

[0124] Reference Figure 8 The positive current collector 133' is made of graphite. The sum of the thicknesses of the two positive active material layers 135 is 60 μm, and the thickness of the positive current collector 133' is 5 μm. The thickness of the negative electrode layer 150 is 70 μm. Apart from the components described above, the remaining components are the same as those of the laminate according to Example 1.

[0125] Table 1 shows the thickness of the positive electrode layer, the material and thickness of the positive current collector, and the thickness of the negative electrode layer of the all-solid-state batteries manufactured in Example 1, Example 2, and Comparative Examples.

[0126] [Table 1]

[0127] Figure 9 The graphs showing the capacity ratio versus charge-discharge rate (C-rate) of all-solid-state batteries manufactured according to Example 1, Example 2 and Comparative Example are shown.

[0128] Reference Figure 9 It can be confirmed that the output characteristics of the all-solid-state battery manufactured according to Example 1 and Example 2 are better than the output characteristics of the all-solid-state battery manufactured according to the comparative example.

[0129] While this disclosure has been described in conjunction with what is now considered to be actual embodiments, it should be understood that this disclosure is not limited to the disclosed embodiments, and rather, by comparison, is intended to cover various variations and equivalent arrangements included within the spirit and scope of the appended claims.

[0130] <Explanation of reference numerals in the attached figures> 1000: All-solid-state battery 100, 100', 100'': Layered bodies 110: Solid electrolyte layer 130: Positive electrode layer 133: Positive current collector 135: Positive electrode active material layer 137: Opening 150: Negative electrode layer 153: Negative electrode current collector 155: Negative electrode active material layer 170: Edge 180: Insulation layer 210: First Sheet 220: Second sheet 230: Third sheet 200: First external electrode 300: Second external electrode.

Claims

1. An all-solid-state battery, comprising: A laminate includes a first surface and a second surface opposite to each other in a first direction, a third surface and a fourth surface opposite to each other and connecting the first surface and the second surface in a second direction, and a fifth surface and a sixth surface opposite to each other and connecting the first surface and the second surface in a third direction, and the laminate includes a solid electrolyte layer and positive electrode layers and negative electrode layers alternately stacked in the third direction, and the solid electrolyte layer is located between the positive electrode layer and the negative electrode layer; The first external electrode is connected to the positive electrode layer and disposed outside the laminate; as well as The second external electrode is connected to the negative electrode layer and disposed outside the laminate. The positive electrode layer includes a positive electrode current collector containing aluminum foil. The negative electrode layer comprises a negative electrode active material containing graphite, and The positive electrode layer is connected to the first external electrode on the first surface, the third surface, and the fourth surface of the laminate.

2. The all-solid-state battery according to claim 1, wherein, The positive current collector includes a first outer surface and a second outer surface that are opposite to each other in the third direction, and The positive electrode active material is disposed on at least one of the first outer surface and the second outer surface.

3. The all-solid-state battery according to claim 2, wherein, The positive electrode active material is disposed on the first outer surface and the second outer surface, respectively.

4. The all-solid-state battery according to claim 2, wherein, The positive electrode active material is disposed on only one of the first outer surface and the second outer surface.

5. The all-solid-state battery according to claim 1, wherein, When viewed along the third direction, the positive current collector includes: The main body has a rectangular shape and includes a first side and a second side opposite to each other in the first direction, and a third side and a fourth side opposite to each other in the second direction; A first extension protrudes from the third side of the body toward the third surface of the laminate; and The second extension protrudes from the fourth side of the main body toward the fourth surface of the laminate, and The first side of the main body is in contact with the first surface of the laminate, and the second side of the main body is spaced apart from the second surface of the laminate.

6. The all-solid-state battery according to claim 5, wherein, The first extension contacts the first surface and the third surface of the laminate, and The second extension contacts the first surface and the fourth surface of the laminate.

7. The all-solid-state battery according to claim 1, further comprising: A first edge portion is disposed between the second surface of the laminate and the positive electrode layer.

8. The all-solid-state battery according to claim 7, wherein, The first edge portion includes at least one of a solid electrolyte and an insulating material.

9. The all-solid-state battery according to claim 8, wherein, The solid electrolyte included in the first edge portion is the same as the solid electrolyte included in the solid electrolyte layer.

10. The all-solid-state battery according to claim 8, wherein, The solid electrolyte included in the first edge portion is different from the solid electrolyte included in the solid electrolyte layer.

11. The all-solid-state battery according to claim 1, wherein, The negative electrode layer is connected to the second external electrode on the second surface of the laminate.

12. The all-solid-state battery according to claim 11, further comprising: The second edge portion is disposed between the first surface of the laminate and the negative electrode layer.

13. The all-solid-state battery according to claim 12, wherein, The second edge portion includes at least one of a solid electrolyte and an insulating material.

14. The all-solid-state battery according to claim 13, wherein, The solid electrolyte included in the second edge portion is the same as the solid electrolyte included in the solid electrolyte layer.

15. The all-solid-state battery according to claim 13, wherein, The solid electrolyte included in the second edge portion is different from the solid electrolyte included in the solid electrolyte layer.

16. The all-solid-state battery according to claim 1, wherein, The positive electrode layer has a shape different from that of the negative electrode layer.

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