13results about How to "Alleviate volume effect" patented technology

The invention relates to a silicon-carbon composite material, a preparation method and application thereof, and a battery. The silicon-carbon composite material comprises: a porous carbon matrix; the metal coating is positioned on the hole wall of the porous carbon substrate; the silicon alloy particles are positioned on the surface of the metal coating; the amorphous silicon particles grow along the epitaxy of the silicon alloy particles; and a carbon coating layer, wherein the carbon coating layer is located at the outer layer. The silicon-carbon composite material disclosed by the invention has excellent conductivity and structural stability, and the battery adopting the silicon-carbon composite material can realize high mass specific capacity and excellent high-temperature and low-temperature cycling stability.

The present invention relates to the field of sodium ion batteries, and discloses a caged cobalt iron sulfide carbon nanofiber composite material and a preparation method and application thereof, the method comprising: obtaining a caged cobalt iron Prussian blue analog by a coprecipitation method, and preparing a spinning solution with a high molecular polymer as the main raw material; obtaining a beaded fiber precursor by electrostatic spinning, and after pre-oxidation in air and pyrolysis in an inert protective atmosphere, heat-treating it together with a sulfur source or a selenium source to obtain a caged cobalt iron sulfide (CoS2 / FeS2 or CoSe2 / FeSe2) carbon nanofiber composite material. The cage structure in the present invention can increase the contact area between the electrode active material and the electrolyte, and the carbon fiber skeleton can effectively improve the conductivity and alleviate the volume change of the electrode material during the charge and discharge process. When the prepared composite material is used as the negative electrode material of the sodium ion battery, it exhibits excellent long cycle performance and rate performance.

The invention relates to the technical field of lithium batteries, and discloses a ZIF-derived high-nano-silicon-loaded silicon-carbon negative electrode material, a preparation method and a battery, and the preparation method comprises the following steps: S1, surface modification of nano silicon; s2, preparing a ZIF precursor solution; s3, mixing the surface modified nano silicon with the ZIF precursor solution, and compounding by adopting mechanical ball milling; and S4, carrying out carbonization treatment on the composite material to prepare the ZIF-derived high-nano-silicon-loaded silicon-carbon negative electrode material. According to the preparation method disclosed by the invention, high-uniformity distribution of nano silicon in a carbon-based skeleton is realized based on a mechanical ball-milling method by modifying the surface of the nano silicon, optimizing the structural design of a ZIF material and introducing a silicon precursor, and a carbon network with excellent conductivity is formed by controlling a carbonization process, so that the electrochemical performance and the cycling stability of the composite material are remarkably improved.

The invention provides a lithium-aluminum alloy negative electrode and a preparation method and application thereof, and the preparation method comprises the following steps: in a protective gas, an aluminum foil, a lithium sheet, a diaphragm and an electrolyte are adopted to prepare a battery cell, the aluminum foil is a positive electrode, and the lithium sheet is a negative electrode; the method comprises the following steps: preparing an aluminum foil on the surface of a battery cell, then discharging the battery cell with the discharging voltage range of 0.03-0.4 V to generate a beta-LiAl alloy layer on the surface of at least one side of the aluminum foil, disassembling the battery cell after discharging is finished, and taking the disassembled aluminum foil loaded with the beta-LiAl alloy layer on the surface as the lithium-aluminum alloy negative electrode. According to the preparation method disclosed by the invention, the lithium-aluminum alloy with a fixed crystal form is formed on the surface of the aluminum foil in advance, and the conversion of the beta-LiAl alloy between a lithium-rich state and a lithium-poor state is realized by regulating and controlling the voltage range in the charging and discharging process, and the conversion between phases is not involved, so that the cycling stability of the battery is improved, and the service life of the battery is prolonged. The problem that the volume change of the lithium-aluminum alloy in the charging and discharging process is large is solved.

The application discloses a silicon-carbon negative electrode material, a preparation method and a battery, and relates to the technical field of battery materials. The preparation method comprises the following steps: placing a porous carbon material in an inert atmosphere, pre-treating by heating, and removing impurities and moisture on the surface of the material; depositing a nano-silicon layer on the surface of the pre-treated porous carbon material in a gas phase; then depositing a carbon coating layer on the surface of the nano-silicon layer; and performing oxidation passivation treatment on the surface of the carbon coating layer, thereby obtaining the silicon-carbon negative electrode material.

The invention discloses a silicon oxide-based negative electrode material and its preparation and application, belonging to the technical field of lithium ion battery preparation, comprising the following steps: nitrous oxide plasma bombards pure silicon oxide powder to form modified porous silicon oxide powder with N attached, wherein the porosity can accommodate more lithium ions for embedding and de-embedding, and also helps to alleviate the volume effect of the material in the electrochemical reaction process, thereby extending the cycle life of the battery, and at the same time, the N element is doped in the generated carbon layer, thereby improving the conductivity and lithium storage capacity; the two coating layers prepared by the invention form a dense carbon coating layer after high-temperature carbonization, thereby enhancing the structural integrity of the silicon oxide negative electrode material in the charging and discharging process, and in the process of embedding and de-embedding of lithium ions, the dense carbon coating layer can effectively alleviate the stress caused by volume change and reduce the repeated generation and rupture of SEI film, thereby improving the initial coulomb efficiency and helping to maintain the capacity and performance stability of the battery.

This invention discloses a method for preparing hierarchical porous indium oxide nanotubes for lithium-ion battery anodes, comprising the following steps: Step (1) Indium salt and terephthalic acid are placed in an organic solvent and stirred evenly under oil bath conditions to obtain a homogeneous dispersion; Step (2) The homogeneous dispersion is further heated and stirred continuously to carry out the reaction, and after the reaction is completed, it is naturally cooled to room temperature to obtain a mixed reaction system; Step (3) The mixed reaction system is filtered, and the solid product obtained by filtration is washed with anhydrous ethanol and dried to obtain the precursor MIL-68(In); Step (4) The precursor MIL-68(In) is placed in a tube furnace and pyrolyzed in an air atmosphere to obtain hierarchical porous indium oxide nanotubes. This invention can solve the problems of poor cycle performance and rate performance of existing In2O3-based anode materials.

This invention relates to the field of batteries and discloses a method for preparing nickel disulfide / copper sulfide / carbon composite hollow spheres and their applications. The invention uses hollow spherical Ni-MOF as a precursor, combined with subsequent ion exchange, PDA coating, glucose coating, carbonization, and sulfidation to prepare nickel disulfide / copper sulfide / carbon composite hollow spheres. This material inherits the porous hollow structure of Ni-MOF, providing a high-speed and efficient transport channel for ion diffusion in electrode materials, while mitigating volume change effects and improving the cycle life of sodium-ion batteries. Furthermore, the controllable introduction of appropriate amounts of copper ions through ion exchange to form a nickel-copper bimetallic sulfide heterostructure can accelerate ion diffusion kinetics, reduce the ion diffusion barrier, and enhance structural stability. Finally, the nitrogen-doped carbon derived from polydopamine carbonization in the middle layer improves the conductivity of the composite material and increases sodium storage active sites, while the outermost carbon layer derived from glucose carbonization further enhances the structural stability of the composite material.

A silicon-based negative electrode composite material. Zinc and tin are doped in a silicon-based negative electrode material. The presence of a tin and zinc alloy improves the conductivity of the silicon-based material, and a coated carbon shell has pores, facilitating the infiltration of an electrolyte while improving the ionic conductivity and electronic conductivity of the material, so that the rate performance of the composite material is enhanced.

The present invention relates to a coated modified positive electrode material and a preparation method and application thereof, wherein the preparation method comprises the following steps: mixing a D-A type conjugated polymer organic solution with a positive electrode material, removing the organic solvent, and obtaining the coated modified positive electrode material. The present invention uses a D-A type conjugated polymer to coat and modify the positive electrode material, and can form a uniform and dense coating layer on the surface of the material, and the thickness of the coating layer is controllable; moreover, the D-A type conjugated polymer has excellent chemical stability, and its good ductility can be used as a buffer matrix to slow down the volume effect of the charge and discharge process, and also has good conductivity; the coated modified positive electrode material of the present invention is used in a battery, which can make the battery have excellent rate performance and cycle performance.

The present application provides a negative electrode plate, which includes: a negative electrode active material layer; an inner layer film covering the negative electrode active material layer; and an outer layer film covering the inner layer film, wherein the negative electrode active material layer includes graphite, the inner layer film includes at least 10 monolayers of metal organic compounds, and the outer layer film includes at least 40 monolayers of organic polymers.

The invention relates to a novel method for preparing a flexible self-supporting electrode by a one-step method, and belongs to the technical field of electrochemistry. The method comprises the following steps: preparing a mixed binder for preparing a flexible self-supporting electrode; mixing and pulping the mixed binder, a conductive agent and an active material according to a certain proportion to prepare active material slurry; a glass plate is coated with the slurry, a flexible electrode with a self-supporting structure is obtained through thermal drying, the electrode is pretreated through an electrolyte solvent before being used, an electrode porous structure is constructed, and the electrode has high flexibility and electrochemical performance.

The present invention discloses a carbon-based composite material for lithium batteries and its preparation method and application, belonging to the technical field of battery materials. The present invention grows carbon nanotubes on the surface of silicon powder, and then coats the outer layer with a silicon dioxide layer and a hard carbon layer to form a negative electrode material with a cage-like structure with an internal mesh and an external carbon layer. The lithium battery prepared using the negative electrode material has a high discharge capacity and a cycle performance of not less than 90%, and can effectively regulate the volume expansion during the electrode reaction, improve the transmission efficiency of lithium ions, and the preparation method is simple, the process conditions are mild, and it is suitable for large-scale application and promotion.