Preparation method of sodium-ion battery anode material

Abstract

The invention discloses a preparation method of a sodium-ion battery anode material. The preparation method comprises the steps that a sodium source, an iron source and a manganese source are evenly mixed to obtain a mixture; the mixture is mixed with an oxidizing agent, and oxidation reaction is performed through ultrasonic oscillation to obtain a reactant; the reactant is dried and activated to obtain a precursor; the precursor is calcinated in the air, and rapid cooling is performed to obtain the anode material, wherein the anode material is hexagonal crystal ionic compound Na2 / 3Fe1 / 2Mn1 / 2O2. The iron and manganese sources having high activity are adopted as raw materials, pre-oxidation is performed by utilizing the oxidizing agent to improve the activity of the reactant, accordingly the synthesis temperature of the material is reduced, the synthesis time is shortened, and the obtained product has high crystallinity and excellent electrochemical performance.

Description

technical field [0001] The invention relates to the field of sodium ion batteries, in particular to a method for preparing a positive electrode material of a sodium ion battery. Background technique [0002] In recent years, due to the rapid depletion of lithium resources, people are actively looking for alternative battery systems. Sodium-ion batteries have attracted extensive attention due to the abundant reserves and low price of sodium. Na 2 / 3 Fe 1 / 2 mn 1 / 2 o 2 It is a new type of anode material for sodium-ion batteries. It has two crystal structures: hexagonal crystal (P2) and octahedral crystal (O3). Among them, the hexagonal crystal Na 2 / 3 Fe 1 / 2 mn 1 / 2 o 2 The theoretical specific capacity is as high as 260mAh / g, which is suitable as a positive electrode material for energy storage batteries; however, the lower electronic conductivity and ionic conductivity inhibit the performance of electrochemical performance (such as capacity, cycle performance, rate perfo...

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Problems solved by technology

Although the ordinary high-temperature solid-phase method has a simple process, the raw materials need to be mixed for a long time and are difficult to mix evenly. Due to the high calcination temperature, the product particles are coarse and the particle size distribution is uneven, and the product performance is poor.

Co-precipitation process is more complex, and it is easy to introduce impurities into the product, the product particle size is larger, and the capacity is lower

Although the electrospinning method can produce linear nano-scale products, it has high requirements on equipment and environment (humidity), and additional polymers need to be added as a binder, which has high cost, low output, and low tap density of the product. Poor electrochemical performance

[0004] It has been reported above that the preparation of hexagonal Na 2 / 3 Fe 1 / 2 mn 1 / 2 o 2 In the traditional method, inorganic iron source and inorganic manganese source are mostly used as raw materials, and the synthesis temperature is high (generally 900 ° C ~ 1000 ° C) and the time is long

In addition, the Na prepared by the above method 2 / 3 Fe 1 / 2 mn 1 / 2 o 2 Although the positive electrode material belongs to the hexagonal crystal system, the product particles are all irregular in shape and do not show obvious hexagonal crystal particle morphology, indicating that the crystallinity of the product is not high, which will greatly affect the electrochemical performance of the material. performance

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