All-solid-state battery

Abstract

An all-solid-state battery includes: a solid electrolyte layer; and a first electrode layer and a second electrode layer disposed in a stacking direction with the solid electrolyte layer interposed therebetween, and the first electrode layer and the second electrode layer have different polarities. Each of the first electrode layer and the second electrode layer includes a central portion and an outer portion located outside the central portion. The central portion of the first electrode layer and the central portion of the second electrode layer overlap each other in the stacking direction and overlap the solid electrolyte layer. The outer side portion of the first electrode layer and the outer side portion of the second electrode layer are stacked with the solid electrolyte layer in the stacking direction, and have corner portions located on opposite sides of each other along a diagonal direction in different electrode layers.

Description

Technical Field

[0001] The present disclosure relates to a all-solid-state battery. Background Art

[0002] Since portable electronic devices are generally used for a long time, high-capacity batteries are required, and due to the popularization of wearable electronic devices, requirements for battery safety are raised. Therefore, the development of all-solid-state batteries using solid electrolytes instead of liquid electrolytes is being actively carried out.

[0003] An all-solid-state battery is a battery that uses a solid electrolyte instead of an existing liquid electrolyte, and can greatly reduce the explosion risk caused by the flammability of the liquid electrolyte. Moreover, since the all-solid-state battery does not use a liquid electrolyte, it can be stably operated even in a harsh environment of relatively high temperature and high pressure. In addition, since the batteries can be stacked without a separate cooling unit and a high energy density can be achieved in the same volume, all-solid-state batteries are expected to be used in the future.

[0004] The above information disclosed in this background art section is only for enhancing the understanding of the background of the described technology, and thus may include information that does not constitute the prior art known to those of ordinary skill in the art. Summary of the Invention

[0005] Technical Problem

[0006] The described technology has been made in an effort to provide an all-solid-state battery capable of increasing the battery capacity and improving the charging and discharging rates within a given volume.

[0007] However, the problems to be solved by the embodiments are not limited to the above problems, and various extensions can be made within the scope of the technical concept included in the present invention.

[0008] Solution to the Problem

[0009] An embodiment provides an all-solid-state battery including: a solid electrolyte layer; and a first electrode layer and a second electrode layer, which are disposed in a stacking direction with the solid electrolyte layer interposed therebetween, and the first electrode layer and the second electrode layer have different polarities. Each of the first electrode layer and the second electrode layer includes a central portion and an outer portion located outside the central portion. The central portions of the first electrode layer and the second electrode layer are stacked on each other in the stacking direction and are stacked with the solid electrolyte layer. The outer portions of the first electrode layer and the second electrode layer are stacked with the solid electrolyte layer in the stacking direction, and have corner portions located on opposite sides of each other along a diagonal direction in different electrode layers.

[0010] The central portion may include four edges. The outer portion may include two linear portions that are bent and integrally connected at the corner portion, and may be in contact with all of two adjacent edges of the central portion.

[0011] The all-solid-state battery may further include: an insulating layer that is in contact with each of the first electrode layer and the second electrode layer in a planar direction. The insulating layer may include two linear portions that are bent and integrally connected, and may be in contact with all of the other two edges of the central portion and the end portion of the outer portion.

[0012] The central portion may include four edges. The outer portion may include two linear portions that are bent and integrally connected at the corner portion, and may be in contact with all of one edge of the central portion and a part of the other edge.

[0013] The all-solid-state battery may further include: an insulating layer that is in contact with each of the first electrode layer and the second electrode layer in a planar direction. The insulating layer may include three linear portions that are bent and integrally connected, and may be in contact with all of the other two adjacent edges of the central portion, the remaining part of the other edge, and the end portion of the outer portion.

[0014] The solid electrolyte layer may include two corner portions that are opposite to each other in a diagonal direction. The first electrode layer and the second electrode layer may be symmetric with respect to a virtual line connecting the vertices of the two corner portions.

[0015] The solid electrolyte layer may include a first corner portion and a second corner portion that are opposite to each other in a diagonal direction.

[0016] The corner portion of the outer portion of the first electrode layer may be stacked with the first corner portion in the stacking direction. The corner portion of the outer portion of the second electrode layer may be stacked with the second corner portion in the stacking direction.

[0017] The solid electrolyte layer may include a first edge portion and a second edge portion that are in contact with the first corner portion and a third edge portion and a fourth edge portion that are in contact with the second corner portion. The outer edge of the first electrode layer may be stacked with a part of the first edge portion and a part of the second edge portion in the stacking direction. The outer edge of the second electrode layer may be stacked with a part of the third edge portion and a part of the fourth edge portion in the stacking direction.

[0018] The all-solid-state battery may further include: a first insulating layer and a second insulating layer, each contacting the first electrode layer and the second electrode layer in a planar direction. An edge of the first insulating layer may overlap the remainder of the first edge portion, the remainder of the second edge portion, the third edge portion, and the fourth edge portion in the stacking direction. An edge of the second insulating layer may overlap the first edge portion, the second edge portion, the remainder of the third edge portion, and the remainder of the fourth edge portion in the stacking direction.

[0019] The outer side portions of the first electrode layer and the second electrode layer, and each of the first insulating layer and the second insulating layer may include two linear portions that are bent and integrally connected. The outer side portion of the first electrode layer and the first insulating layer may form a quadrilateral frame to surround the central portion of the first electrode layer. The outer side portion of the second electrode layer and the second insulating layer may form a quadrilateral frame to surround the central portion of the second electrode layer.

[0020] The outer side portions of the first electrode layer and the second electrode layer may include two linear portions that are bent and integrally connected at the corner portions. Each of the first insulating layer and the second insulating layer may include three linear portions that are bent and integrally connected. The outer side portion of the first electrode layer and the first insulating layer may form a quadrilateral frame to surround the central portion of the first electrode layer, and the outer side portion of the second electrode layer and the second insulating layer may form a quadrilateral frame to surround the central portion of the second electrode layer.

[0021] Another embodiment provides an all-solid-state battery, the all-solid-state battery including: a solid electrolyte layer; a first electrode layer and a second electrode layer, arranged in a stacking direction with the solid electrolyte layer interposed between the first electrode layer and the second electrode layer, and the first electrode layer and the second electrode layer having different polarities; and a first external electrode and a second external electrode, respectively connected to the first electrode layer and the second electrode layer. Each of the first electrode layer and the second electrode layer includes a central portion and an outer side portion located outside the central portion. The central portion overlaps the solid electrolyte layer and different electrode layers in the stacking direction. The outer side portion may include: a corner portion, overlapping the solid electrolyte layer in the stacking direction and located on opposite sides along the diagonal direction in different electrode layers; and two linear portions, bent at the corner portion and integrally connected. The first external electrode and the second external electrode may be connected to two adjacent edges of the outer side portion.

[0022] The all-solid-state battery may further include a first insulating layer. The first insulating layer may be in contact with the first electrode layer in a planar direction and have two linear portions that are bent and integrally connected. The outer portion of the first electrode layer and the first insulating layer may form a quadrilateral frame to surround the central portion of the first electrode layer.

[0023] The all-solid-state battery may further include a second insulating layer. The second insulating layer may be in contact with the second electrode layer in a planar direction and have two linear portions that are bent and integrally connected. The outer portion of the second electrode layer and the second insulating layer may form a quadrilateral frame to surround the central portion of the second electrode layer.

[0024] The all-solid-state battery may further include a first insulating layer. The first insulating layer may be in contact with the first electrode layer in a planar direction and have three linear portions that are bent and integrally connected. The outer portion of the first electrode layer and the first insulating layer may form a quadrilateral frame to surround the central portion of the first electrode layer.

[0025] The all-solid-state battery may further include a second insulating layer. The second insulating layer may be in contact with the second electrode layer in a planar direction and have three linear portions that are bent and integrally connected. The outer portion of the second electrode layer and the second insulating layer may form a quadrilateral frame to surround the central portion of the second electrode layer.

[0026] The solid electrolyte layer may include two corner portions that are opposite to each other in a diagonal direction. The outer portion of the first electrode layer and the outer portion of the second electrode layer may be symmetric with respect to a virtual line connecting the vertices of the two corner portions.

[0027] The solid electrolyte layer, the first electrode layer, and the second electrode layer may constitute a unit stack. The solid electrolyte layer may include a first corner portion and a second corner portion that are opposite to each other in a diagonal direction. The first external electrode may surround the first corner portion and contact two adjacent side surfaces of the unit stack, and the second external electrode may surround the second corner portion and contact the other two adjacent side surfaces of the unit stack.

[0028] Advantageous Effects of the Invention

[0029] According to an embodiment, the all-solid-state battery can increase the capacity of the electrode active material layer within a given volume to improve the battery capacity and shorten the electron movement path between the electrode layer and the external electrode to improve the charge / discharge rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a perspective view showing an all-solid-state battery according to an embodiment.

[0031] Figure 2 is a cross-sectional view taken along line II-II' Figure 1 .

[0032] Figure 3 is a partial exploded perspective view showing the Figure 1 all-solid-state battery shown in

[0033] Figure 4 is a partial exploded perspective view showing the all-solid-state battery according to the comparative example with partial disassembly.

[0034] Figure 5 is a diagram schematically showing Figure 4 the electron movement path between the electrode layer and the external electrode in the all-solid-state battery of the comparative example shown in

[0035] Figure 6 is a diagram schematically showing Figure 1 the electron movement path between the electrode layer and the external electrode in the all-solid-state battery of the example shown in

[0036] Figure 7 is a perspective view showing the all-solid-state battery according to another example.

[0037] Figure 8 is a partial exploded perspective view showing the Figure 7 all-solid-state battery shown in

[0038] Figure 9 is a graph showing the results of the Cole-Cole plot of the all-solid-state batteries according to Example 1, Example 2, and the comparative example. DETAILED DESCRIPTION

[0039] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings so that those skilled in the art to which the present disclosure pertains can easily practice the present disclosure. To clearly explain the present disclosure in the drawings, parts irrelevant to the description are omitted, and the same reference numerals are used for the same or similar components throughout the specification. In addition, it should be noted that some components shown in the drawings are exaggerated, omitted, or schematically shown, and the size of each component does not precisely reflect its actual size.

[0040] It should be understood that the accompanying drawings are provided only to allow easy understanding of the embodiments of the present disclosure, and the spirit of the present disclosure is not limited by the drawings, but includes all variations, equivalents, and alternatives included in the spirit and scope of the present disclosure.

[0041] Terms including ordinal numbers such as first, second, etc. may be used to describe various components, but the components are not limited to these terms. These terms are only used to distinguish one component from another component.

[0042] In addition, it should be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" another element, it may be "directly on" the other element or there may be intervening elements between them. In contrast, it should be understood that when any element is referred to as being "directly on" another element, there may be no element between them. Additionally, when an element is referred to as being "on" a reference element, it may be positioned on or below the reference element and not necessarily positioned "above" or "on" the reference element in the direction opposite to gravity.

[0043] It should also be understood that the terms "comprising" or "having" used in this specification indicate the presence of the features, numbers, steps, operations, components, parts, or combinations thereof mentioned in this specification, but do not preclude the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof. Thus, unless explicitly described to the contrary, "comprising" any component will be understood to imply including other components rather than excluding other components.

[0044] Throughout the specification, the term "plan view" refers to the view when observing the target from the top, and the term "cross-sectional view" refers to the view of the cross-section taken along the vertical direction when observing the target from the side.

[0045] Throughout the specification, when referred to as "connected", this does not mean that two or more components are directly connected, but means that two or more components are indirectly connected through another component, two or more components are physically connected and electrically connected, or two or more components are referred to by different names according to their positions or functions, but are integral.

[0046] In the description of the all-solid-state battery in this specification, the direction in which the main components of the all-solid-state battery are stacked is defined as the "stacking direction", but it may also be the "thickness direction". Additionally, the direction parallel to the plane perpendicular to the stacking direction may be defined as the "plane direction", and the plane direction may include the "first direction" and the "second direction" that are orthogonal to each other.

[0047] Figure 1 is a perspective view showing an all-solid-state battery according to an exemplary embodiment, and Figure 2 is along Figure 1 the line II-II' taken cross-sectional view.

[0048] Referring to Figure 1 and Figure 2, the all-solid-state battery 100 according to the embodiment includes electrode layers 120 and 140 and a solid electrolyte layer 130 positioned adjacent to the electrode layers 120 and 140 in the stacking direction (the z-axis direction in the drawings). The electrode layers 120 and 140 may mainly include current collectors 121 and 141 extending in the planar direction (the x-y plane direction in the drawings) and electrode active material layers 122 and 142 located on at least one surface of the current collectors 121 and 141.

[0049] In this embodiment, the electrode layers 120 and 140 include a positive electrode layer 120 and a negative electrode layer 140 having different polarities. The solid electrolyte layer 130 includes a solidified electrolyte and may function as a medium for transferring ions between the positive electrode layer 120 and the negative electrode layer 140. The positive electrode layer 120 may be the first electrode layer, and the negative electrode layer 140 may be the second electrode layer.

[0050] The positive electrode layer 120 includes a positive electrode current collector 121 and a positive electrode active material layer 122 located on at least one surface of the positive electrode current collector 121. The negative electrode layer 140 includes a negative electrode current collector 141 and a negative electrode active material layer 142 located on at least one surface of the negative electrode current collector 141. The electrode active material layers 122 and 142 may be located on the entire one surface of the current collectors 121 and 141.

[0051] For example, the negative electrode layer 140 located at the top in the stacking direction may include a negative electrode active material layer 142 located on one surface (the lower surface) of the negative electrode current collector 141, and the positive electrode layer 120 located at the bottom may include a positive electrode active material layer 122 located on one surface (the upper surface) of the positive electrode current collector 121. Additionally, the positive electrode layer 120 between the top and the bottom may include positive electrode active material layers 122 located on both surfaces of the positive electrode current collector 121, and the negative electrode layer 140 between the top and the bottom may include negative electrode active material layers 142 located on both surfaces of the negative electrode current collector 141.

[0052] The solid electrolyte layer 130 may be disposed adjacent to each other in the stacking direction between the positive electrode active material layer 122 of the positive electrode layer 120 and the negative electrode active material layer 142 of the negative electrode layer 140. Therefore, within the all-solid-state battery 100, a plurality of positive electrode layers 120 and a plurality of negative electrode layers 140 may be alternately arranged, and the solid electrolyte layer 130 may be interposed between and stacked on the negative electrode layer 120 and the positive electrode layer 140.

[0053] For example, garnet-type solid electrolytes, Li superionic conductor (LiSICON)-type solid electrolytes, perovskite-type solid electrolytes, Na superionic conductor (NaSICON)-type solid electrolytes, etc. may be used as the solid electrolyte layer 130.

[0054] The positive electrode layer 120, the solid electrolyte layer 130, and the negative electrode layer 140 may be stacked as described above to form a cell stack of the all-solid-state battery 100. The outer insulating layer 135 covering the negative electrode current collector 141 may be located at the uppermost outer portion of the cell stack, and the outer insulating layer 136 covering the positive electrode current collector 121 may be located at the lowermost outer portion of the cell stack. In addition, protective layers 137 and 138 including an insulating material are further located outside the outer insulating layers 135 and 136 to prevent ion leakage and ensure insulation performance.

[0055] Figure 3 is a partial disassembly view Figure 1 showing the partial exploded perspective view of the all-solid-state battery shown in

[0056] Referring to Figure 3 , the positive electrode layer 120, the solid electrolyte layer 130, and the negative electrode layer 140 are configured as polygons in a plane and may be configured as, for example, quadrilaterals.

[0057] The solid electrolyte layer 130 may include a first corner portion 131a and a second corner portion 131b that are opposite to each other in the diagonal direction, a first edge portion 132a and a second edge portion 132b that are in contact with the first corner portion 131a, and a third edge portion 132c and a fourth edge portion 132d that are in contact with the second corner portion 131b. The second edge portion 132b and the third edge portion 132c may be in contact with a third corner portion 131c, and the first edge portion 132a and the fourth edge portion 132d may be in contact with a fourth corner portion 131d.

[0058] The first edge portion 132a and the third edge portion 132c may be parallel to a first direction (the x-axis direction in the drawing), and the second edge portion 132b and the fourth edge portion 132d may be parallel to a second direction (the y-axis direction in the drawing). The first edge portion 132a and the third edge portion 132c are opposite to each other along the second direction, and the second edge portion 132b and the fourth edge portion 132d are opposite to each other along the first direction.

[0059] The positive electrode layer 120 may include a central portion 125 and an outer portion 126 located outside the central portion 125. The central portion 125 may have a quadrilateral shape, and the outer portion 126 may include two linear portions 126a and 126b that are bent and integrally connected, and the outer portion 126 may be in contact with all two adjacent edges of the central portion 125. The outer portion 126 includes a corner portion 126c located between the two linear portions 126a and 126b. The corner portion 126c of the outer portion 126 may be stacked with the first corner portion 131a in the stacking direction, and the edges of the two linear portions 126a and 126b of the outer portion 126 may be stacked with a part of the first edge portion 132a and a part of the second edge portion 132b in the stacking direction.

[0060] The positive electrode layer 120 may be in contact with the insulating layer 151 in the planar direction. The insulating layer 151 may include two linear portions that are bent and integrally connected, and may be in contact with all of the remaining edges of the central portion 125 and the ends of the outer portion 126. The insulating layer 151 and the outer portion 126 may form a quadrilateral frame to surround the central portion 125 without a gap.

[0061] The combined area of the positive electrode layer 120 and the insulating layer 151 may be equal to the area of the solid electrolyte layer 130. The corners of the insulating layer 151 may be stacked with the second corner portion 131b in the stacking direction, and the two edges of the insulating layer 151 may be stacked with the entire third edge portion 132c and the entire fourth edge portion 132d in the stacking direction.

[0062] The negative electrode layer 140 may include a central portion 145 and an outer portion 146 located outside the central portion 146. The central portion 145 may have a quadrilateral shape, and the outer portion 146 may include two linear portions 146a and 146b that are bent and integrally connected, and the outer portion 146 may be in contact with all of the two adjacent edges of the central portion 145. The outer portion 146 includes a corner portion 146c located between the two linear portions 146a and 146b. The corner portion 146c of the outer portion 146 may be stacked with the second corner portion 131b in the stacking direction, and the two edges of the outer portion 146 may be stacked with a part of the third edge portion 132c and a part of the fourth edge portion 132d in the stacking direction.

[0063] The negative electrode layer 140 may be in contact with the insulating layer 152 in the planar direction. The insulating layer 152 may include two linear portions that are bent and integrally connected, and may be in contact with all of the remaining edges of the central portion 145 and the ends of the outer portion 146. The insulating layer 152 and the outer portion 146 may form a quadrilateral frame to surround the central portion 145 without a gap.

[0064] The combined area of the negative electrode layer 140 and the insulating layer 152 may be equal to the area of the solid electrolyte layer 130. The corners of the insulating layer 152 may be stacked with the first corner portion 131a in the stacking direction, and the two edges of the insulating layer 152 may be stacked with the entire first edge portion 132a and the entire second edge portion 132b in the stacking direction.

[0065] The central portion 125 of the positive electrode layer 120 is stacked with the central portion 145 of the solid electrolyte layer 130 and the negative electrode layer 140 in the stacking direction. That is, the central portions 125 and 145 are stacked with the solid electrolyte layer 130 and other electrode layers in the stacking direction. The outer portion 126 of the positive electrode layer 120 is stacked with the solid electrolyte layer 130 in the stacking direction, but not with the negative electrode layer 140. The outer portion 146 of the negative electrode layer 140 is stacked with the solid electrolyte layer 130 in the stacking direction, but not with the positive electrode layer 120.

[0066] That is, the outer portions 126 and 146 have corner portions 126c and 146c. The corner portions 126c and 146c are located on opposite sides along the diagonal direction and do not overlap with other electrode layers in the stacking direction. The entire outer portions 126 and 146 are also located on opposite sides along the diagonal direction and are opposite to each other along the diagonal direction.

[0067] The insulating layer 151 in contact with the positive electrode layer 120 may be the first insulating layer, and the insulating layer 152 in contact with the negative electrode layer 140 may be the second insulating layer. The outer portion 126 of the positive electrode layer 120 overlaps with the solid electrolyte layer 130 and the second insulating layer 152 in the stacking direction, and the outer portion 146 of the negative electrode layer 140 overlaps with the solid electrolyte layer 130 and the first insulating layer 151 in the stacking direction. The positive electrode layer 120 and the negative electrode layer 140 may be symmetric with respect to a virtual line L10 connecting the vertices of the third corner portion 131c and the fourth corner portion 131d.

[0068] Referring to Figures 1 to 3 , two adjacent edges of the positive electrode layer 120 and two adjacent edges of the negative electrode layer 140 may be exposed on the side surfaces of the cell stack, and the external electrodes 161 and 162 may be connected and bonded to the two adjacent edges of the exposed positive electrode layer 120 and the two adjacent edges of the negative electrode layer 140. The external electrodes 161 and 162 may include an external positive electrode 161 connected to the positive electrode layer 120 and having a positive electrode and an external negative electrode 162 connected to the negative electrode layer 140 and having a negative electrode. The external positive electrode 161 may be the first external electrode, and the external negative electrode 162 may be the second external electrode.

[0069] Two adjacent edges of the positive electrode layer 120 (specifically, two adjacent edges of the outer portion 126) may be exposed on the two side surfaces of the cell stack, and the external positive electrode 161 may surround the first corner portion 131a and may be located at a position in contact with the two adjacent side surfaces of the cell stack. Two adjacent edges of the negative electrode layer 140 (specifically, two adjacent edges of the outer portion 146) may be exposed on the other two side surfaces of the cell stack, and the external negative electrode 162 may surround the second corner portion 131b and may be located at a position in contact with the other two adjacent side surfaces of the cell stack.

[0070] The insulating layers 151 and 152 are located between the positive electrode layer 120 and the external negative electrode 162 and between the negative electrode layer 140 and the external positive electrode 161 to insulate the positive electrode layer 120 from the external negative electrode 162 and to insulate the negative electrode layer 140 from the external positive electrode 161. The outer portions 126 and 146 and the insulating layers 151 and 152 may have a constant width, and the width w1 of the outer portions 126 and 146 may be equal to the width w2 of the insulating layers 151 and 152.

[0071] The above-mentioned all-solid-state battery 100 is configured to maximize the areas of the electrode active material layers 122 and 142 within a given volume and to expand the contact areas between the electrode layers 120 and 140 and the external electrodes 161 and 162. Therefore, the above-mentioned all-solid-state battery 100 can increase the battery capacity by increasing the capacities of the electrode active material layers 122 and 142, and can shorten the electron movement paths between the electrode layers 120 and 140 and the external electrodes 161 and 162 to improve the charging / discharging rate.

[0072] Figure 4 FIG. is a partially exploded perspective view showing a partially disassembled all-solid-state battery according to a comparative example.

[0073] Referring to Figure 4 , in the all-solid-state battery of the comparative example, the positive electrode layer 11 and the negative electrode layer 12 are located on opposite sides of each other along a first direction (the x-axis direction in the drawing).

[0074] Specifically, one edge of the positive electrode layer 11 may overlap a part of one side (left side) edge of the solid electrolyte layer 13 in the stacking direction, and the other three edges of the positive electrode layer 11 may overlap the insulating layer 14 in the planar direction. In this case, the insulating layer 14 may include three linear portions that are bent and integrally connected. One edge of the negative electrode layer 12 may overlap a part of the other side (right side) edge of the solid electrolyte layer 13 in the stacking direction, and the other three edges of the negative electrode layer 12 may contact the insulating layer 15 in the planar direction. In this case, the insulating layer 15 may include three linear portions that are bent and integrally connected.

[0075] The external positive electrode 16 may be connected and bonded to one edge of the positive electrode layer 11 that is exposed on one side of the unit stack. The external negative electrode 17 may be connected and bonded to one edge of the negative electrode layer 12 that is exposed on the opposite side of the unit stack. The external positive electrode 16 and the external negative electrode 17 are opposite to each other along the first direction.

[0076] Referring to Figure 3 and Figure 4 , in the all-solid-state battery of the exemplary embodiment and the all-solid-state battery of the comparative example, when assuming that the areas of the solid electrolyte layers 130 and 13, the volume of the unit stack, and the widths of the insulating layers 151, 152, 14, and 15 are equal, the total area occupied by the electrode active material layers 122 and 142 in the all-solid-state battery 100 of the exemplary embodiment is larger than the total area occupied by the electrode active material layers in the all-solid-state battery of the comparative example.

[0077] Specifically, in the all-solid-state battery 100 of the exemplary embodiment, compared with the area occupied by the electrode active material layer in the comparative example, the increased area occupied by the electrode active material layers 122 and 142 is the area occupied by one of the two linear portions constituting the outer portions 126 and 146. Therefore, the all-solid-state battery 100 of the exemplary embodiment can increase the capacity of the electrode active material layers 122 and 142 to improve the battery capacity.

[0078] Figure 5 is a schematic diagram showing Figure 4 the electron movement path between the electrode layer and the external electrode in the all-solid-state battery of the comparative example shown in Figure 6 is a schematic diagram showing Figure 1 the electron movement path between the electrode layer and the external electrode in the all-solid-state battery of the exemplary embodiment shown in

[0079] Referring to Figure 5 , in the all-solid-state battery of the comparative example, the external electrodes 16 and 17 are in contact with one edge of the electrode layers 11 and 12. In this case, around one edge of the electrode active material layer close to the external electrodes 16 and 17, the electron movement path is short, but as it moves away from the external electrodes 16 and 17 in the first direction, the electron movement path becomes longer.

[0080] Referring to Figure 1 and Figure 6 , in the all-solid-state battery 100 of the exemplary embodiment, the external electrodes 161 and 162 are continuously connected to two edges of the electrode layers 120 and 140, and the contact length between the external electrodes 161 and 162 and the electrode layers 120 and 140 is approximately twice the contact length between the external electrode and the electrode layer in the comparative example. Therefore, compared with the case of the comparative example, the all-solid-state battery 100 of the exemplary embodiment can overall shorten the electron movement path and improve the charge / discharge rate.

[0081] Figure 7 is a perspective view showing an all-solid-state battery according to another embodiment, Figure 8 is a perspective view showing a partially disassembled Figure 7 all-solid-state battery shown in

[0082] Referring to Figure 7 and Figure 8 , the all-solid-state battery 200 according to another embodiment may include as referred to Figures 1 to 3The same basic structure as that of the described all-solid-state battery 100. That is, in the all-solid-state battery 200, the positive electrode layer 120 and the negative electrode layer 140 may include a central portion 125 and 145 and outer portions 127 and 147 located outside the central portions 125 and 145. The central portions 125 and 145 may be stacked with the solid electrolyte layer 130 and other electrode layers in the stacking direction, and the outer portions 127 and 147 may be stacked with the solid electrolyte layer 130 in the stacking direction. The outer portions 127 and 147 have corner portions 127c and 147c, and the corner portions 127c and 147c are located on opposite sides along the diagonal direction and are not stacked with other electrode layers in the stacking direction. The entire outer portions 127 and 147 are also located on opposite sides along the diagonal direction and are opposite to each other along the diagonal direction.

[0083] The outer portion 127 of the positive electrode layer 120 may include two linear portions (i.e., the first linear portion 127a and the second linear portion 127b) that are bent and integrally connected, and a corner portion 127c located between the first linear portion 127a and the second linear portion 127b. The insulating layer 153 in contact with the positive electrode layer 120 may include three linear portions (i.e., the third linear portion 153a, the fourth linear portion 153b, and the fifth linear portion 153c) that are bent and integrally connected. The first linear portion 127a, the second linear portion 127b, the third linear portion 153a, the fourth linear portion 153b, and the fifth linear portion 153c may form a quadrilateral frame to surround the central portion 125 of the positive electrode layer 120 without gaps.

[0084] One edge of the central portion 125 may be in continuous contact with the first linear portion 127a and the fifth linear portion 153c, and the ends of the first linear portion 127a and the fifth linear portion 153c may be in contact with each other. The edges of the first linear portion 127a and the fifth linear portion 153c may be stacked with the first edge portion 132a of the solid electrolyte layer 130 in the stacking direction. The first linear portion 127a and the fifth linear portion 153c may have the same length, but this is not limited to this example. The external positive electrode 163 may be connected and bonded to two adjacent edges of the outer portion 127.

[0085] The outer portion 147 of the negative electrode layer 140 may include two linear portions (i.e., the sixth linear portion 147a and the seventh linear portion 147b) that are bent and integrally connected, and a corner portion 147c located between the sixth linear portion 147a and the seventh linear portion 147b. The insulating layer 154 in contact with the negative electrode layer 140 may include three linear portions (i.e., the eighth linear portion 154a, the ninth linear portion 154b, and the tenth linear portion 154c) that are bent and integrally connected. The sixth linear portion 147a, the seventh linear portion 147b, the eighth linear portion 154a, the ninth linear portion 154b, and the tenth linear portion 154c may form a quadrilateral frame to surround the central portion 145 of the negative electrode layer 140 without gaps.

[0086] One edge of the central portion 145 may be in continuous contact with the sixth linear portion 147a and the tenth linear portion 154c, and the ends of the sixth linear portion 147a and the tenth linear portion 154c may be in contact with each other. The edges of the sixth linear portion 147a and the tenth linear portion 154c may be stacked with the third edge portion 132c of the solid electrolyte layer 130 in the stacking direction. The sixth linear portion 147a and the tenth linear portion 154c may have the same length, but are not limited to this example. The external negative electrode 164 may be connected and bonded to the two edges of the outer side portion 147.

[0087] The length of the first linear portion 127a may be the same as the length of the sixth linear portion 147a. The positive electrode layer 120 and the negative electrode layer 140 may be symmetric with respect to the imaginary line L10 connecting the vertices of the third corner portion 131c and the fourth corner portion 131d.

[0088] Compared with the all-solid-state battery 100 described with reference to Figures 1 to 3 In the all-solid-state battery 200 according to the embodiment, the total area occupied by the electrode active material layers 122 and 142 is smaller, but a larger distance between the external positive electrode 163 and the external negative electrode 164 can be ensured, thereby reducing the interference between the external positive electrode 163 and the external negative electrode 164.

[0089] The resistances of the external electrodes in the all-solid-state batteries according to Example 1 and Example 2 and the comparative example were measured and are shown in Table 1. The all-solid-state battery of Example 1 is the all-solid-state battery according to the exemplary embodiment described with reference to Figures 1 to 3 The all-solid-state battery of Example 2 is the all-solid-state battery according to another embodiment described with reference to Figure 7 and Figure 8 described.

[0090] [Table 1]

[0091] Example 1 Example 2 Comparative Example Resistance (kΩ) 3.2 5.6 9.3

[0092] Figure 9 is a graph showing the results of the Cole-Cole plot of the all-solid-state batteries according to Example 1 and Example 2 and the comparative example.

[0093] Referring to Figure 9 and Table 1, it can be seen that the resistance of the external electrode is the highest in the all-solid-state battery of the comparative example, the lowest in the all-solid-state battery of Example 1, and at an intermediate level in the all-solid-state battery of Example 2. The all-solid-state batteries of Example 1 and Example 2 can reduce the resistance of the external electrode to improve the charge / discharge rate.

[0094] Although the preferred embodiments have been described above, the present invention is not limited thereto, and the present invention can be variously modified within the scope of the claims, the specific embodiments of the invention, and the drawings, and it is naturally understood that various modifications also fall within the scope of the present invention.

[0095] <Description of Reference Numerals>

[0096] 100, 200: All-solid-state battery

[0097] 120, 140: Electrode layer

[0098] 120: Positive electrode layer

[0099] 121: Positive electrode current collector

[0100] 122: Positive electrode active material layer

[0101] 140: Negative electrode layer

[0102] 141: Negative electrode current collector

[0103] 142: Negative electrode active material layer

[0104] 125 and 145: Central part 126, 127, 146, 147: Outer part

[0105] 151, 152, 153, 154: Insulating layer 130: Solid electrolyte layer

[0106] 135, 136: Outer insulating layer 137, 138: Protective layer

[0107] 161, 162: Outer electrode

[0108] 161, 163: External positive electrode

[0109] 162, 164: External negative electrode

Claims

1. A all-solid-state battery, comprising: a solid electrolyte layer; and a first electrode layer and a second electrode layer, which are arranged in a stacking direction and the solid electrolyte layer is interposed between the first electrode layer and the second electrode layer, and the first electrode layer and the second electrode layer have different polarities, wherein each of the first electrode layer and the second electrode layer includes a central portion and an outer portion located outside the central portion, the central portion of the first electrode layer and the central portion of the second electrode layer are stacked on each other in the stacking direction and are stacked with the solid electrolyte layer, and the outer portion of each of the first electrode layer and the second electrode layer is stacked with the solid electrolyte layer in the stacking direction and has corner portions located on opposite sides of each other along the diagonal direction in different electrode layers.

2. The all-solid-state battery according to claim 1, wherein: the central portion includes four edges, and the outer portion includes two linear portions that are bent and integrally connected at the corner portion and are in contact with all of two adjacent edges of the central portion.

3. The all-solid-state battery according to claim 2, the all-solid-state battery further comprises: an insulating layer, which is in contact with each of the first electrode layer and the second electrode layer in a planar direction, wherein the insulating layer includes two linear portions that are bent and integrally connected and is in contact with all of the remaining edges of the central portion and the ends of the outer portion.

4. The all-solid-state battery according to claim 1, wherein: the central portion includes four edges, and the outer portion includes two linear portions that are bent and integrally connected at the corner portion and are in contact with all of one edge of the central portion and a part of the remaining edges.

5. The all-solid-state battery according to claim 4, the all-solid-state battery further comprises: an insulating layer, which is in contact with each of the first electrode layer and the second electrode layer in a planar direction, wherein the insulating layer includes three linear portions that are bent and integrally connected and is in contact with all of the remaining adjacent edges of the central portion, the remaining part of the remaining edges, and the ends of the outer portion.

6. The all-solid-state battery according to claim 1, wherein: the solid electrolyte layer includes two corner portions that are opposite to each other in the diagonal direction, and the first electrode layer and the second electrode layer are symmetric with respect to a virtual line connecting the vertices of the two corner portions.

7. The all-solid-state battery according to claim 1, wherein: the solid electrolyte layer includes a first corner portion and a second corner portion that are opposite to each other in the diagonal direction, the corner portion of the outer portion of the first electrode layer is stacked with the first corner portion in the stacking direction, and the corner portion of the outer portion of the second electrode layer is stacked with the second corner portion in the stacking direction.

8. The all-solid-state battery according to claim 7, wherein: the solid electrolyte layer includes a first edge portion and a second edge portion in contact with the first corner portion and a third edge portion and a fourth edge portion in contact with the second corner portion, The outer edge of the first electrode layer overlaps with a part of the first edge portion and a part of the second edge portion in the stacking direction, and the outer edge of the second electrode layer overlaps with a part of the third edge portion and a part of the fourth edge portion in the stacking direction.

9. The all-solid-state battery according to claim 8, the all-solid-state battery further comprises: A first insulating layer and a second insulating layer, each in contact with the first electrode layer and the second electrode layer in the planar direction, wherein the edge of the first insulating layer overlaps with the remaining part of the first edge portion, the remaining part of the second edge portion, the third edge portion, and the fourth edge portion in the stacking direction, and the edge of the second insulating layer overlaps with the first edge portion, the second edge portion, the remaining part of the third edge portion, and the remaining part of the fourth edge portion in the stacking direction.

10. The all-solid-state battery according to claim 9, wherein: The outer portion of the first electrode layer, the outer portion of the second electrode layer, and each of the first insulating layer and the second insulating layer include two linear portions that are bent and integrally connected.

11. The all-solid-state battery according to claim 10, wherein: The outer portion of the first electrode layer and the first insulating layer form a quadrilateral frame to surround the central portion of the first electrode layer, and The outer portion of the second electrode layer and the second insulating layer form a quadrilateral frame to surround the central portion of the second electrode layer.

12. The all-solid-state battery according to claim 9, wherein: The outer portions of the first electrode layer and the second electrode layer include two linear portions that are bent and integrally connected at the corner portion, and Each of the first insulating layer and the second insulating layer includes three linear portions that are bent and integrally connected.

13. The all-solid-state battery according to claim 12, wherein: The outer portion of the first electrode layer and the first insulating layer form a quadrilateral frame to surround the central portion of the first electrode layer, and The outer portion of the second electrode layer and the second insulating layer form a quadrilateral frame to surround the central portion of the second electrode layer.

14. An all-solid-state battery, comprises: A solid electrolyte layer; A first electrode layer and a second electrode layer, arranged in a stacking direction with the solid electrolyte layer interposed between the first electrode layer and the second electrode layer, and the first electrode layer and the second electrode layer having different polarities; and A first external electrode and a second external electrode, respectively connected to the first electrode layer and the second electrode layer, wherein each of the first electrode layer and the second electrode layer includes a central portion and an outer portion located outside the central portion, the central portion overlaps with the solid electrolyte layer and different electrode layers in the stacking direction, The outer portion includes: a corner portion that is stacked with the solid electrolyte layer in the stacking direction and is located on opposite sides of each other along a diagonal direction in different electrode layers; and two linear portions that are bent at the corner portion and integrally connected, and the first outer electrode and the second outer electrode are connected to two adjacent edges of the outer portion.

15. The all-solid-state battery according to claim 14, the all-solid-state battery further comprises: a first insulating layer that contacts the first electrode layer in a planar direction and has two linear portions that are bent and integrally connected, wherein the outer portion of the first electrode layer and the first insulating layer form a quadrilateral frame to surround the central portion of the first electrode layer.

16. The all-solid-state battery according to claim 15, the all-solid-state battery further comprises: a second insulating layer that contacts the second electrode layer in a planar direction and has two linear portions that are bent and integrally connected, wherein the outer portion of the second electrode layer and the second insulating layer form a quadrilateral frame to surround the central portion of the second electrode layer.

17. The all-solid-state battery according to claim 14, the all-solid-state battery further comprises: a first insulating layer that contacts the first electrode layer in a planar direction and has three linear portions that are bent and integrally connected, wherein the outer portion of the first electrode layer and the first insulating layer form a quadrilateral frame to surround the central portion of the first electrode layer.

18. The all-solid-state battery according to claim 17, the all-solid-state battery further comprises: a second insulating layer that contacts the second electrode layer in a planar direction and has three linear portions that are bent and integrally connected, wherein the outer portion of the second electrode layer and the second insulating layer form a quadrilateral frame to surround the central portion of the second electrode layer.

19. The all-solid-state battery according to claim 14, wherein: the solid electrolyte layer includes two corner portions that are opposite to each other in a diagonal direction, and the outer portions of the first electrode layer and the second electrode layer are symmetric with respect to a virtual line connecting the vertices of the two corner portions.

20. The all-solid-state battery according to claim 14, wherein: the solid electrolyte layer, the first electrode layer, and the second electrode layer constitute a unit stack, the solid electrolyte layer includes a first corner portion and a second corner portion that are opposite to each other in a diagonal direction, the first outer electrode surrounds the first corner portion and contacts two adjacent side surfaces of the unit stack, and the second outer electrode surrounds the second corner portion and contacts the remaining two adjacent side surfaces of the unit stack.

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