A kind of lithium titanate-carbon nanotube composite material and preparation method thereof

Abstract

The invention discloses a novel method for preparing a lithium titanate-carbon nanotube electrode material. The method comprises the steps that S1 an NMP mixture containing 4 wt% carbon nanotube, dioland titanate are added to a homogeneous reaction device, and stirred for polymerization reaction to form polymer mixed slurry A with the carbon nanotube and suction filtration slurry A, and washing with a methanol solution is carried out to acquire a polymer M with the carbon nanotube; S2 the carbon nanotube-containing polymer M and a lithium compound are mixed and dissolved in water, and then placed in a homogeneous reactor, and after stirring and hydrolysis reaction, mixture slurry B and suction filtration slurry B are acquired and washed with a methanol solution to acquire a solid N; and S3 after the solid N is sintered in an inert atmosphere in a high-temperature furnace, the lithium titanate-carbon nanotube electrode material is acquired. The lithium titanate-carbon nanotube electrode material prepared by the preparation method provided by the invention can realize charge and discharge under large current, and overcomes the problems of capacity attenuation and poor rate performance during charge and discharge under large current.

Description

technical field [0001] The invention relates to lithium titanate-carbon nanotube, a lithium ion battery negative electrode material with high capacity and deep charge and discharge capability, and a preparation method thereof. Background technique [0002] At present, lithium titanate anode materials (Li 4 Ti 5 o 12 ), which has the advantages of high safety performance, good high-rate charge-discharge performance, excellent cycle performance, and stable charge-discharge voltage. However, Li 4 Ti 5 o 12 The electronic conductivity of the material itself (and the mobility of lithium ions) is low, so the capacitance decays greatly and the rate performance is poor when charging and discharging with a large current. [0003] In the prior art, lithium titanate is mainly mixed with a conductive agent with excellent conductivity, such as graphene, activated carbon, etc., to prepare electrode materials, so as to make up for the defect of lithium titanate material's insufficient...

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Problems solved by technology

[0002] At present, lithium titanate anode materials (Li 4 Ti 5 o 12 ), which has the advantages of high safety performance, good high-rate charge-discharge performance, excellent cycle performance, and stable charge-discharge voltage. However, Li 4 Ti 5 o 12 The electronic conductivity of the material itself (and the mobility of lithium ions) is low, so the capacitance attenuation is large and the rate performance is poor when charging and discharging at a high current.

[0003] In the existing technology, lithium titanate is mainly mixed with conductive agents with excellent conductivity, such as graphene and activated carbon, to prepare electrode materials, so as to make up for the defect of lithium titanate material's lack of electron conductivity.

Usually, the preparation of lithium titanate-activated carbon composite electrode materials will cause pore blockage, reduce the pore volume of activated carbon and the specific surface area of ​​the composite material, which is not conducive to the full play of adsorption performance.

In the preparation process of lithium titanate-graphene composite electrode, limited by the preparation method, graphene is difficult to disperse evenly in the slurry, and the battery capacity and charge-discharge rate of the electrode are not ideal.

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