All-solid-state lithium ion battery composite positive electrode diaphragm and manufacturing method thereof

Abstract

The invention discloses a preparation method of a composite positive electrode diaphragm of an all-solid-state lithium ion battery. The preparation method comprises the following steps: preparing a cobalt-free high-nickel lithium ion positive electrode active material; mixing the cobalt-free high-nickel lithium ion positive electrode active material with a solid electrolyte, a conductive agent and a binder to obtain a positive electrode diaphragm raw material; preparing the all-solid-state lithium ion battery composite positive electrode membrane from the positive electrode membrane raw material; the addition ratio of the cobalt-free high-nickel lithium ion positive electrode active material to the solid electrolyte is (7-9): (1-2). Correspondingly, the invention also provides the all-solid-state lithium ion battery composite positive electrode diaphragm prepared by the method, and the capacity and the rate capability of the all-solid-state lithium ion battery can be effectively improved.

Description

Technical field [0001] The present invention relates to the field of full solid state cells, and more particularly to a fully solid-state lithium ion battery composite positive electrode diaphragm and a method of manufacturing the same. Background technique [0002] At present, the market is multi-reactor with an electrolyte with an organic electrolyte, while the long cycle, the electrolyte and the positive electrode material, eroding the positive electrode of the lithium ion battery, and the growth of the lithium bleeding is also exposed to the traditional liquid electrolyte field. Security problem. Using a full solid-state electrolyte replacement electrolyte, the safety of lithium-ion batteries is greatly protected while lifting the cycle performance of lithium battery. [0003] The existing full solid-state lithium ion battery composite positive electrode material is mixed with a positive electrode active material, a solid electrolyte, an electron conductive additive, and a po...

AI Technical Summary

Problems solved by technology

[0004] The replacement of some nickel ions with cobalt and aluminum ions has the following problems. The nickel-based active positive electrode material in the existing all-solid-state lithium-ion battery composite positive electrode has a large potential barrier directly due to divalent nickel ions and trivalent nickel ions, and Due to the similar radius of divalent nickel ions and lithium ions, lithium ions volatilize in the form of lithium oxide during high-temperature sintering, causing the lattice to collapse and form lithium vacancies, and incompletely oxidized divalent nickel ions may replace lithium ions in the lithium layer. Cause lithium-nickel mixing phenomenon, and form non-stoichiometric lithium-deficient compounds

While replacing some nickel ions with cobalt and aluminum ions, the capacity of the material is inevitably reduced, and the reduction of cobalt ion content reduces the cycle stability of all-solid-state lithium-ion batteries during long cycles.

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