Preparation method for lithium titanate and graphene composite electrode materials

Abstract

A preparation method for lithium titanate and graphene composite electrode materials comprises the following steps: solution A containing lithium ion is prepared by dissolving surface-active agent, template agent and lithium compound into deionized water; titanium compound is added into graphene solution with the concentration of 0.1 to 0.5 g / l, and solution B containing titanium ions is prepared through ultrasound and stirring; under the effect of ultrasonic wave field, the solution A is added into the solution B, then bonding agent is added, and solution C is prepared; the solution C is moved into a polytetrafluoroethylene reaction kettle, and reaction is performed under 140 to 200 DEG C; then leaching, washing and drying to the solution are performed, and eventually, composite products are produced under the atmosphere of argon gas. The lithium titanate in the composite product is nanosheet lithium titanate, can be fully mixed and contacted with the sheet graphene, and the electric conductance and ion electric conductance of the lithium titanate material are improved greatly; and the composite product is classified as electrode material with excellent and high rate charge-discharge performance.

Description

technical field [0001] The invention relates to a method for preparing a composite material of lithium titanate and graphene, in particular to a method for preparing a composite electrode material of sheet lithium titanate and graphene and the composite electrode material. Background technique [0002] Energy and environmental problems are becoming more and more serious, and the development and use of clean energy is imminent. The development of electric vehicles is an inevitable trend of future development. The large-scale application of green energy such as wind energy, solar energy, and geothermal energy has put forward higher requirements for energy storage devices, especially for the service life of energy storage batteries. [0003] The rapid development of various electronic devices as well as electric vehicles and hybrid vehicles has put forward more stringent requirements for lithium-ion batteries that provide energy, especially their power performance. The current...

AI Technical Summary

Problems solved by technology

Lithium-ion power batteries currently being studied usually use lithium iron phosphate, nickel-cobalt-manganese ternary materials, and lithium manganese oxide as positive electrode materials, and carbon materials as negative electrode materials. When the battery is used in an abnormal state, the lithium-intercalated carbon negative electrode material will react violently with the electrolyte, releasing a large amount of heat and flammable gas, causing the battery to fail or even explode.

The safety problem of large-capacity and high-power lithium-ion power batteries using carbon materials as negative electrodes has not been effectively resolved, which seriously restricts its application in electric vehicles, so how to solve the safety problem of lithium-ion power batteries has become a problem The fundamental problem of its industrialization development is also the key problem hindering the industrialization of electric vehicles

Although the solid-phase synthesis method has simple process and low cost, most of the products are micron-sized, and the particle distribution is uneven, and the high-rate performance is poor.

[0010] Currently, increasing the Li 4 Ti 5 o 12 The method of rate performance is also to use Li 4 Ti 5 o 12 Composite with carbon materials such as graphene, carbon nanotubes, carbon nanowires, etc., these methods can well improve its rate performance, but due to the Li 4 Ti 5 o 12 They all exist in the form of three-dimensional particles, and cannot fully contact with one-dimensional and two-dimensional materials such as carbon nanotubes and graphene during compounding, and the contact area is limited, which limits the further improvement of its performance

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