Lithium ion battery positive electrode material lithium iron manganese phosphate and liquid phase preparation method thereof

Abstract

The invention discloses a lithium ion battery positive electrode material lithium iron manganese phosphate which has a general chemical formula of LiFe1-xMnxPO4, wherein x is equal to 0.2-0.8. The liquid phase preparation method of the lithium ion battery positive electrode material lithium iron manganese phosphate comprises the following steps: synthesizing a precursor, namely weighing an iron salt, a manganese salt and oxalate according to a molar ratio, preparing a solution A from the iron salt, the manganese salt and an antioxidant, preparing the oxalate into a solution B, and preparing ammonia water into a solution C; measuring the solution B to serve as a base solution; simultaneously dripping the solution A and the solution C, and dripping the solution B; filtering, washing and performing vacuum drying, thereby obtaining an iron manganese oxalate precipitate precursor; dosing, namely weighing a carbon source, adding a lithium source, the precursor and a phosphorus source, mixing and performing ball-milling; compounding, namely adding the mixed materials into a compounding furnace, and treating the materials for calcining; and sintering, namely controlling the temperature rise rate, and performing furnace cooling on the compounded precursor powder to room temperature under the protection of inert gas atmosphere, thereby obtaining the carbon-coated lithium iron manganese phosphate positive electrode material.

Description

technical field [0001] The invention relates to a battery positive electrode material and a preparation method thereof in the field of materials, in particular to a lithium iron manganese battery positive electrode material lithium iron manganese phosphate and a liquid phase preparation method thereof. Background technique [0002] Now, lithium-ion batteries have been widely used in portable electric devices, and are gradually developing towards large-scale electric devices. However, high cost, safety issues, and toxicity have become the main obstacles for the current lithium-ion batteries to be used in electric vehicles or large-scale electrostatic energy storage systems, especially lithium-cobalt-based oxide cathode materials. Cathode material LiMPO 4 (M=Fe, Mn, Ni, Co) series materials have been recognized by researchers because of their environmental friendliness, high thermal stability, relatively high energy density and abundant resources, and they believe that polya...

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Problems solved by technology

[0003] The purpose of the present invention is to provide a lithium-ion battery capable of improving the electronic conductivity of lithium manganese phosphate positive electrode material, solving the problem of structural instability in lithium manganese phosphate due to the ginger-Taylor effect of manganese element, and improving the discharge specific capacity and rate performance Cathode material lithium iron manganese phosphate;

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