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CN-122025754-A - LATP-CeO2Composite oxide electrolyte, composite positive plate, solid-state battery and preparation methods thereof

CN122025754ACN 122025754 ACN122025754 ACN 122025754ACN-122025754-A

Abstract

The invention provides a LATP-CeO 2 composite oxide electrolyte, a composite positive plate, a solid-state battery and preparation methods thereof. The LATP-CeO 2 composite oxide electrolyte replaces weak interaction of physical mixing through covalent bond connection between the LATP and the CeO 2 , avoids interface debonding and phase separation, improves electrolyte density, improves the condition that interface stripping easily occurs in a traditional composite coating and causes interface impedance to be increased, and the composite oxide electrolyte constructs a 'fast ion conduction-oxygen vacancy regulation' dual-function layered coating, so that ion fast transmission and transition metal ion dissolution inhibition are realized, meanwhile, ion transmission efficiency and interface stability are considered, and battery cycle performance and safety performance are improved.

Inventors

  • WANG SHUNRUI

Assignees

  • 固态离子能源科技(武汉)有限公司

Dates

Publication Date
20260512
Application Date
20251225
Priority Date
20251223

Claims (10)

  1. 1. A LATP-CeO 2 composite oxide electrolyte is characterized in that the raw materials comprise LATP and CeO 2 .
  2. 2. The LATP-CeO 2 composite oxide electrolyte as claimed in claim 1, wherein the mass ratio of the LATP to the CeO 2 is (8-10): 1.
  3. 3. The preparation method of the LATP-CeO 2 composite oxide electrolyte according to any one of claims 1 to 2, which is characterized by comprising the following steps of S1, uniformly mixing the mixture of the LATP and the CeO 2 with absolute ethyl alcohol, adding a dispersing agent, and grinding to obtain slurry; s2, drying the slurry, grinding and sieving to obtain powder; And S3, sintering the powder in an inert atmosphere to obtain the LATP-CeO 2 composite oxide electrolyte.
  4. 4. The method for preparing the LATP-CeO 2 composite oxide electrolyte as claimed in claim 3, wherein the sintering temperature is 900-1000 ℃ and the sintering time is 4-6h.
  5. 5. A composite positive plate characterized in that raw materials comprise a positive electrode roll and the LATP-CeO 2 composite oxide electrolyte as claimed in any one of claims 1 to 2 coated on the surface of the positive electrode roll.
  6. 6. The method for preparing the composite positive plate according to claim 5, comprising the steps of S1, dissolving a binder and a dispersing agent in a solvent, adding the LATP-CeO 2 composite oxide electrolyte, uniformly mixing, and sieving to obtain composite oxide electrolyte slurry; S2, uniformly mixing the anode material, the binder, the conductive agent and the solvent, coating the mixture on an aluminum foil, drying and rolling the mixture to obtain an anode coil; and S3, coating the composite oxide electrolyte slurry on the surface of the positive electrode roll, drying, rolling and die cutting to obtain the composite positive electrode sheet.
  7. 7. The method for preparing a composite positive electrode sheet according to claim 6, wherein the thickness of the composite oxide electrolyte slurry coated in the step S3 is 10 to 20 μm.
  8. 8. The method for preparing a composite positive electrode sheet according to claim 6, wherein the binder in steps S1 and S2 comprises PVDF, the dispersant comprises PVP, and the solvent in steps S1 and S2 comprises NMP.
  9. 9. The method for preparing the composite positive plate according to claim 8, wherein the mass ratio of the LATP-CeO 2 composite oxide electrolyte, the binder and the dispersing agent in the step S1 is (85-95): 8.5-10): 0.2-1.
  10. 10. A solid-state battery comprising the composite positive electrode sheet according to claim 5.

Description

LATP-CeO 2 composite oxide electrolyte, composite positive plate, solid-state battery and preparation methods thereof Technical Field The invention relates to the technical field of solid-state battery materials, in particular to a LATP-CeO 2 composite oxide electrolyte, a composite positive plate, a solid-state battery and a preparation method thereof. Background Lithium ion batteries have become a core power source for portable electronic devices, electric vehicles and large-scale energy storage systems by virtue of their high energy density, long cycle life and low self-discharge rate. Along with the continuous expansion of application fields and the continuous increase of market demands, higher requirements are put on the energy density, the power output and the service life of the battery. However, with this, the safety of the battery is becoming a key bottleneck restricting its further development, and is receiving high attention from industry and consumers. Lithium ion batteries currently in commercial use primarily employ liquid electrolyte systems, which are typically composed of lithium salts (e.g., lithium hexafluorophosphate) dissolved in carbonate-based organic solvents. The organic solvent has the characteristics of high volatility, low flash point and inflammability, and under the abnormal conditions of overheat, overcharge, internal short circuit or mechanical abuse of the battery, thermal runaway is extremely easy to be caused, so that the battery smokes, fires and even explodes, and obvious potential safety hazards exist. In addition, the interfacial side reaction between the liquid electrolyte and the high-activity positive and negative electrode materials (especially high-energy density positive electrodes such as high nickel, lithium-rich manganese base and the like) is severe, active lithium can be continuously consumed, the interfacial impedance is increased, and the cycle life and the operating temperature window (usually-20 ℃ to 60 ℃) of the battery are limited. In order to improve the safety, the industry tries to add electrolyte additives, use high-concentration salt or flame-retardant solvents and other improvements, but the methods often have trade-offs in terms of cost, ionic conductivity or electrochemical stability, and the inherent combustion risk of the organic solvents is difficult to eliminate fundamentally. To thoroughly solve the safety problem caused by flammable electrolytes, all-solid-state lithium batteries are regarded as an important development direction of next-generation battery technology. The non-combustible inorganic solid electrolyte (such as oxide, sulfide, polymer and the like) is adopted to completely replace the liquid electrolyte, so that the intrinsic safety of the battery can be greatly improved theoretically. Among them, oxide solid electrolytes are widely studied for their good chemical stability, wide electrochemical window, and high mechanical strength. However, when the oxide solid electrolyte is directly applied to a battery, a prominent technical problem is that the oxide solid electrolyte is in solid-solid contact with the particles of the positive electrode active material, the interface contact is poor, the impedance is high, the ion transmission efficiency is low, and the multiplying power and the cycle performance of the battery are severely restricted. This problem is more pronounced especially for thick loaded positive pole pieces. Traditional solutions, such as coating solid electrolytes, tend to be complex to implement and costly. Therefore, how to effectively improve the interface contact between the positive electrode and the solid electrolyte without introducing flammable components and construct the positive electrode-electrolyte interface with high ion transmission efficiency and excellent chemical stability becomes a key for developing high-performance and high-safety solid lithium batteries. Disclosure of Invention In view of the above, the invention provides a LATP-CeO 2 composite oxide electrolyte, a composite positive plate, a solid-state battery and a preparation method thereof. LATP and CeO 2 in the LATP-CeO 2 composite oxide electrolyte are connected through covalent bonds, weak interaction of physical mixing is replaced, interface debonding and phase separation are avoided, electrolyte compactness is improved, the condition that interface resistance is increased due to interfacial stripping easily occurring in a traditional composite coating is improved, the composite oxide electrolyte is provided with a 'fast ion conduction-oxygen vacancy regulation' dual-function layered coating, ion fast transmission and transition metal ion dissolution inhibition are achieved, meanwhile, ion transmission efficiency and interface stability are considered, and battery circulation and safety performance are improved. The technical scheme of the invention is realized as follows: In a first aspect, the present invention provides a LATP-Ce