On July 31, 2019, Huawei filed a new patent for a Silicon-carbon composite material and its preparation method as well as a lithium-ion battery. Now, this patent was published on February 2, 2021, in China with publication number CN112310363A.
The patent document shows that the embodiment of this invention provides a strong composite material, including a core and an alkali layer coated on the surface of the core. It also provides a preparation method of the silicon-carbon composite material and a meat cell containing the silicon-carbon composite material.
The core includes a stone cover skeleton filled with amorphous carbon. The silicon material distributed in the amorphous carbon and composite material only has a pore structure with a pore size less than or equal to 50nm, and there is no pore structure with a pore size greater than 50nm.
The silicon-carbon composite material has a small internal pore size that can effectively reduce the contact area between the silicon material and the electrolyte, which reduces the occurrence of side reactions and extend the battery life.
At the same time, the silicon material is evenly dispersed around the graphite skeleton without agglomeration, so that the graphite skeleton can effectively relieve the material volume expansion and contraction to improve the structural stability and energy density of the composite material.