Amorphous carbon material with graphitizing characteristics and preparation method of amorphous carbon material

Abstract

The invention discloses an amorphous carbon material with graphitizing characteristics. The amorphous carbon material with graphitizing characteristics comprises an amorphous carbon base body, wherein a graphitized microcrystalline area is distributed inside the amorphous carbon base body; furthermore, a transition metal element is also contained in the amorphous carbon material with graphitizing characteristics; and measured by an XRD (X-ray diffraction) method, the amorphous carbon material with graphitizing characteristics has a typical graphite characteristic diffraction peak d002 peak. The preparation method of the amorphous carbon material roughly comprises the steps of taking and uniformly mixing ultrafine powder containing a carbon precursor and / or the transition metal element and / or compound containing the transition metal element in water and / or an organic solvent to form a homogeneous dispersion system; drying the mixture at low temperature, sintering the mixture at high temperature, and cooling the mixture to room temperature to obtain the target product. According to the invention, partial graphitization temperature of the carbon material is reduced, so that the amorphous carbon material containing graphite crystallite is prepared; the defects that heavy current charging performance of the graphite material is poor and the structure is not stable can be overcome, and usable embedded lithium capacity of the amorphous carbon material is also improved.

Description

Technical field [0001] The invention specially involves a non -fixed carbon material and its manufacturing method with graphite characteristics. Background technique [0002] The negative materials for lithium -ion batteries used for products are currently using artificial graphite or natural graphite with graphite characteristics. The negative materials of graphite have a high lithium embedded capacity.However, graphite materials are more likely to occur in the process of lithium ion dehydration due to its layer -like structure, causing unstable structural instability, battery life, etc. at the same time.In the case, the negative electrode of graphite also limits the use of solvents with high -agency constants with acrylic carbonate.In addition, because the lithium embedded power level of graphite materials is close to the electrochemical sedimentation potential of metal lithium, when lithium ion batteries are charged by large current or charged at low temperatures, lithium surf...

AI Technical Summary

Problems solved by technology

However, due to its layered structure, graphite-based materials are more likely to peel off the layer structure during the lithium ion deintercalation process, resulting in structural instability and affecting battery life; at the same time, due to the presence of solvent co-intercalation, the graphite layer peels off However, graphite-based negative electrodes also limit the use of solvents with high dielectric constants, including acrylic carbonates.

In addition, since the lithium intercalation potential of graphite materials is relatively close to the electrochemical deposition potential of metal lithium, when a lithium-ion battery is charged with a large current or charged at a low temperature, it is often easy to form lithium surface deposition, which will damage the battery performance. Lithium dendrites will even be generated to further pose safety hazards

Then people began to use amorphous carbon materials with non-graphitic layered structure, including low-temperature carbonized hard carbon and soft carbon. However, when these materials exhibit good structural stability, their available lithium intercalation capacity usually decreases relatively low