Lithium supplementing method and lithium supplementing device for all-solid-state battery and application

Abstract

The invention relates to the technical field of all-solid-state lithium battery manufacturing, in particular to a lithium supplementing method and a lithium supplementing device for an all-solid-state battery and application. The lithium supplementing method for the all-solid-state battery comprises the following steps: (a) providing a solid-state electrolyte membrane, and transferring a lithium supplementing material to the surface of one side of the solid-state electrolyte membrane to form a complex in which a lithium supplementing layer is tightly attached to the solid-state electrolyte membrane; and (b) transferring the composite body to the surface of a negative pole piece, so that the lithium supplementing layer is clamped between the negative pole piece and the solid electrolyte membrane to form a composite structure in which the negative pole piece, the lithium supplementing layer and the solid electrolyte membrane are stacked in sequence. According to the lithium supplementing method for the all-solid-state battery, through a two-time continuous transfer printing process, the problems of edge burrs and sharp protrusions generated in the direct lithium strip transfer printing process are solved, the risk of short circuit in the battery is reduced, and the safety of the battery manufacturing process and recycling is improved.

Description

Technical Field

[0001] This invention relates to the field of all-solid-state lithium battery manufacturing technology, and more specifically, to an all-solid-state battery lithium replenishment method, lithium replenishment device, and application. Background Technology

[0002] All-solid-state batteries experience significant irreversible loss of active lithium during the initial charge and discharge cycle, requiring lithium replenishment for compensation. Direct transfer of lithium strips to the negative electrode poses significant safety risks; the metal burrs generated during direct transfer can easily induce lithium dendrite growth, causing battery short circuits and severely hindering large-scale application. Direct lithium powder replenishment to the negative electrode also carries significant safety risks, as coating the negative electrode surface with both lithium powder and adhesive can obstruct and unevenly distribute lithium ions, increasing the risk of localized overcharging and over-discharging.

[0003] Therefore, this invention is proposed. Summary of the Invention

[0004] This invention addresses the safety risks and high interface impedance issues of existing solid-state battery lithium replenishment technologies by proposing a method, device, and application for all-solid-state battery lithium replenishment. This method eliminates burrs and sharp protrusions during the lithium strip replenishment process, reduces battery short-circuit rate, improves safety, reduces the material impedance between the lithium powder replenishment layer and the negative electrode, and improves lithium-ion transport.

[0005] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted: A method for replenishing lithium in an all-solid-state battery includes the following steps: (a) providing a solid electrolyte membrane and transferring a lithium replenishing material onto one side surface of the solid electrolyte membrane to form a composite in which the lithium replenishing layer and the solid electrolyte membrane are tightly bonded; (b) transferring the composite onto the surface of a negative electrode sheet, so that the lithium replenishing layer is sandwiched between the negative electrode sheet and the solid electrolyte membrane to form a composite structure in which the negative electrode sheet, the lithium replenishing layer and the solid electrolyte membrane are stacked in sequence.

[0006] The described all-solid-state battery lithium replenishment method eliminates edge burrs and sharp protrusions generated during direct lithium strip transfer through a two-step continuous transfer process, reducing the risk of internal short circuits and improving the safety of battery manufacturing and cycling. It avoids the lithium-ion transport obstruction problem caused by the introduction of adhesives in traditional lithium powder replenishment processes, forming a low-impedance lithium-ion transport interface. With the help of the solid electrolyte membrane's encapsulation and protection of the lithium layer, it not only reduces the environmental exposure area of ​​lithium materials by more than 90%, eliminating the risk of thermal runaway caused by lithium reacting with air, but also improves the initial coulombic efficiency to over 92% and increases the battery's cycle life by more than 30%, achieving synergistic optimization of safety, interface compatibility, and electrochemical performance.

[0007] A lithium replenishment device for implementing the aforementioned all-solid-state battery lithium replenishment method includes: a first transfer unit for transferring lithium replenishment material onto a solid electrolyte membrane, the first transfer unit including a first roller press and a second roller press arranged opposite to each other; a second transfer unit located downstream of the first transfer unit for transferring a solid electrolyte composite membrane with a lithium replenishment layer onto a negative electrode sheet, the second transfer unit including a third roller press and a fourth roller press arranged opposite to each other; an unwinding mechanism for conveying the solid electrolyte membrane, the lithium replenishment material, and the negative electrode sheet respectively; and a winding mechanism for winding up the transferred composite structure and the waste base tape.

[0008] The aforementioned all-solid-state battery lithium replenishment device, by setting up a first transfer unit and a second transfer unit, constructs a continuous two-stage transfer production line, realizing precise and efficient transfer from lithium replenishment material to solid electrolyte membrane and then to negative electrode sheet. This avoids the problems of uneven dispersion and agglomeration in traditional lithium powder spraying processes, as well as process failures such as roller sticking and strip breakage during the direct pressing of lithium strips. By applying differentiated roller pressure in the first and second transfer units, the device ensures that the lithium replenishment layer maintains its integrity and uniform thickness throughout the transfer process, and forms a seamless bond with the interface of adjacent layers. This significantly reduces safety risks in the production process, significantly improves product consistency and yield, and provides a reliable equipment solution for the large-scale, low-cost, and high-quality manufacturing of all-solid-state batteries.

[0009] A method for preparing a lithium-replenished composite anode for all-solid-state batteries, comprising the aforementioned lithium-replenishing method for all-solid-state batteries.

[0010] A solid-state battery, comprising a lithium-filled composite anode prepared by the method for preparing a lithium-filled composite anode for a solid-state battery.

[0011] An electrical device comprising the aforementioned all-solid-state battery.

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows: The all-solid-state battery lithium replenishment method provided by this invention eliminates the edge burrs and sharp protrusions generated during the direct lithium strip transfer process through a two-step continuous transfer process, minimizing the risk of internal short circuits and improving the safety of battery manufacturing and cycling. It avoids the lithium-ion transport obstruction problem caused by the introduction of adhesives in traditional lithium powder replenishment processes, forming a low-impedance lithium-ion transport interface. With the help of the solid electrolyte membrane's encapsulation and protection of the lithium layer, it not only reduces the environmental exposure area of ​​lithium materials by more than 90%, eliminating the risk of thermal runaway caused by lithium reacting with air, but also improves the initial coulombic efficiency to over 92% and increases the battery's cycle life by more than 30%, achieving synergistic optimization of safety, interface compatibility, and electrochemical performance.

[0013] The lithium replenishment device for all-solid-state batteries provided by this invention constructs a continuous two-stage transfer production line by setting up a first transfer unit and a second transfer unit. This achieves precise and efficient transfer from the lithium replenishment material to the solid electrolyte membrane and then to the negative electrode sheet, completely avoiding the problems of uneven dispersion and agglomeration in traditional lithium powder spraying processes, as well as process failures such as roller sticking and strip breakage during the direct pressing of lithium strips. By applying differentiated roller pressure in the first and second transfer units, the device ensures that the lithium replenishment layer maintains its morphological integrity and uniform thickness throughout the transfer process, and forms a seamless bond with the interface of adjacent layers. This significantly reduces safety risks in the production process, significantly improves product consistency and yield, and provides a reliable equipment solution for the large-scale, low-cost, and high-quality manufacturing of all-solid-state batteries. Attached Figure Description

[0014] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0015] Figure 1 A process flow diagram of the lithium replenishment method for all-solid-state batteries provided in an embodiment of the present invention.

[0016] Figure label: 1-Lithium metal strip loaded on baseband, 2-Solid electrolyte membrane loaded on baseband, 3-Lithium strip baseband, 4-Composite loaded on baseband, 5-Negative electrode sheet, 6-Composite structure loaded on baseband, 7-Electrolyte membrane baseband, 10-First roller press, 20-Second roller press, 30-Third roller press, 40-Fourth roller press. Detailed Implementation

[0017] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and specific embodiments. However, those skilled in the art will understand that the embodiments described below are some embodiments of the present invention, but not all embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0018] One aspect of the present invention relates to a method for replenishing lithium in an all-solid-state battery, comprising the following steps: (a) A solid electrolyte membrane is provided, and a lithium replenishing material is transferred onto one side surface of the solid electrolyte membrane to form a composite in which the lithium replenishing layer and the solid electrolyte membrane are closely bonded. (b) The composite is transferred to the surface of the negative electrode 5, so that the lithium replenishment layer is sandwiched between the negative electrode 5 and the solid electrolyte membrane, forming a composite structure in which the negative electrode 5, the lithium replenishment layer and the solid electrolyte membrane are stacked in sequence.

[0019] Solid-state batteries experience irreversible loss of active lithium during the initial charge-discharge cycle (e.g., SEI film formation on the negative electrode, phase transition on the positive electrode), requiring lithium replenishment techniques to compensate. Because solid-state batteries are constrained during charge-discharge, there is no residue after lithium replenishment at the negative electrode; the space created by the replenishment disappears under the constraint force. Therefore, negative electrode lithium replenishment has a significant advantage over positive electrode lithium replenishment techniques. The following are the main negative electrode lithium replenishment techniques: 1. Direct lithium strip transfer technology: This technology uses mechanical rolling to directly bond thin lithium strips to the surface of the negative electrode. This technology relies on the ductility of lithium metal to achieve interfacial bonding, but the high viscosity of lithium can easily lead to edge breakage and the formation of lithium metal burrs during the transfer process. It is also prone to process problems such as roller sticking and strip breakage, as well as safety issues such as micro-short circuits and lithium dendrites.

[0020] 2. Direct lithium powder replenishment technology: Lithium powder is directly attached to the negative electrode through spraying or slurry coating. Due to the large specific surface area and poor air stability of lithium powder, there are problems such as uneven dispersion and severe agglomeration. In addition, voids are easily formed at the interface with the negative electrode, resulting in low lithium replenishment efficiency.

[0021] Existing technologies cannot simultaneously meet the three-dimensional requirements of all-solid-state batteries for "safety, lithium replenishment efficiency, and process stability".

[0022] The described all-solid-state battery lithium replenishment method eliminates edge burrs and sharp protrusions generated during direct lithium strip transfer through a two-step continuous transfer process, minimizing the risk of internal short circuits and improving the safety of battery manufacturing and cycling. It avoids the lithium-ion transport obstruction caused by the introduction of adhesives in traditional lithium powder replenishment processes, forming a low-impedance lithium-ion transport interface. Furthermore, the solid electrolyte membrane's encapsulation and protection of the lithium layer reduces the environmental exposure area of ​​the lithium material by more than 90%, eliminating the risk of thermal runaway caused by lithium reacting with air. This improves the initial coulombic efficiency to over 92% and increases the battery's cycle life by more than 30%, achieving synergistic optimization of safety, interface compatibility, and electrochemical performance.

[0023] The lithium replenishment method for all-solid-state batteries described herein employs a two-step transfer process, providing a suitable method for replenishing lithium in all-solid-state batteries. The core of the two-step transfer process is that the lithium strip, the lithium replenishment material, is transferred onto the solid electrolyte in the first step, and then the solid electrolyte containing the lithium replenishment material is transferred onto the negative electrode 5 in the second step.

[0024] Lithium metal readily reacts with O2 and H2O in the air to form Li2O and LiOH. This not only causes the lithium metal to lose its activity, failing to achieve the desired lithium replenishment effect, but also releases heat (enthalpy change ΔH = -598 kJ / mol), causing localized temperature rises (up to 60°C or higher), increasing the risk of thermal runaway and easily leading to lithium powder combustion and safety malfunction. This requires eliminating physical hazards to achieve a significant safety leap in the lithium replenishment process.

[0025] When lithium materials (lithium strips) are rolled up, they are largely isolated from air, ensuring the safety of the lithium metal. After being loaded onto the surface of a solid electrolyte, the lithium material forms an electrolyte-lithium composite structure, reducing the exposed area of ​​the lithium material by more than 90% (only a small amount is exposed at the edges, with an exposed area ≤ 5mm). 2 / piece). After the second transfer, the lithium layer is completely sandwiched between the electrolyte and the negative electrode, forming a "sealed structure". The barrier effect of the electrolyte prevents the lithium from coming into contact with the air.

[0026] After the lithium replenishment layer is transferred, it forms a tight interface with the negative electrode, which can quickly carry out lithium alloying of graphite. The lithium metal replenishment layer has high purity and no other impurities, which can effectively avoid the generation of side reactions and avoid reaction residues. The space of the replenishment layer can disappear under the action of the restraint force, and the negative electrode and electrolyte can directly contact each other, effectively reducing the interface resistance.

[0027] Lithium replenishment technology effectively compensates for the loss of active lithium during cycling, increasing the cycle life of all-solid-state batteries by more than 30%. All-solid-state batteries prepared using this invention retain over 85% capacity after 1000 cycles at 1C rate. Through precise lithium replenishment, the battery's initial coulombic efficiency is increased from less than 85% to over 92%, significantly improving the battery's energy density, which is expected to be 15%-20% higher than unreplenished batteries.

[0028] This method is highly compatible with existing solid-state battery manufacturing processes (especially transfer technology) and requires no large-scale modification of production lines. The lithium replenishment process can be carried out under inert gas protection, avoiding the instability of lithium materials in air. By controlling the thickness and distribution of the lithium replenishment layer, dendrite problems that may be caused by excessive local lithium deposition are avoided, thus improving battery safety.

[0029] Furthermore, the thickness of the solid electrolyte membrane is 10~50μm, including but not limited to a point value or a range between any two of 10μm, 15μm, 20μm, 25μm, 30μm, 35μm, 40μm, 45μm, or 50μm. This thickness range allows the electrolyte to possess sufficient mechanical strength to encapsulate the lithium layer, control the edge exposure area, and provide a suitable ion conduction path, enabling it to remain in direct contact with the negative electrode even after the lithium layer is consumed.

[0030] Furthermore, the solid electrolyte membrane includes at least one of a sulfide electrolyte membrane, an oxide electrolyte membrane, or a polymer-based composite solid electrolyte membrane.

[0031] Furthermore, the sulfide electrolyte membrane includes, but is not limited to: Li8P2S9 and / or Li 10 GeP2S 12 .

[0032] Furthermore, the oxide electrolyte membrane includes, but is not limited to, LLZO.

[0033] Furthermore, the polymer-based composite solid electrolyte membrane comprises a polymer matrix and lithium salt and inorganic filler dispersed in the polymer matrix.

[0034] Furthermore, the polymer matrix includes, but is not limited to, polyethylene oxide and / or polyvinylidene fluoride.

[0035] Furthermore, the lithium salt includes, but is not limited to, at least one of: lithium bis(trifluoromethanesulfonyl)imide, lithium bis(fluorosulfonyl)imide, lithium bis(oxalatoborate) or lithium hexafluorophosphate.

[0036] Furthermore, the inorganic filler includes, but is not limited to, silica and / or alumina.

[0037] Furthermore, the lithium replenishment material includes lithium metal.

[0038] Furthermore, the lithium replenishment material is transferred to one side surface of the solid electrolyte membrane in the form of a lithium metal strip.

[0039] Furthermore, the thickness of the lithium metal strip is 1~5μm, including but not limited to a single value or a range between any two of 1μm, 2μm, 3μm, 4μm, or 5μm. This thickness precisely matches the lithium replenishment requirement: the lower limit ensures compensation for the initial irreversible capacity loss, the upper limit avoids the risk of dendrite formation due to excessive lithium replenishment, and the thin-layer design allows the space to close under restraint force after lithium consumption. The lithium metal strip is loaded on a polymer material substrate, which does not participate in subsequent processes and is not required to perform these processes.

[0040] Furthermore, the width of the lithium metal strip is 50~220mm, including but not limited to any one of 50mm, 60mm, 70mm, 80mm, 90mm, 100mm, 110mm, 120mm, 130mm, 140mm, 150mm, 160mm, 170mm, 180mm, 190mm, 200mm, 210mm, or 220mm, or a range between any two. This width covers mainstream battery electrode specifications, is compatible with existing roll-to-roll production lines, ensures uniform pressure distribution during large-format transfer printing, and avoids defects such as insufficient edge compaction.

[0041] Further, in step (a), the transfer temperature of the lithium replenishment material is 23~27°C, including but not limited to any one of 23°C, 24°C, 25°C, 26°C, or 27°C, or a range between any two. This temperature range allows the lithium metal to maintain suitable plasticity, enabling it to fill the micropores on the electrolyte surface to form a tight contact, while avoiding high temperatures that could lead to increased lithium oxidation activity or softening and deformation of the electrolyte film, thus ensuring the quality of the interface bonding.

[0042] Further, in step (a), the transfer pressure of the lithium replenishment material is 1~8T, including but not limited to any one of 1T, 2T, 3T, 4T, 5T, 6T, 7T or 8T, or any range between two of them. This pressure range is sufficient to peel the lithium strip from the substrate and transfer it smoothly to the electrolyte surface, while avoiding excessive pressure that may cause edge burrs or damage to the electrolyte structure, thus achieving a defect-free first transfer.

[0043] Further, in step (a), the transfer speed of the lithium replenishment material is 5~50m / min, including but not limited to any one of 5m / min, 10m / min, 15m / min, 20m / min, 25m / min, 30m / min, 35m / min, 40m / min, 45m / min or 50m / min or any range between two.

[0044] Limiting the conveyor belt speed for two transfers balances production efficiency and interface bonding quality, ensuring that the material has sufficient time to form a reliable bond in the roller pressing zone, while matching the speeds of the two processes to achieve continuous production.

[0045] Furthermore, the width of the negative electrode sheet 5 is 50~220mm, including but not limited to any one of 50mm, 60mm, 70mm, 80mm, 90mm, 100mm, 110mm, 120mm, 130mm, 140mm, 150mm, 160mm, 170mm, 180mm, 190mm, 200mm, 210mm, or 220mm, or a range between any two. This perfectly matches the width of the lithium strip, achieving 100% coverage of the negative electrode active area by the lithium replenishment region, avoiding under-replenishment at the edges or waste of lithium material.

[0046] Furthermore, the negative electrode 5 includes any one of the following: graphite negative electrode 5, silicon-based negative electrode 5, lithium metal negative electrode 5, or composite negative electrode 5.

[0047] Further, in step (b), the transfer temperature of the composite is 23~27℃, including but not limited to a point value of any one of 23℃, 24℃, 25℃, 26℃ or 27℃, or a range between any two. Room temperature conditions allow the lithium layer and the anode material to undergo a moderate pre-alloying reaction to enhance interfacial bonding, while avoiding excessive lithium diffusion or damage to the anode structure due to excessively high temperatures, thus ensuring interfacial stability.

[0048] Further, in step (b), the transfer pressure of the composite is 2~30T, including but not limited to any one of 2T, 3T, 4T, 5T, 6T, 7T, 8T, 9T, 10T, 15T, 20T, 25T, or 30T, or a range between any two. A transfer pressure higher than the first one compacts the composite onto the negative electrode surface, allowing the lithium layer to form an atomically close contact with the negative electrode to reduce interfacial impedance, while avoiding excessive compaction that could damage the electrolyte membrane.

[0049] Further, in step (b), the transfer speed of the composite is 5~50m / min, including but not limited to any one of 5m / min, 10m / min, 15m / min, 20m / min, 25m / min, 30m / min, 35m / min, 40m / min, 45m / min or 50m / min or any range between two.

[0050] Another aspect of the present invention relates to a lithium replenishment apparatus for implementing the aforementioned all-solid-state battery lithium replenishment method, comprising: First transfer unit: used to transfer lithium replenishment material onto solid electrolyte membrane, the first transfer unit includes a first roller press 10 and a second roller press 20 arranged opposite to each other; The second transfer unit is located downstream of the first transfer unit and is used to transfer the solid electrolyte composite film with the lithium replenishment layer onto the negative electrode sheet 5. The second transfer unit includes a third roller press 30 and a fourth roller press 40 arranged opposite to each other. Unwinding mechanism: used to separately convey solid electrolyte membrane, lithium replenishment material and negative electrode sheet 5; Rewinding mechanism: Used to rewind the composite structure and waste base tape after transfer printing.

[0051] The aforementioned all-solid-state battery lithium replenishment device, by setting up a first transfer unit and a second transfer unit, constructs a continuous two-stage transfer production line, realizing precise and efficient transfer from the lithium replenishment material to the solid electrolyte membrane and then to the negative electrode sheet 5. This completely avoids the problems of uneven dispersion and agglomeration in the traditional lithium powder spraying process, as well as process failures such as roller sticking and strip breakage during the direct pressing of lithium strips. By applying differentiated roller pressure in the first and second transfer units, the device ensures that the lithium replenishment layer maintains its integrity and uniform thickness throughout the transfer process, and forms a seamless bond with the interface of adjacent layers. This significantly reduces safety risks in the production process, significantly improves product consistency and yield, and provides a reliable equipment solution for the large-scale, low-cost, and high-quality manufacturing of all-solid-state batteries.

[0052] Another aspect of the present invention relates to a method for preparing a lithium-replenishing composite negative electrode for all-solid-state batteries, including the aforementioned lithium-replenishing method for all-solid-state batteries.

[0053] Another aspect of the present invention relates to an all-solid-state battery, comprising a lithium-filled composite anode prepared by the method for preparing the all-solid-state battery lithium-filled composite anode.

[0054] Another aspect of the invention relates to an electrical device comprising the aforementioned all-solid-state battery.

[0055] The embodiments of the present invention will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of the invention. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer are followed. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0056] Example 1 The lithium replenishment method for all-solid-state batteries provided in this embodiment, such as Figure 1 As shown, it includes the following steps: (1) Lithium metal strip transferred to solid electrolyte membrane The lithium metal strip and the solid electrolyte membrane are supplied separately by the unwinding mechanism. The lithium metal strip 1 and the solid electrolyte membrane 2 loaded on the base strip are conveyed to the first transfer unit at the same belt speed. In the first transfer unit, the lithium metal strip and the solid electrolyte membrane are tightly bonded under pressure. When the bonded composite layer leaves the rolling zone, the lithium metal strip is peeled off from the lithium strip base strip 3 and transferred to the surface of the solid electrolyte membrane, forming a composite with the lithium supplement layer and the solid electrolyte membrane tightly bonded, resulting in the composite 4 loaded on the base strip. The lithium strip base strip 3 is then recycled by the waste base strip take-up roller. The lithium metal strip and the solid electrolyte membrane have the same conveying speed of 20m / min, the same width of 160mm, the transfer temperature of 25℃, the transfer pressure of 2T, the thickness of the solid electrolyte membrane of 30μm, and the thickness of the lithium metal strip of 1.5μm.

[0057] After rolling, the lithium metal strip is transferred to the surface of the electrolyte membrane because the peeling force of the lithium metal strip to the base strip is less than that of the solid electrolyte membrane to the base strip. The lithium metal residual rate was measured, and the results are shown in Table 1.

[0058] (2) Solid electrolyte membrane is transferred to the surface of negative electrode 5. The composite material carried on the baseband and the negative electrode 5 carried on the baseband are conveyed to the second transfer unit at the same conveyor speed. In the second transfer unit, the composite material and the negative electrode 5 are tightly bonded under pressure. When the bonded multilayer structure leaves the rolling zone, the lithium replenishment layer and the solid electrolyte membrane are peeled off from the baseband as a whole and transferred to the surface of the negative electrode 5, forming a composite structure in which the negative electrode 5, the lithium replenishment layer and the solid electrolyte membrane are stacked in sequence, resulting in a composite structure 6 loaded on the baseband. The electrolyte membrane baseband 7 is recycled by the waste baseband take-up roller, and the final composite structure is collected by the composite structure take-up roller. The conveyor speed of the composite and the negative electrode 5 is the same, 20m / min. The width of the negative electrode 5 is 160mm. The transfer temperature is 25℃ and the transfer pressure is 4T.

[0059] After rolling, due to the different peeling forces of the two materials on the baseband (electrolyte membrane < negative electrode 5), lithium metal and electrolyte are transferred together to the surface of negative electrode 5.

[0060] Example 2 The only difference between this embodiment and Embodiment 1 is that the transfer pressure of the lithium metal strip to the solid electrolyte membrane is 1T. Specifically, the following steps are included: (1) Transfer of lithium metal strip to solid electrolyte membrane: Lithium metal strip and solid electrolyte membrane are supplied separately through the unwinding mechanism. The lithium metal strip 1 loaded on the base strip and the solid electrolyte membrane 2 loaded on the base strip are conveyed to the first transfer unit at the same belt speed. In the first transfer unit, the lithium metal strip and the solid electrolyte membrane are tightly bonded under pressure. When the bonded composite layer leaves the rolling area, the lithium metal strip is peeled off from the lithium strip base strip 3 and transferred to the surface of the solid electrolyte membrane to form a composite with the lithium supplement layer and the solid electrolyte membrane tightly bonded, resulting in a composite 4 loaded on the base strip. The lithium strip base strip 3 is then recycled by the waste base strip take-up roller. (2) Solid electrolyte membrane is transferred to the surface of negative electrode 5: The composite material carried on the baseband and the negative electrode 5 carried on the baseband are transported to the second transfer unit at the same belt speed; in the second transfer unit, the composite material and the negative electrode 5 are tightly bonded under pressure; when the bonded multilayer structure leaves the rolling area, the lithium replenishment layer and the solid electrolyte membrane are peeled off from the baseband as a whole and transferred to the surface of the negative electrode 5, forming a composite structure in which the negative electrode 5, the lithium replenishment layer and the solid electrolyte membrane are stacked in sequence, and a composite structure 6 loaded on the baseband is obtained; the electrolyte membrane baseband 7 is recycled by the waste baseband take-up roller, and the final composite structure is collected by the composite structure take-up roller.

[0061] Example 3 The only difference between this embodiment and Embodiment 1 is that the transfer pressure of the lithium metal strip to the solid electrolyte membrane is 4T. Specifically, the following steps are included: (1) Transfer of lithium metal strip to solid electrolyte membrane: Lithium metal strip and solid electrolyte membrane are supplied separately through the unwinding mechanism. The lithium metal strip 1 loaded on the base strip and the solid electrolyte membrane 2 loaded on the base strip are conveyed to the first transfer unit at the same belt speed. In the first transfer unit, the lithium metal strip and the solid electrolyte membrane are tightly bonded under pressure. When the bonded composite layer leaves the rolling area, the lithium metal strip is peeled off from the lithium strip base strip 3 and transferred to the surface of the solid electrolyte membrane to form a composite with the lithium supplement layer and the solid electrolyte membrane tightly bonded, resulting in a composite 4 loaded on the base strip. The lithium strip base strip 3 is then recycled by the waste base strip take-up roller. (2) Solid electrolyte membrane is transferred to the surface of negative electrode 5: The composite material carried on the baseband and the negative electrode 5 carried on the baseband are transported to the second transfer unit at the same belt speed; in the second transfer unit, the composite material and the negative electrode 5 are tightly bonded under pressure; when the bonded multilayer structure leaves the rolling area, the lithium replenishment layer and the solid electrolyte membrane are peeled off from the baseband as a whole and transferred to the surface of the negative electrode 5, forming a composite structure in which the negative electrode 5, the lithium replenishment layer and the solid electrolyte membrane are stacked in sequence, and a composite structure 6 loaded on the baseband is obtained; the electrolyte membrane baseband 7 is recycled by the waste baseband take-up roller, and the final composite structure is collected by the composite structure take-up roller.

[0062] Example 4 The only difference between this embodiment and Embodiment 1 is that the transfer pressure of the solid electrolyte membrane to the surface of the negative electrode 5 is different, which is 8T. Specifically, it includes the following steps: (1) Transfer of lithium metal strip to solid electrolyte membrane: Lithium metal strip and solid electrolyte membrane are supplied separately through the unwinding mechanism. The lithium metal strip 1 loaded on the base strip and the solid electrolyte membrane 2 loaded on the base strip are conveyed to the first transfer unit at the same belt speed. In the first transfer unit, the lithium metal strip and the solid electrolyte membrane are tightly bonded under pressure. When the bonded composite layer leaves the rolling area, the lithium metal strip is peeled off from the lithium strip base strip 3 and transferred to the surface of the solid electrolyte membrane to form a composite with the lithium supplement layer and the solid electrolyte membrane tightly bonded, resulting in a composite 4 loaded on the base strip. The lithium strip base strip 3 is then recycled by the waste base strip take-up roller. (2) Solid electrolyte membrane is transferred to the surface of negative electrode 5: The composite material carried on the baseband and the negative electrode 5 carried on the baseband are transported to the second transfer unit at the same belt speed; in the second transfer unit, the composite material and the negative electrode 5 are tightly bonded under pressure; when the bonded multilayer structure leaves the rolling area, the lithium replenishment layer and the solid electrolyte membrane are peeled off from the baseband as a whole and transferred to the surface of the negative electrode 5, forming a composite structure in which the negative electrode 5, the lithium replenishment layer and the solid electrolyte membrane are stacked in sequence, and a composite structure 6 loaded on the baseband is obtained; the electrolyte membrane baseband 7 is recycled by the waste baseband take-up roller, and the final composite structure is collected by the composite structure take-up roller.

[0063] Example 5 The only difference between this embodiment and Embodiment 1 is that the transfer pressure of the solid electrolyte membrane to the surface of the negative electrode 5 is 2T, and the specific steps include: (1) Transfer of lithium metal strip to solid electrolyte membrane: Lithium metal strip and solid electrolyte membrane are supplied separately through the unwinding mechanism. The lithium metal strip 1 loaded on the base strip and the solid electrolyte membrane 2 loaded on the base strip are conveyed to the first transfer unit at the same belt speed. In the first transfer unit, the lithium metal strip and the solid electrolyte membrane are tightly bonded under pressure. When the bonded composite layer leaves the rolling area, the lithium metal strip is peeled off from the lithium strip base strip 3 and transferred to the surface of the solid electrolyte membrane to form a composite with the lithium supplement layer and the solid electrolyte membrane tightly bonded, resulting in a composite 4 loaded on the base strip. The lithium strip base strip 3 is then recycled by the waste base strip take-up roller. (2) Solid electrolyte membrane is transferred to the surface of negative electrode 5: The composite material carried on the baseband and the negative electrode 5 carried on the baseband are transported to the second transfer unit at the same belt speed; in the second transfer unit, the composite material and the negative electrode 5 are tightly bonded under pressure; when the bonded multilayer structure leaves the rolling area, the lithium replenishment layer and the solid electrolyte membrane are peeled off from the baseband as a whole and transferred to the surface of the negative electrode 5, forming a composite structure in which the negative electrode 5, the lithium replenishment layer and the solid electrolyte membrane are stacked in sequence, and a composite structure 6 loaded on the baseband is obtained; the electrolyte membrane baseband 7 is recycled by the waste baseband take-up roller, and the final composite structure is collected by the composite structure take-up roller.

[0064] Example 6 The only difference between this embodiment and Embodiment 1 is that the transfer pressure of the solid electrolyte membrane to the surface of the negative electrode 5 is different, which is 6T. Specifically, it includes the following steps: (1) Transfer of lithium metal strip to solid electrolyte membrane: Lithium metal strip and solid electrolyte membrane are supplied separately through the unwinding mechanism. The lithium metal strip 1 loaded on the base strip and the solid electrolyte membrane 2 loaded on the base strip are conveyed to the first transfer unit at the same belt speed. In the first transfer unit, the lithium metal strip and the solid electrolyte membrane are tightly bonded under pressure. When the bonded composite layer leaves the rolling area, the lithium metal strip is peeled off from the lithium strip base strip 3 and transferred to the surface of the solid electrolyte membrane to form a composite with the lithium supplement layer and the solid electrolyte membrane tightly bonded, resulting in a composite 4 loaded on the base strip. The lithium strip base strip 3 is then recycled by the waste base strip take-up roller. (2) Solid electrolyte membrane is transferred to the surface of negative electrode 5: The composite material carried on the baseband and the negative electrode 5 carried on the baseband are transported to the second transfer unit at the same belt speed; in the second transfer unit, the composite material and the negative electrode 5 are tightly bonded under pressure; when the bonded multilayer structure leaves the rolling area, the lithium replenishment layer and the solid electrolyte membrane are peeled off from the baseband as a whole and transferred to the surface of the negative electrode 5, forming a composite structure in which the negative electrode 5, the lithium replenishment layer and the solid electrolyte membrane are stacked in sequence, and a composite structure 6 loaded on the baseband is obtained; the electrolyte membrane baseband 7 is recycled by the waste baseband take-up roller, and the final composite structure is collected by the composite structure take-up roller.

[0065] Example 7 The only difference between this embodiment and Embodiment 1 is that the transfer pressure of the solid electrolyte membrane to the surface of the negative electrode 5 is 10T. Specifically, the following steps are included: (1) Transfer of lithium metal strip to solid electrolyte membrane: Lithium metal strip and solid electrolyte membrane are supplied separately through the unwinding mechanism. The lithium metal strip 1 loaded on the base strip and the solid electrolyte membrane 2 loaded on the base strip are conveyed to the first transfer unit at the same belt speed. In the first transfer unit, the lithium metal strip and the solid electrolyte membrane are tightly bonded under pressure. When the bonded composite layer leaves the rolling area, the lithium metal strip is peeled off from the lithium strip base strip 3 and transferred to the surface of the solid electrolyte membrane to form a composite with the lithium supplement layer and the solid electrolyte membrane tightly bonded, resulting in a composite 4 loaded on the base strip. The lithium strip base strip 3 is then recycled by the waste base strip take-up roller. (2) Solid electrolyte membrane is transferred to the surface of negative electrode 5: The composite material carried on the baseband and the negative electrode 5 carried on the baseband are transported to the second transfer unit at the same belt speed; in the second transfer unit, the composite material and the negative electrode 5 are tightly bonded under pressure; when the bonded multilayer structure leaves the rolling area, the lithium replenishment layer and the solid electrolyte membrane are peeled off from the baseband as a whole and transferred to the surface of the negative electrode 5, forming a composite structure in which the negative electrode 5, the lithium replenishment layer and the solid electrolyte membrane are stacked in sequence, and a composite structure 6 loaded on the baseband is obtained; the electrolyte membrane baseband 7 is recycled by the waste baseband take-up roller, and the final composite structure is collected by the composite structure take-up roller.

[0066] Example 8 The only difference between this embodiment and Embodiment 1 is that the lithium metal strip is transferred to the solid electrolyte membrane at the same speed of 10m / min, while the transfer pressure of the solid electrolyte membrane to the surface of the negative electrode 5 is different at 8T. Specifically, the following steps are included: (1) Transfer of lithium metal strip to solid electrolyte membrane: Lithium metal strip and solid electrolyte membrane are supplied separately through the unwinding mechanism. The lithium metal strip 1 loaded on the base strip and the solid electrolyte membrane 2 loaded on the base strip are conveyed to the first transfer unit at the same belt speed. In the first transfer unit, the lithium metal strip and the solid electrolyte membrane are tightly bonded under pressure. When the bonded composite layer leaves the rolling area, the lithium metal strip is peeled off from the lithium strip base strip 3 and transferred to the surface of the solid electrolyte membrane to form a composite with the lithium supplement layer and the solid electrolyte membrane tightly bonded, resulting in a composite 4 loaded on the base strip. The lithium strip base strip 3 is then recycled by the waste base strip take-up roller. (2) Solid electrolyte membrane is transferred to the surface of negative electrode 5: The composite material carried on the baseband and the negative electrode 5 carried on the baseband are transported to the second transfer unit at the same belt speed; in the second transfer unit, the composite material and the negative electrode 5 are tightly bonded under pressure; when the bonded multilayer structure leaves the rolling area, the lithium replenishment layer and the solid electrolyte membrane are peeled off from the baseband as a whole and transferred to the surface of the negative electrode 5, forming a composite structure in which the negative electrode 5, the lithium replenishment layer and the solid electrolyte membrane are stacked in sequence, and a composite structure 6 loaded on the baseband is obtained; the electrolyte membrane baseband 7 is recycled by the waste baseband take-up roller, and the final composite structure is collected by the composite structure take-up roller.

[0067] Example 9 The difference between this embodiment and Embodiment 1 is only that the lithium metal strip is transferred to the solid electrolyte membrane at the same speed of 5 m / min, while the transfer pressure of the solid electrolyte membrane to the surface of the negative electrode 5 is different at 8T. Specifically, the following steps are included: (1) Transfer of lithium metal strip to solid electrolyte membrane: Lithium metal strip and solid electrolyte membrane are supplied separately through the unwinding mechanism. The lithium metal strip 1 loaded on the base strip and the solid electrolyte membrane 2 loaded on the base strip are conveyed to the first transfer unit at the same belt speed. In the first transfer unit, the lithium metal strip and the solid electrolyte membrane are tightly bonded under pressure. When the bonded composite layer leaves the rolling area, the lithium metal strip is peeled off from the lithium strip base strip 3 and transferred to the surface of the solid electrolyte membrane to form a composite with the lithium supplement layer and the solid electrolyte membrane tightly bonded, resulting in a composite 4 loaded on the base strip. The lithium strip base strip 3 is then recycled by the waste base strip take-up roller. (2) Solid electrolyte membrane is transferred to the surface of negative electrode 5: The composite material carried on the baseband and the negative electrode 5 carried on the baseband are transported to the second transfer unit at the same belt speed; in the second transfer unit, the composite material and the negative electrode 5 are tightly bonded under pressure; when the bonded multilayer structure leaves the rolling area, the lithium replenishment layer and the solid electrolyte membrane are peeled off from the baseband as a whole and transferred to the surface of the negative electrode 5, forming a composite structure in which the negative electrode 5, the lithium replenishment layer and the solid electrolyte membrane are stacked in sequence, and a composite structure 6 loaded on the baseband is obtained; the electrolyte membrane baseband 7 is recycled by the waste baseband take-up roller, and the final composite structure is collected by the composite structure take-up roller.

[0068] Example 10 The only difference between this embodiment and Embodiment 1 is that the lithium metal strip is transferred to the solid electrolyte membrane at the same speed of 30m / min, while the transfer pressure of the solid electrolyte membrane to the surface of the negative electrode 5 is different at 8T. Specifically, the following steps are included: (1) Transfer of lithium metal strip to solid electrolyte membrane: Lithium metal strip and solid electrolyte membrane are supplied separately through the unwinding mechanism. The lithium metal strip 1 loaded on the base strip and the solid electrolyte membrane 2 loaded on the base strip are conveyed to the first transfer unit at the same belt speed. In the first transfer unit, the lithium metal strip and the solid electrolyte membrane are tightly bonded under pressure. When the bonded composite layer leaves the rolling area, the lithium metal strip is peeled off from the lithium strip base strip 3 and transferred to the surface of the solid electrolyte membrane to form a composite with the lithium supplement layer and the solid electrolyte membrane tightly bonded, resulting in a composite 4 loaded on the base strip. The lithium strip base strip 3 is then recycled by the waste base strip take-up roller. (2) Solid electrolyte membrane is transferred to the surface of negative electrode 5: The composite material carried on the baseband and the negative electrode 5 carried on the baseband are transported to the second transfer unit at the same belt speed; in the second transfer unit, the composite material and the negative electrode 5 are tightly bonded under pressure; when the bonded multilayer structure leaves the rolling area, the lithium replenishment layer and the solid electrolyte membrane are peeled off from the baseband as a whole and transferred to the surface of the negative electrode 5, forming a composite structure in which the negative electrode 5, the lithium replenishment layer and the solid electrolyte membrane are stacked in sequence, and a composite structure 6 loaded on the baseband is obtained; the electrolyte membrane baseband 7 is recycled by the waste baseband take-up roller, and the final composite structure is collected by the composite structure take-up roller.

[0069] Table 1

[0070] Example 11 The lithium replenishment device provided in this embodiment includes: First transfer unit: used to transfer lithium replenishment material onto solid electrolyte membrane, the first transfer unit includes a first roller press 10 and a second roller press 20 arranged opposite to each other; The second transfer unit is located downstream of the first transfer unit and is used to transfer the solid electrolyte composite film with the lithium replenishment layer onto the negative electrode sheet 5. The second transfer unit includes a third roller press 30 and a fourth roller press 40 arranged opposite to each other. Unwinding mechanism: used to separately convey solid electrolyte membrane, lithium replenishment material and negative electrode sheet 5; Rewinding mechanism: Used to rewind the composite structure and waste base tape after transfer printing.

[0071] This invention has the following advantages: 1. High safety in the lithium replenishment process: The lithium replenishment material (lithium strip) is in a rolled state, which eliminates most of the chance of contact with air and ensures the safety of lithium metal; after the lithium replenishment material is loaded on the surface of the solid electrolyte, it forms an "electrolyte-lithium" composite structure, reducing the exposed area of ​​lithium material by more than 90%; after the secondary transfer, the lithium layer is completely sandwiched between the electrolyte and the negative electrode, forming a sealed structure, and the barrier effect of the electrolyte prevents lithium from contacting air.

[0072] 2. Low interface impedance: After the lithium replenishment layer is transferred, it forms a tight interface contact with the negative electrode, which can quickly carry out lithium alloying of graphite. The lithium metal replenishment layer has high purity and no other impurities, which can effectively avoid the generation of side reactions and avoid reaction residues. The space of the lithium replenishment layer can disappear under the action of the restraint force, and the negative electrode and electrolyte can directly contact each other, which effectively reduces the interface impedance.

[0073] 3. Significantly improved cycle life: The lithium replenishment technology effectively compensates for the loss of active lithium during cycling, increasing the cycle life of the all-solid-state battery by more than 30%. The all-solid-state battery prepared using this invention retains more than 85% of its capacity after 1000 cycles at 1C rate.

[0074] 4. Significantly improved initial coulombic efficiency: Through precise lithium replenishment, the battery's initial coulombic efficiency is increased from less than 85% to over 92%, thereby significantly improving the battery's energy density, which is 15%-20% higher than that of unreplenished batteries.

[0075] 5. Good process compatibility: This method is highly compatible with existing solid-state battery manufacturing processes (especially transfer technology), requiring no large-scale modification of production lines. The lithium replenishment process can be carried out under inert gas protection, avoiding the instability of lithium materials in air.

[0076] 6. High safety: By controlling the thickness and distribution of the lithium replenishment layer, dendrite problems that may be caused by excessive local lithium deposition are avoided, thus improving the safety of the battery.

[0077] Although the present invention has been illustrated and described with specific embodiments, it should be understood that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; those skilled in the art should understand that modifications can be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein, without departing from the spirit and scope of the present invention; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for replenishing lithium in an all-solid-state battery, characterized in that, Includes the following steps: (a) A solid electrolyte membrane is provided, and a lithium replenishment material is transferred onto one side surface of the solid electrolyte membrane to form a composite in which the lithium replenishment layer and the solid electrolyte membrane are closely bonded. (b) The composite is transferred to the surface of the negative electrode sheet, so that the lithium replenishment layer is sandwiched between the negative electrode sheet and the solid electrolyte membrane, forming a composite structure in which the negative electrode sheet, the lithium replenishment layer and the solid electrolyte membrane are stacked in sequence.

2. The lithium replenishment method for all-solid-state batteries according to claim 1, characterized in that, In step (a), the transfer temperature of the lithium replenishment material is 23~27℃, the transfer pressure is 1~8T, and the tape speed is 5~50m / min.

3. The lithium replenishment method for all-solid-state batteries according to claim 1, characterized in that, In step (b), the transfer temperature of the composite is 23~27℃, the transfer pressure is 2~30T, and the belt speed is 5~50m / min.

4. The lithium replenishment method for all-solid-state batteries according to claim 1, characterized in that, The thickness of the solid electrolyte membrane is 10~50μm.

5. The lithium replenishment method for all-solid-state batteries according to claim 1, characterized in that, The lithium replenishment material is transferred onto one side surface of the solid electrolyte membrane in the form of a lithium metal strip; Preferably, the thickness of the lithium metal strip is 1~5μm.

6. The lithium replenishment method for all-solid-state batteries according to claim 5, characterized in that, The width of the lithium metal strip is 50~220mm; And / or, the width of the negative electrode sheet is 50~220mm.

7. A lithium replenishment apparatus for implementing the all-solid-state battery lithium replenishment method according to any one of claims 1 to 6, characterized in that, include: First transfer unit: used to transfer lithium replenishment material onto solid electrolyte membrane, the first transfer unit includes a first roller press and a second roller press arranged opposite to each other; The second transfer unit is located downstream of the first transfer unit and is used to transfer the solid electrolyte composite film with a lithium replenishment layer onto the negative electrode sheet. The second transfer unit includes a third roller press and a fourth roller press arranged opposite to each other. Unwinding mechanism: used to separately convey solid electrolyte membrane, lithium replenishment material and negative electrode sheet; Rewinding mechanism: Used to rewind the composite structure and waste base tape after transfer printing.

8. A method for preparing a lithium-added composite anode for all-solid-state batteries, characterized in that, The method for replenishing lithium in an all-solid-state battery as described in any one of claims 1 to 6.

9. An all-solid-state battery, characterized in that, The lithium-filled composite anode prepared by the method for preparing the all-solid-state battery lithium-filled composite anode as described in claim 8.

10. An electrical device, characterized in that, Including the all-solid-state battery as described in claim 9.

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