Preparation method of three-dimensional ordered spherical lithium iron phosphate material

Abstract

The invention discloses a preparation method of a three-dimensional ordered spherical lithium iron phosphate material. The preparation method comprises the following steps: preparing polystyrene colloidal crystals by a soap-free emulsion polymerization method, preparing lithium iron phosphate precursor sol, and dropwisely adding the lithium iron phosphate precursor sol into the polystyrene colloidal crystal, after the lithium iron phosphate precursor sol wets the whole polystyrene colloidal crystal, drying the polystyrene colloidal crystal under air flow overnight, and then sintering and naturally cooling the polystyrene colloidal crystal to obtain the three-dimensional ordered spherical lithium iron phosphate material. The sphere diameter of the polystyrene colloidal crystal is adjusted by controlling the polymerization reaction time of a soap-free emulsion polymerization method, the ionic strength of a system and the concentration of an ionic copolymer. According to the prepared three-dimensional ordered spherical lithium iron phosphate material, the integrity and uniformity of a spherical structure can be reserved to the maximum extent, meanwhile, the particle size of lithium iron phosphate can be adjusted according to the sphere diameter of polystyrene microspheres, and the prepared lithium iron phosphate material has the characteristics of large specific surface area, highporosity and the like of a common spherical material.

Description

technical field [0001] The invention relates to the fields of new energy materials and chemical batteries, in particular to a method for preparing a three-dimensional ordered spherical lithium iron phosphate material. Background technique [0002] Goodenough et al. discovered in 1997 that LiFePO4 with an olivine structure could reversibly intercalate and remove lithium ions at a potential value of 3.4V (vs. Li+ / Li). Due to its low synthesis cost, non-toxicity, and good safety and stability, it has become It is the cathode material widely used in lithium-ion batteries at present. Battery-grade lithium iron phosphate is often prepared and studied by high-temperature solid-phase method, hydrothermal method, sol-gel method, co-precipitation method, etc. The iron phosphate phase formed by lithium iron phosphate during charging is The two phases are reinverted. Since 2019, with the continuous decline of subsidies for new energy vehicles, the cost advantage of lithium iron phosph...

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Problems solved by technology

Most of the early porous materials were prepared by the foaming method and the substitution method, but the porous materials prepared by these methods had different pore sizes and pore shapes, which limited their application.

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