Composite positive electrode of lithium ion battery as well as preparation method and application to all-solid-state battery thereof

Abstract

The invention discloses a composite positive electrode of a lithium ion battery as well as a preparation method and application to an all-solid-state battery thereof. The composite positive electrode of the lithium ion battery comprises a positive active material, inorganic solid electrolyte and a conductive oxide additive, wherein the positive active material is any one of lithium cobaltate, lithium manganate, lithium iron phosphate and nickel-cobalt-manganese ternary material; the inorganic solid electrolyte is at least one of lithium borate, lithium metaborate and lithium fluoride; the conductive oxide additive is any one of indium tin oxide, indium oxide, tin dioxide, zinc oxide, nickel oxide and ferroferric oxide. The method comprises the steps of (1) mixing the positive active material, the inorganic solid electrolyte and the conductive oxide additive, carrying out ball milling, drying, and carrying out tabletting to obtain a ceramic piece; and (2) sintering the ceramic piece to obtain the composite positive electrode. The composite positive electrode is good in mass ratio capacity, area ratio capacity and cycle performance, can be used for preparing the all-solid-state lithium ion battery, and can be used at high temperature.

Description

technical field [0001] The invention relates to a lithium-ion battery composite positive electrode, a preparation method thereof and an application in assembling an all-solid-state lithium-ion battery, belonging to the technical field of lithium-ion batteries. Background technique [0002] Lithium-ion batteries have the advantages of high energy density, long cycle life, and no memory effect. As commercialized high-efficiency energy storage devices, they are widely used in daily life and production. However, the safety hazard caused by flammable organic electrolytes in commercial Li-ion batteries is still a major challenge plaguing Li-ion batteries, especially in large-scale applications such as electric vehicles and energy storage power stations. [0003] All-solid-state lithium-ion batteries use solid-state electrolytes to replace the organic liquid electrolytes used in commercial lithium-ion batteries, which can fundamentally solve the safety problem of lithium-ion batter...

AI Technical Summary

Problems solved by technology

Sulfur-based electrolytes have a low softening temperature and are easy to prepare composite structures, but they are sensitive to moisture in the air, which brings many problems to preparation, testing and application

In addition, the interface between the chalcogenide electrolyte and some positive electrode materials is unstable, and the positive electrode material needs to be coated with oxides before use, which is a complicated process

The reported oxide electrolyte system composite positive electrodes are generally thin film or thick film type, and the thickness of the composite positive electrode is not more than 10 μm, which severely limits the area specific capacity of the composite positive electrode and the energy density of the all-solid-state battery.

In addition, no conductive additives have been added to the composite cathode of the oxide electrolyte system, which severely limits the electrochemical performance of the composite cathode at high rate and high current charge and discharge.

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