A kind of preparation method of binderless lithium ion battery negative electrode material

Abstract

The invention discloses a method for preparing a binder-free lithium-ion battery negative electrode material, and belongs to the technical field of nanometer material preparation technology. The electrode material based on the mixed structure of multi-walled carbon nanotubes and graphite flakes has a special structure, does not require binders of polymer compounds and metal copper foil or aluminum foil current collectors, has high conductivity and specific capacity, and shows good performance. Charge-discharge cycle performance. The preparation method of the present invention is simple and low in cost, and at the same time, the process of preparing the electrode material to assemble the electrode of the lithium ion battery is simple, the process is easy to control, and is suitable for industrial production.

Description

technical field [0001] The invention belongs to the field of battery energy, and in particular relates to a preparation method of a lithium-ion battery negative electrode material with a multi-walled carbon nanotube-graphite sheet mixed structure without a binder and a current collector. Background technique [0002] Compared with traditional nickel-cadmium batteries and nickel-hydrogen batteries, lithium-ion batteries have the advantages of high open circuit voltage, high capacity density, no memory effect, long service life, less pollution and low self-discharge rate. Since Sony Corporation adopted petroleum coke as the anode of lithium-ion batteries in 1990, carbonaceous anode materials have received widespread attention. Carbonaceous materials have high specific capacity and low electrode potential (less than 1.0V vs. Li + / Li), long cycle life, high cycle efficiency (greater than 95%) and low cost. At present, the carbonaceous materials that have been studied more in...

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Problems solved by technology

Among them, graphite has a good layered structure and a good voltage platform, but its specific capacity is only 372mAh / g. In addition, during the charging and discharging process, the interlayer spacing of graphite changes greatly, so that lithium and organic solvents are inserted into the graphite layer together. It is easy to cause the graphite layer to peel off and reduce the life of the graphite material. It can be seen that it is far from an ideal lithium-ion battery negative electrode material; mesophase carbon microspheres have a large lithium intercalation capacity, but the high heat treatment temperature makes the production cost high, and there is an electrode potential. Too high, voltage hysteresis and other shortcomings, can not be used commercially; Petroleum coke has an amorphous state, but it will cause volume expansion when intercalating lithium, reducing battery life; Nanotubes and nanoparticles in carbon nanomaterials are nano-sized, they The interstitial space is also at the nanometer level, which can provide a large amount of intercalation space for lithium ions, making it have excellent lithium intercalation characteristics, which is beneficial to the charge and discharge capacity and cycle life of lithium ion batteries, but there is voltage hysteresis and the charge and discharge potential platform is not good. Obvious disadvantages

[0003] Although there are currently many promising non-carbon anode materials that may be used in the field of commercial lithium-ion batteries, they still face many challenges. Therefore, in the near future, the improvement of the performance of lithium-ion batteries will still rely on Development and Perfection of Carbon Anode Materials

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