Self-supporting porous lithium titanate composite precursor and negative electrode material and preparation method thereof

Abstract

The invention discloses a self-supporting porous lithium titanate composite precursor and a negative electrode material and a preparation method thereof, and the preparation method of the precursor comprises the following steps: weighing titanium dioxide, a lithium source and graphene oxide, dispersing in deionized water, and carrying out ball milling, ultrasonic treatment and high-speed homogenization to obtain slurry A; and taking melamine foam as a structural framework, immersing the melamine foam into the slurry A, fully filling foam pores with the slurry A, drying, and tabletting under a certain pressure to obtain the self-supporting porous lithium titanate composite precursor. According to the method, the integrated porous lithium titanate negative electrode material is constructed, and the electronic conductivity and the lithium ion diffusion rate of the material can be improved at the same time. Under the same test condition, the battery performance of the composite negative electrode material is obviously superior to that of a conventional lithium titanate material. Meanwhile, according to the method, a coating process can be omitted, the lithium ion battery can be directly used as a battery pole piece, a conductive agent, a binder and a current collector are not needed, so that the cost is low, the lithium ion battery is more environment-friendly, and the manufactured pole piece has higher energy density.

Description

technical field [0001] The invention relates to the field of lithium ion battery materials, in particular to a preparation method of a high energy density lithium ion battery negative electrode material. Background technique [0002] With the trend of miniaturization of electrical equipment becoming more and more obvious, more and more equipment needs to rely on lithium-ion batteries for energy supply. However, for some high-power devices, it is often required that the battery can be discharged with a large current under the premise of ensuring safety, and the battery must have a long cycle life under this working condition. Lithium-ion batteries based on traditional electrode materials are often difficult to balance all the above properties, and cannot be widely used in high-power equipment. [0003] Lithium titanate (Li 4 Ti 5 o 12 ) is a "zero-strain" lithium-ion battery anode material. Due to the unique lithium-ion intercalation mechanism, its high-rate charge-discha...

AI Technical Summary

Problems solved by technology

However, the internal conductive carbon skeleton of this type of material largely adopts a "point-to-point" connection method, and it is difficult to construct a three-dimensional conductive network with a continuous, stable structure and good contact inside the material, which limits the further improvement of the rate performance of lithium titanate materials.

In addition, this type of material can only be prepared by traditional homogenization, coating, and drying processes. The proportion of lithium titanate active materials in the pole piece is very low, and the theoretical capacity of lithium titanate itself is low, so the pole piece The overall energy density is very low, making it difficult to adapt to the trend of equipment miniaturization

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