CN109935888A - Current collector structure, lithium battery cell and its lithium battery - Google Patents

Abstract

The present invention relates to field of lithium, specifically include current collector structure, lithium battery electric core and its lithium battery, wherein the collector includes two opposite main surfaces, column crystal anode layer is formed in one of main surface, using the anode structure as a lithium battery electric core.Lithium battery electric core and its lithium battery provided by the present invention can be realized to be connected in series or in parallel between multiple lithium battery electric cores.By the way that positive and negative anodes are arranged on two faces of collector, to form the collector of positive and negative copolar, it can be achieved that prepared by multiple lithium battery electric core laminations, to realize the large scale preparation and popularization of inexpensive solid lithium battery.It can also be directly using collector as the electrode of lithium battery, to simplify the encapsulating structure of the lithium battery.

Description

Current collector structure, lithium battery cell and its lithium battery

【Technical field】

The invention relates to the field of lithium batteries, in particular to a current collector structure, a lithium battery cell and a lithium battery.

【Background technique】

All-solid-state lithium batteries have become an important development direction of secondary batteries due to their advantages such as safety and excellent cycle performance. At the same time, due to the small atomic radius of metal lithium and the lowest electrochemical potential, all-solid-state lithium batteries are compared with other sodium-ion batteries. It has greater market application potential.

At present, the energy density of lithium battery cell material system can only reach 250-300Wh/kg. The essential problem is the limitation of battery electrode materials. Specifically, graphite or C-Si negative electrode is used as negative electrode material, and lithium iron phosphate, ternary material and lithium cobalt oxide are used as positive electrode to cause the above results.

The existing solid-state lithium batteries based on solid-phase sintering and other methods cannot guarantee the uniformity of large-area material preparation, and cannot fundamentally solve the generation of lithium dendrites. Area battery samples. The existing technology cannot meet the preparation requirements of large-area all-solid-state lithium batteries.

The above problems limit the large-scale fabrication and promotion of low-cost all-solid-state lithium batteries.

[Content of the invention]

In order to overcome the existing problems that the large-scale preparation and promotion of low-cost all-solid-state lithium batteries cannot be realized, the present invention provides a current collector structure, a lithium battery cell and a lithium battery.

The present invention provides a technical solution to solve the above technical problems as follows: a current collector structure, which includes a current collector, the current collector includes two opposite main surfaces, and a columnar crystal positive electrode layer is formed on one of the main surfaces to serve as a In the positive electrode structure of a lithium battery cell, a negative electrode layer is formed on the other main surface to serve as the negative electrode structure of another lithium battery cell.

The present invention provides another technical solution to solve the above technical problems as follows: a lithium battery cell, which includes a first current collector, the first current collector includes two opposite main surfaces, and a columnar crystal positive electrode is formed on one of the main surfaces. layer to serve as the positive electrode structure of the lithium battery cell, and a negative electrode layer is formed on the other main surface to serve as the negative electrode structure of another lithium battery cell.

Preferably, the thickness of the columnar crystal positive electrode layer is 10 nm-100 μm; the columnar crystal positive electrode layer comprises one or a combination of V, Mo, Mn, Ni, Fe, Co, Cr, Ti or Bi metal elements Metal oxides and lithium-containing metal oxides.

Preferably, the lithium battery cell includes a second current collector and a negative electrode layer formed on one surface of the second current collector, the negative electrode layer comprises a lithium silicon carbon composite negative electrode layer, and the negative electrode layer faces the columnar crystal positive electrode layer.

Preferably, the lithium-silicon-carbon composite negative electrode layer comprises a silicon-lithium alloy deposited on the negative electrode current collector, and carbon nanoparticles are composited in the silicon-lithium alloy.

Preferably, a carbon-based material layer is formed on the surface of the lithium-silicon-carbon composite negative electrode layer facing the positive electrode structure or a carbon-based material layer is formed on the surface of the lithium-silicon-carbon composite negative electrode layer facing the second current collector.

Preferably, a first electrolyte layer covering the columnar crystals is filled between the columnar crystal positive electrode layer and the lithium-silicon-carbon composite negative electrode layer, and the thickness of the first electrolyte layer is 1 nm-50 μm.

Preferably, the lithium battery cell includes a second electrolyte layer formed on the side of the first electrolyte layer facing the negative electrode layer, and the thickness of the second electrolyte layer is 1-3000 nm.

The present invention provides a technical solution to solve the above-mentioned technical problems as follows: a lithium battery, which includes at least two lithium battery cells arranged in a continuous stack, and a positive and negative value is shared between the at least two lithium battery cells that are directly stacked and arranged Common electrode current collector, the positive and negative common electrode current collector plate includes two opposite main surfaces, and a columnar crystal positive electrode layer is formed on one of the main surfaces to serve as the positive electrode structure of one of the lithium battery cells, and the other main surface is formed The negative electrode layer is used as the negative electrode structure of another lithium battery cell.

Preferably, two lithium battery cells sharing a positive and negative common current collector are connected in series or in parallel.

Compared with the prior art, the current collector structure, the lithium battery cell and the lithium battery provided by the present invention have the following beneficial effects:

In the current collector structure, lithium battery cell and lithium battery provided by the present invention, the current collector includes two opposite main surfaces, and a columnar crystal positive electrode layer is formed on one of the main surfaces to serve as the positive electrode structure of a lithium battery cell, A negative electrode layer is formed on the other main surface to serve as the negative electrode structure of another lithium battery cell. By arranging positive and negative electrodes on both sides of the current collector to form a current collector of positive and negative common electrodes, multiple lithium battery cells can be fabricated by stacking, thereby realizing the fabrication of large-area all-solid-state lithium batteries.

The use of positive and negative common current collectors can also reduce the overall thickness of lithium battery cells and lithium batteries. Further, by using the current collectors of the positive and negative electrodes, a series connection between a plurality of lithium battery cells can be realized. When the lithium battery cells in the lithium battery are connected in series, the current collector can be directly used as the electrode of the lithium battery, thereby simplifying the packaging structure of the lithium battery.

In addition, in the present invention, a positive electrode material with a columnar crystal structure is used as the positive electrode layer, so that the formed complete columnar crystals can provide smooth diffusion and migration channels for lithium ions in the process of charging and discharging. The purpose of the columnar crystals is to match the High-performance anode materials to improve the efficiency of lithium insertion and extraction of cathode materials.

In the present invention, the lithium battery cell and the lithium battery may further use a lithium silicon carbon composite negative electrode layer formed on the side of the negative electrode current collector facing the positive electrode structure. The use of the lithium-silicon-carbon composite negative electrode layer can further improve the energy density of the lithium battery, thereby obtaining high-performance lithium battery cells and lithium batteries.

The lithium battery cell and the lithium battery provided by the present invention further include a carbon-based material layer, and the carbon-based material layer can be formed between the lithium-silicon-carbon composite negative electrode layer and the second current collector to form a carbon-based material layer. The base material layer or the carbon-based material layer may be formed on the side of the lithium-silicon-carbon composite negative electrode layer facing the positive electrode structure. The arrangement of the carbon-based material layer can enhance electrical conductivity, thereby improving the stability and safety of the lithium battery cell and the lithium battery.

In the lithium battery cell and the lithium battery of the present invention, a first electrolyte layer is formed by filling between the columnar crystal positive electrode layer and the lithium silicon carbon composite negative electrode layer, and the thickness of the first electrolyte layer is 1 nm-50 μm. The first electrolyte layer can cover the columnar crystal positive electrode layer, so it has a larger surface area, so the formation of the first electrolyte layer can provide more reaction interfaces between the electrolyte and the positive electrode layer in the lithium battery, which is beneficial to the battery Complete reaction of charge and discharge process.

In the lithium battery cell and the lithium battery of the present invention, a second electrolyte layer can also be formed on the surface of the first electrolyte layer, which can further improve the flatness of the first electrolyte layer and the uniformity of the electric field distribution on the surface of the negative electrode. At the same time, the hardness of the first electrolyte layer can also be increased to prevent short circuit caused by the contact between the positive and negative electrodes.

【Description of drawings】

FIG. 1 is a schematic diagram of the layer structure of the current collector structure provided by the first embodiment of the present invention.

FIG. 2 is a schematic diagram of a layer structure of a lithium battery cell provided by a second embodiment of the present invention.

FIG. 3 is a schematic diagram of a layer structure of a lithium battery cell of another embodiment shown in FIG. 2 .

FIG. 4A is a schematic diagram of a layer structure of a specific implementation manner of a lithium battery cell provided by the third embodiment of the present invention.

4B is a schematic diagram of a layer structure of another specific implementation manner of a lithium battery cell provided by the third embodiment of the present invention.

FIG. 5 is a schematic structural diagram of a lithium battery provided by a fourth embodiment of the present invention.

FIG. 6 is a schematic structural diagram of a lithium battery provided by a fifth embodiment of the present invention.

FIG. 7 is a schematic structural diagram of a lithium battery provided by a sixth embodiment of the present invention.

FIG. 8 is a schematic flowchart of a method for preparing a lithium battery according to a seventh embodiment of the present invention.

【Detailed ways】

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and implementation examples. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention.

Referring to FIG. 1, a first embodiment of the present invention provides a current collector structure 100, the current collector structure 100 includes a current collector 101, the current collector 101 includes two opposite main surfaces 109, one of the main surfaces A columnar crystal positive electrode layer 102 is formed on 109 to serve as a positive electrode structure of a lithium battery cell, and a negative electrode layer 103 is formed on the other main surface 109 to serve as a negative electrode structure of another lithium battery cell.

In this and all the following embodiments of the present invention, the material of the current collector is limited as follows: the current collector may include one of other metals such as Cu, Al, Ni, Ag, Au, Cr, Ta, Ti, Mo, etc. Elemental metal or metal alloy obtained by one or a combination of several.

Referring to FIG. 2, a second embodiment of the present invention provides a lithium battery cell 10, which includes a first current collector 11 and a second current collector 12, wherein the first current collector 11 includes two opposite mains On the surfaces 110 , a positive electrode layer 111 is formed on one main surface 110 to serve as the positive electrode structure of the lithium battery cell 10 , and a negative electrode layer 112 is formed on the other main surface to serve as the negative electrode structure of another lithium battery cell 10 . The second current collector 12 also includes two opposite main surfaces 120 , and a negative electrode layer 121 is formed on one of the main surfaces 120 to serve as the negative electrode structure of the lithium battery cell 10 . A positive electrode layer 122 is formed on the other main surface of the 12 to serve as a positive electrode structure of another lithium battery cell 10 .

In the present invention, the thicknesses of the first current collector 11 and the second current collector 12 are 10 nm-100 μm, and specifically, the thicknesses of the first current collector 11 and the second current collector 12 may also be 10nm, 15nm, 20nm, 24nm, 56nm, 143nm, 350nm, 567nm, 778nm, 983nm, 1µm, 19µm, 31µm, 45µm, 50µm, 61µm, 76µm, 89µm or 100µm.

In some specific embodiments of the present invention, the positive electrode layer 111 may include columnar crystals, and the thickness of the positive electrode layer 111 is 10 nm-100 μm; specifically, the thickness of the positive electrode layer 111 may be further: 10 nm, 15 nm, 20 nm , 24nm, 56nm, 143nm, 350nm, 567nm, 778nm, 983nm, 1µm, 19µm, 31µm, 45µm, 50µm, 61µm, 76µm, 89µm or 100µm.

The thickness of the negative electrode layer 111 can be 10 nm-100 μm, specifically, the thickness of the negative electrode layer 111 can be further: 10 nm, 15 nm, 20 nm, 24 nm, 56 nm, 143 nm, 350 nm, 567 nm, 778 nm, 983 nm, 1 μm, 19 μm, 31μm, 45μm, 50μm, 61μm, 76μm, 89μm or 100μm.

In the present invention, the material of the columnar crystal may further include: metal oxides and lithium-containing metal oxides including one or more combinations of metal elements such as V, Mo, Mn, Ni, Fe, Co, Cr, Ti or Bi Metal oxide. The positive electrode layer 111 includes at least one layer of columnar crystals. Specifically, the columnar crystals may be V ₂ O ₅ columnar crystals, V ₆ O ₁₃ columnar crystals, MnO ₂ columnar crystals, Mo ₂ O ₃ columnar crystals, Co _1.5 V _0.5 O ₃ columnar crystals, and the like.

Specifically, in other specific embodiments of the present invention, the positive electrode layer 111 may include columnar crystals such as lithium iron phosphate, lithium cobalt oxide, or a ternary positive electrode material.

In the positive electrode layer 111, the columnar crystals are regularly arranged, therefore, it can provide smooth diffusion and migration channels for lithium ions during the charging and discharging process, so as to facilitate the insertion and extraction of lithium, thereby improving the performance of lithium batteries. rate characteristics, and the positive electrode layer 111 can have a higher capacity density.

Specifically, the adjacent columnar crystals are densely arranged without gaps. The larger the number of the columnar crystals that can be provided within the same area, the further increase the capacity density of the positive electrode structure prepared therefrom.

The size of the columnar crystals here and below in the present invention refers to the size along the thickness direction of the positive electrode structure. The size of the columnar crystals is 1 nm-100 μm. In some specific embodiments of the present invention, the size of the columnar crystals is specifically 1 nm, 3 nm, 5 nm, 7 nm, 10 nm, 17 nm, 23 nm, 26 nm, 46 nm, 57 nm, 101 nm, 143 nm, 350 nm, 567 nm, 778 nm, 983 nm, 1 μm, 19 μm, 31 μm, 45 μm, 50 μm, 61 μm, 76 μm, 89 μm or 100 μm.

As shown in FIG. 3 , in some specific embodiments of the present invention, the columnar crystal positive electrode layer 111 is formed in the first current collector 11 using PVD technologies such as magnetron sputtering, electron beam evaporation, pulsed laser deposition, and atomic layer deposition. formed by deposition on a major surface.

Likewise, the positive electrode layer 122 forming the columnar crystals of the other lithium battery cell 10 can also be deposited on the second current collector 12 in the same manner.

In some specific embodiments of the present invention, the above-mentioned negative electrode layer 112 may further include a lithium-silicon-carbon composite negative electrode. When the lithium-silicon-carbon composite negative electrode material is used as the negative electrode layer 112, the thickness of the negative electrode layer 112 is 2nm-20 μm, and specifically, the thickness of the lithium-silicon-carbon composite negative electrode layer can be further: 2nm, 4nm, 7nm , 10nm, 20nm, 67nm, 250nm, 345nm, 456nm, 778nm, 983nm, 1μm, 3μm, 4.5μm, 5μm, 7μm, 11μm, 15μm or 20μm.

In some specific embodiments of the present invention, the lithium-silicon-carbon composite negative electrode layer can be deposited to form a silicon-lithium alloy by using PVD techniques such as magnetron sputtering, electron beam evaporation, pulsed laser deposition, and atomic layer deposition, and further hot pressing is used. The technology is made by compounding carbon nanoparticles in a silicon-lithium alloy.

Specifically, before hot pressing, carbon nanoparticles can be dissolved in a lithium salt solution to form a coating slurry, and then coated on the surface of the lithium-silicon composite negative electrode, and then heated and pressurized with a high-temperature corrosion-resistant substrate, In order to make the slurry hot-pressed into the lithium-silicon alloy, under the action of high temperature, the slurry solution will be dissipated completely, so as to obtain the required lithium-silicon-carbon composite negative electrode layer.

As further shown in FIG. 2 , in the first specific implementation of this embodiment, in the lithium battery cell 10 , between the columnar crystal positive electrode layer 111 and the lithium silicon carbon composite negative electrode layer 121 A first electrolyte layer 13 covering the surface of the columnar crystal is filled and formed, and the thickness of the first electrolyte layer 13 is 1 nm-50 μm. Specifically, the thickness of the first electrolyte layer 13 may be 1 nm, 3 nm, 5 nm, 7 nm, 10 nm, 15 nm, 26 nm, 31 nm, 46 nm, 57 nm, 101 nm, 147 nm, 250 nm, 356 nm, 567 nm, 778 nm, 983 nm, 1 μm, 19μm, 31μm, 45μm or 50μm.

The material of the first electrolyte layer 13 includes perovskite type solid electrolyte, NASICON type solid electrolyte, garnet type solid electrolyte, LiGePS type sulfide solid state electrolyte, LiSiPS type sulfide solid state electrolyte or LiSnPS type sulfide solid state electrolyte one or several combinations.

Unlike in the prior art, the electrolyte material is directly filled between the positive and negative electrode materials, because in this embodiment, the positive electrode layer 11 adopts columnar grains, which have a large surface area, so the formation of the first electrolyte layer 13 can More reaction interfaces are provided between the electrolyte in the lithium battery and the positive electrode layer 111, thus, it is beneficial to the complete reaction of the battery charging and discharging process. Further, when the thickness of the first electrolyte layer 13 is relatively large, the surface of the first electrolyte layer 13 is uniform, thereby ensuring that the surface electric field of the negative electrode layer 121 is also uniformly distributed.

Please continue to refer to FIG. 3 , in the second specific implementation of this embodiment, the difference from the above-mentioned first specific implementation is that when the surface of the first electrolyte layer 13 is uneven, the The core 10 further includes a second electrolyte layer 14 formed on the side of the first electrolyte layer 13 facing the negative electrode layer 121 , and the thickness of the second electrolyte layer 14 is 1-3000 nm. Specifically, the thickness of the second electrolyte layer 14 is 1 nm, 3 nm, 5 nm, 7 nm, 10 nm, 17 nm, 23 nm, 26 nm, 46 nm, 57 nm, 101 nm, 143 nm, 350 nm, 567 nm, 778 nm, 983 nm, 1000 nm, 1500 nm, 2100 nm , 2189nm or 3000nm.

In the present invention, the arrangement of the second electrolyte layer 14 is to fill in the uneven thickness distribution of the first electrolyte layer 13, so as to improve the uniformity of the surface electric field distribution of the negative electrode layer 121. The second electrolyte layer 14 can further increase the hardness of the electrolyte layer to prevent short circuit caused by the contact between the positive and negative electrodes.

Please continue to refer to FIG. 4A and FIG. 4B , a third embodiment of the present invention provides a lithium battery cell 20 . The difference between this embodiment and the above-mentioned second embodiment is that the lithium battery cell 20 further includes a carbon-based battery cell 20 . Material layer 29 . The carbon-based material layer 29 is specifically a graphite thin layer, a carbon nanotube, a graphene thin film layer, etc., which is only used as an example, and is not a limitation of the present invention.

The role of the carbon-based material layer 29 is to improve the electric field distribution on the surface of the negative electrode, enhance the conductivity, facilitate the insertion or extraction of the lithium negative electrode, and prevent the lithium negative electrode from forming lithium dendrites.

As shown in FIG. 4A , in some embodiments of the present invention, the carbon-based material layer 29 may be formed on the surface of the negative electrode layer 221 facing the first electrolyte layer 23 .

As shown in FIG. 4B , in other embodiments of the present invention, the carbon-based material layer 29 may be disposed between the negative electrode layer 221 and the second current collector 22 .

In some specific embodiments of the present invention, the carbon-based material layer 29 is formed on the surface of the negative electrode layer 221 facing the first electrolyte layer 23 or facing the second current collector 22 through a hot pressing process. The base material layer 29 will realize a certain depth of gradient carbon material distribution inside the negative electrode layer 221 , and form a coating and support for the negative electrode layer 221 to a certain extent, so as to enhance the strength of the negative electrode layer 221 and prevent the negative electrode layer 221 from collapsing.

In some specific embodiments of the present invention, the carbon-based material layer 29 can also be formed on the surface of the negative electrode layer 221 facing the first electrolyte layer 23 or facing the second current collector 22 by coating. A carbon-based material layer 29 of thickness is required.

Referring to FIG. 5 , a fourth embodiment of the present invention provides a lithium battery 30 . The lithium battery 30 may include two consecutively stacked first lithium battery cells 301 and second lithium battery cells 302 . A positive and negative common electrode current collector 31 is shared between the first lithium battery cell 301 and the second lithium battery cell 302 , and the positive and negative common electrode current collector 31 includes two opposite main surfaces 310 , one of which is on the main surface 310 A columnar crystal positive electrode layer 311 is formed to serve as the positive electrode structure of the first lithium battery cell 301 , and a negative electrode layer 312 is formed on the other main surface 310 to serve as the negative electrode structure of the second lithium battery cell 302 .

Continuing as shown in FIG. 5 , the first lithium battery cell 301 further includes a negative electrode current collector 32 , and the second lithium battery cell 302 includes a positive electrode current collector 35 . A negative electrode layer 321 is formed on the side of the negative electrode current collector 32 facing the columnar crystal positive electrode layer 311 , and a positive electrode layer 351 is formed on the surface of the positive electrode current collector 35 facing the positive and negative common electrode current collectors 31 . Relevant definitions of 321 and the positive electrode layer 351 are as shown in the second embodiment and the third embodiment, and will not be repeated here.

In some specific implementations of this embodiment, the first lithium battery cell 301 further includes a first electrolyte layer 33 filled and formed between the columnar crystal positive electrode layer 311 and the negative electrode layer 321 , and a first electrolyte layer 33 formed on the first The electrolyte layer 33 faces the second electrolyte layer 34 on the surface of the negative electrode layer 312 . The second lithium battery cell 302 further includes a first electrolyte layer 33 formed between the positive electrode layer 351 and the negative electrode layer 312 , and a second electrolyte layer 33 formed on the surface of the first electrolyte layer 33 facing the negative electrode layer 321 . The electrolyte layer 34 , the surface of the negative electrode layer 312 facing the second electrolyte layer 34 may further include a carbon-based material layer 39 .

In another embodiment of the present invention, the first lithium battery cell 301 and the second lithium battery cell 302 may be any one of the lithium battery cells 10 or The specific layer structure of the lithium battery cell 20 can be adjusted according to actual battery performance requirements. The above limitation on the layer structure is only an example, and not a limitation of the present invention.

In some other embodiments of the present invention, when the lithium battery 30 may further include two or more lithium battery cells 301 or 302, at least some of the lithium battery cells 301 or 302 are formed by continuous lamination to form a whole, The lithium battery cells 301 or 302 arranged in the middle of the continuous stack share a current collector, while the current collectors of the lithium battery cells 10 arranged at both ends only serve as positive current collectors or negative electrode current collectors.

Please refer to FIG. 6 for details. A fifth embodiment of the present invention provides a lithium battery 40 . The lithium battery 40 includes a plurality of lithium battery cells 10 . The lithium battery 40 can be fabricated by layer-by-layer stacking. The number of stacked lithium-ion single cells 10 is not limited.

The lithium ion single cell 10 includes a first current collector 41 , a positive electrode layer 44 , a solid electrolyte layer 43 , a negative electrode layer 45 and a second current collector 42 that are stacked. Adjacent lithium-ion single cells 10 are stacked together by sharing one positive electrode current collector 41 or negative electrode current collector 42 .

As shown in FIG. 6 , the superposition of two adjacent lithium battery cells 10 share the second current collector 42 , that is, the second current collector 42 is a positive and negative common current collector. As shown in the figure, the positive electrode layer 44 and the negative electrode layer 45 are respectively disposed on both sides of the second current collector 42 . As shown in FIG. 6 , the plurality of lithium battery cells 40 may be connected in series. When the lithium battery cells in the lithium battery are connected in series, the current collector can be directly used as the electrode of the lithium battery, thereby simplifying the packaging structure of the lithium battery.

Referring to FIG. 7 , a sixth embodiment of the present invention provides a lithium battery 50 . In this embodiment, the lithium battery 50 includes five lithium battery cells, which are the first lithium batteries that are stacked in sequence. Cells 501 , second lithium battery cells 502 , third lithium battery cells 503 , fourth lithium battery cells 504 and fifth lithium battery cells 505 . As shown in FIG. 7 , the above-mentioned multiple lithium battery cells may include: a first current collector 51 , a positive electrode layer 54 , a solid electrolyte layer 53 , a negative electrode layer 55 and a second current collector 52 .

As shown in FIG. 7 , a second current collector 52 is shared between the first lithium battery cells 501 and the second lithium battery cells 502 , and negative electrode layers are provided on both opposite main surfaces of the second current collector 52 55. It can be seen that the first lithium battery cell 501 and the second lithium battery cell 502 may be connected in parallel.

The second current collector 52 is also shared between the second lithium battery cell 502 and the third lithium battery 503 , and a positive electrode layer 54 and a negative electrode are respectively provided on the two opposite main surfaces of the second current collector 52 Layer 55, it can be seen that the second lithium battery cell 502 and the third lithium battery cell 503 can be connected in series.

Further, the second current collector 532 of the third lithium battery cell 503 and the first current collector 541 of the fourth lithium battery cell 504 are superposed and arranged, and the first current collector 532 and the second current collector 541 are respectively represented as The positive electrode current collector or the negative electrode current collector of the third lithium battery cell 503 and the fourth lithium battery cell 504 . It can be seen that the third lithium battery cell 503 and the fourth lithium battery cell 504 can form a parallel connection relationship through an external circuit.

In this embodiment, the relative positions of the positive electrode layer 54 and the negative electrode layer 55 , the first current collector 51 and the second current collector 52 can be adjusted.

7 is only an example. In an actual lithium battery 50, the specific connection method can be adjusted according to the performance requirements of the actual lithium battery, which is not a limitation of the present invention.

Please continue to refer to FIG. 8 , a seventh embodiment of the present invention provides a method S10 for preparing a lithium battery, wherein a specific implementation includes the following steps:

Step S11, providing a first current collector, and forming a columnar crystal positive electrode layer on one side of the first current collector;

Step S12, forming a first electrolyte layer by coating on the surface of the columnar crystal positive electrode layer away from the first current collector;

Step S13, forming a second electrolyte layer on the surface of the first electrolyte layer;

Step S14, forming a carbon-based material layer on the surface of the second electrolyte layer away from the first electrolyte layer;

Step S15, forming a negative electrode layer on the surface of the carbon-based material layer away from the second electrolyte layer;

Step S16, forming a second current collector on the surface of the negative electrode layer away from the carbon-based material layer.

So far, the above steps S11 to S16 have completed the preparation of a single lithium battery cell.

In other implementations of this embodiment, the above steps S14 to S16 may be:

Step S14b: forming a negative electrode layer on the surface of the second electrolyte layer away from the first electrolyte layer;

Step S15b, forming a carbon-based material layer on the surface of the negative electrode layer away from the second electrolyte layer;

Step S16b, forming a second current collector on the surface of the carbon-based material layer away from the carbon-based material layer.

In order to continue to obtain a lithium battery with multiple lithium battery cells superimposed, in some specific implementations of this embodiment, the following steps may be further included after the above step S16 or step S16b:

Step S17a, depositing a positive electrode layer of another lithium battery cell on the side of the second current collector opposite to the negative electrode layer.

In step S18a, the above steps S12-S16 or steps S12-S16b are repeated until the number of lithium battery cells included in the lithium battery reaches a predetermined requirement.

Step S19a, encapsulating a plurality of lithium battery cells that are continuously stacked to obtain a desired lithium battery.

In other specific implementations of this embodiment, the following steps may be further included after the above step S16:

Step S17b, forming a negative electrode layer of another lithium battery cell on the opposite side of the first current collector with the positive electrode layer;

Step P18b, forming a carbon-based material layer on the negative electrode layer;

Step P19b, forming a second electrolyte layer and a first electrolyte layer in sequence on the side of the carbon-based material layer away from the negative electrode layer;

Step P20b, forming a positive electrode layer and a second current collector in sequence on the surface of the first electrolyte layer away from the negative electrode layer;

Step S21b, depositing a negative electrode layer of another lithium battery cell on the opposite side of the second current collector with the positive electrode layer.

In step P22b, the above steps P18b to P21b are repeated until the number of lithium battery cells included in the lithium battery reaches a predetermined requirement.

Step S23b, encapsulating a plurality of lithium battery cells that are continuously stacked to obtain a desired lithium battery.

Specifically, the thickness and material selection for the first current collector, the second current collector, the positive electrode layer, the negative electrode layer, the carbon-based material layer, the first electrolyte layer or the second electrolyte layer in the above steps are as described in the second embodiment and the second embodiment. It is described in the third embodiment and will not be repeated here.

In particular, in the preparation method S10 of the above-mentioned lithium battery, before the positive electrode layer or the negative electrode layer is formed on the first current collector and/or the second current collector, it is necessary to conduct the first current collector and/or the second current collector. The upper surface is flattened to ensure that the surface of the current collector is flat and has no oxide surface layer. Among them, the planarization treatment can use chemical mechanical polishing process, an abrasive plus a polishing machine for partial polishing and grinding.

It should be noted that the solid electrolytes used for preparing the first electrolyte layer and the second electrolyte layer include perovskite type solid electrolytes, NASICON type solid electrolytes, garnet type solid electrolytes, LiGePS type sulfide solid electrolytes, One or a combination of LiSiPS type sulfide solid state electrolyte or LiSnPS type sulfide solid state electrolyte.

In some specific embodiments of the present invention, in the above step S11, the formation of the columnar crystal positive electrode layer on the current collector can be prepared by the method of magnetron sputtering grazing incidence:

(1) Put the substrate into the magnetron sputtering cavity, set the included angle between the vertical substrate direction and the vertical target direction to be greater than 45°, and keep the substrate water-cooled at room temperature;

(2) evacuate to 10 ^-5 Pa, feed argon gas, adjust the working pressure of the cavity to 2Pa and start to deposit the lithium iron phosphate positive electrode material;

(3) At the same time, the substrate rotates, and after 50 minutes of deposition, a 2-micron columnar crystal is formed.

The above-mentioned preparation method for the columnar crystal positive electrode layer is only an example, and not a limitation of the present invention.

The eighth embodiment of the present invention further provides a method P60 for preparing a lithium battery, which is different from the seventh embodiment in that it first forms a positive electrode layer and a negative electrode layer on the upper and lower surfaces of a current collector structure.

The preparation method P60 of the lithium battery specifically includes the following steps:

Step P11, providing a first current collector, depositing a columnar crystal positive electrode layer on one side of the first current collector, and depositing a lithium-silicon-carbon composite negative electrode layer on the other side of the current collector;

The deposition of the columnar crystal positive electrode layer and the deposition of the lithium-silicon-carbon composite negative electrode layer can be performed simultaneously or sequentially.

After step P11, it can be subdivided into the following two ways:

The first is to use the side where the columnar crystal positive electrode layer is deposited as the base material layer, and to continue to form the required functional layer on it. The specific steps include:

Step P12a, forming a first electrolyte layer and a second electrolyte layer on the columnar crystal positive electrode layer in sequence;

Step P13a, forming a carbon-based material layer on the side of the second electrolyte layer away from the positive electrode layer;

Step P14a, forming a negative electrode layer on the surface of the carbon-based material layer away from the second electrolyte layer.

Step P15a, forming a second current collector on the surface of the negative electrode layer away from the carbon-based material layer.

The second is to use the side deposited with the lithium-silicon-carbon composite negative electrode layer as the base material layer, and continue to form the required functional layer on it, and the specific steps include:

Step P12b, forming a carbon-based material layer on the lithium-silicon-carbon composite negative electrode layer;

Step P13b, forming a second electrolyte layer and a first electrolyte layer in sequence on the side of the carbon-based material layer away from the negative electrode layer;

Step P14b, forming a positive electrode layer and a second current collector in sequence on the surface of the first electrolyte layer away from the negative electrode layer;

After the above step P11, the order of depositing the required functional layers layer by layer on the side where the columnar crystal positive electrode layer is deposited or layer by layer on the side where the columnar crystal positive electrode layer is deposited is not limited, and can be performed sequentially, or can be performed simultaneously.

Further, the above-mentioned steps P12a-step P15 and steps P12b-step P14b can be repeated until the lithium battery with the required number of lithium battery cells is completed and stopped.

In this implementation, the carbon-based material layer can also be formed on the side of the lithium-silicon-carbon composite negative electrode layer away from the second electrolyte layer, and its specific position can be adjusted according to actual needs. as a limitation of the present invention.

Specifically, the thickness and material selection for the first current collector, the second current collector, the positive electrode layer, the negative electrode layer, the carbon-based material layer, the first electrolyte layer or the second electrolyte layer in the above steps are as described in the second embodiment and the second embodiment. It is described in the third embodiment and will not be repeated here.

Compared with the prior art, the current collector structure, the lithium battery cell and the lithium battery provided by the present invention have the following beneficial effects:

(1) The current collector structure, lithium battery cell and lithium battery provided by the present invention, wherein the current collector includes two opposite main surfaces, and a columnar crystal positive electrode layer is formed on one of the main surfaces to serve as a lithium battery cell. For the positive electrode structure, a negative electrode layer is formed on the other main surface to serve as the negative electrode structure of another lithium battery cell. By arranging positive and negative electrodes on both sides of the current collector to form a current collector of positive and negative common electrodes, multiple lithium battery cells can be fabricated by stacking, thereby realizing the fabrication of large-area all-solid-state lithium batteries.

The use of positive and negative common current collectors can also reduce the overall thickness of lithium battery cells and lithium batteries. Further, by using the current collectors of the positive and negative electrodes, a series connection between a plurality of lithium battery cells can be realized. When the lithium battery cells in the lithium battery are connected in series, the current collector can be directly used as the electrode of the lithium battery, thereby simplifying the packaging structure of the lithium battery.

In addition, in the present invention, a positive electrode material including columnar crystals is used as the positive electrode layer, so as to provide smooth diffusion and migration channels for lithium ions in the process of charging and discharging. utilization to improve the efficiency of lithium intercalation and extraction.

(2) In the present invention, the lithium battery cell and the lithium battery may further use a lithium silicon carbon composite negative electrode layer formed directly on the negative electrode current collector. The use of the lithium-silicon-carbon composite negative electrode layer can further improve the energy density of the lithium battery, thereby obtaining a high-energy lithium ion core and its lithium battery.

(3) The lithium battery cell and the lithium battery provided by the present invention further include a lithium-silicon-carbon composite negative electrode layer formed on the surface of the lithium-silicon-carbon composite negative electrode layer facing the positive electrode structure or on the lithium-silicon-carbon composite negative electrode layer away from the positive electrode structure. A carbon-based material layer is formed on the surface (ie, the surface of the lithium-silicon-carbon composite negative electrode layer facing the second current collector). The arrangement of the carbon-based material layer can prevent the appearance of lithium dendrites, thereby improving the stability and safety of the lithium battery cells and the lithium battery.

(4) In the lithium battery cell and lithium battery of the present invention, a first electrolyte layer is formed by filling between the columnar crystal positive electrode layer and the lithium silicon carbon composite negative electrode layer, and the thickness of the first electrolyte layer is 1 nm -50μm. The first electrolyte layer can cover the columnar crystal positive electrode layer, so it has a larger surface area, so the formation of the first electrolyte layer can provide more reaction interfaces between the electrolyte and the positive electrode layer in the lithium battery, which is beneficial to the battery Complete reaction of charge and discharge process.

(5) In the lithium battery cell and lithium battery of the present invention, a second electrolyte layer can be formed on the surface of the first electrolyte layer, which can further improve the flatness of the first electrolyte layer and the electric field distribution on the surface of the negative electrode The uniformity can also be increased, and the hardness of the first electrolyte layer can also be increased to prevent short circuit caused by the contact between the positive and negative electrodes.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the principles of the present invention should be included within the protection scope of the present invention.

Claims (10)

1. a kind of current collector structure, it is characterised in that: including collector, the collector includes two opposite main surfaces, In column crystal anode layer, using the anode structure as a lithium battery electric core, shape in another main surface are formed in a main surface At negative electrode layer, using the negative pole structure as another lithium battery electric core.

2. a kind of lithium battery electric core, it is characterised in that: it includes the first collector, which includes two opposite masters Surface forms column crystal anode layer, using the anode structure as the lithium battery electric core, another main table in one of main surface Negative electrode layer is formed on face, using the negative pole structure as another lithium battery electric core.

3. lithium battery electric core as stated in claim 2, it is characterised in that: the column crystal anode layer with a thickness of 10nm- 100μm；The column crystal anode layer includes one or more of groups in V, Mo, Mn, Ni, Fe, Co, Cr, Ti or Bi metallic element The metal oxide of conjunction and contain lithium metal oxide.

4. lithium battery electric core as stated in claim 2, it is characterised in that: the lithium battery electric core include the second collector and It is formed in the negative electrode layer on one surface of the second collector, which includes lithium silicon-carbon composite cathode layer, and the negative electrode layer is towards described Column crystal anode layer.

5. lithium battery electric core as claimed in claim 4, it is characterised in that: the lithium silicon-carbon composite cathode layer includes that deposition is formed Silicon-lithium alloy on the negative current collector, carbon nano-particle are compounded within silicon-lithium alloy.

6. lithium battery electric core as claimed in claim 5, it is characterised in that: the lithium silicon-carbon composite cathode layer is towards the anode The surface of structure forms a carbon base material layer or the surface of the lithium silicon-carbon composite cathode layer towards second collector is formed One carbon base material layer.

7. lithium battery electric core as claimed in claim 4, it is characterised in that: in the column crystal anode layer and the lithium silicon-carbon Filling forms the first electrolyte layer for coating the column crystal between composite negative pole layer, first electrolyte layer with a thickness of 1nm-50μm。

8. lithium battery electric core as recited in claim 7, it is characterised in that: the lithium battery electric core includes being formed in described first The second electrolyte layer in one side of the electrolyte layer towards the negative electrode layer, second electrolyte layer with a thickness of 1- 3000nm。

9. a kind of lithium battery, it is characterised in that: it includes the lithium battery electric core of at least two continuous lamination settings, and directly superposition is set A positive and negative copolar collector is shared between at least two lithium battery electric cores set, which includes two opposite Main surface forms column crystal anode layer in one of main surface, using the anode structure as a wherein lithium battery electric core, separately Negative electrode layer is formed in one main surface, using the negative pole structure as another lithium battery electric core.

10. lithium battery as claimed in claim 9, it is characterised in that: share two lithium batteries of a positive and negative copolar collector It is to be connected in series or in parallel between core.