A kind of ultrafine solid electrolyte and preparation method thereof

Abstract

The invention discloses an ultrafine solid electrolyte and a preparation method thereof. The particle size D10 of the electrolyte is 50-100nm, D50 is 100-200nm, D90 is 200-400nm, and Dmax≤500nm. The preparation method of the ultrafine solid electrolyte comprises: 1) according to the ion ratio Li:Al:M:P is 1+X:X:2-X:3, 0≤X≤1, weighing the reaction raw materials, and then adding Wet milling in the dispersion system of the thickener until the particle size is less than 1 μm to obtain a spray precursor; 2) spray drying to obtain a sintered precursor; 3) sintering and sand milling to a particle size Dmax≤500nm to obtain an ultrafine solid electrolyte. The electrolyte has good processability and composite performance, high ion conductivity, and is suitable for battery application. The method has the advantages of simple preparation process, low raw material cost, environmental friendliness, high product yield and convenient industrial production.

Description

technical field [0001] The invention relates to the field of lithium-ion batteries, lithium metal batteries, lithium-sulfur batteries, and lithium-air battery solid electrolytes. Specifically, the invention relates to an ultrafine multi-component solid electrolyte material and a preparation method thereof. Background technique [0002] Lithium-ion batteries have been widely used in portable electronic products and electric vehicles because of their advantages such as high working voltage, long cycle life, no memory effect, small self-discharge, and environmental friendliness. At present, many countries, including China, have formulated medium and long-term strategic goals for further increasing the energy density of power batteries to 300-400 Wh / kg. It is estimated that the weight energy density limit of liquid lithium-ion power batteries composed of high-voltage layered transition metal oxides and graphite as positive and negative electrode active materials is about 280Wh / k...

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Problems solved by technology

[0003] However, at present, the main methods for preparing solid electrolytes are high-temperature solid-phase method and sol-gel method. Although the high-temperature solid-phase method has a simple process, it will lead to poor mixing effect of the precursors, and the required phase formation temperature is high. Severe; for example non-patent literature (H.Aono.et al, J.Electrochem.Soc.137 (1990) 1023) adopts solid-phase method to prepare lithium titanium aluminum phosphate solid state electrolyte can cause the phenomenon that product sticks crucible wall seriously, is therefore difficult to industrialization

In the patent literature, CN105609881A discloses a method for preparing solid electrolyte materials using sol-gel, although it can avoid the disadvantages of the high-temperature solid-phase method, but the sol-gel needs to add organic or inorganic additives, and the process of sol evaporation to dryness is too time-consuming. long, leading to an increase in production costs and unfavorable industrial production

CN105406118A discloses the preparation of solid electrolyte by spray drying. This method adopts a simple method of mixing precursor and solvent. The process of operation cannot avoid the phenomenon of product sticking to the wall, which affects the yield of the product, and the particle size of the final prepared solid electrolyte is At the level of one micron, this will lead to poor processing performance and composite performance, and the interface with the electrode and the resistance between the particles will become larger, which is not conducive to subsequent utilization

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