Solid-state battery clusters and battery modules

Abstract

The present invention relates to the field of battery technology, specifically to a solid-state battery cluster and a battery module. The solid-state battery cluster includes a plurality of battery cells, and the battery cells include a solid electrolyte, a lithium-based negative electrode fixedly arranged on the left side of the solid electrolyte, and a composite positive electrode fixedly arranged on the right side of the solid electrolyte. The right side wall of the lithium-based negative electrode is integrally formed with a conical metal lithium, and the left side wall of the solid electrolyte is provided with a conical groove that matches the conical metal lithium. A sol-type polymer modified layer is provided between the solid electrolyte and the composite positive electrode. An insulating shell is fixedly sleeved on the outer wall of the solid electrolyte, and a glue injection hole is provided on the upper surface of the insulating shell. A sealing block is fixedly provided in the glue injection hole. The present invention pushes the part of the solid electrolyte close to the insulating shell toward the composite positive electrode after the conical metal lithium expands, so that the sol-type polymer modified layer and the composite positive electrode are more tightly combined, which significantly improves the interface compatibility between the two solid phases and improves the service life of the battery cell.

Description

Technical Field

[0001] The present invention relates to the field of battery technology, in particular to a solid-state battery cluster and a battery module. Background Art

[0002] With the acceleration of energy transformation, new battery technologies have received widespread attention. Among them, solid-state batteries have become a type of battery that has attracted much attention due to their advantages such as high energy density, high safety, and long life. Solid-state batteries are mainly composed of positive electrodes, solid electrolytes, and negative electrodes. Among them, the material of the positive electrode can be selected from lithium-ion embedded compounds or elemental sulfur and sulfides that do not contain lithium elements. The material of the negative electrode can use a high-capacity lithium-based negative electrode. The use of solid-state electrolytes can not only solve battery safety problems, but also expand the range of choices for positive and negative electrode materials, thereby increasing the specific energy of the battery.

[0003] At present, solid-state batteries have the following problems: 1. The volume change and high activity of the lithium-based negative electrode lead to an increase in the metal lithium / solid electrolyte interface impedance, which in turn leads to battery failure; 2. The interface between the solid electrolyte and the positive and negative electrodes has a defect of large contact resistance, resulting in low interface stability of the solid-state battery. Summary of the invention

[0004] The object of the present invention is to provide a solid-state battery cluster and a battery module to solve the problems raised in the above-mentioned background technology.

[0005] To achieve the above-mentioned purpose, on the one hand, the present invention provides the following technical solutions: a solid-state battery cluster, comprising a plurality of battery cells connected in series, wherein the battery cells include a solid electrolyte, a lithium-based negative electrode fixedly arranged on the left side of the solid electrolyte, and a composite positive electrode fixedly arranged on the right side of the solid electrolyte, the right side wall of the lithium-based negative electrode is integrally formed with a conical metallic lithium, the axis of the conical metallic lithium is coaxial with the transverse axis of the lithium-based negative electrode, the left side wall of the solid electrolyte is provided with a conical groove matching the conical metallic lithium, a sol-type polymer modified layer is provided between the solid electrolyte and the composite positive electrode, an insulating shell is fixedly sleeved on the outer wall of the solid electrolyte, a glue injection hole penetrating inside and outside is provided on the upper surface of the insulating shell, and a sealing block threadedly connected to the insulating shell is fixedly provided in the glue injection hole.

[0006] Optionally, the material of the solid electrolyte is Li 2 SP 2 S 5 The material of the composite positive electrode is LiCoO 2 The material of the sol-type polymer modified layer is Li 2 SiO 3 .

[0007] Optionally, the material of the solid electrolyte is Li 3 PS 4 The material of the composite positive electrode is LiNi 1 / 3 Mn 1 / 3 Co 1 / 3 O 2 The material of the sol-type polymer modified layer is LiAlO 2 .

[0008] Optionally, the conical metal lithium is a regular tetrahedral pyramid structure, and the composite positive electrode is a rectangular parallelepiped structure.

[0009] Optionally, several of the battery cells are connected in series in the left-right direction, and a covering structure is commonly sleeved on the outside of the battery cells. Two electrode sheets arranged left and right are fixed on the upper surface of the covering structure. The electrode sheet on the left is connected to the positive current collector on the far left through a wire, and the electrode sheet on the right is connected to the negative current collector on the far right through a wire.

[0010] Optionally, a left embedding hole is opened at the left end of the insulating shell, a negative electrode current collector is fixedly provided on the left side wall of the lithium-based negative electrode, and the left end of the negative electrode current collector extends out of the left embedding hole;

[0011] A right embedding hole is formed at the right end of the insulating shell, a positive electrode current collector is fixedly provided on the right side wall of the composite positive electrode, and the right end of the positive electrode current collector extends out of the right embedding hole;

[0012] Two battery cells located in the left-right direction and adjacent to each other are connected in series, and the positive electrode current collector of the battery cell located on the left side abuts against the negative electrode current collector of the battery cell located on the right side.

[0013] Optionally, the thickness of the sol-type polymer modified layer is greater than the outer diameter of the sealing block, the upper surface of the sealing block is provided with a S-shaped groove, a cross groove, or a hexagonal groove, and the bottom of the sealing block is a conical structure. When the upper surface of the sealing block is flush with the upper surface of the insulating shell, the bottom of the sealing block is located inside the insulating shell.

[0014] Optionally, the battery cell installation method includes the following steps:

[0015] S1, first fixing the negative electrode current collector on the lithium-based negative electrode, then inserting the lithium-based negative electrode into the insulating shell, and finally fixing and connecting the negative electrode current collector to the insulating shell;

[0016] S2, first fixing the positive electrode current collector on the composite positive electrode, then inserting the composite positive electrode into the insulating shell, and finally fixing and connecting the positive electrode current collector to the insulating shell;

[0017] S3, removing the sealing block, injecting the sol-type polymer modified material into the injection hole under a vacuum environment, and when the polymer modified material fills the injection hole, immediately tightening the sealing block until the upper surface of the sealing block is flush with the upper surface of the insulating shell;

[0018] S4, placing the sol-type polymer modified material at 30-60° C. and waiting for polymerization for 2-6 hours to obtain a battery monomer.

[0019] On the other hand, the present invention also provides the following technical solution: a battery module, comprising the above-mentioned solid-state battery cluster, wherein a plurality of solid-state battery clusters are arranged together, and the electrode sheets of each solid-state battery cluster are connected together in series.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. The present invention pushes the part of the solid electrolyte close to the insulating shell toward the composite positive electrode after the cone-shaped metal lithium expands, so that the sol-type polymer modified layer has local microflow on the composite positive electrode, so that the sol-type polymer modified layer and the composite positive electrode are more closely combined, the interface compatibility between the two solid phases is significantly improved, the interface impedance between the solid electrolyte and the composite positive electrode is effectively reduced, and the service life of the battery cell is increased;

[0022] 2. The present invention extrude the uncured sol-type polymer modified material through the sealing block, so that the sol-type polymer modified material is extruded toward the solid electrolyte and the composite positive electrode. The sol-type polymer modified material can fill the porous structure of the composite positive electrode, so that the sol-type polymer modified layer is more tightly combined with the composite positive electrode, which significantly improves the interface compatibility between the two solid phases. The operation is simple and the cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the structure of several battery cells in the present invention;

[0024] Figure 2 A partial cross-sectional view of a battery cell in the present invention;

[0025] Figure 3 for Figure 2 The enlarged structural diagram of the middle A part;

[0026] Figure 4 It is a schematic diagram of the structure of the solid-state battery cluster in the present invention;

[0027] Figure 5 It is a partial cross-sectional view of the solid-state battery cluster in the present invention.

[0028] In the figure: 100, solid electrolyte; 101, conical groove; 200, lithium-based negative electrode; 201, conical metal lithium; 202, negative electrode current collector; 300, composite positive electrode; 301, positive electrode current collector; 400, sol-type polymer modified layer; 500, insulating shell; 501, glue injection hole; 502, sealing block; 503, left embedded hole; 504, right embedded hole; 600, coating structure; 700, electrode sheet. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] Example 1

[0031] See also Figures 1 to 3 The present invention provides a solid-state battery cluster, comprising a plurality of battery cells connected in series, wherein the battery cells include a solid electrolyte 100, a lithium-based negative electrode 200 fixedly arranged on the left side of the solid electrolyte 100, and a composite positive electrode 300 fixedly arranged on the right side of the solid electrolyte 100. The material of the solid electrolyte 100 is Li 2 SP 2 S 5 The material of the composite positive electrode 300 is LiCoO 2 A sol-type polymer modified layer 400 is provided between the solid electrolyte 100 and the composite positive electrode 300. The material of the sol-type polymer modified layer 400 is Li 2 SiO 3 .

[0032] The right side wall of the lithium-based negative electrode 200 is integrally formed with a conical metal lithium 201, the axis of the conical metal lithium 201 is coaxial with the transverse axis of the lithium-based negative electrode 200, the conical metal lithium 201 is a regular tetrahedral pyramid structure, and the left side wall of the solid electrolyte 100 is provided with a conical groove 101 that matches the conical metal lithium 201. The composite positive electrode 300 is a rectangular parallelepiped structure, and the outer wall of the solid electrolyte 100 is fixedly sleeved with an insulating shell 500, and the upper surface of the insulating shell 500 is provided with a glue injection hole 501 that penetrates inside and outside, and a sealing block 502 that is threadedly connected to the insulating shell 500 is fixedly provided in the glue injection hole 501.

[0033] After the battery cell is used for a long time, the volume of the lithium-based negative electrode 200 will increase. Since the thickness of the cone-shaped metal lithium 201 at the axis is greater than the volume thickness of the regular tetrahedron edge of the cone-shaped metal lithium 201, the regular tetrahedron edge of the cone-shaped metal lithium 201 is more likely to expand in volume. When the lithium-based negative electrode 200 expands, the regular tetrahedron edge of the cone-shaped metal lithium 201 will expand first, thereby pushing the part of the solid electrolyte 100 close to the insulating shell 500 to squeeze toward the composite positive electrode 300, causing the edge of the sol-type polymer modified layer 400 to flow toward the lateral axis of the composite positive electrode 300, so that the sol-type polymer modified layer 400 has a local micro-flow on the composite positive electrode 300, so that the sol-type polymer modified layer 400 and the composite positive electrode 300 are more closely combined, the interface compatibility between the two solid phases is significantly improved, and the interface impedance between the solid electrolyte 100 and the composite positive electrode 300 is effectively reduced, and the service life of the battery cell is improved.

[0034] On the basis of the above embodiment, a number of battery cells are connected in series in the left-right direction, and a covering structure 600 is commonly sleeved on the outside of the battery cells. Two electrode sheets 700 arranged on the left and right are fixed on the upper surface of the covering structure 600. The electrode sheet 700 on the left is connected to the positive electrode collector 301 on the far left through a wire, and the electrode sheet 700 on the right is connected to the negative electrode collector 202 on the far right through a wire.

[0035] On the basis of the above embodiment, the left port of the insulating shell 500 is provided with a left embedding hole 503, the left side wall of the lithium-based negative electrode 200 is fixedly provided with a negative electrode collector 202, and the left end of the negative electrode collector 202 extends out of the left embedding hole 503. The right port of the insulating shell 500 is provided with a right embedding hole 504, the right side wall of the composite positive electrode 300 is fixedly provided with a positive electrode collector 301, and the right end of the positive electrode collector 301 extends out of the right embedding hole 504. Two battery cells located in the left and right directions and adjacent to each other are connected in series, and the positive electrode collector 301 of the battery cell located on the left side abuts against the negative electrode collector 202 of the battery cell located on the right side.

[0036] In this embodiment, the negative electrode current collector 202 is fixedly connected to the insulating shell 500 , and the positive electrode current collector 301 is fixedly connected to the insulating shell 500 , so that the lithium-based negative electrode 200 and the composite positive electrode 300 are fixed in position in the insulating shell 500 .

[0037] Based on the above embodiment, the thickness of the sol-type polymer modified layer 400 is greater than the outer diameter of the sealing block 502, and the upper surface of the sealing block 502 is provided with a S-shaped groove, a cross groove, or a hexagonal groove, and the bottom of the sealing block 502 is a conical structure. When the upper surface of the sealing block 502 is flush with the upper surface of the insulating shell 500, the bottom of the sealing block 502 is located inside the insulating shell 500.

[0038] Based on the above embodiment, the method for installing a battery cell includes the following steps:

[0039] S1, first fix the negative electrode current collector 202 on the lithium-based negative electrode 200, then insert the lithium-based negative electrode 200 into the insulating shell 500, and finally fix the negative electrode current collector 202 and the insulating shell 500;

[0040] S2, first fix the positive electrode current collector 301 on the composite positive electrode 300, then insert the composite positive electrode 300 into the insulating shell 500, and finally fix the positive electrode current collector 301 and the insulating shell 500;

[0041] S3, remove the sealing block 502, and inject the sol-type polymer modified material into the injection hole 501 under a vacuum environment. When the polymer modified material fills the injection hole 501, immediately tighten the sealing block 502 until the upper surface of the sealing block 502 is flush with the upper surface of the insulating shell 500;

[0042] S4, placing the sol-type polymer modified material at 30-60° C. and waiting for polymerization for 2-6 hours to obtain a battery monomer.

[0043] In this embodiment, the sol-type polymer modified layer 400 is used as the interface modified layer between the solid electrolyte 100 and the composite positive electrode 300, which can not only effectively reduce the side reactions at the interface, but also reduce the contact resistance between the solid electrolyte 100 and the composite positive electrode 300. In this embodiment, the uncured sol-type polymer modified material is squeezed through the sealing block 502, so that the sol-type polymer modified material is squeezed toward the solid electrolyte 100 and the composite positive electrode 300. The sol-type polymer modified material can fill the porous structure of the composite positive electrode 300, so that the sol-type polymer modified layer 400 and the composite positive electrode 300 are more closely combined, and the interface compatibility between the two solid phases is significantly improved. The operation is simple and the cost is low.

[0044] Example 2

[0045] The difference between this embodiment and embodiment 1 is that the material of the solid electrolyte 100 is Li 3 PS 4 The material of the composite positive electrode 300 is LiNi 1 / 3 Mn 1 / 3 Co 1 / 3 O 2 The material of the sol-type polymer modified layer 400 is LiAlO 2 .

[0046] The present invention also provides a battery module, including the above-mentioned solid-state battery cluster, wherein a plurality of solid-state battery clusters are provided, the plurality of solid-state battery clusters are arranged together, and the electrode sheets 700 of each solid-state battery cluster are connected together in series.

[0047] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A solid-state battery cluster, comprising a plurality of battery cells connected in series, wherein the battery cells comprise a solid electrolyte (100), a lithium-based negative electrode (200) fixedly arranged on the left side of the solid electrolyte (100), and a composite positive electrode (300) fixedly arranged on the right side of the solid electrolyte (100), characterized in that: The right side wall of the lithium-based negative electrode (200) is integrally formed with a conical metal lithium (201), the axis of the conical metal lithium (201) is coaxial with the transverse axis of the lithium-based negative electrode (200), the left side wall of the solid electrolyte (100) is provided with a conical groove (101) that matches the conical metal lithium (201), a sol-type modified layer (400) is provided between the solid electrolyte (100) and the composite positive electrode (300), the material of the sol-type modified layer (400) is Li2SiO3, the outer wall of the solid electrolyte (100) is fixedly sleeved with an insulating shell (500), the upper surface of the insulating shell (500) is provided with a glue injection hole (501) that penetrates inside and outside, and a sealing block (502) that is threadedly connected to the insulating shell (500) is fixedly provided in the glue injection hole (501).

2. A solid-state battery cluster according to claim 1, characterized in that: The material of the solid electrolyte (100) is Li2S-P2S5, and the material of the composite positive electrode (300) is LiCoO2.

3. A solid-state battery cluster according to claim 1, characterized in that: The material of the solid electrolyte (100) is Li3PS4, and the material of the composite positive electrode (300) is Li(Ni 1 / 3 Mn 1 / 3 Co 1 / 3 )O2, the material of the sol-type modified layer (400) is LiAlO2.

4. A solid-state battery cluster according to claim 1, characterized in that: The conical metal lithium (201) is a regular quadrangular pyramid structure, and the composite positive electrode (300) is a rectangular parallelepiped structure.

5. The solid-state battery cluster according to claim 1, characterized in that: A plurality of battery cells are sequentially connected in series in the left-right direction, and a coating structure (600) is commonly sleeved outside the plurality of battery cells. Two electrode sheets (700) arranged on the left and the right are fixedly provided on the upper surface of the coating structure (600). The electrode sheet (700) located on the left is connected to the positive electrode current collector (301) located on the far left through a wire, and the electrode sheet (700) located on the right is connected to the negative electrode current collector (202) located on the far right through a wire.

6. A solid-state battery cluster according to claim 1, characterized in that: The left end of the insulating shell (500) is provided with a left embedding hole (503), the left side wall of the lithium-based negative electrode (200) is fixedly provided with a negative electrode current collector (202), and the left end of the negative electrode current collector (202) extends out of the left embedding hole (503); The right end of the insulating shell (500) is provided with a right embedding hole (504), the right side wall of the composite positive electrode (300) is fixedly provided with a positive electrode current collector (301), and the right end of the positive electrode current collector (301) extends out of the right embedding hole (504); Two battery cells located in the left-right direction and adjacent to each other are connected in series, and the positive electrode current collector (301) of the battery cell located on the left side abuts against the negative electrode current collector (202) of the battery cell located on the right side.

7. A solid-state battery cluster according to claim 6, characterized in that: The thickness of the sol-type modified layer (400) is greater than the outer diameter of the sealing block (502); the upper surface of the sealing block (502) is provided with a straight groove, a cross groove, or a hexagonal groove; the bottom of the sealing block (502) is a conical structure; when the upper surface of the sealing block (502) is flush with the upper surface of the insulating shell (500), the bottom of the sealing block (502) is located inside the insulating shell (500).

8. A solid-state battery cluster according to claim 7, characterized in that: The battery cell installation method comprises the following steps: S1, first fixing the negative electrode current collector (202) on the lithium-based negative electrode (200), then inserting the lithium-based negative electrode (200) into the insulating shell (500), and finally fixing and connecting the negative electrode current collector (202) and the insulating shell (500); S2, first fixing the positive electrode current collector (301) on the composite positive electrode (300), then inserting the composite positive electrode (300) into the insulating shell (500), and finally fixing and connecting the positive electrode current collector (301) and the insulating shell (500); S3, removing the sealing block (502), injecting the sol-type polymer modified material into the injection hole (501) under a vacuum environment, and when the polymer modified material fills the injection hole (501), immediately tightening the sealing block (502) until the upper surface of the sealing block (502) is flush with the upper surface of the insulating shell (500); S4, placing the sol-type polymer modified material at 30-60° C. and waiting for polymerization for 2-6 hours to obtain a battery monomer.

9. A battery module, characterized in that: It comprises a solid-state battery cluster as claimed in any one of claims 1 to 8, wherein a plurality of solid-state battery clusters are provided, the plurality of solid-state battery clusters are arranged together, and the electrode sheets (700) of the solid-state battery clusters are connected together in series.

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