Abstract: A silicon-carbon composite material, a preparation method thereof, and a secondary battery are provided. The silicon-carbon composite material includes a silicon-carbon composite core and a carbon coating layer coated on the silicon-carbon composite core, and multiple closed pores are dispersed in the silicon-carbon composite core. The preparation method includes steps of (I) a surface modification treatment of a high-molecular polymer, (II) a preparation of a nano-silicon dispersion, (III) a preparation of a first precursor, (IV) a preparation of a second precursor, and (V) carbon coating. The closed pores in the silicon-carbon composite core can effectively alleviate the significant volume effect of silicon generated during lithium intercalation and deintercalation, and the combination of the silicon-carbon composite core and the carbon coating layer can ensure structural stability and high strength of the material.

Abstract: The present invention relates to the field of anode materials of lithium batteries, and in particular, relates to a silicon/carbon composite material with a highly compact structure. The silicon/carbon composite material with the highly compact structure includes silicon particles and a carbon coating layer, and further includes a highly compact carbon matrix, wherein the silicon particles are distributed inside the highly compact carbon matrix evenly and dispersively and forms an inner core; and the silicon/carbon composite with the highly compact structure is compact inside without voids or has few closed voids inside. The present invention provides the silicon/carbon composite material with the highly compact structure with a reduced volumetric expansion effect and an improved cycle performance, a method for preparing the same, and a use thereof.

Abstract: A three-dimensional porous silicon/carbon composite material includes a three-dimensional porous skeleton, a filler layer, and a coating layer. The three-dimensional porous skeleton is a three-dimensional porous carbon skeleton; the filler layer includes silicon particles and conductive carbon; the filler layer is formed by scattering the silicon particles evenly and dispersively in the conductive carbon; and the coating layer is a carbon coating layer. The present invention provides the three-dimensional porous silicon/carbon composite material with long cycle and low expansion, a method for preparing the same, and a use thereof.

Abstract: A silicon-carbon composite material includes a matrix core, a silicon-carbon composite shell formed by uniformly dispersing nano silicon particles in conductive carbon, and a coating layer. The nano silicon particles are formed by high-temperature pyrolysis of a silicon source, and the conductive carbon is formed by high-temperature pyrolysis of an organic carbon source. The coating layer is a carbon coating layer including at least one layer, and the thickness of its single layer is 0.2-3 ?m. A silicon-carbon composite material precursor is formed by simultaneous vapor deposition and is then subjected to carbon coating to form the pitaya-like silicon-carbon composite material which has advantages of high first-cycle efficiency, low expansion and long cycle. The grain growth of the silicon material is slowed down during the heat treatment process, the pulverization of the material is effectively avoided, and the cycle performance, conductivity and rate performance of the material are enhanced.

Abstract: A long-cycle and low-expansion silicon-carbon composite material with an internal pore structure includes a silicon source, a closed pore, a filling layer and a carbon coating layer. The closed pore is a large closed pore or composed of a plurality of small closed pores and the filling layer is a carbon filling layer. The invention provides a long-cycle and low-expansion silicon-carbon composite material with an internal pore structure which is reduced in volume expansion effect and improved in volume effect of cycle performance. The invention further provides a preparation method and application of a long-cycle and low-expansion silicon-carbon composite material with an internal pore structure. The process is simple. The volume expansion effect being reduced and the cycle performance being improved are of great significance to the application of silicon-based materials in lithium-ion batteries.

Abstract: The present invention relates to the field of anode materials of lithium batteries, and in particular, relates to a silicon/carbon composite material with a highly compact structure. The silicon/carbon composite material with the highly compact structure includes silicon particles and a carbon coating layer, and further includes a highly compact carbon matrix, wherein the silicon particles are distributed inside the highly compact carbon matrix evenly and dispersively and forms an inner core; and the silicon/carbon composite with the highly compact structure is compact inside without voids or has few closed voids inside. The present invention provides the silicon/carbon composite material with the highly compact structure with a reduced volumetric expansion effect and an improved cycle performance, a method for preparing the same, and a use thereof.

Abstract: A three-dimensional porous silicon/carbon composite material includes a three-dimensional porous skeleton, a filler layer, and a coating layer. The three-dimensional porous skeleton is a three-dimensional porous carbon skeleton; the filler layer includes silicon particles and conductive carbon; the filler layer is formed by scattering the silicon particles evenly and dispersively in the conductive carbon; and the coating layer is a carbon coating layer. The present invention provides the three-dimensional porous silicon/carbon composite material with long cycle and low expansion, a method for preparing the same, and a use thereof.

Abstract: The present invention relates to the field of anode materials for batteries, and in particular, relates to a self-filled coated silicon-based composite material. The self-filled coated silicon-based composite material is composed of a nano-silicon material, a filler material, and a surface modification material. The nano-silicon material has a particle size D50 being less than 200 nm; and the filler material is a carbon filler material filled among the nano-silicon material. The present invention provides the self-filled coated silicon-based composite material having the advantages of high initial efficiency, low expansion, long cycle, and the like. The present invention further provides a method for preparing the self-filled coated silicon-based composite material, and a use of the self-filled coated silicon-based composite material, which is simple and practicable in process and stable in product performance, and shows good application prospects.

Abstract: The present invention relates to the field of anode materials for batteries, and in particular, relates to a silicon-based composite material with a pomegranate-like structure. The silicon-based composite material with the pomegranate-like structure is composed of nano-silicon particles, exfoliated graphite, and a filler modification layer. The nano-silicon particles are dispersed in pores inside the exfoliated graphite. The filler modification layer is filled in the nano-silicon particles or filled between the nano-silicon particles and the exfoliated graphite. The present invention provides the silicon-based composite material with the pomegranate-like structure and a method for preparing the same, whereby a volumetric expansion effect can be reduced, and a cycle performance and a rate performance can be improved.

Abstract: A multi-element-coating silicon-based composite material with high initial efficiency consists of a plurality of multi-element nano-silicon particle and a modified layer; the multi-element nano-silicon particle includes a first nano-silicon layer, a nano-silicon oxide layer, a second nano-silicon layer and a carbon coating layer in sequence from inside to outside; and the filled and modified layer is a carbon filled and modified layer. The present invention provides the multi-element-coating silicon-based composite material with high initial efficiency, a method for preparing the same, and a use thereof. The multi-element-coating silicon-based composite material with high initial efficiency is simple and practicable in process and stable in product performance, and has good application prospects.

Abstract: A silicon-carbon composite material includes a matrix core, a silicon-carbon composite shell formed by uniformly dispersing nano silicon particles in conductive carbon, and a coating layer. The nano silicon particles are formed by high-temperature pyrolysis of a silicon source, and the conductive carbon is formed by high-temperature pyrolysis of an organic carbon source. The coating layer is a carbon coating layer including at least one layer, and the thickness of its single layer is 0.2-3 ?m. A silicon-carbon composite material precursor is formed by simultaneous vapor deposition and is then subjected to carbon coating to form the pitaya-like silicon-carbon composite material which has advantages of high first-cycle efficiency, low expansion and long cycle. The grain growth of the silicon material is slowed down during the heat treatment process, the pulverization of the material is effectively avoided, and the cycle performance, conductivity and rate performance of the material are enhanced.

Abstract: A hollow/porous silicon-based composite material includes a hollow/porous structure, a silicon-carbon composite layer and a carbon coating layer. The silicon-carbon composite layer is formed by uniformly dispersing nano silicon/silicon oxide in a conductive carbon mesh formed by high-temperature pyrolysis of a binder. The composite material is prepared by uniformly mixing nano silicon/silicon oxide, the binder and the salt, and then carrying out spray granulation, high-temperature sintering, water washing for desalination, and a coating treatment. The grain growth of the silicon material is slowed down during the heat treatment process, the pulverization of the material is effectively avoided, the volume expansion effect of the silicon-based material is alleviated, the cycle performance of the silicon-based material is improved, and the conductivity and rate performance of the material is enhanced.