Molten-state lithium battery negative electrode material, preparation method and all-solid-state lithium battery

Abstract

According to the molten lithium battery negative electrode material, the preparation method and the all-solid-state lithium battery provided by the invention, a small amount of Si3N4 is added into molten Li, the surface tension of the molten Li is adjusted, and the molten Li-Si-N after reaction can change point contact of lithium and a garnet interface into surface contact, so that the wettability of a garnet electrolyte and metal lithium is improved, and the lithium ion battery negative electrode material is prepared. The interface impedance of the two is reduced, and a uniform electric field is provided for lithium deposition and stripping processes. After being assembled into a symmetrical battery, the material shows excellent cycling stability (stable cycling for 1500 hours under the current density of 0.2 mA cm <-2 > and stable cycling for 1000 hours under the current density of 0.4 mA cm <-2 >) and relatively high critical current density (1.8 mA cm <-2 >). The first specific discharge capacity of the assembled all-solid-state battery under the current density of 2C reaches up to 145mAh g <-1 >, and the capacity is kept at 97% after 100 cycles under the current density of 1C.

Description

technical field [0001] The invention relates to a molten lithium battery negative electrode material with low surface tension, a preparation method and an all-solid-state lithium battery, and belongs to the technical field of all-solid-state lithium batteries. Background technique [0002] Since the commercialization of the first rechargeable lithium-ion battery by Japan's Sony Corporation in the 1990s, scholars around the world have initiated a research boom in lithium-ion batteries. Recently, lithium-ion batteries have begun to be used in the field of electric vehicles, but traditional lithium-ion batteries have limited their development in the field of electric vehicles due to low energy density and safety issues caused by flammable electrolytes. The solid-state electrolyte in the all-solid-state battery has good compatibility with lithium metal, and metal lithium as the "ultimate" negative electrode material of the lithium battery has an ultra-high theoretical specific c...

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Problems solved by technology

However, in practice, this improvement effect is relatively limited, and the interface resistance at room temperature still needs to be further reduced.

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