Preparation method of anode-free lithium ion solid-state battery

Abstract

The invention belongs to the field of solid-state lithium metal batteries, and particularly discloses a preparation method of an anodeless lithium ion solid-state battery, which comprises the following steps: (1) in a glove box in an argon atmosphere, stirring and mixing liquid metal, a solvent and a lithium salt in proportion to obtain a mixed liquid; the lithium salt is one or more of lithium bis (trifluoromethanesulfonic acid) imide, lithium bis (fluorosulfonyl) imide, lithium perchlorate, lithium hexafluorophosphate, lithium tetrafluoroborate and lithium bis (oxalato) borate; the liquid metal is one or more of gallium, gallium-based alloy, bismuth-based alloy and sodium-potassium alloy. The solvent is one or more of ethylene carbonate, dimethyl carbonate, methyl ethyl carbonate, 1, 2-dimethoxyethane, tetrahydrofuran, vinylene carbonate and fluoroethylene carbonate. (2) in a glove box in an argon atmosphere, coating the mixed liquid on the surface of a solid electrolyte to serve as a solid-state battery anode, and then assembling a button cell; the solid electrolyte is an inorganic solid electrolyte, and is preferably selected from at least one of a garnet type solid electrolyte, an LISICON type solid electrolyte, an NASICON type solid electrolyte, a LiTa2PO8 type solid electrolyte, a halide electrolyte and a perovskite type solid electrolyte. The mixed liquid taking the liquid metal as the substrate can be coated on the surface of the solid electrolyte to serve as the substrate for lithium ion deposition; the lithium ion battery is rich in lithium ions, so that the loss of the lithium ions in the cycle process of the solid-state battery can be effectively supplemented, and the performance of the solid-state battery is improved. Through simple stirring and mixing procedures, the preparation of the anode-free lithium ion solid-state battery is realized, and the electrochemical performance is improved.

Description

Technical Field

[0001] The present invention belongs to the field of solid-state lithium metal batteries, and in particular relates to a method for preparing an anode-free lithium-ion solid-state battery. Background Art

[0002] With the continuous growth of energy demand and the increasingly serious environmental problems, lithium-ion batteries, as energy storage devices with high energy density and long cycle life, have been widely used in portable electronic devices, electric vehicles and renewable energy storage systems. However, traditional lithium-ion batteries have several limitations, including safety hazards caused by the liquid state of the electrolyte, limited improvement of battery energy density, and easy thermal runaway during high temperature or long-term use. Therefore, the development of safer, more efficient and durable energy storage technology has become an important issue in the current energy field.

[0003] Solid-state batteries, especially anode-free lithium-ion solid-state batteries, as a new type of battery technology, have attracted widespread attention in recent years. Anode-free lithium-ion solid-state batteries do not require anode materials in the traditional sense. Instead, they directly use lithium metal as the negative electrode and rely on solid electrolytes to provide ion conduction, thereby eliminating the safety hazards of electrolyte leakage, combustion and thermal runaway in traditional liquid electrolytes. In addition, solid-state batteries have significant advantages in energy density, cycle stability and service life, which makes them have broad application prospects in future high-energy density battery systems.

[0004] Despite this, the development of solid-state batteries faces some technical challenges. For example, the interface problem between solid electrolytes and electrode materials, the ionic conductivity of solid electrolytes is usually lower than that of liquid electrolytes, and the stability of solid-state batteries at high temperatures still limit their commercialization process. In particular, anode-free lithium-ion solid-state batteries, due to the use of lithium metal, bring a higher risk of dendrite growth. How to effectively avoid the battery short circuit problem caused by dendrites and ensure its long-term stable performance is still a technical problem that needs to be solved urgently. Summary of the invention

[0005] The purpose of the present invention is to broaden the preparation method of anode-free lithium-ion solid-state batteries, assemble anode-free lithium-ion solid-state batteries, reduce the interface impedance of the batteries, and improve the comprehensive performance of the batteries.

[0006] To this end, the present invention provides a method for preparing an anode-free lithium-ion solid-state battery, comprising:

[0007] In a glove box under an argon atmosphere, the liquid metal is stirred and mixed with a solvent and a lithium salt in proportion to obtain a mixed liquid. In a glove box under an argon atmosphere, the mixed liquid is coated on the surface of a solid electrolyte as a solid-state battery anode, and then button batteries are assembled. The solid electrolyte is an inorganic solid electrolyte, preferably selected from a garnet-type solid electrolyte, a LISICON-type solid electrolyte, a NASICON-type solid electrolyte, a LiTa 2 PO 8 At least one of a type solid electrolyte, a halide electrolyte and a perovskite solid electrolyte.

[0008] Furthermore, the NASICON solid electrolyte is Li (1+x) Al x Ti (2-x) P 3 O 12 or / and Li (1+y) Al y Ge (2-y) P 3 O 12 , 0≤x≤2, 0≤y≤2; the perovskite solid electrolyte is Li 3z La 2 / 3-z TiO 3 , 0≤z≤2 / 3; the LISICON type solid electrolyte is Li 14 Zn(GeO 4 ) 4 ; The garnet-type solid electrolyte is Li 7-m La 3 Zr 2-m M m O 12 (M=Ta, Nb; 0≤m≤2), Li 7-2n La 3 Zr 2-n NnO 12 (N=W, Mo; 0≤n≤2), Li 7-3d D d La 3 Zr 2 O 12 (D=Ga, Al; 0≤d≤7 / 3), the LiTa 2 PO 8 The solid electrolyte is Li a Ta b M c P d O e(M = one or more elements selected from Nb, Zr, Ga, Sn, Hf, Bi, W, B, F, Mo, Si, Al and Ge; 0.5 < a < 2.0, 1.0 < b ≤ 2.0, 0 < c < 0.5, 0.5 < d < 1.0, 5.0 < e ≤ 8.0); the halide solid electrolyte is Li 3 InCl 6 、LiYCl 6 , Li 4 I 6 , Li 3 Yb 6 , Li 3 InBr 6 , Li 4 GeCl 6 , Li 3 InI 6 , Li 3 YI 6 , Li 7 Ge 3 Cl 12 , Li 5 InCl 12 One or a mixture of two or more materials.

[0009] Furthermore, the lithium salt is one or more of lithium bis(trifluoromethanesulfonate)imide, lithium bis(fluorosulfonyl)imide, lithium perchlorate, lithium hexafluorophosphate, lithium tetrafluoroborate, and lithium bis(oxalatoborate).

[0010] Furthermore, the liquid metal is one or more of gallium, gallium-based alloy, bismuth-based alloy, and sodium-potassium alloy.

[0011] Furthermore, the solvent is one or more of ethylene carbonate, dimethyl carbonate, ethyl methyl carbonate, 1,2-dimethoxyethane, tetrahydrofuran, vinylene carbonate, and fluoroethylene carbonate.

[0012] Furthermore, the lithium salt concentration is 0.01 to 80 wt%, preferably 1 to 20 wt%.

[0013] Furthermore, the amount of the solution added per unit area is 0.1 to 20 μL / cm 2 .

[0014] On the other hand, the present invention also provides a mixed liquid prepared according to the above preparation method.

[0015] Furthermore, the solid-state lithium metal battery comprises: a positive electrode, a negative electrode, a solid electrolyte and the mixed liquid according to claim 8.

[0016] Furthermore, the positive electrode is LiFePO 4、LiCoO 2 、LiNi b Co c Mn 1-b-c O 2 (0≤b≤1,0≤c≤1), LiNi 0.8 Co 0.15 Al 0.05 、LiMn 2 O 4 , lithium-rich phase aLi 2 MnO 3·(1-a) LiMO 2 (M=Mn, Ni or Co, 0≤a≤1), S, Li 2 S.O. 2 At least one of .

[0017] The advantages of the present invention are:

[0018] (1) The method used is simple, environmentally friendly, low-cost, fast, and does not require the use of complex equipment;

[0019] (2) The anode-free solid-state battery prepared by this method has low interface impedance, and the related capacity stability performance and cycle stability are also relatively excellent, and has good application prospects in the fields of energy and materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a flow chart for the preparation of the anode-free lithium-ion solid-state battery.

Claims

1. A method for preparing an anode-free lithium-ion solid-state battery, characterized in that: include: In a glove box under an argon atmosphere, the liquid metal is stirred and mixed with a solvent and a lithium salt in proportion to obtain a mixed liquid. In a glove box under an argon atmosphere, the mixed liquid is coated on the surface of a solid electrolyte as a solid-state battery anode, and then button batteries are assembled. The solid electrolyte is an inorganic solid electrolyte, preferably selected from at least one of a garnet-type solid electrolyte, a LISICON-type solid electrolyte, a NASICON-type solid electrolyte, a LiTa2PO8-type solid electrolyte, a halide electrolyte, and a perovskite-type solid electrolyte.

2. A preparation method according to claim 1, characterized in that: The NASICON solid electrolyte is Li (1+x) Al x Ti (2-x) P3O 12 or / and Li (1+y) Al y Ge (2-y) P3O 12 , 0≤x≤2, 0≤y≤2; the perovskite solid electrolyte is Li 3z La 2 / 3-z TiO3, 0≤z≤2 / 3; the LISICON type solid electrolyte is Li 14 Zn(GeO4)4; the garnet-type solid electrolyte is Li 7-m LqCy 2-m M m O 12 (M=Ta, Nb; 0≤m≤2), Li 7-2n LqCy 2-n NnO 12 (N=W, Mo; 0≤n≤2), Li 7-3d D d La3Zr2O 12 (D = Ga, Al; 0 ≤ d ≤ 7 / 3), the LiTa2PO8 type solid electrolyte is Li a Ta b M c P d O e (M=one or more elements selected from Nb, Zr, Ga, Sn, Hf, Bi, W, B, F, Mo, Si, Al and Ge; 0.5<a<2.0, 1.0<b≤2.0, 0<c<0.5, 0.5<d<1.0, 5.0<e≤8.0); the halide solid electrolyte is Li3InCl6, LiYCl6, Li4GeI6, Li3YBr6, Li3InBr6, Li4GeCl6, Li3InI6, Li3YI6, Li7Ge3Cl 12 、Li5InCl 12 One or a mixture of two or more materials.

3. The preparation method according to claim 1 or 2, characterized in that: The lithium salt is one or more of lithium bis(trifluoromethanesulfonate)imide, lithium bis(fluorosulfonyl)imide, lithium perchlorate, lithium hexafluorophosphate, lithium tetrafluoroborate, and lithium bis(oxalatoborate).

4. The preparation method according to any one of claims 1 to 3, characterized in that The liquid metal is one or more of gallium, gallium-based alloy, bismuth-based alloy, and sodium-potassium alloy.

5. The preparation method according to any one of claims 1 to 4, characterized in that: The solvent is one or more of ethylene carbonate, dimethyl carbonate, ethyl methyl carbonate, 1,2-dimethoxyethane, tetrahydrofuran, vinylene carbonate, and fluoroethylene carbonate.

6. The preparation method according to claims 1-5, characterized in that: The lithium salt concentration is 0.01 to 80 wt %, preferably 1 to 20 wt %.

7. The preparation method according to any one of claims 1 to 6, characterized in that: The amount of the mixed liquid added per unit area is 0.1 to 20 μL / cm 2 .

8. A mixed liquid prepared by the preparation method according to any one of claims 1 to 7.

9. A solid-state lithium metal battery, characterized in that: include: A positive electrode, a negative electrode, a solid electrolyte and the mixed liquid according to claim 8.

10. The anode-free solid-state battery according to claim 9, characterized in that: The positive electrode is LiFePO4, LiCoO2, LiNi b Co c Mn 1-b-c O2(0≤b≤1,0≤c≤1), LiNi 0.8 Co 0.15 Al 0.05 , LiMn2O4, lithium-rich phase aLi2MnO 3.(1-a) At least one of LiMO2 (M = Mn, Ni or Co, 0≤a≤1), S, Li2S, O2.

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