CN-122025766-A - Solid-state battery electrolyte and preparation method and application thereof

Abstract

The invention provides a solid-state battery electrolyte, a preparation method and application thereof, and relates to the technical field of lithium ion batteries. Specifically, the solid-state battery electrolyte of the present invention comprises a first level and a second level, wherein the first level and the second level comprise at least one of sulfide electrolyte or halide electrolyte, and the second level further comprises a filler comprising at least one of inorganic metal sulfide or oxide electrolyte. The invention plays a role in inhibiting the growth of lithium dendrite by carrying out layering design and adding specific filler in the solid electrolyte, thereby greatly improving the cycle life and the safety of the solid battery.

Inventors

• SONG FEIFEI
• XIONG WEIQIANG
• FU FANG
• ZHANG JIUZHOU
• XU TENG
• XU MEI

Assignees

• 奇瑞汽车股份有限公司

Dates

Publication Date

20260512

Application Date

20260325

Claims (10)

1. 1. A solid state battery electrolyte, wherein the solid state battery electrolyte comprises a first level and a second level; The first and second levels include at least one of a sulfide electrolyte or a halide electrolyte; The second level further includes a filler including at least one of an inorganic metal sulfide or oxide electrolyte.
2. 2. The solid state battery electrolyte of claim 1, wherein the solid state battery electrolyte has a thickness of 20 μιη to 100 μιη; and/or the thickness ratio of the first level to the second level is 1:0.2-0.3.
3. 3. The solid state battery electrolyte of claim 1 wherein the inorganic metal sulfide comprises at least one of SnS, znS, pbS.
4. 4. The solid state battery electrolyte of claim 1 wherein the oxide electrolyte comprises at least one of LLTO, LLZO, LLZTO, LATP, LAGP, LZP, li 3 OCl.
5. 5. The solid state battery electrolyte of claim 1, wherein the filler is present at 5wt.% to 10wt.% of the second level.
6. 6. A method for preparing the solid-state battery electrolyte according to claim 1 to 5, comprising the steps of: preparing a first sizing agent, coating and drying to obtain a first level, preparing a second sizing agent, coating the first level, and drying to obtain a second level; wherein the first slurry and the second slurry independently comprise an electrolyte, a binder, and a solvent, and the second slurry further comprises a filler.
7. 7. The method of claim 6, wherein the solids content of the first slurry and the second slurry are independently taken from 50wt.% to 65wt.%.
8. 8. A solid-state battery, characterized in that the solid-state battery comprises a positive electrode, a negative electrode, and the solid-state battery electrolyte according to claims 1 to 5; and the second level is proximate to the negative electrode.
9. 9. A method of manufacturing a solid-state battery according to claim 8, comprising the steps of: And (3) transferring the solid-state battery electrolyte onto a pole piece of the negative electrode through rolling, and compositing the pole piece of the positive electrode onto the surface of the other side of the solid-state battery electrolyte to obtain the solid-state battery.
10. 10. A powered device comprising the solid state battery of claim 8.

Description

Solid-state battery electrolyte and preparation method and application thereof Technical Field The invention relates to the technical field of lithium ion batteries, in particular to a solid-state battery electrolyte, a preparation method and application thereof. Background Solid-state batteries are widely regarded as the core direction of next-generation high-energy-density energy storage technologies, but the problem of lithium precipitation at the negative electrode interface remains a key bottleneck restricting commercialization. In the charge and discharge process, uneven nucleation and growth of lithium metal are easily caused by uneven local current density, high interface impedance caused by poor solid-solid contact and fluctuation of lithium deposition overpotential on the surface of the negative electrode, and the uneven deposition gradually evolves into needle-shaped or dendritic lithium dendrites. Because the currently mainstream solid electrolyte, whether oxide, sulfide or polymer system, has certain limitations on compactness, mechanical strength or electrochemical stability, the grain boundary, pore or defect of the solid electrolyte often becomes a stress concentration point, and the tip stress of dendrites cannot be effectively inhibited. As the cycle proceeds, dendrites continue to spread along these fragile pathways, eventually penetrating the electrolyte layer, directly connecting the positive and negative electrodes, resulting in internal micro-shorting or even thermal runaway. Therefore, how to realize the fundamental regulation and control of lithium deposition behavior from the angles of interface engineering and electrolyte intrinsic structure optimization so as to solve or avoid the potential safety hazard formed by lithium dendrites is a difficult problem to be solved urgently in the current solid-state battery field. In view of this, the present invention has been made. Disclosure of Invention The first object of the present invention is to provide a solid-state battery electrolyte, which solves the defect that lithium is easy to be separated out during charging and discharging of a negative electrode of a solid-state battery by optimizing an electrolyte layer, and avoids or reduces the safety risk of battery short circuit caused by piercing the solid-state electrolyte by lithium dendrites. A second object of the present invention is to provide a method for producing the solid-state battery electrolyte. A third object of the present invention is to provide a solid-state battery. A fourth object of the present invention is to provide a method of manufacturing a solid-state battery. A fifth object of the present invention is to provide a powered device. In order to achieve the above object of the present invention, the following technical solutions are specifically adopted: A solid state battery electrolyte comprising a first level and a second level; The first and second levels include at least one of a sulfide electrolyte or a halide electrolyte; The second level further includes a filler including at least one of an inorganic metal sulfide or oxide electrolyte. In one embodiment, the solid state battery electrolyte has a thickness of 20 μm to 100 μm. In one embodiment, the thickness ratio of the first level to the second level is 1:0.2-0.3. In one embodiment, the inorganic metal sulfide includes at least one of SnS, znS, pbS. In one embodiment, the oxide electrolyte includes at least one of LLTO, LLZO, LLZTO, LATP, LAGP, LZP, li OCl. In an embodiment, the mass fraction of the filler in the second level is 5wt.% to 10wt.%. A method for preparing the solid-state battery electrolyte, comprising the following steps: preparing a first sizing agent, coating and drying to obtain a first level, preparing a second sizing agent, coating the first level, and drying to obtain a second level; wherein the first slurry and the second slurry independently comprise an electrolyte, a binder, and a solvent, and the second slurry further comprises a filler. In one embodiment, the solids content of the first slurry and the second slurry are independently taken from 50wt.% to 65wt.%. A solid-state battery comprising a positive electrode, a negative electrode, and said solid-state battery electrolyte; and the second level is proximate to the negative electrode. A method of manufacturing the solid-state battery, comprising the steps of: And (3) transferring the solid-state battery electrolyte onto a pole piece of the negative electrode through rolling, and compositing the pole piece of the positive electrode onto the surface of the other side of the solid-state battery electrolyte to obtain the solid-state battery. A powered device includes the solid-state battery. Compared with the prior art, the invention creatively provides the electrolyte layer of the solid-state battery and the preparation method thereof, and adopts a coating mode to prepare the double-layer electrolyte structure, wherein the elec