Equipment and process for preparing pre-lithium structure, pre-lithium structure and lithium ion battery

Abstract

The present disclosure provides equipment and processes for preparing a pre-lithium structure, a pre-lithium structure and a lithium-ion battery, and belongs to the field of battery materials. The equipment for preparing a pre-lithium structure includes a BMB pre-processor, a metal lithium evaporation source and a conductive metal evaporation source, and a front main roller, a transfer roller and a rear main roller that are arranged in sequence; the BMB pre-processor is located on the left side of the front main roller, and is used to form a first protective layer; the metal lithium evaporation source is located below the front main roller, and is used to form a pre-lithium layer on the surface of the first protective layer; the conductive metal evaporation source is located below the rear main roller, and is used to form an electronic conductive layer on the surface of the pre-lithium layer. The present disclosure adopts an integrated evaporation barrier mode to form a dense interface structure between the first protective layer and the metal lithium layer, thereby improving the pre-lithium effect; and the operation is simple, the process is relatively few, and it is suitable for large-scale production. The present disclosure solves the technical problems that the existing equipment and methods for preparing pre-lithium structures have many production processes, poor pre-lithium effects, and are difficult to achieve large-scale production.

Description

Technical Field

[0001] The present disclosure relates to the field of battery materials, and in particular to a device and process for preparing a pre-lithium structure, a pre-lithium structure and a lithium-ion battery. Background Art

[0002] Pre-lithium is also called lithium replenishment, which means adding lithium source to the battery before the lithium-ion battery works to replenish lithium ions, compensating for the irreversible lithium loss caused by the formation of the solid electrolyte interface (SEI) film during the first charging process, thereby improving the capacity and cycle performance of the lithium-ion battery. The pre-lithium structure of "protective layer I + metal lithium layer + electronic conductive layer + protective layer II" has a good lithium replenishment effect and can increase the safety, cycle performance and energy density of lithium-ion batteries.

[0003] Traditional lithium replenishment methods mainly include chemical synthesis and physical vapor deposition (PVD). The chemical synthesis method of lithium replenishment has problems such as difficult operation, uneven dispersion of lithium powder, high cost, and complicated process steps; therefore, the pre-lithiation method based on the PVD method has become a feasible method for pre-lithiation. However, traditional PVD equipment needs to prepare the pre-lithiation structure of "protective layer I + metal lithium layer + electronic conductive layer + protective layer II" according to the mode of "sputtering + barrier evaporation + sputtering + sputtering". On the one hand, there are too many production processes, resulting in low production efficiency; on the other hand, the material utilization rate of metal lithium is low, making it difficult to achieve industrial production.

[0004] Therefore, how to propose a device and process for preparing a pre-lithium structure, a pre-lithium structure and a lithium-ion battery to solve or at least alleviate at least one of the above-mentioned technical problems existing in the existing pre-lithium structure is a technical problem that needs to be solved urgently. Summary of the invention

[0005] In view of the above technical problems, the present disclosure provides an apparatus and process for preparing a pre-lithium structure, a pre-lithium structure and a lithium-ion battery, which realize large-scale production, improve production efficiency, material utilization rate of metallic lithium and pre-lithium effect; and the equipment is simple and the production process is relatively few.

[0006] According to a specific embodiment of the present disclosure, in a first aspect, the present disclosure provides an apparatus for preparing a pre-lithium structure, comprising a BMB (Bombard, tubular Hall ion source) pre-processor, a metal lithium evaporation source, a conductive metal evaporation source, a front main roller, a transfer roller and a rear main roller, wherein the front main roller, the transfer roller and the rear main roller are sequentially arranged at intervals;

[0007] The BMB pre-processor is located on the left side of the front main roller shaft and is used to form a first protective layer;

[0008] The metal lithium evaporation source is located below the front main roller shaft and is used to form a pre-lithium layer on the surface of the first protective layer;

[0009] The conductive metal evaporation source is located below the rear main roller shaft and is used to form an electronic conductive layer on the surface of the pre-lithium layer.

[0010] Furthermore, the equipment for preparing the pre-lithium structure also includes a BMB post-processor, which is located on the right side of the rear main roller and is used to form a second protective layer on the surface of the electronic conductive layer.

[0011] Furthermore, the equipment for preparing the pre-lithium structure also includes a unwinding device and a winding device, wherein the unwinding device is arranged in front of the BMB pre-processor for releasing the substrate; the winding device is arranged behind the BMB post-processor for winding the pre-lithium structure.

[0012] Furthermore, a first flattening roller is provided between the unwinding device and the BMB pre-processor.

[0013] Furthermore, a second flattening roller is provided between the BMB pre-processor and the front main roller.

[0014] Furthermore, a third flattening roller is provided between the front main roller and the transfer roller.

[0015] Furthermore, a fourth flattening roller is provided between the transfer roller and the rear main roller.

[0016] Furthermore, a fifth flattening roller is provided between the rear main roller and the BMB post-processor.

[0017] Furthermore, a sixth flattening roller is provided between the BMB post-processor and the winding device.

[0018] Furthermore, the number of BMB dies of the BMB pre-processor is 20-40 groups.

[0019] Furthermore, the number of BMB dies of the BMB post-processor is 10-20 groups.

[0020] Furthermore, the surface of each BMB tube core of the BMB pre-processor is coated with lithium foil.

[0021] Furthermore, the surface of each BMB tube core of the BMB post-processor is coated with lithium foil.

[0022] Furthermore, the metallic lithium evaporation source is an induction evaporation source.

[0023] Furthermore, the conductive metal evaporation source is an induction evaporation source or a barrier evaporation source.

[0024] According to a specific embodiment of the present disclosure, in a second aspect, the present disclosure provides a preparation process of a pre-lithium structure, comprising the following steps:

[0025] Provide and start any of the above-mentioned devices for preparing a pre-lithium structure, place a substrate at the BMB pre-processor, and transfer the substrate through the front main roller, the transfer roller, and the rear main roller;

[0026] The BMB preprocessor generates plasma, the plasma bombards the surface of the substrate, and deposits a first protective layer on the surface of the substrate;

[0027] The metal lithium evaporation source evaporates the metal lithium into gaseous metal lithium, and the gaseous metal lithium is deposited on the surface of the first protective layer to form a lithium supplement layer; and

[0028] The conductive metal evaporation source evaporates the conductive metal material into a gaseous state, and the gaseous conductive metal material is deposited on the surface of the lithium replenishing layer to form an electronic conductive layer.

[0029] Furthermore, after forming the electronic conductive layer, the preparation process of the pre-lithium structure further includes the following steps: a BMB post-processor generates plasma, the plasma bombards the surface of the substrate, and a second protective layer is deposited on the surface of the electronic conductive layer.

[0030] Furthermore, the output power of each BMB die of the BMB pre-processor is 100-500W.

[0031] Furthermore, the output power of each BMB die of the BMB post-processor is 200-400W.

[0032] Furthermore, the ionized gas corresponding to the BMB preprocessor is carbon dioxide, nitrogen or a mixed gas of carbon dioxide and nitrogen.

[0033] Furthermore, the ionized gas corresponding to the BMB post-processor is carbon dioxide, nitrogen, or a mixed gas of carbon dioxide and nitrogen.

[0034] Furthermore, the ventilation flow rate of the ionized gas corresponding to each BMB die of the BMB pre-processor is 20-100 sccm.

[0035] Furthermore, the ventilation flow rate of the ionized gas corresponding to each BMB die of the BMB post-processor is 30-80 sccm.

[0036] Furthermore, the crucible heating temperature of the metal lithium evaporation source is controlled at 300-500° C., the induction frequency is controlled at 10000-20000 Hz, and the evaporation rate is controlled based on online eddy current electricity.

[0037] Furthermore, the conductive metal evaporation source is an induction evaporation source, the crucible heating temperature used is controlled at 1300-1500° C., the induction frequency is controlled at 80000-120000 Hz, and the evaporation rate is controlled by online eddy current electricity.

[0038] Furthermore, the conductive metal evaporation source is a vapor barrier evaporation source, the heating power of the evaporation boat used is controlled at 7-9kW, the wire feeding speed is 200-700mm / min, and the evaporation rate is controlled by online eddy current electricity.

[0039] According to a specific embodiment of the present disclosure, in a third aspect, the present disclosure provides a pre-lithium structure, and the pre-lithium structure is obtained by using any preparation process of the pre-lithium structure as described above.

[0040] According to a specific embodiment of the present disclosure, in a fourth aspect, the present disclosure provides a lithium-ion battery, comprising a positive electrode, a negative electrode and a separator, wherein the separator is arranged between the positive electrode and the negative electrode, and the lithium-ion battery comprises any of the pre-lithium structures described above.

[0041] Compared with the prior art, the above scheme provided by the present disclosure has at least the following beneficial effects: the equipment for preparing the pre-lithium structure provided by the present disclosure includes a BMB pre-processor, a metal lithium evaporation source and a conductive metal evaporation source, the pre-lithium structure is prepared by an integrated evaporation resistance mode, and the first protective layer is prepared by the BMB pre-processor, and a dense interface structure is formed between the first protective layer and the metal lithium layer, which can improve the transmission efficiency of lithium ions, make the distribution of lithium ions at the interface more uniform, reduce the formation of lithium dendrites, reduce the formation of impurities formed by the contact between the metal lithium layer and the air, avoid the pre-lithium structure from cracking, stratification and the like, thereby improving the pre-lithium effect of the pre-lithium structure and the stability of the pre-lithium structure, and can achieve large-scale production, improve production efficiency and material utilization rate of metal lithium. The present disclosure further sets a BMB post-processor, uses the BMB post-processor to prepare the second protective layer, forms a dense interface structure between the second protective layer and the electronic conductive layer, reduces the formation of impurities formed by the contact between the electronic conductive layer and the air, further improves the transmission efficiency of lithium ions, and improves the pre-lithium effect of the pre-lithium structure and the stability of the pre-lithium structure. By setting the pre-lithiation process parameters of the three main components, namely the BMB pre-processor, the metallic lithium evaporation source, and the conductive metal evaporation source, or the four main components, namely the BMB pre-processor, the metallic lithium evaporation source, the conductive metal evaporation source, and the BMB post-processor, the degree of pre-lithiation can be precisely controlled and sufficient pre-lithiation amount can be provided, thereby effectively improving the first coulombic efficiency and overall performance of the lithium-ion battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The drawings herein are incorporated into the specification and constitute a part of the specification, showing embodiments consistent with the present disclosure, and together with the specification, are used to explain the principles of the present disclosure. Obviously, the drawings described below are only some embodiments of the present disclosure, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0043] Figure 1 A schematic diagram of the structure of an apparatus for preparing a pre-lithium structure provided in an embodiment of the present disclosure;

[0044] Figure 2 A schematic cross-sectional structure diagram of a BMB (Bombard, tubular Hall ion source) pre-processor provided in an embodiment of the present disclosure;

[0045] Figure 3 A flow chart of a preparation process of a pre-lithium structure provided in an embodiment of the present disclosure;

[0046] Figure 4 A schematic diagram of the structure of the pre-lithium structure provided in an embodiment of the present disclosure;

[0047] Figure 5 A schematic diagram of the structure of a lithium-ion battery provided in an embodiment of the present disclosure.

[0048] The reference numerals in the specific implementation manner are as follows:

[0049] Equipment 100 for preparing a pre-lithium structure, BMB pre-processor 1, BMB tube core 11, metal lithium evaporation source 2, conductive metal evaporation source 3, BMB post-processor 4, front main roller 5, transfer roller 6, rear main roller 7, unwinding device 8, winding device 9, first flattening roller 10, second flattening roller 11, third flattening roller 12, fourth flattening roller 13, fifth flattening roller 14, sixth flattening roller 15;

[0050] Pre-lithium structure 20, first protective layer 21, metal lithium layer 22, electronic conductive layer 23, second protective layer 24;

[0051] Positive electrode 30 , negative electrode 40 , pre-lithium separator 50 , separator substrate 51 . DETAILED DESCRIPTION

[0052] In order to make the purpose, technical solutions and advantages of the present disclosure clearer, the present disclosure will be further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0053] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present disclosure belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure.

[0054] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a product or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such product or device. In the absence of more restrictions, the elements defined by the sentence "comprises a" do not exclude the presence of other identical elements in the product or device including the elements.

[0055] In the description of the embodiments of the present disclosure, the orientations or positional relationships indicated by technical terms such as "up", "down", "left", "right", and "thickness" are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the embodiments of the present disclosure and simplifying the description. They do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present disclosure.

[0056] In the description of the embodiments of the present disclosure, the term "and / or" is used only to describe the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0057] In the description of the embodiments of the present disclosure, the symbol “-” represents the two endpoint data before and after the “-” and all data between the two endpoints. For example, AB represents all data greater than or equal to A and less than or equal to B.

[0058] Reference to "embodiments" in this disclosure means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the disclosure. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in this disclosure may be combined with other embodiments.

[0059] Traditional preparation methods for lithium-replenishing structures mainly include chemical synthesis and physical vapor deposition (PVD). The chemical synthesis method for lithium replenishment has problems such as difficult operation, uneven lithium powder dispersion, high cost, and complicated process steps; the pre-lithiation method based on the PVD method has become a feasible method for pre-lithiation. The pre-lithiation structure of "protective layer I + metal lithium layer + electronic conductive layer + protective layer II" has a good lithium replenishment effect, can increase the safety, cycle performance, energy density and other properties of lithium-ion batteries, and has been widely recognized by the industry.

[0060] However, the inventors have found through research that traditional PVD equipment needs to prepare the pre-lithium structure of "protective layer I + metal lithium layer + electronic conductive layer + protective layer II" according to the mode of "sputtering + evaporation barrier + sputtering + sputtering". On the one hand, there are too many production processes, resulting in low production efficiency; on the other hand, the material utilization rate of metal lithium is low, making it difficult to achieve industrial production. The inventors have also found through research that the pre-lithium structure can be prepared by adopting an integrated evaporation barrier mode. The integrated evaporation barrier mode has the advantages of high lithium deposition quality, good stability of the pre-lithium structure, and controllable degree of pre-lithiation. However, the interface structure between the protective layer and the metal lithium layer of the pre-lithium structure obtained by the integrated evaporation barrier mode is loose. The loose interface structure greatly affects the pre-lithium effect, and the loose interface is prone to rupture and stratification, making it difficult to achieve large-scale production of the pre-lithium structure.

[0061] In order to solve or at least alleviate the above technical problems, the present disclosure provides an apparatus and process for preparing a pre-lithium structure, which adopts an overall system including a BMB (Bombard, tubular Hall ion source) processor, a metal lithium evaporation source and a conductive metal evaporation source; and based on the pre-lithium process parameters of the three main components, a pre-lithium structure of "protective layer + metal lithium layer + electronic conductive layer" is prepared. The apparatus and process disclosed in the present disclosure adopt an integrated evaporation resistance mode to prepare a pre-lithium structure, which can realize large-scale production, improve production efficiency and material utilization of metal lithium; and use the BMB processor as a basis to prepare a protective layer, forming a dense interface structure between the protective layer and the metal lithium layer, thereby improving the pre-lithium effect and structural stability of the pre-lithium structure.

[0062] Specifically, an embodiment of the present disclosure provides an apparatus for preparing a pre-lithium structure, comprising a BMB pre-processor, a metal lithium evaporation source, a conductive metal evaporation source, a front main roller, a transfer roller, and a rear main roller, wherein the front main roller, the transfer roller, and the rear main roller are sequentially arranged at intervals;

[0063] The BMB pre-processor is located on the left side of the front main roller shaft and is used to form a first protective layer;

[0064] The metal lithium evaporation source is located below the front main roller shaft and is used to form a pre-lithium layer on the surface of the first protective layer;

[0065] The conductive metal evaporation source is located below the rear main roller shaft and is used to form an electronic conductive layer on the surface of the pre-lithium layer.

[0066] In some embodiments, the apparatus for preparing a pre-lithium structure further includes a BMB post-processor located on the right side of the rear main roller and configured to form a second protective layer on the surface of the electronic conductive layer.

[0067] The present disclosure also provides a process for preparing a pre-lithium structure, comprising the following steps:

[0068] Provide and start any of the above-mentioned devices for preparing a pre-lithium structure, place a substrate at the BMB pre-processor, and transfer the substrate through the front main roller, the transfer roller, and the rear main roller;

[0069] The BMB preprocessor generates plasma, the plasma bombards the surface of the substrate, and deposits a first protective layer on the surface of the substrate;

[0070] The metal lithium evaporation source evaporates the metal lithium into gaseous metal lithium, and the gaseous metal lithium is deposited on the surface of the first protective layer to form a lithium supplement layer; and

[0071] The conductive metal evaporation source evaporates the conductive metal material into a gaseous state, and the gaseous conductive metal material is deposited on the surface of the lithium replenishing layer to form an electronic conductive layer.

[0072] In some embodiments, after the electronic conductive layer is formed, the following steps are further included: a BMB post-processor generates plasma, the plasma bombards the surface of the substrate, and a second protective layer is deposited on the surface of the electronic conductive layer.

[0073] In the technical solution disclosed in the present invention, the equipment for preparing the pre-lithium structure includes a BMB pre-processor, a metal lithium evaporation source and a conductive metal evaporation source, and the pre-lithium structure is prepared by an integrated evaporation resistance mode, and the first protective layer is prepared based on the BMB pre-processor, and a dense interface structure is formed between the first protective layer and the metal lithium layer, which can improve the transmission efficiency of lithium ions, make the distribution of lithium ions at the interface more uniform, reduce the formation of lithium dendrites, reduce the metal lithium layer and the air to form impurities, avoid the pre-lithium structure from cracking, stratification and other phenomena, thereby improving the pre-lithium effect of the pre-lithium structure and the stability of the pre-lithium structure, and can achieve large-scale production, improve production efficiency and material utilization of metal lithium. In some embodiments, a BMB post-processor is further provided, and a second protective layer is prepared based on the BMB post-processor, and a dense interface structure is formed between the second protective layer and the electronic conductive layer, reducing the electronic conductive layer and the air to form impurities, further improving the transmission efficiency of lithium ions, and improving the pre-lithium effect of the pre-lithium structure and the stability of the pre-lithium structure. Moreover, by setting the pre-lithiation process parameters of the three main components of the BMB pre-processor, the metal lithium evaporation source, and the conductive metal evaporation source, or the four main components of the BMB pre-processor, the metal lithium evaporation source, the conductive metal evaporation source and the BMB post-processor, the degree of pre-lithiation can be precisely controlled and sufficient pre-lithiation amount can be provided, thereby effectively improving the initial coulombic efficiency and overall performance of the lithium-ion battery; and the prepared first protective layer, lithium replenishing layer, electronic conductive layer and second protective layer have uniform thickness and dense structure, further improving the replenishing effect.

[0074] The optional embodiments of the present disclosure are described in detail below with reference to the accompanying drawings.

[0075] See also Figure 1 The first embodiment of the present disclosure provides an apparatus 100 for preparing a pre-lithium structure, comprising a BMB pre-processor 1, a metal lithium evaporation source 2, a conductive metal evaporation source 3, and a BMB post-processor 4. A front main roller 5, a transfer roller 6, and a rear main roller 7 are sequentially arranged between the BMB pre-processor 1 and the BMB post-processor 4. The front main roller 5, the transfer roller 6, and the rear main roller 7 are used to transport the substrate, so that the substrate passes through the BMB pre-processor 1, the metal lithium evaporation source 2, the conductive metal evaporation source 3, and the BMB post-processor 4 in sequence. The metal lithium evaporation source 2 is located below the front main roller 5, and the conductive metal evaporation source 3 is located below the rear main roller 7; the BMB pre-processor 1 is used to generate plasma, and directly form a first protective layer on the surface of the substrate by plasma bombardment, and the BMB post-processor 4 is used to generate plasma, and directly form a second protective layer on the surface of the electronic conductive layer by plasma bombardment.

[0076] It can be understood that the BMB post-processor 4 is an optional component. In some embodiments, the device 100 for preparing a pre-lithium structure includes a BMB pre-processor 1, a metal lithium evaporation source 2, and a conductive metal evaporation source 3, but does not include a BMB post-processor 4. At this time, the obtained pre-lithium structure includes a first protective layer, a pre-lithium layer, and an electronic conductive layer, but does not include a second protective layer.

[0077] In some embodiments, the device 100 for preparing a pre-lithium structure also includes a unwinding device 8 and a winding device 9. The unwinding device 8 is arranged in front of the BMB pre-processor 1 for releasing the substrate; the winding device 9 is arranged behind the BMB post-processor 4 for winding the prepared pre-lithium structure.

[0078] In some embodiments, the device 100 for preparing a pre-lithium structure further includes a plurality of flattening rollers for flattening the surface of the substrate. In this embodiment, a first flattening roller 10 is provided between the unwinding device 8 and the BMB preprocessor 1, a second flattening roller 11 is provided between the BMB preprocessor 1 and the front main roller 5, a third flattening roller 12 is provided between the front main roller 5 and the transfer roller 6, a fourth flattening roller 13 is provided between the transfer roller 6 and the rear main roller 7, a fifth flattening roller 14 is provided between the rear main roller 7 and the BMB postprocessor 4, and a sixth flattening roller 15 is provided between the BMB postprocessor 4 and the winding device 9.

[0079] See also Figure 2 , the BMB preprocessor 1 preferably includes a plurality of BMB tube cores 11. In some embodiments, the number of BMB tube cores 11 of the BMB preprocessor 1 is preferably, but not limited to, 20-40 groups. Preferably, the surface of each BMB tube core 11 is coated with lithium foil. When the first protective layer is formed by plasma bombardment, the lithium foil can be used as a sputtering source, and lithium atoms or lithium ions are released during the plasma bombardment process, which can supplement or replace the lithium organic metal compound originally used to provide the lithium source to a certain extent. In some embodiments, the thickness of the lithium foil is preferably, but not limited to, 50-200 μm.

[0080] In some embodiments, the metal lithium evaporation source 2 is an induction evaporation source, and the evaporation vessel used is a crucible. The crucible is preferably made of, but not limited to, one of tungsten, molybdenum, niobium, tantalum and rhenium.

[0081] In some embodiments, the metal lithium evaporation source 2 includes a plurality of sub-evaporation sources, and the number, spacing and electrode spacing of the sub-evaporation sources can be adjusted according to actual conditions. In some preferred embodiments, the number of sub-evaporation sources of the metal lithium evaporation source 2 is 20-30, the spacing between the sub-evaporation sources is 5-10 cm, and the electrode spacing is 10-15 cm. In this embodiment, the number of sub-evaporation sources of the metal lithium evaporation source 2 is 27, the spacing between the sub-evaporation sources is 7 cm, and the electrode spacing is 13 cm.

[0082] The conductive metal evaporation source 3 is preferably an induction evaporation source or a resistance evaporation source. In some embodiments, the conductive metal evaporation source 3 includes a plurality of sub-evaporation sources, and the number, spacing and electrode spacing of the sub-evaporation sources can be adjusted according to actual conditions. In some preferred embodiments, the number of sub-evaporation sources of the conductive metal evaporation source 3 is 20-30, the spacing between the sub-evaporation sources is 5-10 cm, and the electrode spacing is 10-15 cm. In this embodiment, the number of sub-evaporation sources in the conductive metal evaporation source 3 is 27, the spacing between the sub-evaporation sources is 7 cm, and the electrode spacing is 13 cm.

[0083] In some embodiments, the conductive metal evaporation source 3 is an induction evaporation source, and the evaporation vessel used is a crucible, and the crucible is preferably made of ceramic. In other embodiments, the conductive metal evaporation source 3 is a barrier evaporation source, and the evaporation vessel used is an evaporation boat, and the evaporation boat is preferably made of a quaternary evaporation boat.

[0084] The BMB post-processor 4 preferably includes a plurality of BMB dies 11. In some embodiments, the number of BMB dies 11 of the BMB post-processor 4 is preferably, but not limited to, 10-20 groups. Preferably, the surface of each BMB die 11 is coated with lithium foil, and the thickness of the lithium foil is preferably, but not limited to, 50-200 μm.

[0085] The BMB pre-processor 1 and the BMB post-processor 2 have substantially the same structure, except that in some embodiments, the number of BMB dies 11 of the BMB pre-processor 1 and the BMB post-processor 2 are different.

[0086] See also Figure 3 The second embodiment of the present disclosure provides a preparation process of a pre-lithium structure, comprising the following steps:

[0087] Step (S1), providing and starting any device 100 for preparing a pre-lithium structure as described in the first embodiment, placing a substrate at the BMB pre-processor 1, and transmitting the substrate through the front main roller 5, the transfer roller 6 and the rear main roller 7;

[0088] Step (S2), the BMB preprocessor 1 generates plasma, the plasma bombards the surface of the substrate, and deposits a first protective layer on the surface of the substrate;

[0089] Step (S3), the metal lithium evaporation source 2 evaporates the metal lithium into gaseous metal lithium, and the gaseous metal lithium is deposited on the surface of the first protective layer on the substrate to form a lithium supplement layer;

[0090] Step (S4), the conductive metal evaporation source 3 evaporates the conductive material into a gaseous state, and the gaseous conductive material is deposited onto the surface of the lithium replenishing layer on the substrate to form an electronic conductive layer; and

[0091] Step (S5), the BMB post-processor 4 generates plasma, the plasma bombards the surface of the substrate, and deposits a second protective layer on the surface of the electronic conductive layer to obtain the pre-lithium structure.

[0092] It can be understood that in some embodiments, the device 100 for preparing a pre-lithium structure includes a BMB pre-processor 1, a metal lithium evaporation source 2 and a conductive metal evaporation source 3, but does not include a BMB post-processor 4. At this time, the preparation process of the pre-lithium structure includes steps (S1) to (S4), but does not include step (S5). The obtained pre-lithium structure includes a first protective layer, a pre-lithium layer and an electronic conductive layer, but does not include a second protective layer.

[0093] The device 100 for preparing a pre-lithium structure includes all the technical features described in the first embodiment, which will not be described in detail here.

[0094] In step (S1), the substrate is preferably released at the BMB preprocessor 1 by the unwinding device 8. In some embodiments, the substrate is a lithium-ion battery separator matrix, and the obtained pre-lithium structure is a pre-lithium separator. In some embodiments, the substrate is a lithium-ion battery negative electrode sheet, and the obtained pre-lithium structure is a pre-lithium negative electrode.

[0095] In some embodiments, in step (S2), ionized gas and a precursor gas for forming a first protective layer are introduced into the BMB preprocessor 1, and the plasma generated by the precursor gas bombards the surface of the substrate to form a first protective layer on the surface of the substrate.

[0096] The first protective layer material may be a protective layer material commonly used in a pre-lithium structure. The precursor gas is selected according to the first protective layer material. As an example, the first protective layer material may include Li 2 CO 3 , Li 3 N、LiTiO 3 , Li 3 P or LiF, etc.

[0097] The output power of each BMB tube core 11 of the BMB preprocessor 1 is preferably, but not limited to, 100-500W. The ionized gas of the BMB preprocessor 1 can be carbon dioxide, nitrogen, or a mixture of carbon dioxide and nitrogen. The ventilation flow rate of the ionized gas corresponding to each BMB tube core 11 of the BMB preprocessor 1 is preferably 20-100sccm. The surface of each BMB tube core 11 of the BMB preprocessor 1 is coated with lithium foil. When the first protective layer is formed by plasma bombardment, the lithium foil can be used as a sputtering source, and lithium atoms or lithium ions are released during the plasma bombardment process, which can supplement or replace the lithium organic metal compound originally used to provide a lithium source to a certain extent. The thickness of the lithium foil is preferably 50-200μm.

[0098] In some embodiments, in step (S3), the crucible heating temperature used by the metal lithium evaporation source 2 is controlled at 300-500°C, the induction frequency is controlled at 10000-20000 Hz, and the evaporation rate is controlled by online eddy current electricity.

[0099] The evaporation material in the metal lithium evaporation source 2 includes but is not limited to one or more of metal lithium, lithium silicon alloy, lithium magnesium alloy, lithium copper alloy, lithium silver alloy, lithium beryllium alloy, lithium zinc alloy, lithium cadmium alloy, lithium aluminum alloy, lithium gold alloy and lithium boron alloy.

[0100] In some embodiments, in step (S4), the material of the electronic conductive layer includes metal, and the metal material preferably includes at least one of Au, Ag, Cu, Zn, Mg and metal alloys thereof. In some preferred embodiments, the material of the electronic conductive layer is a metal material.

[0101] When the conductive metal evaporation source 3 is an induction evaporation source, the crucible heating temperature is controlled at 1300-1500°C, the induction frequency is controlled at 80000-120000Hz, and the evaporation rate is controlled by online eddy current electricity; when the conductive metal evaporation source 3 is a resistance evaporation source, the evaporation boat heating power is controlled at 7-9kW, the wire feeding speed is 200-700mm / min, and the evaporation rate is controlled by online eddy current electricity.

[0102] In some embodiments, in step (S5), ionized gas and a precursor gas for forming a second protective layer are introduced into the BMB post-processor 4, and the plasma generated by the precursor gas bombards the surface of the substrate to form a second protective layer on the surface of the electronic conductive layer.

[0103] The second protective layer material may be a protective layer material commonly used in pre-lithium structures. The precursor gas is selected according to the second protective layer material. As an example, the first protective layer material may include Li 2 CO 3 , Li 3N、LiTiO 3 , Li 3 P or LiF, etc.

[0104] The output power of each BMB tube core 11 of the BMB post-processor 4 is preferably, but not limited to, 200-400W. The ionized gas of the BMB post-processor 4 can be carbon dioxide, nitrogen, or a mixture of carbon dioxide and nitrogen. The ventilation flow rate of the corresponding ionized gas of each BMB tube core 11 of the BMB post-processor 4 is preferably 30-80sccm. The surface of each BMB tube core 11 of the BMB post-processor 4 is coated with lithium foil. When the second protective layer is formed by plasma bombardment, the lithium foil can be used as a sputtering source, and lithium atoms or lithium ions are released during the plasma bombardment process, which can supplement or replace the lithium organic metal compound originally used to provide the lithium source to a certain extent. The thickness of the lithium foil is preferably 50-200μm.

[0105] In some embodiments, after the step (S5), the winding device 9 is further used to wind up the pre-lithium structure for standby use.

[0106] The third embodiment of the present disclosure provides a pre-lithium structure, which is obtained by using any of the above-mentioned preparation processes for the pre-lithium structure. Figure 4 In some embodiments, the pre-lithium structure 20 includes a first protective layer 21, a metal lithium layer 22, an electronic conductive layer 23, and a second protective layer 24 stacked in sequence. The first protective layer 21, the metal lithium layer 22, the electronic conductive layer 23, and the second protective layer 24 have all the same technical features as those described in the second embodiment, and are not described in detail herein.

[0107] It can be understood that in some embodiments, the device 100 for preparing a pre-lithium structure includes a BMB pre-processor 1, a metal lithium evaporation source 2 and a conductive metal evaporation source 3, but does not include a BMB post-processor 4, and the obtained pre-lithium structure 20 includes a first protective layer 21, a pre-lithium layer 22 and an electronic conductive layer 23, but does not include a second protective layer 24.

[0108] In some embodiments, the pre-lithium structure 20 is disposed on the surface of a lithium-ion battery separator substrate to form a pre-lithium separator, and the first protective layer 21 is in contact with the separator substrate. In other embodiments, the pre-lithium structure 20 is disposed on the surface of a lithium-ion battery negative electrode sheet to form a pre-lithium negative electrode, and the first protective layer 21 is in contact with the negative electrode sheet.

[0109] A fourth embodiment of the present disclosure provides a lithium-ion battery, comprising a positive electrode, a negative electrode and a separator, wherein the separator is disposed between the positive electrode and the negative electrode, and the lithium-ion battery comprises any of the aforementioned pre-lithium structures.

[0110] In some embodiments, the diaphragm includes a diaphragm substrate and a pre-lithium structure 20 as described above, the pre-lithium structure is arranged on the surface of the diaphragm substrate, and the first protective layer 21 is in contact with the diaphragm substrate; and / or the negative electrode includes a negative electrode sheet and a pre-lithium structure 20 as described above, the pre-lithium structure 20 is arranged on the surface of the negative electrode sheet, and the first protective layer 21 is in contact with the negative electrode sheet.

[0111] See also Figure 5 In some embodiments, the lithium-ion battery includes a positive electrode 30, a negative electrode 40 and a pre-lithium separator 50, the pre-lithium separator 50 is located between the positive electrode 30 and the negative electrode 40, the pre-lithium separator 50 includes a separator substrate 51 and a pre-lithium structure 20, the separator substrate 51 is close to the positive electrode 30, the first protective layer 21 of the pre-lithium structure 20 is arranged on the separator substrate, and the second protective layer 24 of the pre-lithium structure 20 is close to the negative electrode 40.

[0112] The preparation process, test methods and test data of the embodiments and comparative examples are introduced below:

[0113] Embodiment 1:

[0114] A device for preparing a pre-lithium structure, comprising: an unwinding device 8, a BMB pre-processor 1, a front main roller 5, a transfer roller 6, a rear main roller 7, a BMB post-processor 4 and a winding device 9; a metal lithium evaporation source 2 is provided below the front main roller 5, and a conductive metal evaporation source 3 is provided below the rear main roller 7;

[0115] A first flattening roller 10 is provided between the unwinding device 8 and the BMB pre-processor 1, a second flattening roller 11 is provided between the BMB pre-processor 1 and the front main roller 5, a third flattening roller 12 is provided between the front main roller 5 and the transfer roller 6, a fourth flattening roller 13 is provided between the transfer roller 6 and the rear main roller 7, a fifth flattening roller 14 is provided between the rear main roller 7 and the BMB post-processor 4, and a sixth flattening roller 15 is provided between the BMB post-processor 4 and the winding device 9;

[0116] The number of BMB tube cores 11 of the BMB pre-processor 1 is 40 groups, and the number of BMB tube cores 11 of the BMB post-processor 4 is 10 groups; the surface of each BMB tube core 11 of the BMB pre-processor 1 and the BMB post-processor 4 is coated with a commercial lithium foil with a thickness of 200 μm;

[0117] The metal lithium evaporation source 2 is an induction evaporation source, the evaporation vessel used is a tungsten crucible, the number of sub-evaporation sources is 27, the spacing between the sub-evaporation sources is 7 cm, and the electrode spacing is 13 cm;

[0118] Conductive metal evaporation source 3 is a conductive metal evaporation source, which is an induction evaporation source. The evaporation vessel used is a ceramic crucible. The number of sub-evaporation sources is 27, the spacing between the sub-evaporation sources is 7 cm, and the electrode spacing is 13 cm.

[0119] A preparation process of a pre-lithium structure comprises the following steps:

[0120] Step (S1), starting the equipment for preparing the pre-lithium structure, the unwinding device 8 releases the substrate, and the substrate is transmitted through the front main roller 5, the transfer roller 6, and the rear main roller 7;

[0121] Step (S2), the BMB preprocessor 1 generates plasma, the plasma bombards the surface of the substrate, and deposits a first protective layer on the surface of the substrate, wherein the output power of each BMB tube core of the BMB preprocessor 1 is 100W, the corresponding ionized gas is nitrogen, the ventilation flow rate of the corresponding ionized gas for each BMB tube core is 100sccm, and the thickness of the commercial lithium foil coated on the surface of the BMB tube core is 200μm;

[0122] Step (S3), the metal lithium evaporation source 2 evaporates the metal lithium into gaseous metal lithium, and the gaseous metal lithium is deposited on the surface of the first protective layer on the substrate to form a lithium supplement layer, wherein the crucible heating temperature used by the metal lithium evaporation source 2 is controlled at 500° C., the induction frequency is controlled at 20000 Hz, and the evaporation rate is controlled according to online eddy current electricity;

[0123] Step (S4), the conductive metal evaporation source 3 evaporates the conductive material into a gaseous state, and the gaseous conductive material is deposited on the surface of the lithium replenishing layer on the substrate to form an electronic conductive layer, wherein the crucible heating temperature used by the conductive metal evaporation source is controlled at 1500° C., the induction frequency is controlled at 120000 Hz, and the evaporation rate is controlled according to online eddy current electricity; and

[0124] In step (S5), the BMB post-processor 4 generates plasma, the plasma bombards the surface of the substrate, and a second protective layer is deposited on the surface of the electronic conductive layer to obtain the pre-lithium structure, wherein the output power of each BMB tube core of the BMB post-processor 4 is 400W, the corresponding ionized gas type is nitrogen, the ventilation flow rate of the ionized gas corresponding to each BMB tube core is 80sccm, and the thickness of the commercial lithium foil coated on the surface of the BMB tube core is 200μm; the pre-lithium structure is wound by a winding device 9.

[0125] Embodiment 2:

[0126] The equipment for preparing the pre-lithium structure in this embodiment is basically the same as that in Embodiment 1, except that the materials and parameters of some components in the equipment for preparing the pre-lithium structure are different, specifically:

[0127] The number of BMB tube cores in the BMB pre-processor 1 is 20 groups, and the number of BMB tube cores in the BMB post-processor 4 is 20 groups; the surface of each BMB tube core of the BMB pre-processor 1 and the BMB post-processor 4 is coated with a commercial lithium foil with a thickness of 50 μm;

[0128] The metal lithium evaporation source 2 is an induction evaporation source, the evaporation vessel used is a molybdenum crucible, the number of sub-evaporation sources is 27, the spacing between the sub-evaporation sources is 7 cm, and the electrode spacing is 13 cm;

[0129] The conductive metal evaporation source is a barrier evaporation source, the evaporation vessel used is a quaternary evaporation boat, the number of sub-evaporation sources is 27, the spacing between the sub-evaporation sources is 7 cm, and the electrode spacing is 13 cm.

[0130] The steps of the preparation process of the pre-lithium structure in this embodiment are basically the same as those in the first embodiment, and the only difference is that the process parameters in the preparation process are different, specifically:

[0131] In step (S2), the output power of each BMB tube core of the BMB preprocessor 1 is 500W, the corresponding ionized gas is carbon dioxide gas, the ventilation flow rate of the corresponding ionized gas of each BMB tube core is 20sccm, and the thickness of the commercial lithium foil coated on the surface of the BMB tube core is 50μm.

[0132] In step (S3), the crucible heating temperature used by the metal lithium evaporation source 2 is controlled at 300° C., the induction frequency is controlled at 10000 Hz, and the evaporation rate is controlled based on online eddy current electricity.

[0133] In step (S4), the heating power of the evaporation boat used by the conductive metal evaporation source is controlled at 9 kW, the wire feeding speed is 700 mm / min, and the evaporation rate is controlled based on online eddy current electricity.

[0134] In step (S4), the output power of each BMB tube core of the BMB post-processor 4 is 200W, the corresponding ionized gas is carbon dioxide gas, the ventilation flow rate of each BMB tube core corresponding to the ionized gas is 30sccm, and the thickness of the commercial lithium foil coated on the surface of the BMB tube core is 50μm.

[0135] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure, rather than to limit them; although the present disclosure has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present disclosure, and they should all be included in the scope of the claims and specification of the present disclosure. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present disclosure is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A device for preparing a pre-lithium structure, characterized in that: It includes a BMB (Bombard, tubular Hall ion source) pre-processor, a metal lithium evaporation source, a conductive metal evaporation source, a front main roller shaft, a transfer roller shaft and a rear main roller shaft, wherein the front main roller shaft, the transfer roller shaft and the rear main roller shaft are arranged in sequence; The BMB pre-processor is located on the left side of the front main roller shaft and is used to form a first protective layer; The metal lithium evaporation source is located below the front main roller shaft and is used to form a pre-lithium layer on the surface of the first protective layer; The conductive metal evaporation source is located below the rear main roller shaft and is used to form an electronic conductive layer on the surface of the pre-lithium layer.

2. The device for preparing a pre-lithium structure according to claim 1, characterized in that: The equipment for preparing the pre-lithium structure also includes a BMB post-processor, which is located on the right side of the rear main roller and is used to form a second protective layer on the surface of the electronic conductive layer.

3. The device for preparing a pre-lithium structure according to claim 2, characterized in that: The equipment for preparing the pre-lithium structure also includes an unwinding device and a winding device, wherein the unwinding device is arranged in front of the BMB pre-processor and is used to release the substrate; the winding device is arranged behind the BMB post-processor and is used to wind the pre-lithium structure; And / or; a first flattening roller is provided between the unwinding device and the BMB pre-processor; and / or a second flattening roller is provided between the BMB pre-processor and the front main roller; and / or a third flattening roller is provided between the front main roller and the transfer roller; and / or a fourth flattening roller is provided between the transfer roller and the rear main roller; and / or a fifth flattening roller is provided between the rear main roller and the BMB post-processor; and / or a sixth flattening roller is provided between the BMB post-processor and the winding device.

4. The device for preparing a pre-lithium structure according to any one of claims 1 to 3, characterized in that: The number of BMB dies of the BMB pre-processor is 20-40 groups, and / or the number of BMB dies of the BMB post-processor is 10-20 groups; and / or, the surface of each BMB tube core of the BMB pre-processor is coated with lithium foil, and / or the surface of each BMB tube core of the BMB post-processor is coated with lithium foil; And / or, the metal lithium evaporation source is an induction evaporation source; And / or, the conductive metal evaporation source is an induction evaporation source or a barrier evaporation source.

5. A process for preparing a pre-lithium structure, characterized in that: The following steps are involved: Providing and starting the apparatus for preparing a pre-lithium structure according to any one of claims 1 to 4, placing a substrate at the BMB preprocessor, and transmitting the substrate through the front main roller, the transfer roller, and the rear main roller; The BMB preprocessor generates plasma, the plasma bombards the surface of the substrate, and deposits a first protective layer on the surface of the substrate; The metal lithium evaporation source evaporates the metal lithium into gaseous metal lithium, and the gaseous metal lithium is deposited on the surface of the first protective layer to form a lithium supplement layer; as well as The conductive metal evaporation source evaporates the conductive metal material into a gaseous state, and the gaseous conductive metal material is deposited on the surface of the lithium replenishing layer to form an electronic conductive layer.

6. The preparation process of the pre-lithium structure according to claim 5, characterized in that: After the electron conductive layer is formed, the method further includes the following steps: a BMB post-processor generates plasma, the plasma bombards the surface of the substrate, and a second protective layer is deposited on the surface of the electron conductive layer.

7. The process for preparing the pre-lithium structure according to claim 5 or 6, characterized in that: The output power of each BMB die of the BMB pre-processor is 100-500W, and / or the output power of each BMB die of the BMB post-processor is 200-400W; and / or, the ionized gas corresponding to the BMB pre-processor is carbon dioxide, nitrogen, or a mixture of carbon dioxide and nitrogen, and / or the ionized gas corresponding to the BMB post-processor is carbon dioxide, nitrogen, or a mixture of carbon dioxide and nitrogen; And / or, the ventilation flow rate of the ionized gas corresponding to each BMB tube core of the BMB pre-processor is 20-100 sccm, and / or the ventilation flow rate of the ionized gas corresponding to each BMB tube core of the BMB post-processor is 30-80 sccm.

8. The process for preparing the pre-lithium structure according to claim 5 or 6, characterized in that: The crucible heating temperature of the metal lithium evaporation source is controlled at 300-500° C., the induction frequency is controlled at 10000-20000 Hz, and the evaporation rate is controlled based on online eddy current electricity; And / or, the conductive metal evaporation source is an induction evaporation source, the crucible heating temperature is controlled at 1300-1500°C, the induction frequency is controlled at 80000-120000Hz, and the evaporation rate is controlled by online eddy current electricity; or, the conductive metal evaporation source is a resistance evaporation source, the evaporation boat heating power is controlled at 7-9kW, the wire feeding speed is 200-700mm / min, and the evaporation rate is controlled by online eddy current electricity.

9. A pre-lithium structure, characterized in that: The pre-lithium structure is obtained by using the preparation process of the pre-lithium structure as described in any one of claims 5 to 8.

10. A lithium ion battery, comprising a positive electrode, a negative electrode and a separator, wherein the separator is arranged between the positive electrode and the negative electrode, characterized in that: The lithium-ion battery comprises the pre-lithium structure as claimed in claim 9.

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