CN-122025732-A - Solid-state battery, battery device, and power consumption device

Abstract

The invention relates to a solid-state battery, a battery device and an electric device, wherein the solid-state battery comprises a positive electrode, a solid electrolyte isolating film and a surface modified lithium metal negative electrode, the surface modified lithium metal negative electrode is obtained by treating the lithium metal negative electrode with a surface treatment liquid containing an active ingredient and a diluent, the active ingredient comprises a non-fluorinated carbonate solvent, a fluorinated carbonate solvent and lithium salt, and the diluent is fluorinated ether. The lithium metal is immersed into a local high-concentration electrolyte treatment solution containing multiple fluorinated solvents or additives to spontaneously react to obtain the LiF-rich organic-inorganic hybrid solid electrolyte membrane by utilizing the extremely strong reduction activity of the lithium metal, the lithium metal is induced to be uniformly deposited on the surface of a negative electrode by virtue of the high interfacial energy and the high Young modulus of LiF, lithium dendrites are inhibited from penetrating through the solid electrolyte membrane, the problem that an inorganic SEI membrane is easy to break is relieved by utilizing the flexibility of organic components, and the stable operation of a solid battery is realized by the synergistic effect of the organic and inorganic components in the SEI membrane.

Inventors

• TANG WENJIE
• HOU MIN
• REN QIANG
• Du Zepu
• QIN ZHONGZHENG
• CUI YI
• LI BIN
• LIU CHAN

Assignees

• 瑞浦兰钧能源股份有限公司
• 瑞浦赛克动力电池有限公司
• 上汽通用五菱汽车股份有限公司
• 柳州赛克科技发展有限公司

Dates

Publication Date

20260512

Application Date

20260415

Claims (13)

1. 1. The solid-state battery is characterized by comprising a positive electrode, a solid electrolyte isolating film and a surface modified lithium metal negative electrode, wherein the surface modified lithium metal negative electrode is obtained by carrying out surface modification treatment on the lithium metal negative electrode by using a surface treatment liquid; The surface treatment liquid comprises an active ingredient and a diluent, wherein the active ingredient comprises a non-fluorinated carbonate solvent, a fluorinated carbonate solvent and lithium salt, and the diluent comprises a fluorinated ether solvent.
2. 2. The solid-state battery according to claim 1, wherein the non-fluorinated carbonate-based solvent is a non-fluorinated cyclic carbonate-based solvent; And/or the fluorinated carbonate solvent is a fluorinated cyclic carbonate solvent.
3. 3. The solid-state battery according to claim 2, wherein the non-fluorinated carbonate-based solvent is a non-fluorinated unsaturated cyclic carbonate-based solvent.
4. 4. The solid state battery of claim 1, wherein the non-fluorinated carbonate-based solvent comprises one or more of ethylene carbonate, propylene carbonate, vinylene carbonate, vinyl ethylene carbonate; and/or the fluorocarbonate solvent comprises one or more of fluoroethylene carbonate, difluoroethylene carbonate and trifluoropropylene carbonate; and/or the lithium salt comprises one or more of lithium bis-fluorosulfonyl imide and lithium hexafluorophosphate; And/or the number of the groups of groups, the fluoroether solvent comprises 1, 2-tetrafluoroethyl-2, 2-trifluoroethyl ether, bis (2, 2-trifluoroethyl) ether 2, 3-tetrafluoropropyl-1, 2-tetrafluoroethyl ether, 1, 2-tetrafluoroethyl ethyl ether one or more of bis (2, 2-difluoroethyl) ether.
5. 5. The solid-state battery according to claim 1, wherein the mass ratio of lithium salt in the active ingredient is 15% -30%; and/or the mass ratio of the non-fluorinated carbonate solvent to the lithium salt is 0.1-2:60-80:15-25; And/or the mass ratio of the active ingredient to the diluent is 1:7-10.
6. 6. The solid-state battery according to claim 1, wherein the surface modification treatment is a reaction of immersing the lithium metal negative electrode in a surface treatment liquid, followed by a drying treatment, to obtain a surface-modified lithium metal negative electrode.
7. 7. The solid-state battery according to claim 6, wherein the surface modification treatment is under inert gas protection; And/or immersing the lithium metal anode into the surface treatment liquid for reaction for 10-60 min.
8. 8. The solid-state battery according to claim 1, wherein the positive electrode includes a positive electrode current collector and a positive electrode film layer on at least one surface of the positive electrode current collector, and the solid-state electrolyte separator is provided on the surface of the positive electrode film layer.
9. 9. The solid-state battery according to claim 8, wherein the preparation method of the solid-state electrolyte separator is a dry preparation process or a wet preparation process; The wet method for preparing the solid electrolyte isolating film comprises the step of coating solid electrolyte isolating film slurry on the surface of a positive electrode film layer, wherein a plurality of through holes are formed in the positive electrode current collector.
10. 10. The solid-state battery according to claim 9, wherein the pore diameter of the through-hole is 20 to 100 μm, and/or the porosity of the positive electrode current collector is 30 to 60%.
11. 11. The solid state battery of claim 1, wherein the positive electrode comprises a positive electrode current collector and a positive electrode film layer on at least one surface of the positive electrode current collector, the positive electrode active material in the positive electrode film layer comprising one or more of: (a) Li a1 (Ni x1 Co y1 Mn 1-x1-y1 ) 1-b1 M b1 O 2-c A c , wherein 0.75≤a1≤ 1.2,0.5≤x1 <1,0< y1≤ 0.15,1-x1-y1>0, 0≤b1≤ 0.01,0≤c≤0.2, M is selected from one or more of Al, zr, ti, Y, sr, W, mg, A is selected from one or more of S, F, N; (b) Li a2 (Fe x2 N 1-x2 ) 1-b2 N' b2 PO 4 , wherein a2 is more than or equal to 0.75 and less than or equal to 1.2,0.5 and less than or equal to x2 is more than or equal to 1, N is selected from one or more of Mn, ni and Co, b2 is more than or equal to 0 and less than or equal to 0.01, and N' is selected from one or more of Mg, ti and V; (c) Li a3 (Mn x3 Ni 1-x3 ) 2-b3 R b3 O 4 is a metal oxide, wherein a3 is more than or equal to 0.75 and less than or equal to 1.2,0.5 x3 is less than or equal to 1, b3 is less than or equal to 0 less than or equal to 0.01, R is selected from one or more of Al, zr, ti, Y, sr, W, mg; (d) Lithium cobaltate; (f) A lithium-rich manganese-based positive electrode material; And/or the lithium metal cathode is a lithium foil, or the lithium metal cathode comprises a cathode current collector and a lithium metal layer positioned on at least one surface of the cathode current collector.
12. 12. A battery device, characterized in that the battery device comprises a solid-state battery according to any one of claims 1-11.
13. 13. An electric device is characterized in that, the power utilization device comprises a battery device according to claim 12 for providing electrical energy.

Description

Solid-state battery, battery device, and power consumption device Technical Field The invention belongs to the technical field of batteries, and particularly relates to a solid-state battery, a battery device and an electric device. Background At present, the lithium metal cathode almost becomes a necessary choice for realizing an ultra-high energy density battery of 500wh/kg or more by virtue of the ultra-high gram capacity (3860 mAh/g), low electrochemical potential (3.04V relative to a standard hydrogen electrode) and low density (0.534 g/cm 3). However, lithium metal anodes face significant volume change rates and uneven lithium ion exfoliation/deposition during charge and discharge, and thus sustained interfacial side reactions and lithium dendrite problems, which pose serious challenges to the cycle life and safety performance of the battery. In view of the above problems faced by lithium metal anodes, researchers have focused on how to construct a solid and stable artificial SEI film or buffer layer on the lithium metal surface to suppress interfacial side reactions and promote uniform deposition of lithium ions. Research has shown that lithium fluoride (LiF) is an active ingredient in the construction of stable, safe SEI films among various types of SEI film components, and it is important to suppress dendrites and provide the advantage of mechanical stability. The inherent low ionic conductivity and brittleness of LiF, however, determines that it alone cannot constitute a perfect SEI film. Disclosure of Invention The invention aims to solve the problems in the prior art and provides a solid-state battery, a battery device and an electric device. The aim of the invention can be achieved by the following scheme: The invention provides a solid-state battery, which comprises a positive electrode, a solid electrolyte isolating film and a surface modified lithium metal negative electrode, wherein the surface modified lithium metal negative electrode is obtained by carrying out surface modification treatment on the lithium metal negative electrode by using a surface treatment liquid; The surface treatment liquid comprises an active ingredient and a diluent, wherein the active ingredient comprises a non-fluorinated carbonate solvent, a fluorinated carbonate solvent and lithium salt, and the diluent comprises one or more of fluorinated ether solvents. In the prior art, an organic-inorganic hybrid SEI film is generally formed in a battery system using a liquid electrolyte, however, the design of the liquid electrolyte often needs to take into consideration multiple factors, such as the influence on the positive electrode active material, the influence on the viscosity and the ionic conductivity of the liquid electrolyte, the influence on the high and low temperature performance and gas production of the battery, and the like. These mutually restricted requirements severely limit the selection and content adjustment of the liquid electrolyte components, thereby affecting the formation of the SEI film, and it is generally difficult to form a stable structure having a high LiF content. For example, the lithium salt content in the electrolyte is usually lower than 15%, if the concentration of the lithium salt in the electrolyte is too high, the viscosity of the electrolyte is significantly increased to hinder ion migration in the electrolyte and reduce the conductivity of the electrolyte, and if the concentration of the fluorocarbons solvent is too high, the viscosity of the electrolyte is too high to reduce the ionic conductivity and wettability of the electrolyte, so that in practical application, the concentration of the fluorocarbons in the electrolyte is generally not more than 10%. The surface treatment liquid is only used for the surface modification treatment of the lithium metal anode, is not added into a battery, is independent of a battery system and is not limited by the factors, so that the surface treatment liquid has great flexibility in the aspects of component selection and content adjustment, and is convenient for adjusting the organic/inorganic content and components in the SEI film. In addition, the surface treatment liquid adopts the combination of the active ingredient and the diluent, the diluent is mutually dissolved with the solvent in the active ingredient, but does not dissolve the lithium salt, namely does not destroy the coordination structure of the lithium salt and the solvent in the original active ingredient, the lithium salt is still closely surrounded by solvent molecules in microcosmic view, the mass ratio of each component in the active ingredient is basically kept unchanged, a microenvironment with high local lithium ion concentration is formed, the diluent does not react with lithium metal, the effect of physical dilution is achieved on the active ingredient, the reaction speed of the active ingredient and the lithium metal can be reduced, and the loose and undensified SEI