Solid-state electrolyte slurry, solid-state electrolyte film, 5v integrated solid-state lithium ion battery and flexible electronic product

Abstract

The application provides a solid electrolyte slurry, a solid electrolyte film, a 5V integrated solid lithium ion battery and a flexible electronic product, the solid electrolyte slurry comprises a blended polymer, a lithium salt, an inorganic filler and N,N-dimethylformamide; wherein, the inorganic filler is used in an amount of 5%-30% and the lithium salt is used in an amount of 5%-20% based on 100% of the total weight of the blended polymer; the blended polymer comprises a mixture of polyacrylonitrile and other polymers, and the polyacrylonitrile is used in an amount of 30%-50% based on 100% of the total weight of the blended polymer. The integrated solid lithium ion battery is an integrated seamless connection solid lithium battery with a discharge voltage of more than 5V, high discharge capacity, high energy density and excellent cycle performance, stability, reliability and mechanical flexibility, and shows superior flexible energy storage application prospects in flexible electronic products.

Description

Technical Field

[0001] This invention relates to a solid electrolyte slurry, a solid electrolyte membrane, a 5V integrated solid lithium-ion battery, and flexible electronic products, belonging to the field of lithium battery technology. Background Technology

[0002] As society gradually enters the intelligent era, numerous flexible / wearable consumer electronics products are widely used, which has greatly stimulated market demand for flexible lithium-ion batteries that combine high energy density and high safety. At the same time, this has also placed high demands on the cycle life, power density, and maintenance costs of flexible lithium-ion batteries. With the increasing market demand for flexible / wearable consumer electronics products year by year, the market prospects for flexible lithium-ion batteries, as one of the most important components of these products, are enormous. However, their development is not yet fully complete and is still in its early stages. Furthermore, currently common flexible lithium-ion batteries are usually assembled based on traditional stacked structures. Battery components include electrodes, separators, liquid electrolytes, metal current collectors, and encapsulation materials. However, this traditional flexible lithium-ion battery model struggles to simultaneously achieve safety, cleanliness, stability, and high-energy supply.

[0003] Furthermore, currently common flexible lithium-ion batteries also suffer from low energy density and poor resistance to mechanical deformation. The structural drawbacks of flexible lithium-ion batteries based on the traditional sandwich stacked structure are obvious. On the one hand, the numerous electrochemically inert components, such as current collectors and packaging, occupy a large weight / volume ratio of the battery, severely reducing the battery's energy density (typically below 200 Wh / L). -1 Furthermore, when the battery is subjected to mechanical deformation, the stacked structure also leads to poor mechanical stability and durability of flexible lithium batteries. This is mainly due to the fact that there is only simple physical contact between the battery stack layers, which makes it unable to effectively and continuously transfer the load. This also leads to severe relative displacement between battery layers and irreversible deformation under bending conditions. Specifically, ordinary flexible lithium batteries will experience up to 30% capacity decay after only a few thousand bends.

[0004] In addition, since ordinary flexible lithium batteries use liquid organic electrolytes, there is also a risk of leakage during the deformation process, which can bring significant safety hazards.

[0005] Therefore, developing lithium batteries with excellent assemblability, outstanding flexibility, high energy density, and ultra-high safety has become a pressing technical problem to be solved in this field. Summary of the Invention

[0006] To address the aforementioned shortcomings and deficiencies, one objective of this invention is to provide a solid electrolyte slurry.

[0007] Another object of the present invention is to provide a solid electrolyte membrane.

[0008] Another object of the present invention is to provide a 5V integrated solid-state lithium-ion battery.

[0009] Another object of the present invention is to provide a flexible electronic product comprising the aforementioned 5V integrated solid-state lithium-ion battery.

[0010] To achieve the above objectives, in one aspect, the present invention provides a solid electrolyte slurry, wherein the solid electrolyte slurry comprises a blended polymer, a lithium salt, an inorganic filler, and N,N-dimethylformamide (DMF);

[0011] Wherein, based on the total weight of the blended polymer as 100%, the amount of inorganic filler is 5%-30%, and the amount of lithium salt is 5%-20%;

[0012] The blended polymer comprises a mixture of polyacrylonitrile (PAN) and other polymers, with the amount of polyacrylonitrile being 30%-50% based on the total weight of the blended polymer being 100%.

[0013] As a specific embodiment of the solid electrolyte slurry described above in this invention, the other polymers include one or a combination of several of polyvinylidene fluoride-co-hexafluoropropylene (PVHF), polyvinylidene fluoride (PVDF), polyvinylpyrrolidone (PVP), polymethyl methacrylate (PMMA), and polyvinyl alcohol (PVA).

[0014] In one specific embodiment of the solid electrolyte slurry described above in this invention, when the other polymers are any combination of polyvinylidene fluoride-co-hexafluoropropylene, polyvinylidene fluoride, polyvinylpyrrolidone, polymethyl methacrylate and polyvinyl alcohol, the amount of each other polymer is the same.

[0015] In a specific embodiment of the solid electrolyte slurry described above in this invention, the blended polymer is prepared by a method comprising the following steps:

[0016] The blended polymer is obtained by blending other polymers with polyacrylonitrile.

[0017] When the other polymers are any combination of polyvinylidene fluoride-co-hexafluoropropylene, polyvinylidene fluoride, polyvinylpyrrolidone, polymethyl methacrylate and polyvinyl alcohol, the other polymers are first mixed, and then the resulting mixture is blended with the polyacrylonitrile to obtain the blended polymer.

[0018] In one specific embodiment of the solid electrolyte slurry described above in this invention, the lithium salt includes lithium trifluoromethanesulfonate (LiOTF) or lithium bis(trifluoromethanesulfonyl)imide (LiTFSI).

[0019] In one specific embodiment of the solid electrolyte slurry described above in this invention, the inorganic filler is selected from one or more combinations of polymer-grafted MXenes, boron nitride (BNs), and graphene oxide (GO), etc.

[0020] The inorganic filler used in this invention has both excellent compatibility and high pressure resistance.

[0021] In one specific embodiment of the solid electrolyte slurry described above in this invention, when the inorganic filler includes any combination of several polymer-grafted MXenes, the amount of each polymer-grafted MXene is the same.

[0022] As a specific embodiment of the solid electrolyte slurry described above in this invention, the monomers used to form the polymer grafted onto the surface of the MXenes include one or a combination of several of methyl acrylate, methyl methacrylate, styrene, acrylonitrile, and N-isopropylacrylamide.

[0023] In a specific embodiment of the solid electrolyte slurry described above in this invention, the polymer-grafted MXenes are prepared by a method comprising the following steps:

[0024] A colloidal solution containing MXenes solids was fully dispersed in water. Then, cerium ammonium nitrate / concentrated nitric acid solution was added to the dispersion to obtain a precursor solution. The polymer monomer was then added dropwise to the precursor solution under an inert atmosphere to carry out a surface polymer grafting reaction. After the reaction was completed, the polymer-grafted MXenes was obtained.

[0025] As a specific embodiment of the solid electrolyte slurry described above in this invention, the preparation method further includes:

[0026] After the reaction was completed, the solid product was collected by vacuum filtration, and then washed with water, ethanol and N,N-dimethylformamide to remove residual monomers and free polymers. Subsequently, the solid product was fully dispersed in N,N-dimethylformamide to obtain a black solution.

[0027] In one specific embodiment of the solid electrolyte slurry described above in this invention, the surface polymer grafting reaction is carried out at 60-80°C for 3-7 hours.

[0028] In a specific embodiment of the solid electrolyte slurry described above in this invention, the concentration of MXenes solid in the dispersion is 5-30 mg / mL, based on the total volume of the dispersion.

[0029] In one specific embodiment of the solid electrolyte slurry described above in this invention, the volume ratio of the dispersion to the cerium ammonium nitrate / concentrated nitric acid solution is 3:1-6:1.

[0030] In one specific embodiment of the solid electrolyte slurry described above in this invention, the amount of concentrated nitric acid used is 10-30 wt%, and the amount of cerium ammonium nitrate is 0.5-3 wt%, based on the total weight of deionized water used to prepare the cerium ammonium nitrate / concentrated nitric acid solution being 100%. In some embodiments of this invention, the concentrated nitric acid is 68 wt% concentrated nitric acid with a density of 1.42 g / mL.

[0031] In one specific embodiment of the solid electrolyte slurry described above in this invention, the volume of the polymer monomer used is 1-5 vol% of the volume of the precursor solution.

[0032] In one specific embodiment of the solid electrolyte slurry described above in this invention, the inert atmosphere may be, for example, a nitrogen atmosphere.

[0033] In a specific embodiment of the solid electrolyte slurry described above in this invention, the polymer-grafted MXenes are prepared by a method comprising the following specific steps:

[0034] First, a colloidal solution containing a certain mass of MXenes solid is dispersed in water to make the concentration of MXenes solid in the resulting dispersion 5-30 mg / mL (this concentration is calculated based on the total volume of the dispersion), and then treated with ultrasound at 200-400 W for 30-60 min to ensure sufficient dispersion.

[0035] Then, according to the volume ratio of dispersion to cerium ammonium nitrate / concentrated nitric acid solution of 3:1-6:1, a certain volume of cerium ammonium nitrate / concentrated nitric acid solution is added to the dispersion to obtain the precursor solution;

[0036] Of which, based on the total weight of deionized water used to prepare cerium ammonium nitrate / concentrated nitric acid solution as 100%, the amount of concentrated nitric acid is 10-30 wt%, and the amount of cerium ammonium nitrate is 0.5-3 wt%.

[0037] Under a nitrogen atmosphere, the polymer monomers were added dropwise to the precursor solution and a surface polymer grafting reaction was carried out at 60-80°C for 3-7 hours. After the reaction was completed, the solid product was collected by vacuum filtration. The solid product was then washed with water, ethanol and N,N-dimethylformamide to remove residual monomers and free polymers. Subsequently, the solid product was dispersed in N,N-dimethylformamide and stirred for 12 hours to ensure complete dispersion, resulting in a black solution.

[0038] The volume of the polymer monomer used is 1-5 vol% of the volume of the precursor solution.

[0039] The MXenes solid used in this invention is a conventional material that is commercially available. In some embodiments of this invention, the MXenes solid may be, for example, MXenes nanosheets.

[0040] This invention does not specify a particular method for preparing the solid electrolyte slurry; it can be prepared according to actual on-site needs. As a specific embodiment of the solid electrolyte slurry described above, the solid electrolyte slurry can be prepared by a method including the following steps:

[0041] The blended polymer, lithium salt, and inorganic filler are dissolved in N,N-dimethylformamide solvent in the above proportions, and a viscous slurry is prepared under certain temperature and stirring conditions. In some embodiments of the present invention, the temperature may be, for example, 70°C.

[0042] On the other hand, the present invention also provides a solid electrolyte membrane, which is obtained by coating the solid electrolyte slurry described above into a film and then drying it under vacuum.

[0043] The temperature and time of the vacuum drying process can be selected according to the actual needs on site, as long as the purpose of vacuum drying can be achieved.

[0044] In another aspect, the present invention also provides a 5V integrated solid-state lithium-ion battery, comprising, from bottom to top, a lower packaging, a first current collector, a negative electrode, a solid electrolyte, a positive electrode, a second current collector, and an upper packaging, wherein the solid electrolyte is the solid electrolyte membrane described above.

[0045] In one specific embodiment of the solid-state lithium-ion battery described above, the negative electrode is lithium metal or a negative electrode slurry containing a negative electrode active material, a conductive agent, and a binder is coated onto a first current collector. The coating process is a conventional technique in the art, and those skilled in the art can perform appropriate operations as needed.

[0046] In one specific embodiment of the solid-state lithium-ion battery described above in this invention, the negative electrode active material includes graphite or lithium titanate.

[0047] In one specific embodiment of the solid-state lithium-ion battery described above, the binder is the solid electrolyte slurry described above.

[0048] In one specific embodiment of the solid-state lithium-ion battery described above, the positive electrode is prepared by coating a positive electrode slurry containing a positive electrode active material, a conductive agent, and a binder onto a solid electrolyte.

[0049] The coating process is a conventional technique in the field, and those skilled in the art can perform it appropriately as needed.

[0050] As a specific embodiment of the solid-state lithium-ion battery described above in this invention, the positive electrode active material includes lithium cobalt manganese oxide (LiCoMnO4) (LCMO) or lithium nickel manganese oxide (LiNi). 0.5 Mn 1.5 O4.

[0051] In one specific embodiment of the solid-state lithium-ion battery described above, the binder is the solid electrolyte slurry described above.

[0052] As a specific embodiment of the solid-state lithium-ion battery described above in this invention, the conductive agent includes one or a combination of several of MXenes nanosheets, carbon black, Superp, and carbon nanotubes.

[0053] In one specific embodiment of the solid-state lithium-ion battery described above in this invention, when the conductive agent is any combination of MXenes nanosheets, carbon black, Superp, and carbon nanotubes, the amount of each conductive agent is the same. The MXenes nanosheets and Superp used in this invention are conventional materials and are commercially available.

[0054] As a specific embodiment of the solid-state lithium-ion battery described above in this invention, the negative electrode slurry or positive electrode slurry, based on a total weight of 100%, contains 50%-80% of negative electrode active material or positive electrode active material, 10%-30% of conductive agent and 10%-20% of binder.

[0055] In one specific embodiment of the solid-state lithium-ion battery described above in this invention, the first current collector or the second current collector includes an MXenes film, carbon nanotube cloth, copper foil, aluminum foil, stainless steel sheet, or titanium foil. The carbon nanotube cloth, copper foil, aluminum foil, stainless steel sheet, or titanium foil used in this invention are all conventional materials and are commercially available.

[0056] In one specific embodiment of the solid-state lithium-ion battery described above in this invention, the thickness of the MXenes film is 5-10 μm.

[0057] In a specific embodiment of the solid-state lithium-ion battery described above, the MXenes film is prepared by a method comprising the following steps:

[0058] One or more of the polymer-grafted MXenes described above, along with the solid electrolyte slurry described above, are dissolved in N,N-dimethylformamide to obtain a slurry; the slurry is then coated to prepare an MXenes membrane.

[0059] As a specific embodiment of the solid-state lithium-ion battery described above in this invention, the amounts of one or more of the polymer-grafted MXenes and the solid electrolyte slurry are respectively 90%-98% and 2%-10% based on the total weight of 100%.

[0060] In one specific embodiment of the solid-state lithium-ion battery described above, the lower or upper packaging includes an aluminum-plastic film, a polyvinylidene fluoride-co-hexafluoropropylene film, or a polyimide (PI) film. The polyvinylidene fluoride-co-hexafluoropropylene film is prepared by coating a slurry obtained by fully dissolving PVHF in DMF.

[0061] In one specific embodiment of the solid-state lithium-ion battery described above in this invention, the thickness of the lower or upper packaging is 20-40 μm.

[0062] Furthermore, this invention also provides a flexible electronic product comprising the aforementioned 5V integrated solid-state lithium-ion battery. The battery provided by this invention, with its excellent electrochemical performance and mechanical stability, can serve as a power source for flexible electronic products requiring high energy density and high stability.

[0063] The solid electrolyte membrane used in the 5V integrated solid-state lithium-ion battery provided by this invention is prepared by coating the aforementioned solid electrolyte slurry into a film and then vacuum drying it. The resulting solid electrolyte membrane is a high-voltage resistant solid electrolyte, capable of withstanding 5V high voltage. Furthermore, the solid electrolyte slurry can also be used as a binder in the preparation of electrodes and current collectors. That is, the solid electrolyte slurry participates in the fabrication of the current collector, electrodes, and solid electrolyte membrane of the solid-state lithium-ion battery, penetrating the entire battery and encapsulating all components, truly achieving seamless, tight, and high-strength connections between the component layers. This specific structure of the solid-state lithium-ion battery endows it with excellent mechanical flexibility, allowing it to withstand various complex mechanical deformations (such as bending, twisting, winding, and folding), with minimal capacity loss (<10%).

[0064] The 5V integrated solid-state lithium-ion battery provided by this invention is a flexible integrated solid-state high-voltage lithium-ion battery. The solid electrolyte used in this battery is a solid polymer electrolyte (SPE) constructed from polyacrylonitrile (PAN) and polyvinylidene fluoride-co-hexafluoropropylene (PVHF) and other polymers, supplemented with polymer-grafted MXenes as inorganic fillers that can withstand high voltage and improve ion mobility. The use of the solid electrolyte enables the solid-state lithium-ion battery provided by this invention to have a discharge voltage of more than 5V and excellent high-voltage resistance. In addition, the solid-state lithium-ion battery uses 5V-level lithium cobalt manganese oxide (LiCoMnO4) with a spinel structure as the positive electrode material, which has the highest discharge plateau voltage among lithium-ion batteries. Previously, there had been no reports in the field of LCMO-based batteries that could be stably cycled (generally less than 100 cycles), while the solid-state lithium-ion battery provided by this invention still retains a very high capacity after more than 300 cycles, indicating that it has very good cycle stability.

[0065] Specifically, embodiments of the present invention have fabricated 5V-level integrated Li / LCMO flexible solid-state lithium-ion batteries and 5V-level integrated graphite / LCMO flexible solid-state lithium-ion batteries, both of which can provide up to 5.0V (relative to Li). + The discharge voltage of / Li) and high capacity (121mAh g) -1 Both battery systems exhibited excellent cycle performance (the former showed a capacity loss of no more than 10% after 500 cycles, and the latter showed a capacity loss of no more than 15% after 300 cycles). Furthermore, they possessed high energy density (243Wh / L). -1The 5V integrated graphite / LCMO flexible solid-state lithium-ion battery also exhibits excellent mechanical flexibility, capable of withstanding various deformations (such as bending 10,000 times, twisting 10,000 times, winding 5,000 times, and folding 200 times) with very low capacity loss (less than 5%) during deformation, indicating that this integrated seamless solid-state battery has superior durability.

[0066] In summary, the integrated solid-state lithium-ion battery provided by this invention is an integrated seamless solid-state lithium battery with a discharge voltage of over 5V, high discharge capacity, high energy density, and excellent cycle performance, stability, reliability, and mechanical flexibility. It shows superior application prospects for flexible energy storage in flexible electronic products. Attached Figure Description

[0067] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments 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 based on these drawings without creative effort.

[0068] Figure 1 The cyclic voltammetry curve for battery A is shown.

[0069] Figure 2 The constant current charge-discharge curve of battery A is shown.

[0070] Figure 3 The graph shows the cycle performance results for battery A.

[0071] Figure 4 The cyclic voltammetry curve for battery B is shown.

[0072] Figure 5 The constant current charge-discharge curve of battery B.

[0073] Figure 6 The graph shows the cycle performance results for battery B.

[0074] Figure 7 The charge-discharge curve of battery B after 100,000 static bending cycles is shown.

[0075] Figure 8 The graph shows the cycle performance of battery B after undergoing 100,000 dynamic bending cycles.

[0076] Figure 9 The graph shows the cycle performance results of battery B after undergoing bending, twisting, winding, and folding processes.

[0077] Figure 10The graph shows the results of a linear voltammetric scan of the solid electrolyte used in battery A.

[0078] Figure 11 This is a schematic diagram showing the ionic conductivity results of the solid electrolyte used in battery A.

[0079] Figure 12a This is a schematic diagram illustrating the experimental process and results of cutting battery A.

[0080] Figure 12b This is a schematic diagram illustrating the test process and results of a low-temperature freezing test on battery A. Detailed Implementation

[0081] The “range” disclosed in this document is given in the form of a lower limit and an upper limit. There can be one or more lower limits and one or more upper limits, respectively. A given range is defined by selecting a lower limit and an upper limit. The selected lower and upper limits define the boundaries of the particular range. All ranges defined in this way are composable, meaning that any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, it is also expected that ranges of 60-110 and 80-120 are also expected. Furthermore, if the listed minimum range values ​​are 1 and 2, and the listed maximum range values ​​are 3, 4, and 5, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5.

[0082] In this invention, unless otherwise stated, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" have been listed herein, and "0-5" is simply a shortened representation of these numerical combinations.

[0083] In this invention, unless otherwise specified, all embodiments and preferred embodiments mentioned herein can be combined to form new technical solutions.

[0084] In this invention, unless otherwise specified, all the technical features and preferred features mentioned herein can be combined to form new technical solutions.

[0085] In this invention, unless otherwise specified, the term "comprising" as used herein can be open-ended or closed-ended. For example, "comprising" may mean that it may also include other materials and / or elements not listed, or it may only include the listed materials and / or elements.

[0086] To provide a clearer understanding of the technical features, objectives, and beneficial effects of the present invention, the technical solution of the present invention will now be described in detail with reference to the following specific embodiments, but this should not be construed as limiting the scope of implementation of the present invention.

[0087] Example 1

[0088] This embodiment provides a high-pressure resistant inorganic filler, MXenes nanosheets (MXenes-g-PAN) grafted with polyacrylonitrile, which is prepared by a method including the following specific steps:

[0089] 0.5 g of MXenes colloidal solution was dispersed in water to 100 mL, i.e., the colloidal solution was diluted to 100 mL and ultrasonically dispersed at 200 W for 30 min. Then, 20 mL of initiator solution (in this example, the initiator solution used was cerium ammonium nitrate / concentrated nitric acid solution, with a ratio of 18.2 mL deionized water, 1.8 mL of 68 wt% concentrated nitric acid (density 1.42 g / mL), and 0.175 g cerium ammonium nitrate) was added to obtain a precursor solution. Nitrogen gas was purged for 30 min. Then, 2 mL of acrylonitrile monomer was added to the precursor solution and reacted at 60 °C for 4 h. After the reaction was completed, the obtained product was centrifuged, washed three times each with water, ethanol, and DMF. Then, it was redispersed in DMF solution and stirred for 12 h to ensure full dispersion, preparing a solution with a solid content of 5 mg / mL for later use.

[0090] Example 2

[0091] This embodiment provides a high-pressure resistant inorganic filler, MXenes nanosheets (MXenes-g-PMMA), grafted with polymethyl acrylate, which is prepared by a method including the following specific steps:

[0092] 0.5 g of MXenes colloidal solution was dispersed in water to 100 mL, i.e., the colloidal solution was diluted to 100 mL and ultrasonically dispersed at 300 W for 30 min. Then, 20 mL of initiator solution (in this example, the initiator solution used was cerium ammonium nitrate / concentrated nitric acid solution, with a ratio of 18.2 mL deionized water, 1.8 mL of 68 wt% concentrated nitric acid and 0.175 g cerium ammonium nitrate) was added to obtain a precursor solution. Nitrogen gas was purged for 30 min. Then, 1.5 mL of methyl acrylate monomer was added to the precursor solution and reacted at 75 °C for 6 h. After the reaction was completed, the obtained product was centrifuged, washed three times each with water, ethanol and DMF. Then, it was redispersed in DMF solution and stirred for 12 h to ensure full dispersion, and a solution with a solid content of 5 mg / mL was prepared for use.

[0093] Example 3

[0094] This embodiment provides a 5V integrated solid-state lithium-ion battery, comprising, from bottom to top, a lower packaging, a first current collector, a negative electrode, a solid electrolyte, a positive electrode, a second current collector, and an upper packaging. The 5V integrated solid-state lithium-ion battery is manufactured using a method including the following specific steps:

[0095] Selection of raw materials and preparation of slurry:

[0096] 1) PAN, PVHF, LiOTF and the MXenes-g-PAN solution (based on solid content) provided in Example 1 were mixed in a weight ratio of 100:230:30:60. The resulting mixture was then added to DMF and stirred at 70°C for a period of time to prepare a solid electrolyte slurry.

[0097] 2) The negative electrode is made of lithium metal foil;

[0098] 3) Mix LCMO, MXenes nanosheets and the solid electrolyte slurry described above in a mass ratio of 75:15:10 to prepare a positive electrode slurry;

[0099] 4) The MXenes-g-PAN solution (based on solid content) provided in Example 1 is mixed with the solid electrolyte slurry prepared in step 1) at a weight ratio of 97:3 and then dissolved in N,N-dimethylformamide to obtain slurry A, which is used to prepare MXenes membranes as the first current collector and the second current collector.

[0100] 5) Dissolve PVHF in DMF to prepare slurry B with a concentration controlled at 1 g / mL, for use in making PVHF films for upper and lower packaging;

[0101] Battery making:

[0102] The battery is manufactured by a layer-by-layer coating or pressing method. First, a layer of slurry B is brushed on to form a PVHF film for the lower packaging.

[0103] Then a layer of slurry A is brushed on to form the MXenes membrane, which serves as the first current collector;

[0104] Then press on a sheet of lithium metal as the negative electrode, and press titanium tabs on its edges;

[0105] Then apply a solid electrolyte slurry to form a solid electrolyte membrane;

[0106] Then apply the positive electrode slurry to form the positive electrode;

[0107] Apply another layer of slurry A to form the MXenes membrane, which serves as the second current collector, and press an aluminum tab onto the edge of this layer;

[0108] Finally, another layer of slurry B is applied to form a PVHF film for packaging. The product is then dried under vacuum to obtain a 5V integrated Li / LCMO flexible solid-state lithium-ion battery, denoted as battery A.

[0109] The thickness of both the lower and upper packaging is 30μm.

[0110] The thickness of both the first and second current collectors is 8 μm.

[0111] Example 4

[0112] This embodiment provides a 5V integrated solid-state lithium-ion battery, comprising, from bottom to top, a lower packaging, a first current collector, a negative electrode, a solid electrolyte, a positive electrode, a second current collector, and an upper packaging. The 5V integrated solid-state lithium-ion battery is manufactured using a method including the following specific steps:

[0113] Selection of raw materials and preparation of slurry:

[0114] 1) PAN, PVHF, PMMA, LiTFSI and the MXenes-g-PMMA solution (based on solid content) provided in Example 2 were mixed in a weight ratio of 100:115:115:30:60. The resulting mixture was then added to DMF and stirred at 70°C for a period of time to prepare a solid electrolyte slurry.

[0115] 2) Mix graphite, MXenes nanosheets and the solid electrolyte slurry described above in a mass ratio of 80:10:10 to prepare a negative electrode slurry;

[0116] 3) Mix LCMO, MXenes nanosheets and the solid electrolyte slurry described above in a mass ratio of 75:15:10 to prepare a positive electrode slurry;

[0117] 4) The MXenes-g-PMMA solution (based on solid content) provided in Example 2 is mixed with the solid electrolyte slurry prepared in step 1) at a weight ratio of 98:2 and then dissolved in N,N-dimethylformamide to obtain slurry A, which is used to prepare MXenes membranes as the first current collector and the second current collector.

[0118] 5) Both the lower and upper packaging use PI film;

[0119] Battery making:

[0120] It is manufactured by layer-by-layer coating or lamination, with PI film as the substrate (lower packaging), and then a layer of slurry A is brushed on the substrate to form the MXenes membrane as the first current collector;

[0121] Then apply negative electrode slurry to form the negative electrode, and press copper electrode tabs onto the edge of the negative electrode;

[0122] Then apply a solid electrolyte slurry to form a solid electrolyte membrane;

[0123] Then apply the positive electrode slurry to form the positive electrode;

[0124] Apply another layer of slurry A to form the MXenes membrane, which serves as the second current collector, and press an aluminum tab onto the edge of this layer;

[0125] Then press on a PI film as the upper packaging;

[0126] The upper and lower PI films are then sewn together with polypropylene fibers, followed by vacuum drying. After drying, the sewn joint is hot-pressed at 120°C to obtain a 5V integrated graphite / LCMO flexible solid-state lithium-ion battery, denoted as Battery B.

[0127] The thickness of both the lower and upper packaging is 20μm.

[0128] The thickness of both the first and second current collectors is 8 μm.

[0129] Test Example 1

[0130] In this test example, the electrochemical performance of battery A was tested using cyclic voltammetry and constant current charge-discharge method at room temperature and pressure.

[0131] in, Figure 1 The cyclic volt-ampere curve for battery A is shown below. Figure 1 As can be seen, battery A has two reduction peaks at 5.05V and 4.8V, and the peak shape basically stabilizes after 10 cycles, indicating that battery A can output a stable voltage higher than 5V.

[0132] Figure 2 The constant current charge-discharge curve of battery A, from Figure 2 As can be seen from the data, battery A has a stable median discharge voltage of 5.1V and can output 138mAh g. -1 The battery A has a high capacity and can still be charged and discharged efficiently at a high rate of 3C, indicating that it has excellent performance.

[0133] Figure 3 The graph shows the cycle performance results for battery A. Figure 3 As can be seen, after 500 cycles, battery A still retains nearly 90% of its capacity, indicating that it has very good cycle stability.

[0134] Test Example 2

[0135] In this test example, the electrochemical performance of battery B prepared in Example 4 was tested using cyclic voltammetry and constant current charge-discharge method at room temperature and pressure, and various deformation tests were performed on it to verify its flexibility.

[0136] in, Figure 4 The cyclic voltammetry curve for battery B is shown below. Figure 4 As can be seen, it has two reduction peaks at 4.98V and 4.78V, and the peak shape remains basically fixed after 10 cycles, indicating that battery B has excellent reversibility and stability.

[0137] Figure 5 The constant current charge-discharge curve of battery B, from Figure 5 As can be seen from the data, battery B has a stable median discharge voltage of 5.05V and can output 121mAh g. -1 The high capacity and efficient charging and discharging at a high 2C rate indicate that battery B has excellent performance.

[0138] Figure 6 The graph shows the cycle performance results for battery B. Figure 6 As can be seen, it retains nearly 85% of its capacity after 300 cycles, indicating that it has very good cycle stability.

[0139] Figure 7 The charge-discharge curve of battery B after undergoing 100,000 static bending cycles is shown below. Figure 7 As can be seen, after undergoing hundreds of thousands of deformations, battery B can still be charged and discharged stably with almost no loss of capacity.

[0140] Figure 8 The graph shows the cycle performance of battery B after undergoing 100,000 dynamic bending cycles. Figure 8 As can be seen, battery B only lost 7.3% of its capacity after undergoing 100,000 dynamic bending cycles, indicating that battery B has very good flexibility.

[0141] Figure 9 The graph shows the cycle performance results of battery B after undergoing bending, twisting, winding, and folding processes. Figure 9 As can be seen, the capacity loss under each deformation is less than 5%, which indicates that the battery still maintains very good deformation stability when faced with complex mechanical deformation.

[0142] Test Example 3

[0143] This test example performs a linear voltammetric scan on the solid electrolyte used in battery A to determine its voltage window, and the results are as follows: Figure 10 As shown, from Figure 10As can be seen, the solid electrolyte used in battery A has a wide voltage window, with a stable voltage window as high as 5.58V vs. Li. + / Li.

[0144] Test Example 4

[0145] This test example uses an electrochemical workstation to test the ionic conductivity of the solid electrolyte used in battery A. The test results are as follows: Figure 11 As shown, from Figure 11 As can be seen, the solid electrolyte used in battery A has a high ionic conductivity, reaching as high as 2 × 10⁻⁶ at room temperature. -4 S cm -1 .

[0146] Test Example 5

[0147] This test example involves performing a cutting test and a low-temperature freezing test on battery A to assess its performance under various harsh environments. The cutting test includes connecting battery A to an LED bulb via a wire and using ceramic scissors to cut off a portion of a corner of battery A. The cutting test process and results are as follows. Figure 12a As shown, from Figure 12a As can be seen from this, after battery A was cut, the connected LED bulb could still work normally, indicating that cutting off some parts of battery A did not affect its performance.

[0148] The low-temperature freezing process includes: placing battery A in water, then immersing it in a freezer to freeze the water, thus sealing the battery in ice. The frozen battery A is then connected to an LED bulb via a wire. The low-temperature freezing test process and results are as follows. Figure 12b As shown, from Figure 12b As can be seen, even in a low-temperature frozen state, battery A can still output energy normally, allowing the light bulb to work properly.

[0149] The results of the cutting test and low-temperature freezing test described above prove that the battery provided in the embodiments of the present invention can withstand various harsh environments.

[0150] In summary, the beneficial technical effects achievable by the integrated solid-state lithium-ion battery provided in this embodiment of the invention include:

[0151] (1) The solid electrolyte used in the integrated solid-state lithium-ion battery provided in this embodiment of the invention has a wide voltage window (up to 5.58V vs. Li). + Li) and high ionic conductivity (up to 2 × 10⁻⁶ at room temperature). -4 S cm -1 ).

[0152] (2) The integrated solid-state lithium-ion battery provided in this embodiment of the invention can support charge-discharge cycles of 5V or higher, and has high discharge capacity and stable cycle performance.

[0153] (3) The integrated solid-state lithium-ion battery provided in this embodiment of the invention presents a seamless connection between the various component layers, and the solid polymer electrolyte runs through the entire battery, enabling the battery to withstand various complex mechanical deformations and have high mechanical stability and durability.

[0154] (4) The integrated solid-state lithium-ion battery provided in this embodiment of the invention can withstand various harsh environments (such as low temperature freezing and cutting).

[0155] The above description is merely a specific embodiment of the present invention and should not be construed as limiting the scope of the invention. Therefore, any substitution of equivalent components or equivalent changes and modifications made within the scope of protection of this patent should still fall within the scope of this patent. Furthermore, the technical features, technical features and technical inventions, and technical inventions in this invention can be freely combined and used.

Claims

1. A solid electrolyte slurry, characterized in that, The solid electrolyte slurry comprises a blended polymer, lithium salt, inorganic filler, and N,N-dimethylformamide; Wherein, based on the total weight of the blended polymer as 100%, the amount of inorganic filler is 5%-30%, and the amount of lithium salt is 5%-20%; The blended polymer comprises a mixture of polyacrylonitrile and other polymers, with the amount of polyacrylonitrile being 30%-50% based on the total weight of the blended polymer being 100%. The inorganic filler is selected from polymer-grafted MXenes. The monomers used to form the polymer grafted onto the surface of the MXenes include one or a combination of methyl acrylate, methyl methacrylate, styrene, acrylonitrile, and N-isopropylacrylamide. The polymer-grafted MXenes are prepared by a method comprising the following steps: A colloidal solution containing MXenes solids was fully dispersed in water. Then, cerium ammonium nitrate / concentrated nitric acid solution was added to the resulting dispersion to obtain a precursor solution. The polymer monomer was then added dropwise to the precursor solution under an inert atmosphere to carry out a surface polymer grafting reaction. After the reaction was completed, the polymer-grafted MXenes was obtained.

2. The solid electrolyte slurry according to claim 1, characterized in that, The other polymers include one or a combination of several of polyvinylidene fluoride-co-hexafluoropropylene, polyvinylidene fluoride, polyvinylpyrrolidone, polymethyl methacrylate, and polyvinyl alcohol.

3. The solid electrolyte slurry according to claim 2, characterized in that, When the other polymers are any combination of polyvinylidene fluoride-co-hexafluoropropylene, polyvinylidene fluoride, polyvinylpyrrolidone, polymethyl methacrylate and polyvinyl alcohol, the amount of each other polymer is the same.

4. The solid electrolyte slurry according to claim 1, characterized in that, The lithium salt includes lithium trifluoromethanesulfonate or lithium bis(trifluoromethanesulfonyl)imide.

5. The solid electrolyte slurry according to claim 1, characterized in that, When the inorganic filler comprises any combination of polymer-grafted MXenes, the amount of each polymer-grafted MXene is the same.

6. The solid electrolyte slurry according to claim 1, characterized in that, The preparation method further includes: After the reaction was completed, the solid product was collected by vacuum filtration, and then washed with water, ethanol and N,N-dimethylformamide to remove residual monomers and free polymers. Subsequently, the solid product was fully dispersed in N,N-dimethylformamide to obtain a black solution.

7. The solid electrolyte slurry according to claim 1, characterized in that, The surface polymer grafting reaction is carried out at 60-80℃ for 3-7 h.

8. The solid electrolyte slurry according to claim 1, characterized in that, Based on the total volume of the dispersion, the concentration of MXenes solid in the dispersion is 5-30 mg / mL.

9. The solid electrolyte slurry according to claim 1, characterized in that, The volume ratio of the dispersion to the cerium ammonium nitrate / concentrated nitric acid solution is 3:1-6:

1.

10. The solid electrolyte slurry according to any one of claims 1, 8-9, characterized in that, Based on the total weight of deionized water used to prepare cerium ammonium nitrate / concentrated nitric acid solution as 100%, the amount of concentrated nitric acid used is 10-30 wt%, and the amount of cerium ammonium nitrate used is 0.5-3 wt%.

11. The solid electrolyte slurry according to claim 1, characterized in that, The volume of the polymer monomer used is 1-5 vol of the volume of the precursor solution.

12. A solid electrolyte membrane, which is prepared by coating the solid electrolyte slurry according to any one of claims 1-11 into a film and then drying it under vacuum.

13. A 5V integrated solid-state lithium-ion battery, comprising, from bottom to top, a lower packaging, a first current collector, a negative electrode, a solid electrolyte, a positive electrode, a second current collector, and an upper packaging, characterized in that, The solid electrolyte is the solid electrolyte membrane as described in claim 12.

14. The solid-state lithium-ion battery according to claim 13, characterized in that, The negative electrode is lithium metal or is prepared by coating a negative electrode slurry containing a negative electrode active material, a conductive agent and a binder onto a first current collector.

15. The solid-state lithium-ion battery according to claim 14, characterized in that, The negative electrode active material includes graphite or lithium titanate.

16. The solid-state lithium-ion battery according to claim 14, characterized in that, The binder is the solid electrolyte slurry according to any one of claims 1-11.

17. The solid-state lithium-ion battery according to claim 13, characterized in that, The positive electrode is prepared by coating a positive electrode slurry containing positive electrode active material, conductive agent and binder onto a solid electrolyte.

18. The solid-state lithium-ion battery according to claim 17, characterized in that, The positive electrode active material includes lithium cobalt manganese oxide (LiCoMnO4) or lithium nickel manganese oxide (LiNi). 0.5 Mn 1.5 O4.

19. The solid-state lithium-ion battery according to claim 17, characterized in that, The binder is the solid electrolyte slurry according to any one of claims 1-11.

20. The solid-state lithium-ion battery according to claim 14 or 17, characterized in that, The conductive agent includes one or a combination of several of MXenes nanosheets, carbon black, Superp, and carbon nanotubes.

21. The solid-state lithium-ion battery according to claim 20, characterized in that, When the conductive agent is any combination of MXenes nanosheets, carbon black, Superp and carbon nanotubes, the amount of each conductive agent is the same.

22. The solid-state lithium-ion battery according to claim 14 or 17, characterized in that, Based on the total weight of the negative electrode slurry or positive electrode slurry (100%), it contains 50%-80% of negative electrode active material or positive electrode active material, 10%-30% of conductive agent and 10%-20% of binder.

23. The solid-state lithium-ion battery according to claim 13, characterized in that, The first or second current collector may be an MXenes membrane, carbon nanotube cloth, copper foil, aluminum foil, stainless steel sheet, or titanium foil.

24. The solid-state lithium-ion battery according to claim 23, characterized in that, The MXenes membrane is prepared by a method comprising the following steps: One or more of the polymer-grafted MXenes and the solid electrolyte slurry according to any one of claims 1-11 are dissolved in N,N-dimethylformamide to obtain a slurry; the slurry is then coated to prepare an MXenes film; wherein, in the polymer-grafted MXenes, the monomers used to form the polymer grafted onto the surface of the MXenes include one or more of methyl acrylate, methyl methacrylate, styrene, acrylonitrile and N-isopropylacrylamide.

25. The solid-state lithium-ion battery according to claim 24, characterized in that, Based on the total weight of one or more of the polymer-grafted MXenes and the solid electrolyte slurry as 100%, the respective amounts of the two are 90%-98% and 2%-10%.

26. The solid-state lithium-ion battery according to claim 13, characterized in that, The lower or upper packaging includes aluminum-plastic film, polyvinylidene fluoride-co-hexafluoropropylene film, or polyimide film.

27. A flexible electronic product comprising the 5 V integrated solid-state lithium-ion battery as described in claim 13.

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