A method for modifying the interface of a halide-based all-solid-state battery and a halide-based all-solid-state lithium metal battery

Abstract

This invention belongs to the field of solid-state batteries, and particularly relates to a method for interface modification of halide-based all-solid-state batteries and a halide-based all-solid-state lithium metal battery. The method for interface modification of halide-based all-solid-state batteries provided by this invention includes the following steps: setting an interface modification layer between the all-solid-state electrolyte and the negative electrode on the negative electrode side of the halide-based all-solid-state battery, wherein the component of the interface modification layer is lithium phosphide. This invention solves the problem of interface deterioration between the halide electrolyte and the lithium negative electrode by introducing lithium phosphide (Li3P) as an interface modification layer between the electrolyte and the negative electrode on the negative electrode side of the halide-based all-solid-state lithium metal battery; based on this, by further optimizing the lithium-phosphide composite material prepared by the rolling process as the negative electrode of the halide-based all-solid-state lithium metal battery, the ion transport rate within the negative electrode bulk phase is improved, and the structural stability of the negative electrode is enhanced.

Description

Technical Field

[0001] This invention belongs to the field of solid-state batteries, and particularly relates to a method for modifying the interface of a halide-based all-solid-state battery and a halide-based all-solid-state lithium metal battery. Background Technology

[0002] Among solid electrolyte materials, halide solid electrolytes are known for their high ionic conductivity (>1 mS / cm). -1 With its high positive electrode stability, wide operating temperature range, and good deformability, halide electrolyte has become one of the most promising solid-state electrolyte materials. However, the reaction between halide electrolytes and lithium anodes, leading to short circuits in the battery, hinders its further development.

[0003] While using sulfides as an interface modification layer between halides and lithium can effectively mitigate interface deterioration, it cannot fundamentally solve the interface problem of halide electrolytes. Secondly, lithium ions diffuse slowly within the lithium metal anode, and the inability of bulk lithium to participate in the reaction easily leads to the formation of lithium-ion depletion regions at the interface. Furthermore, uneven deposition tends to form lithium dendrites, ultimately causing a short circuit in the battery. Thirdly, the significant volume expansion during lithium-ion intercalation eventually leads to the breakage and collapse of the electrode material. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a method for interface modification of halide-based all-solid-state batteries and a halide-based all-solid-state lithium metal battery. This invention solves the problem of interface deterioration between halide electrolyte and lithium anode by introducing lithium phosphide (Li3P) as an interface modification layer between the electrolyte and the anode on the negative side of the halide-based all-solid-state lithium metal battery. On this basis, by further optimizing the lithium phosphide composite material prepared by the rolling process as the anode of the halide-based all-solid-state lithium metal battery, the ion transport rate in the anode bulk phase is improved and the structural stability of the anode is improved.

[0005] This invention provides a method for modifying the interface of a halide-based all-solid-state battery, comprising the following steps:

[0006] An interface modification layer is provided between the all-solid electrolyte and the negative electrode on the negative electrode side of a halide-based all-solid-state battery, and the component of the interface modification layer is lithium phosphide.

[0007] The present invention provides a halide-based all-solid-state lithium metal battery, comprising: a positive electrode, a negative electrode, and an all-solid-state electrolyte disposed between the positive electrode and the negative electrode, wherein an interface modification layer is disposed between the all-solid-state electrolyte on the negative electrode side and the negative electrode, and the component of the interface modification layer is lithium phosphide.

[0008] Preferably, the active material of the positive electrode is one of nickel-cobalt-manganese ternary positive electrode material, lithium iron phosphate, and lithium cobalt oxide.

[0009] Preferably, the positive electrode is a composite positive electrode, and the components of the composite positive electrode include the active material and an all-solid electrolyte on the positive electrode side.

[0010] Preferably, the content of active material in the composite cathode is 70-80 wt%.

[0011] Preferably, the negative electrode is a lithium-phosphine composite negative electrode, which includes a lithium matrix and lithium phosphide embedded in the lithium matrix.

[0012] Preferably, the lithium-phosphorus composite anode is prepared according to the following steps: phosphorus is sprinkled on the surface of lithium sheet, and the sheet is repeatedly folded and rolled to obtain the lithium-phosphorus composite anode.

[0013] Preferably, the mass ratio of phosphorus to lithium is (1-5):100.

[0014] Preferably, the all-solid-state electrolyte includes an all-solid-state electrolyte on the positive electrode side and an all-solid-state electrolyte on the negative electrode side. The all-solid-state electrolyte on the positive electrode side is one of Li3InCl6, Li2ZrCl6, Li3YCl6, and Li3YBr6, and the all-solid-state electrolyte on the negative electrode side is Li6PS5Cl or Li 5.5 PS 4.5 Cl 1.5 .

[0015] Preferably, the mass ratio of the all-solid electrolyte on the positive electrode side, the all-solid electrolyte on the negative electrode side, and the interface modification layer is (50-80):(30-50):(10-15).

[0016] Compared with the prior art, the present invention provides a method for interface modification of halide-based all-solid-state batteries and a halide-based all-solid-state lithium metal battery. The present invention solves the problem of interface deterioration between halide electrolyte and lithium anode by introducing lithium phosphide (Li3P) as an interface modification layer between the electrolyte and the anode on the negative side of the halide-based all-solid-state lithium metal battery. On this basis, by further optimizing the lithium-phosphide composite material (which includes a lithium matrix and lithium phosphide, a fast ion conductor embedded in the lithium matrix) prepared by the rolling process as the anode of the halide-based all-solid-state lithium metal battery, the ion transport rate in the anode phase is improved and the structural stability of the anode is improved. Specifically: (1) Lithium phosphide, as a fast ion transport framework, penetrates the interface modification layer and is uniformly embedded in the lithium metal anode. While significantly improving the interface stability, it forms a continuous ion transport path, which greatly improves the ion transport rate on the anode side and in the anode phase; (2) Lithium phosphide can effectively suppress the volume expansion effect of the anode and significantly improve the structural stability of the lithium anode. Attached Figure Description

[0017] 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 or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0018] Figure 1 The LIC / Li symmetric cell provided in Comparative Example 1 of this invention operates at 0.1 mA·cm⁻¹. -2 Time-voltage curves at current density;

[0019] Figure 2 The LIC / LPSC / Li symmetric cell provided in Comparative Example 2 of this invention operates at 0.1 mA·cm⁻¹. -2 Time-voltage curves at current density;

[0020] Figure 3 The LIC / LPSC / Li3P / Li symmetric cell provided in Embodiment 1 of this invention operates at 0.1 mA·cm⁻¹. -2 Time-voltage curves at current density;

[0021] Figure 4 This is a CCD curve of the symmetrical battery provided in Embodiment 1 of the present invention;

[0022] Figure 5 This is the XRD pattern of the lithium-phosphorus composite material Li@LiP3 provided in Example 2 of the present invention;

[0023] Figure 6 This is a CCD curve of the LIC / LPSC / Li3P / Li@LiP1 symmetric cell provided in Embodiment 3 of the present invention;

[0024] Figure 7 This is a CCD curve of the LIC / LPSC / Li3P / Li@LiP3 symmetric cell provided in Embodiment 4 of the present invention;

[0025] Figure 8 This is the EIS spectrum of the LIC / LPSC / Li3P / Li@LiP3 symmetric cell provided in Embodiment 4 of the present invention;

[0026] Figure 9 The LIC / LPSC / Li3P / Li@LiP3 symmetric cell provided in Embodiment 4 of this invention operates at 0.1 mA·cm⁻¹. -2 Time-voltage curves at current density;

[0027] Figure 10This is a CCD curve of the LIC / LPSC / Li3P / Li@LiP5 symmetric battery provided in Embodiment 5 of the present invention;

[0028] Figure 11 The graph shows the cycle performance test results of the all-solid-state lithium metal battery NCM811 / LIC / LPSC / Li3P / Li@LiP3 provided in Embodiment 6 of the present invention under a 0.5C rate condition. Detailed Implementation

[0029] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. 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.

[0030] This invention provides a method for modifying the interface of a halide-based all-solid-state battery, comprising the following steps:

[0031] An interface modification layer is provided between the all-solid electrolyte and the negative electrode on the negative electrode side of a halide-based all-solid-state battery, and the component of the interface modification layer is lithium phosphide.

[0032] The present invention also provides a halide-based all-solid-state lithium metal battery, comprising: a positive electrode, a negative electrode, and an all-solid-state electrolyte disposed between the positive electrode and the negative electrode, wherein an interface modification layer is disposed between the all-solid-state electrolyte on the negative electrode side and the negative electrode, and the component of the interface modification layer is lithium phosphide.

[0033] In the all-solid-state lithium metal battery provided by the present invention, the active material of the positive electrode is preferably one of the nickel-cobalt-manganese ternary positive electrode material NCM811, lithium iron phosphate, and lithium cobalt oxide; the positive electrode is preferably a composite positive electrode, and the composition of the composite positive electrode preferably includes the active material and an all-solid-state electrolyte on the positive electrode side. The all-solid-state electrolyte can specifically be one of Li3InCl6, Li2ZrCl6, Li3YCl6, and Li3YBr6. The content of the active material in the composite positive electrode is preferably 70-80 wt%, specifically 70 wt%, 71 wt%, 72 wt%, 73 wt%, 74 wt%, 75 wt%, 76 wt%, 77 wt%, 78 wt%, 79 wt%, or 80 wt%.

[0034] In the all-solid-state lithium metal battery provided by the present invention, the negative electrode is preferably a lithium-phosphine composite negative electrode, which includes a lithium matrix and lithium phosphide embedded in the lithium matrix. In the present invention, the lithium-phosphine composite negative electrode is prepared according to the following steps: phosphorus is sprinkled onto the surface of a lithium sheet, and repeatedly folded and rolled to obtain the lithium-phosphine composite negative electrode; wherein, the mass ratio of phosphorus to lithium sheet is preferably (1-5):100, specifically 1:100, 2:100, 3:100, 4:100, or 5:100; the time for repeated folding and rolling is preferably 3-5 minutes.

[0035] In the all-solid-state lithium metal battery provided by the present invention, the all-solid-state electrolyte preferably includes an all-solid-state electrolyte on the positive electrode side and an all-solid-state electrolyte on the negative electrode side; wherein, the all-solid-state electrolyte on the positive electrode side is preferably one of Li3InCl6, Li2ZrCl6, Li3YCl6, and Li3YBr6, and the all-solid-state electrolyte on the negative electrode side is preferably Li6PS5Cl or Li 5.5 PS 4.5 Cl 1.5 .

[0036] In the all-solid-state lithium metal battery provided by the present invention, the mass ratio of the all-solid-state electrolyte on the positive electrode side, the all-solid-state electrolyte on the negative electrode side, and the interface modification layer is preferably (50-80):(30-50):(10-15), and more preferably 70:40:12.

[0037] This invention also provides a method for preparing the halide-based all-solid-state lithium metal battery described above, comprising the following steps:

[0038] The positive electrode side all-solid electrolyte is added into a sealed mold and cold-pressed; then the negative electrode side all-solid electrolyte is added into a sealed mold and cold-pressed; next, the interface modification layer material is evenly sprinkled on the surface of the negative electrode side all-solid electrolyte and cold-pressed; then the mold is inverted, the positive electrode material is sprinkled on the positive electrode side all-solid electrolyte end and cold-pressed; finally, the negative electrode is attached to the interface modification layer side and sealed to obtain a halide-based all-solid lithium metal battery.

[0039] The technical solution provided by this invention solves the problem of interface deterioration between halide electrolyte and lithium anode by introducing lithium phosphide (Li3P) as an interface modification layer between the electrolyte and anode on the anode side of the halide-based all-solid-state lithium metal battery. Based on this, this invention further optimizes the lithium-phosphide composite material (which includes a lithium matrix and lithium phosphide embedded in the lithium matrix through a roll forming process) as the anode of the halide-based all-solid-state lithium metal battery, thereby improving the ion transport rate within the anode phase and enhancing the structural stability of the anode. Specifically: (1) Lithium phosphide, as a fast ion transport framework, penetrates the interface modification layer and is uniformly embedded in the lithium metal anode, significantly improving interface stability while forming a continuous ion transport path that greatly enhances the ion transport rate on the anode side and within the anode phase; (2) Lithium phosphide can effectively suppress the anode volume expansion effect, significantly improving the structural stability of the lithium anode. Furthermore, the lithium-phosphide composite material in this invention is preferably prepared by a roll forming method, which is low-cost and suitable for large-scale industrial production.

[0040] For clarity, the following examples and comparative models will be used to provide a detailed description.

[0041] Comparative Example 1

[0042] The preparation of a LIC / Li symmetric cell involves the following steps: In an argon-filled glove box, commercially available 0.45mm thick lithium sheets are cut into 10mm diameter discs; 70mg of LIC is weighed and evenly sprinkled into a PEEK mold, and pressed under 3 tons of pressure for 3–5 minutes. Subsequently, the 10mm diameter lithium discs are attached to the surface of lithium phosphide and sealed to obtain the symmetric LIC / Li cell.

[0043] The electrical performance of the LIC / Li symmetric cell prepared in Comparative Example 1 was tested, and the results were as follows: Figure 1 As shown, Figure 1 The LIC / Li symmetric cell provided in Comparative Example 1 of this invention operates at 0.1 mA·cm⁻¹. -2 Time-voltage curves at current density. (By...) Figure 1 It can be seen that the LIC / Li symmetrical cell short-circuits directly after two cycles, and is accompanied by a significant voltage increase in the second and third cycles, which is due to the reaction between LIC and Li.

[0044] Comparative Example 2

[0045] The preparation of a LIC / LPSC / Li symmetric cell involves the following steps: In an argon-filled glove box, commercially available 0.45mm thick lithium sheets are cut into 10mm diameter discs; 70mg of LIC is weighed and evenly sprinkled into a PEEK mold, which is then compacted under 1 ton of pressure. Subsequently, 40mg of LPSC is sprinkled on each side of the LIC, and the mixture is pressed under 3 tons of pressure for 3–5 minutes. After attaching the 10mm lithium sheet to the surface of lithium phosphide, the mold is sealed to obtain the symmetric LIC / LPSC / Li cell.

[0046] The electrical performance of the LIC / LPSC / Li symmetric cell prepared in Comparative Example 2 was tested, and the results were as follows: Figure 2 As shown, Figure 2 The LIC / LPSC / Li symmetric cell provided in Comparative Example 2 of this invention operates at 0.1 mA·cm⁻¹. -2 Time-voltage curves at current density. (By...) Figure 2 and Figure 1 The comparison shows that although the addition of LPSC effectively slowed down the reaction between LIC and Li, as the number of cycles increased, due to the reaction between LPSC and Li, the symmetric cell experienced a short circuit after only 150 hours of cycling, accompanied by a significant voltage increase.

[0047] Example 1

[0048] In an argon-filled glove box, commercially available 0.45mm thick lithium sheets were cut into 10mm diameter discs. 70mg of LIC was evenly sprinkled into a PEEK mold and compacted under 1 ton of pressure. 40mg of LPSC was sprinkled on each side of the LIC and compacted under 2 tons of pressure. 12mg of lithium phosphide was sprinkled on each side of the LPSC and pressed under 3 tons of pressure for 3–5 minutes. The 10mm lithium sheet was then attached to the lithium phosphide surface and sealed to obtain a symmetric battery LIC / LPSC / Li3P / Li. The cycle stability and critical current density (CCD) of the symmetric battery were tested, and a control group symmetric battery LIC / LPSC / Li was set up. The results are as follows: Figure 3 and Figure 4 As shown.

[0049] Figure 3 The LIC / LPSC / Li3P / Li symmetric cell provided in Embodiment 1 of this invention operates at 0.1 mA·cm⁻¹. -2 Time-voltage curves at current density. (By...) Figure 3 It can be seen that the LIC / LPSC / Li3P / Li symmetric cell at 0.1 mA·cm -2 The battery can cycle stably for more than 250 hours at current density without significant voltage increase and without short circuit, indicating that lithium phosphide as an interface modification layer can successfully solve the interface problem of halide-based all-solid-state batteries.

[0050] Figure 4 These are CCD curves of the symmetrical battery provided in Embodiment 1 of the present invention, wherein Figure (a) is the symmetrical battery LIC / LPSC / Li, and Figure (b) is the symmetrical battery LIC / LPSC / Li3P / Li. Through... Figure 4 It can be seen that the CCD of the LIC / LPSC / Li3P / Li symmetric cell is increased from 0.8 in the LIC / LPSC / Li symmetric cell to 1.0 mA·cm. -2 This indicates that lithium phosphide, as an interface modification layer, not only hinders chemical / electrochemical processes at the solid-state battery interface but also increases the critical current density of symmetric batteries, enabling lithium metal all-solid-state batteries using lithium phosphide as an interface modification layer to cycle at higher current densities.

[0051] Example 2

[0052] Different masses of elemental phosphorus were uniformly sprinkled onto the surface of lithium sheets in an argon (Ar)-filled glove box at room temperature. The sheets were then repeatedly folded and rolled for 3–5 minutes using a low-cost, commercially viable rolling method. The mass ratios of elemental phosphorus to metallic lithium were 1:100, 2:100, 3:100, 4:100, and 5:100, respectively. The resulting composite materials were denoted as Li@LiP1, Li@LiP2, Li@LiP3, Li@LiP4, and Li@LiP5, respectively.

[0053] The prepared lithium-phosphorus composite material Li@LiP3 was analyzed by XRD, and the results are as follows: Figure 5 As shown, Figure 5 This is the XRD pattern of the lithium-phosphorus composite material Li@LiP3 provided in Example 2 of the present invention. (The last sentence appears to be incomplete and possibly refers to a different XRD pattern.) Figure 5 It can be seen that the composite negative electrode Li@LiP3 is composed of Li, Li3P, and LiOH phases, and no diffraction peaks of P were found. This indicates that at room temperature, the rolling process can completely react elemental phosphorus with metallic lithium to generate the Li3P phase with fast ion transport characteristics. Therefore, this invention uniformly constructs a Li3P framework with fast ion transport characteristics within metallic Li through a rolling process.

[0054] Example 3

[0055] In an argon-filled glove box, a certain mass of lithium sheet was weighed. Elemental phosphorus (weighed at a Li:P mass ratio of 100:1) was evenly sprinkled onto the surface of the lithium sheet. After repeated folding and rolling for 3–5 minutes, it was cut into 10 mm round pieces to obtain the lithium-phosphorus composite anode Li@LiP1. 70 mg of LIC was evenly sprinkled into a PEEK mold and compacted under 1 ton of pressure. 40 mg of LPSC was sprinkled on each side of the LIC and compacted under 2 tons of pressure. 12 mg of lithium phosphide was sprinkled on each side of the LPSC and pressed under 3 tons of pressure for 5 minutes. The lithium-phosphorus composite anode Li@LiP1 was then attached to the surface of the lithium phosphide and sealed to obtain a symmetrical cell LIC / LPSC / Li3P / Li@LiP1. The CCD of the symmetrical cell was tested, and the results are as follows: Figure 6 As shown.

[0056] Figure 6 This is a CCD curve of the LIC / LPSC / Li3P / Li@LiP1 symmetric cell provided in Embodiment 3 of the present invention. By... Figure 6 and Figure 4 The comparison shows that the CCD performance of the LIC / LPSC / Li3P / Li@LiP1 symmetric cell has been further improved to 1.5 mA·cm⁻¹. -2 This enables lithium metal all-solid-state batteries that use lithium phosphide as an interface protection layer and lithium-phosphide composite negative electrode Li@LiP1 to cycle at higher current densities.

[0057] Example 4

[0058] In an argon-filled glove box, a certain mass of lithium sheet was weighed. Elemental phosphorus (weighed at a Li:P mass ratio of 100:3) was evenly sprinkled on the surface of the lithium sheet. After repeated folding and rolling for 3-5 minutes, it was cut into 10mm round pieces to obtain the lithium-phosphorus composite anode Li@LiP3. 70mg of LIC was evenly sprinkled into a PEEK mold and compacted under 1 ton of pressure. 40mg of LPSC was sprinkled on each side of the LIC and compacted under 2 tons of pressure. 12mg of lithium phosphide was sprinkled on each side of the LPSC and pressed under 3 tons of pressure for 5 minutes. The lithium-phosphorus composite anode Li@LiP3 was then attached to the surface of the lithium phosphide and sealed to obtain the symmetrical battery LIC / LPSC / Li3P / Li@LiP3. The electrical performance of the symmetrical battery was tested, and the results are as follows: Figures 7-9 As shown.

[0059] Figure 7 This is a CCD curve of the LIC / LPSC / Li3P / Li@LiP3 symmetric cell provided in Embodiment 4 of the present invention. (The last sentence appears to be incomplete and likely refers to a separate, unrelated statement.) Figure 7 and Figure 6 The comparison shows that with the increase of elemental phosphorus in the composite anode, the CCD of the LIC / LPSC / Li3P / Li@LiP3 symmetric cell is further improved to 1.8 mA·cm⁻¹.-2 This enables lithium metal all-solid-state batteries that use lithium phosphide as an interface protection layer and lithium-phosphide composite anode Li@LiP3 to cycle at higher current densities.

[0060] Figure 8 This is the EIS spectrum of the LIC / LPSC / Li3P / Li@LiP3 symmetric cell provided in Embodiment 4 of the present invention. (The last sentence appears to be incomplete and possibly refers to a different data point.) Figure 8 As can be seen, the symmetric battery LIC / LPSC / Li3P / Li@LiP3 prepared in this embodiment has an extremely low interface resistance of only 1.96 Ωcm. 2 .

[0061] Figure 9 The LIC / LPSC / Li3P / Li@LiP3 symmetric cell provided in Embodiment 4 of this invention operates at 0.1 mA·cm⁻¹. -2 Time-voltage curves at current density. (By...) Figure 9 It can be seen that this symmetrical cell is at 0.1 mA·cm -2 It can cycle stably for more than 1000 hours at current density, showing extremely excellent cycle stability, indicating the high feasibility of an all-solid-state lithium metal battery constructed with lithium phosphide as the interface modification layer and lithium phosphide composite anode.

[0062] Example 5

[0063] In an argon-filled glove box, a certain mass of lithium sheet was weighed. Elemental phosphorus (weighed at a Li:P mass ratio of 100:5) was evenly sprinkled onto the surface of the lithium sheet. After repeated folding and rolling for 3–5 minutes, it was cut into 10 mm round pieces to obtain the lithium-phosphorus composite anode Li@LiP5. 70 mg of LIC was evenly sprinkled into a PEEK mold and compacted under 1 ton of pressure. 40 mg of LPSC was sprinkled on each side of the LIC and compacted under 2 tons of pressure. 12 mg of lithium phosphide was sprinkled on each side of the LPSC and pressed under 3 tons of pressure for 5 minutes. The lithium-phosphorus composite anode Li@LiP5 was then attached to the surface of the lithium phosphide and sealed to obtain a symmetrical cell LIC / LPSC / Li3P / Li@LiP5. The CCD of the symmetrical cell was tested, and the results are as follows: Figure 10 As shown.

[0064] Figure 10 This is a CCD curve of the LIC / LPSC / Li3P / Li@LiP5 symmetric cell provided in Embodiment 5 of the present invention. (The last sentence appears to be incomplete and likely refers to a separate, unrelated statement.) Figure 10 and Figure 7 The comparison shows that as the phosphorus content continues to increase, the CCD of the LIC / LPSC / Li3P / Li@LiP5 symmetric cell decreases from 1.8 mA·cm⁻¹. -2 Reduced to 1.4 mA·cm -2This indicates that the optimal lithium:phosphorus mass ratio for the lithium-phosphorus composite anode is 100:3.

[0065] Example 6

[0066] The nickel-cobalt-manganese ternary cathode NCM811 and LIC were thoroughly mixed at a mass ratio of 75:25 to obtain a composite cathode. 70 mg of LIC was weighed and evenly sprinkled into a PEEK mold, then compacted under 1 ton of pressure. 40 mg of LPSC was sprinkled on one side of the LIC and compacted under 1.5 tons of pressure. 12 mg of lithium phosphide was sprinkled on the LPSC side and compacted under 2 tons of pressure. Approximately 5 mg of the composite cathode was evenly spread on the LIC side and pressed under 3 tons of pressure for 5 minutes. Finally, the composite anode Li@LiP3 was cut into 10 mm discs, attached to the surface of the lithium phosphide, and sealed to obtain the all-solid-state lithium metal battery NCM811 / LIC / LPSC / Li3P / Li@LiP3. The cycle performance of the symmetrical battery was tested, and the results are as follows: Figure 11 As shown.

[0067] Figure 11 The figures shown are the cycle performance test results of the all-solid-state lithium metal battery NCM811 / LIC / LPSC / Li3P / Li@LiP3 provided in Example 6 of this invention under a 0.5C rate condition. Figure (a) shows the charge-discharge curves for different cycle numbers, and Figure (b) shows the curves of specific capacity and coulombic efficiency changes. Figure 11 It can be seen that NCM811 / LIC / LPSC / Li3P / Li@LiP3 has a positive electrode active material loading of 5 mg·cm³. -2 The first discharge specific capacity reached 120.74 mAh·g under 0.5C rate conditions. -1 After 100 cycles, the capacity retention rate was 95.72% and there was still no short circuit, demonstrating extremely excellent cycle stability.

[0068] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A halide-based all-solid-state lithium metal battery, characterized by, The application relates to a lithium battery, which comprises a positive electrode, a negative electrode and a full solid electrolyte arranged between the positive electrode and the negative electrode, an interface modification layer is arranged between the full solid electrolyte on the negative electrode side and the negative electrode, and the composition of the interface modification layer is lithium phosphide. The negative electrode is a lithium-phosphorus composite negative electrode, which comprises a lithium matrix and lithium phosphide embedded in the lithium matrix; the lithium-phosphorus composite negative electrode is prepared by the following steps: spraying elemental phosphorus on the surface of a lithium sheet, repeatedly folding and rolling to obtain the lithium-phosphorus composite negative electrode; and the mass ratio of the elemental phosphorus to the lithium sheet is (1-3):

100. The active material of the positive electrode is one of a nickel-cobalt-manganese ternary positive electrode material, lithium iron phosphate and lithium cobaltate. 2.The halide-based all-solid-state lithium metal battery of claim 1, wherein, The positive electrode is a composite positive electrode, and the composition of the composite positive electrode comprises the active material and a full solid electrolyte on the positive electrode side. 3.The halide-based all-solid-state lithium metal battery of claim 2, wherein, The content of the active material in the composite positive electrode is 70-80 wt%. 4.The halide-based all-solid-state lithium metal battery of claim 3, wherein, The mass ratio of the full solid electrolyte on the positive electrode side, the full solid electrolyte on the negative electrode side and the interface modification layer is (50-80):(30-50):(10-15). 5.The halide-based all-solid-state lithium metal battery of claim 1, wherein, The all-solid-state electrolyte includes an all-solid-state electrolyte on a positive electrode side and an all-solid-state electrolyte on a negative electrode side, the all-solid-state electrolyte on the positive electrode side is one of Li3InCl6, Li2ZrCl6, Li3YCl6, and Li3YBr6, and the all-solid-state electrolyte on the negative electrode side is Li6PS5Cl or Li 5.5 PS 4.5 Cl 1.5 . 6.The halide-based all-solid-state lithium metal battery of claim 5, wherein, ​

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