4 results about "Silicon-tin" patented technology

The invention belongs to the field of lithium ion battery materials, and relates to a graded nano-porous Si quantum dot and C composite material, preparation thereof and application of the graded nano-porous Si quantum dot and C composite material in an all-solid-state lithium ion battery. According to the invention, the silicon-tin quantum dots are prepared through the cooperation of hydro-thermal synthesis and nanosecond pulse laser ablation; carrying out two-step treatment of'high-temperature oxidation-hydrogen reduction 'to prepare the graded nano-porous Si quantum dots; and then a hierarchical porous Si quantum dot core-carbon coating layer-three-dimensional interlaced conductive network composite structure is constructed with a conductive medium through sanding dispersion, ball milling compounding and high-temperature pyrolysis. The material relieves silicon lithiation volume expansion by virtue of a hierarchical porous structure, the electronic conductivity is improved by virtue of a three-dimensional conductive network, and the material is very suitable for constructing a battery negative pole piece and is used for an all-solid-state lithium ion battery. The first coulombic efficiency of the constructed all-solid-state lithium ion battery at the rate of 0.1 C is 85%-90%, and the capacity retention ratio of the constructed all-solid-state lithium ion battery after 100 cycles at the rate of 0.1 C is 95%-99%.

The invention relates to the technical field of lithium ion batteries, and discloses a lithium ion battery nano-material, which comprises a positive electrode and a negative electrode, the negative electrode comprises a composite network of silicon-tin nanoparticles, boron-doped carbon nanotubes and carbon nanosheets, the SiO buffer layer is formed at an interface between the silicon-tin nanoparticles and the boron-doped carbon nanotube-carbon nanosheet composite network, and the thickness of the SiO buffer layer is 2-5nm. According to the lithium ion battery nano material and the preparation method thereof, a synergistic structure of the silicon-tin nano particles, the boron-doped carbon nanotube-carbon nanosheet composite network and the SiO buffer layer is constructed, and the composite network forms a three-dimensional porous structure by means of C-B-C covalent bond interweaving, so that stable support is provided for the silicon-tin nano particles; the SiO buffer layer plays an elastic buffer role at the interface of the two, effectively disperses the volume expansion stress in the charge-discharge process, avoids the fracture of the negative electrode structure, inhibits the desorption of the silicon-tin nanoparticles and the carbon network, maintains the low volume expansion state for a long time, and slows down the battery capacity attenuation.

This invention discloses a method for preparing fluorine-doped carbon materials and their applications, belonging to the field of battery materials technology. Addressing the core bottlenecks of severe volume expansion and unstable SEI (Sediment Interface) in high-energy-density metal-ion batteries, this invention abandons the traditional approach of directly modifying the active material of the negative electrode. Instead, it proposes fluorine doping modification of any carbon component in the metal-ion battery negative electrode. Utilizing the fluorine transfer from the fluorine-doped carbon component to the active material interface during charge-discharge cycles, a stable SEI rich in metal fluorides and active material-fluorine bonds is induced, thereby improving the stability of the negative electrode interface and suppressing volume expansion. Directly coating the active material with a fluorine source results in severe HF etching of active materials such as silicon and tin. This invention achieves fluorine doping by mixing a fluorinated polymer with an HF-resistant carbon material, and then combining it with the active material, fundamentally avoiding the etching risk. Furthermore, the process is simple and cost-controllable, providing a novel approach for the control of the metal-ion battery negative electrode interface.

The application discloses a sulfur-containing carbon source temperature control coated silicon-tin-based negative electrode material and a preparation method and application thereof, a negative electrode and a lithium ion battery, and relates to the technical field of lithium ion battery negative electrode materials. A silicon-tin-based composite material with a silicon-tin-based phase and a metal phase is used as a precursor, in-situ carbonization modification is performed on the precursor by using a sulfur-containing organic carbon source at a gradient temperature, and a high-performance sulfur-containing carbon source temperature control coated silicon-tin-based negative electrode material is prepared. The application has the advantages of simple and controllable process, low cost, high first coulomb efficiency of the prepared material, excellent cycle stability, suitability for large-scale production, and wide application prospect in the field of lithium ion batteries.