4results about How to "Improve interface structure" patented technology

The application belongs to the field of negative electrode materials, and particularly relates to a silicon-graphite composite material, a preparation method, application and a lithium ion battery, wherein the preparation method comprises the following steps: mixing silicon powder, graphite and a composite functional additive, and then performing ball milling modification after slurry treatment to obtain primary composite particles; the composite functional additive comprises an additive A, an additive B and an additive C; the primary composite particles and a carbon source liquid are combined, and then spray drying and heat treatment or direct spray pyrolysis are performed to obtain secondary composite particles; the secondary composite particles obtained in step 2 are modified in a surface modification liquid, and then low-temperature annealing is performed at 150-300 DEG C to obtain the silicon-graphite composite material; the surface modification liquid is an organic solution in which an electrically conductive lithium salt and an additive D are dissolved; and based on the combined control of the preparation process and structure, the silicon-based negative electrode material with super-long cycle life and excellent low-temperature fast charging performance can be obtained.

This invention relates to a device and method for testing the interlayer bond strength of brittle fiber mats. The testing device includes a worktable, a Z-axis linear module, an X-axis linear module, a force gauge, a clamping and fixing structure, a gasket, an online imaging device, and a control and data processing system. The Z-axis linear module is fixed to the worktable, the X-axis linear module is fixed to the Z-axis linear module slider, and the force gauge is fixed to the X-axis linear module slider. The clamping and fixing structure includes a base and two clamping fixtures, with the gasket held at both ends by the fixtures. This invention uses indirect clamping with gaskets to avoid fiber breakage and slippage caused by direct clamping of the sample, eliminating clamping interference. The dual linear modules work together to achieve oblique upward progressive peeling, avoiding violent tearing of the sample and ensuring accurate and repeatable test results. The accompanying online imaging device enables real-time observation of the peeling process, facilitating the establishment of a correlation between macroscopic mechanical response and microscopic damage mechanism, effectively improving the completeness of test data and the depth of mechanism analysis.

The application discloses a phosphorus-carbon-aluminum fluoride composite material, a preparation method and application thereof, and a lithium ion battery negative electrode. The phosphorus-carbon-aluminum fluoride composite material comprises a phosphorus-carbon matrix and aluminum fluoride crystals dispersed in the phosphorus-carbon matrix, stable phosphorus-carbon covalent bonds are formed in the phosphorus-carbon matrix, and the mass ratio of the aluminum fluoride crystals to the phosphorus-carbon matrix is 5-20:80-95. Through mechanical force action of high-energy ball milling, the phosphorus source and the carbon material are promoted to form phosphorus-carbon covalent bonds, and meanwhile, the aluminum fluoride crystals are uniformly dispersed in the phosphorus-carbon matrix. The carbon material improves the conductivity of the material, the phosphorus-carbon bond enhances the interface bonding force and inhibits volume expansion, and the aluminum fluoride optimizes the interface structure, inhibits the dissolution and oxidation of polyphosphorus compounds. The three components synergistically make the material have high conductivity, structural stability and interface stability. The aluminum fluoride as an additive can significantly improve the fast-charging performance and long cycle life of the lithium ion battery.

The invention relates to the technical field of electrochemistry, in particular to an electrochemical sensor for detecting PFOA (perfluorooctanoic acid) based on fluorine-fluorine interaction and an electrochemical detection method of the PFOA. The invention discloses an electrochemical sensor for detecting PFOA (perfluorooctanoic acid) based on fluorine-fluorine interaction. The electrochemical sensor comprises a counter electrode, a reference electrode, a signal acquisition and processing unit, an electrolyte solution and a working electrode, the electrolyte solution is a potassium ferricyanide solution containing 0.1 M of KCl, and the working electrode is formed by dispensing an electrode material F-COF / MWCNTs-NH2 on the electrode; when the working electrode is placed in an electrolyte solution containing PFOA, fluorine atoms in an electrode material F-COF / MWCNTs-NH2 on the working electrode and fluorine atoms on the PFOA adsorb the PFOA on the surface of the working electrode based on fluorine-fluorine interaction, and then potassium ferricyanide is matched to serve as an oxidation-reduction probe, so that electrochemical detection on the PFOA can be effectively realized. Therefore, the detection problem that the PFOA has no electrochemical activity in the prior art is solved, and accurate and high-sensitivity quantitative detection on the PFOA is realized.