CN-121991593-A - Metal lithium surface protection slurry and preparation method and application thereof

Abstract

The invention provides a metal lithium surface protection slurry and a preparation method and application thereof, wherein the surface protection slurry comprises, by weight, 5-20 parts of metal organic framework Materials (MOFs), 70-85 parts of solvents, 3-6 parts of conducting agents, 3-6 parts of thickening agents and 1-4 parts of auxiliary agents, wherein the MOFs comprise MOFs with zinc-based, cobalt-based, vanadium-based, iron-based, aluminum-based, chromium-based, zirconium-based or lanthanide metal-based as metal ions or metal cluster nodes, and the conducting agents comprise organic polymer solid electrolytes or organic-inorganic composite solid electrolyte materials. The surface protection slurry provided by the invention can form a protective layer with excellent lithium-philic property, dendrite resistance and stability on the surface of metallic lithium.

Inventors

• MOU JINGYAN
• SUN ZHAOYONG
• HUAN QINGNA
• WANG WEIZHOU
• ZHAO ZIYUE
• CHEN QIANG
• Chen Zichan

Assignees

• 天津中能锂业有限公司

Dates

Publication Date

20260508

Application Date

20241106

Claims (10)

1. 1. The lithium metal surface protection slurry is characterized by comprising the following components in parts by weight: 5-20 parts of metal organic frame Materials (MOFs); 70-85 parts of a solvent; 3-6 parts of a conductive agent; 3-6 parts of a thickening agent; 1-4 parts of an auxiliary agent, The total weight part is 100 parts.
2. 2. The metallic lithium surface protection paste according to claim 1, wherein the MOFs material comprises MOFs material having zinc-based, cobalt-based, vanadium-based, iron-based, aluminum-based, chromium-based, zirconium-based, or lanthanide metal-based as metal ion or metal cluster nodes; Preferably, the MOFs material is selected from one or a combination of at least two of ZIF series, MIL series, uiO series, IRMOF series, PCN series and NU series, wherein the ZIF series is selected from at least one of ZIF-7, ZIF-8, ZIF-63, ZIF-67, ZIF-71 and ZIF-90, the MIL series is selected from at least one of MIL-53, MIL-88, MIL-96, MIL-100, MIL-101 and MIL-125, the UiO series is selected from at least one of UiO-67, uiO-68, uiO-76, uiO-77 and UiO-84, the IRMOF series is selected from at least one of IRMOF-1, IRMOF-3, IRMOF-6, IRMOF-8, IRMOF-9 and IRMOF-10, the PCN is selected from at least one of PCN-14, PCN-200, PCN-222, PCN-250 and NU-111 and NU-125, and the NU series is selected from at least one of PCN-14, PCN-200, PCN-222, PCN-250 and NU-111.
3. 3. The lithium metal surface protection paste according to claim 1 or 2, wherein the MOFs material is in the form of particles with a particle size D50 of 100-600nm, a pore size of 0.1-2 a, a density of 0.3-0.5g/cm 2 , and a porosity of 70% -80%.
4. 4. A metallic lithium surface protection paste according to any of claims 1-3, wherein said conducting agent is an ionic conducting agent comprising an organic polymer solid electrolyte or an organic-inorganic composite solid electrolyte, wherein the organic polymer solid electrolyte comprises one or more of polystyrene butadiene copolymer (SBR), polyethylene oxide (PEO), polyvinylidene fluoride (PVDF), epoxy resin (EP), polyurethane (PU), wherein the organic-inorganic composite solid electrolyte comprises a mixture of one or more of the above organic polymer solid electrolytes with one or more of lithium salt lithium bis (trifluoromethylsulfonyl) imide (LITFSI) and inorganic solid electrolyte sodium chloride, potassium chloride, calcium chloride, sodium sulfide, potassium sulfide, sodium carbonate, sodium hydroxide, magnesium hydroxide.
5. 5. The lithium metal surface protection paste according to claim 4, wherein the number average molecular weight of the organic polymer solid electrolyte is 10000 to 200000.
6. 6. The lithium metal surface protection slurry according to any one of claims 1 to 5, wherein the solvent comprises one or more of N-methyl pyrrolidone (NMP), ethylene glycol dimethyl ether (DME), dimethyl carbonate (DMC), diethyl carbonate (DEC).
7. 7. The lithium metal surface protection slurry according to any one of claims 1 to 6, wherein the thickener comprises one or more of carboxymethyl cellulose (CMC), sesbania gum, sodium Starch Phosphate (SSP), triethyl phosphate (TEP), polyethylene glycol (PEG 600), sodium Polyacrylate (PAAS).
8. 8. The lithium metal surface protection slurry according to any one of claims 1 to 7, wherein the auxiliary agent comprises a dispersant, a stabilizer, Preferably, the dispersant comprises one or more of Tego Dispers 740W, 750W, 755W, 655, 670, 710 (germany Gao Chuji). Preferably, the stabilizer comprises one or more of 4-tert-butylphenol, 2, 6-di-tert-butyl-p-cresol, beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate.
9. 9. A method for preparing the lithium metal surface protection paste according to any one of claims 1 to 8, comprising the steps of: 1) Drying MOFs material, conductive agent, thickener and auxiliary agent respectively; 2) Stirring and mixing the conductive agent, the thickening agent and the solvent to obtain a premix 1; 3) Stirring and mixing the auxiliary agent and the solvent to obtain a premix 2; 4) And (3) stirring and mixing the MOFs material, the premix 1 and the premix 2 to obtain the metal lithium surface protection slurry.
10. 10. Use of the metal lithium surface protection paste according to any one of claims 1 to 8 in a negative electrode protection layer of a metal lithium battery.

Description

Metal lithium surface protection slurry and preparation method and application thereof Technical Field The invention relates to the field of electrochemistry, in particular to a metal lithium surface protection slurry, a preparation method and application thereof. Background In recent years, a lithium metal negative electrode material has been attracting attention because of its advantages such as high mass specific capacity and good safety, and is expected to be applied to fields such as portable electronic products and electric automobiles. However, in the practical use process, the metal lithium is easy to generate uncontrollable self-discharge and oxidation, so that the service life of the battery is greatly shortened, and the protection of the interface of the metal lithium anode is important. At present, an inorganic coating is generally adopted to passivate the surface of metal lithium to improve the stability, but the method has the following defects that 1) a passivation layer is thin and brittle, microcracks are easy to generate in the circulation process, the microcracks gradually increase with the increase of the circulation times until a lithium sheet fails, 2) some traditional passivation materials such as silicon dioxide, aluminum oxide and the like are difficult to form a completely compact passivation film with the metal lithium, and the preparation cost of the materials is higher. Therefore, in order to improve the stability and cycle life of metallic lithium, it is necessary to develop a novel surface protecting material. Disclosure of Invention In order to solve the problems in the prior art, the invention aims to provide a metal lithium surface protection slurry, and a preparation method and application thereof. According to the invention, MOFs material is used as a raw material of the surface protection coating slurry, and is combined with the conductive agent to improve the hardness, conductivity, corrosion resistance and other properties of the coating, so that the protection slurry can be used for effectively protecting the surface of the metal lithium, and the safety, conductivity and circulation stability of the metal lithium are obviously improved, thereby greatly widening the application field of the metal lithium. In order to achieve the above purpose, the present invention adopts the following technical scheme: in a first aspect, the invention provides a lithium metal surface protection slurry, which comprises the following components in parts by weight: 5-20 parts of metal organic frame Materials (MOFs); 70-85 parts of a solvent; 3-6 parts of a conductive agent; 3-6 parts of a thickening agent; 1-4 parts of an auxiliary agent; The total weight part is 100 parts. According to the invention, MOFs material and conductive agent are mixed for use in the metal lithium surface protection slurry, so that the hardness, conductivity, corrosion resistance and other properties of a coating formed on the surface of the metal lithium can be improved, and the metal lithium negative electrode can exert excellent cycle performance in a metal lithium battery. The MOFs material has a three-dimensional porous structure, so that the problem of volume expansion of the surface of the metal lithium can be relieved, and a compact protective layer can be formed on the surface of the metal lithium in the charge-discharge process of the battery, and the MOFs material plays the role of an intelligent barrier body. The three-dimensional porous structure of the MOFs material can store and regulate uniform deposition of lithium ions, so that the problem of dendrite growth of a lithium metal battery due to stress concentration is solved, and the electrolyte can be further adsorbed by the large specific surface area of the MOFs material, so that the cycling stability of the electrode is further improved. The conductive agent can improve the adhesion between MOFs material and the surface of metallic lithium, can improve the ion conductivity, reduce the surface tension of slurry, improve the performance of a coating process, such as reducing the viscosity, improving the fluidity and playing a role in space stabilization. The MOFs material and the conductive agent are used cooperatively, and the prepared metal lithium surface protection slurry can have a good protection effect on the surface of the metal lithium under the condition of keeping good conductivity and porosity, so that the cycle life and the multiplying power performance of the battery are improved, and the maintenance cost of the battery is greatly reduced. MOFs material is a crystalline porous solid material assembled by organic connectors through a specific connection mode, has very high specific surface area and porosity, and has the characteristics of precise composition control and structural design. The MOFs material has certain chemical activity due to the strong interaction between metal ions and bridging ligands, and can be used as a raw m