Method for manufacturing spinelle lithium titanate for lithium ionic cell cathode material

Abstract

The invention provides a method for preparing spinel lithium titanate used for the negative electrode materials of lithium ion batteries, which comprises the following steps of: mixing compounds of metatitanic acid and lithium according to an atomic ratio of lithium to titanium between 0.8 and 0.88; adding into carbon or powder former body of the carbon; carrying out an even mixing for 5 to 72 hours in a medium and then drying the mixture; carrying out treatment for 2 to 20 hours under the temperature between 200 and 500 DEG C; then synthesizing for 2 to 72 hours under the temperature between 600 and 900 DEG C, to acquire spinel-structure lithium titanate for the negative electrode materials of the lithium ion batteries. Adopting the cheap metatitanic acid as the raw materials and adding into the carbon or powder former body of the carbons, the method for preparing spinel lithium titanate for the negative electrode materials of the lithium ion batteries realizes the synthesis of spinel-structure lithium titanate with grains diameter less than 500 nanometers under lower temperatures and greatly improves the rate capacity, while the traditional high-temperature solid state method, with a sintering temperature generally between 800 and 100 DEG centigrade, only produces larger lithium carbonate particles at micron levels. With simple technique and strong operability, the method for preparing spinel lithium titanate for the negative electrode materials of the lithium ion batteries is easy to realize large-scale production.

Description

technical field [0001] The invention mainly relates to a spinel lithium titanate (Li 4 Ti 5 o 12 ) preparation method, which belongs to the technical field of lithium ion battery negative electrode material preparation. Background technique [0002] Since Sony Corporation of Japan developed lithium-ion batteries using petroleum coke as the negative electrode in 1990, carbon materials have attracted people's attention. The varieties include artificial graphite, natural graphite, mesocarbon microspheres, petroleum coke, carbon fiber, etc., which are commercialized Lithium-ion battery main negative electrode material. However, carbon materials have the following disadvantages: 1. React with the electrolyte to form SEI, resulting in low initial charge and discharge efficiency; 2. Lithium metal is easy to deposit on the surface of the negative electrode, and there is no obvious voltage indication at the end of charging, which is easy to cause safety. 3. Poor compatibility wit...

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Problems solved by technology

However, carbon materials have the following disadvantages: 1. React with the electrolyte to form SEI, resulting in low initial charge and discharge efficiency; 2. Lithium metal is easy to deposit on the surface of the negative electrode, and there is no obvious voltage indication at the end of charging, which is easy to cause safety. 3. Poor compatibility with the electrolyte, such as co-insertion of PC-containing electrolytes in graphite carbon materials, etc.; 4. Large volume changes during charging and discharging, and unsatisfactory cycle stability

[0003] Lithium titanate (Li 4 Ti 5 o 12 ) preparation methods generally include traditional high-temperature solid-phase method, sol-gel method, etc. The traditional high-temperature solid-phase method is based on TiO 2 with Li 2 CO 3 Or LiOH is synthesized at a high temperature of 800°C to 1000°C, and the reaction time is generally 12 to 24 hours. The advantage of this method is that the process is simple and easy to produce on a large scale. The gel method generally uses the organic alkoxide of titanium and lithium as the precursor, and the target product is prepared by hydrolysis and sol-gel process. Compared with the traditional high-temperature solid-phase method, the product has high chemical purity, good uniformity, and finer particles. , but this method uses organic compounds to increase the cost, and the operation is complicated, so it is not suitable for large-scale production

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