A kind of Ga, Al co-doped llzo solid electrolyte, multi-element solid battery and preparation method thereof

Abstract

The invention belongs to the technical field of all-solid-state batteries, and in particular relates to a Ga, Al co-doped LLZO solid electrolyte, a multi-component solid-state battery and a preparation method thereof. The Ga, Al co-doped LLZO inorganic oxide solid electrolyte prepared by the invention has ion conductivity High efficiency, good stability and other excellent performance. The invention introduces Ga, Al co-doped LLZO inorganic oxide solid electrolyte and quantum carbon-based film / metal composite interface layer to prepare multi-component solid-state battery, which effectively solves the three major problems of lithium dendrite growth, low Coulomb effect and interface side reaction. The core problem faced by the mass production of solid-state batteries.

Description

technical field [0001] The invention relates to a Ga and Al co-doped LLZO solid electrolyte, a multi-component solid-state battery and a preparation method thereof, belonging to the technical field of solid-state batteries. Background technique [0002] Inorganic oxide solid electrolyte has the advantages of high thermal stability, chemical stability, good ion conductivity, large potential window, relatively high calcination density, no environmental pollution, and controllable process conditions, and has gradually become a new An important material for a generation of all-solid power batteries. Among them, the garnet-type solid electrolyte (LLZO) is the electrolyte with the best comprehensive performance among the oxide electrolytes. The LLZO solid electrolyte not only has a conductivity as high as 10-4S / cm~10-3S / cm, but also has chemical stability to Li And the shear modulus of 56GPa ~ 60GPa, it may become the core material of the next generation of batteries - all solid-...

AI Technical Summary

Problems solved by technology

[0004] Different from the electrolyte, the LLZO electrolyte has high strength and high brittleness, and it is difficult to fully contact with the positive and negative materials, and this insufficient solid-solid contact will lead to a huge interface impedance between the electrolyte and the electrode, and a poor negative / electrode The impedance of the electrolyte interface is about 1KΩ·cm2, and the impedance of the positive electrode / electrolyte interface without modification is often higher than 1MΩ·cm2. Such a high interface impedance makes solid batteries unable to operate at room temperature, so the interface problem is that LLZO is used Top hurdles to practical application in solid-state batteries

[0005] In addition to the interface problem, another major problem of LLZO electrolytes in battery applications is the growth of lithium dendrites. It was first believed that the strength of inorganic solid electrolytes is high, and lithium dendrites cannot pierce them, so there is no problem of lithium dendrites. However, research It is shown that the position of lithium ions passing through the LLZO electrolyte ion channel reaches the negative electrode is uneven, and there is also a gap between the solid electrolyte and the negative electrode interface, so it is easy to cause irregular deposition of lithium ions, thereby forming lithium dendrites, and once lithium dendrites Appearance means that the lithium ions inside the battery have irreversibly decreased, and at the same time, lithium dendrites will continue to absorb free lithium ions to grow, and eventually may puncture the diaphragm, resulting in direct contact between the positive and negative electrodes of the battery and causing a short circuit

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