A carbon composite method of biological silicon oxide and its product

Abstract

The invention discloses a carbon composite method of bio-silicon oxide, which comprises the following steps: step 1: wet-grinding the bio-silicon oxide material, washing it several times with deionized water, and then drying it; step 2: drying the The final bio-silicon oxide material and high-temperature asphalt particles with a particle size of 1 μm-10 μm are vacuum-mixed for use; step 3: the mixed particles of the step 5 are passed into a mixed gas of acetylene and an inert gas under negative pressure conditions, Among them, the proportion of acetylene in the mixed gas is 1%-5%. After the speed of 1r / min-15r / min, the temperature is raised until the temperature reaches 700°C, and then the temperature is naturally lowered after heat preservation to obtain the wrapped carbon composite bio-silicon oxide material. . The invention also discloses its products. The invention can alleviate the change of the silicon oxide material, is beneficial to form a stable SEI film, improves the first charge and discharge efficiency (coulombic efficiency), and can be mixed with graphite material in a large proportion.

Description

technical field [0001] The invention relates to the field of silicon oxide preparation, in particular to a carbon composite method of biological silicon oxide and a product thereof. Background technique [0002] The development of new energy power has become the common goal of electric vehicles in the world. As the most important part of electric vehicles, the development of power lithium batteries is not only a hot spot that everyone expects, but also a key goal to measure the market application of electric vehicles. [0003] However, the energy density of lithium batteries in the existing technology can only reach 256Wh / kg, which is far from the initial target of 300Wh / kg for power lithium batteries set by the state. [0004] The existing technology through the continuous new development and application of the positive electrode material makes the positive electrode have a greater technical advantage. In contrast, there is still a technical bottleneck in the energy storage...

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Problems solved by technology

[0003] However, the energy density of lithium batteries in the existing technology can only reach 256Wh / kg, which is far from the initial target of 300Wh / kg for power lithium batteries set by the state.

[0004] In the existing technology, through the continuous new development and application of positive electrode materials, the positive electrode has a greater technical advantage. In contrast, there is still a technical bottleneck in the energy storage space of the negative electrode material. It is obviously becoming a development of lithium batteries. one of the obstacles

[0005] The silicon-carbon composite negative electrode material can increase the energy storage space of the negative electrode material, but at the same time, because the mineral silicon material expands by almost 300% when the lithium battery is charged and discharged, the resulting silicon material on the surface of the collector Peeling off, resulting in a decrease in the number of cycles, reducing the energy of the lithium battery

[0006] Therefore, it is difficult to apply a large proportion of the existing silicon-carbon composite negative electrode materials in negative electrode materials.

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