60results about How to "Limit volume expansion" patented technology

The invention discloses a lithium metal electrode, a preparation method thereof, a negative electrode of a lithium metal secondary battery and the battery, and belongs to the technical field of lithium batteries. The lithium metal electrode comprises a foam electrode substrate with a plurality of hole cavities and metal lithium particles distributed in at least one hole cavity of the foam electrode substrate; and the foam electrode substrate is made from a foam metal material or a carbon foam material. The hole cavities of the foam electrode substrate can effectively restrict the volume expansion of the metal lithium particles in the charging and discharging process and reduce the generation of lithium dendrites, so that the stable performance, cycle performance, quick charging performance and safety performance of the lithium metal secondary battery using the lithium metal electrode as the negative electrode are effectively improved.

The invention relates to a negative electrode material with a multi-coating structure as well as a preparation method and application of the negative electrode material. The negative electrode material with the multiple coating structures comprises lithium-containing silicon monoxide as well as a lithium salt coating layer, a carbon coating layer and a polymer coating layer which sequentially coatthe surface of the silicon monoxide. The lithium salt coating layer of the negative electrode material effectively inhibits the volume expansion of the material, improves the ionic conductivity of the surface of the material, improves the cycling stability of an electrode, and reduces the alkalinity of the material; the carbon coating layer of the negative electrode material improves the electronic conductivity of the surface of the material and improves the oxidation-reduction reaction rate of the surface of the material; the polymer coating layer of the negative electrode material improvesthe compatibility between the silicon monoxide and the organic electrolyte, limits the volume expansion of the material to a certain extent, avoids the cracking of the material, and more effectively improves the cycling stability of the electrode.

The invention discloses a preparation method of a polymer lithium ion battery and the polymer lithium ion battery. The preparation method comprises the following steps of: preparing a positive plate and a negative plate which contains a silicon carbon active layer; coating a layer of polymer film on the two surfaces of the positive plate and the negative plate; arranging a diaphragm in the middle of the positive plate and the negative plate so that the positive plate, the diaphragm and the negative plate are prepared into a bare battery cell, and packaging the bare battery cell into the battery shell; injecting liquid electrolyte into the battery shell in a drying room, and sealing the opening of the battery shell to obtain a polymer lithium ion battery precursor; heating and pressurizing the polymer lithium ion battery precursor, and plasticizing to form the polymer lithium ion battery; and performing formation on the polymer lithium ion battery. The volume energy density of the polymer lithium ion battery is improved, the phenomenon that the silicon carbon active layer is powdered or drops from a negative current collector in the process of charging and discharging the negative plate which contains the silicon carbon active layer in the polymer lithium ion battery is avoided, and the cycle performance of the battery is improved.

The invention discloses a preparation method of a negative electrode material for carbon-coated antimony-doped stannic oxide ion batteries. The method comprises the following steps: firstly using antimony to dope stannic oxide through a hydrothermal reaction, then taking glucose as a carbon source, carrying out carbon-coated treatment on the carbon source through the hydrothermal reaction, and then carrying out high-temperature heat treatment to generate the high-performance negative electrode material for ion batteries. During doping at the molar ratio of antimony to tin is 6% to 7%, the generated negative electrode material for the ion batteries is of a uniform nano-particle structure, and also has extremely good electrochemical performance. When the material serves as a negative electrode material for the lithium ion batteries, after 400 circles of circulation at the current density of 0.5 C, the specific discharge capacity of the material still can be maintained to be 1500 to 1820mAh/g. The raw materials used for preparing the negative electrode material for carbon-coated antimony-doped stannic oxide ion batteries comprise glucose, stannic chloride, antimony chloride, ammoniumbicarbonate and the like, and are wide in sources and low in cost; and the electrode material is simple and controllable in preparation technology, mild in condition and simple in equipment.

The invention discloses an apple-shaped embedded silicon carbon negative electrode material and a preparation method thereof, wherein the silicon carbon negative electrode material is orderly composedof a core part, a middle part and an external layer from inside to outside; the core part is a micron-level carbon coated silicon carbon material, the middle part is a micron-level graphite material,and the external layer is a submicron-level carbon coated silicon carbon material; the middle part is cylindric and has a rounded edge, the middle part is filled with the core part, and sunken partsare formed at two ends of the middle part; and the external layer covers a surface of the middle part. The preparation method comprises the following steps: obtaining a hollow apple-shaped graphite material by executing spray drying, carbonization and other means on the graphite, then, filling the inside of a hollow structure with a silicon carbon composite material, meanwhile, covering the external surface with the silicon carbon composite material; then, obtaining a target product through high temperature carbonization. With the carbon coated silicon carbon material in the apple-shaped embedded silicon carbon negative electrode material, specific capacity of the product is improved, and the graphite in the middle part not only can improve electrical conductivity of the silicon carbon material, but also can limit volume expansion of the silicon.

The invention discloses a silicon carbon anode material and a preparation method thereof. The silicon carbon anode material in the invention comprises covalent organic frameworks, a silicon nanomaterial and a carbon nanomaterial; the covalent organic frameworks have hole channels; the silicon nanomaterial is dispersed in the hole channels; and the carbon nanomaterial is dispersed in the covalent organic frameworks and the silicon nanomaterial. The preparation method of the silicon carbon anode material in the invention comprises the steps of: S1, mixing the covalent organic frameworks with thesilicon nanomaterial, so that a mixture is obtained; and S2, adding the mixture into slurry of the carbon nanomaterial; filtering after stirring for 20-50 min, and drying filtrates at 60-100 DEG C for 1-3 h. The silicon nanomaterial is limited in the hole channel by the silicon carbon anode material; the expansion of silicon is inhibited; and the problems of serious pulverization, low cycle lifeand the like due to the fact that the silicon expansion rate is large can be solved.

The invention discloses a MoS2@C composite anode material for a lithium ion battery and a preparation method thereof, MoS2 sheets in the composite anode material are stacked disorderly and intertwinedto form a wormlike microsphere structure, and the MoS2@C composite anode material comprises 38-43% of Mo, 47-53% of S and the balance of C. According to the invention, MoS2 and a carbon material arecompounded; the prepared anode material has a wormlike structure; the diffusion path of Li<+> can be shortened; the composite material has excellent rate capability; and the carbon layer coated on thesurface of the MoS2 sheet can limit the further growth of the MoS2 nanosheet and can inhibit the problem of easy volume expansion of the MoS2 composite material in the cycle process, thereby effectively enhancing the rate capability and cycle stability of the lithium ion battery anode material.

The invention relates to a modification method of a silicon negative electrode material of a lithium ion battery, which is characterized by comprising the following steps: by taking nano silicon powder and tetrabutyl titanate as raw materials, reacting under a hydrothermal condition, filtering and drying to obtain a precursor; and uniformly mixing the precursor and a carbon/nitrogen source according to a certain ratio, and carrying out heat treatment to obtain the two-layer coated silicon negative electrode lithium ion battery material which takes silicon nanoparticles as a core, takes a titanium nitride layer as a middle layer and takes a carbon layer as an outermost layer. The preparation method provided by the invention is simple and effective, and the prepared silicon-based negative electrode material has a carbon layer with good conductivity and a titanium nitride layer with a stable structure in a lithium ion deintercalation process, so that volume expansion of silicon in a charging and discharging process can be effectively slowed down. The core is elemental silicon with high specific capacity. Therefore, the material has good lithium storage performance.

The invention relates to a preparation method and application of a nitrogen-doped porous carbon-coated cobalt diselenide composite material, and the preparation method comprises the following steps: respectively dissolving cobalt salt and selenium powder in a solvent, and carrying out first stirring to respectively obtain a cobalt salt solution and a selenium powder solution; pouring the selenium powder solution into the cobalt salt solution, adding a liquid acrylonitrile oligomer, stirring for the second time, and adding a hydrazine hydrate solution after stirring to obtain a mixed solution; transferring the mixed solution into a hydrothermal reaction kettle, carrying out hydrothermal reaction, and then cooling, centrifuging and drying to obtain a precipitate; and calcining the precipitate, cooling, grinding and sieving to obtain the nitrogen-doped porous carbon coated cobalt diselenide composite material. The prepared nitrogen-doped porous carbon coated cobalt diselenide composite material is prepared into a lithium ion battery negative electrode, and the lithium ion battery negative electrode still has the specific discharge capacity of 644mAh/g after 300 times of charge-discharge cycles under the current density of 0.2 A/g.

The invention provides a bimetallic selenide carbon microsphere composite material as well as a preparation method and application thereof. In the bimetallic selenide carbon microsphere composite material, two kinds of metal selenide are cross-linked with each other through the carbon matrix and are uniformly combined to form microspheres; in the two kinds of metal selenide, the metal valence state of one is relatively high, and the metal valence state of the other is relatively low. By introducing the high-valence metal, the electron and ion transmission effect of the low-valence metal can be improved, and the synergistic effect of the double metals is generated, so that the activity and the sodium storage performance of the material are improved. The carbon matrix not only provides a conductive network, but also limits the volume expansion of the material.

The invention provides hollow porous carbon nanofiber with tin oxide loaded on an inner tube wall as well as a preparation method and application of the hollow porous carbon nanofiber. The preparation method comprises the following steps of mixing polyacrylonitrile, polymethyl methacrylate and polyvinylpyrrolidone to obtain a shell layer spinning solution; dissolving polyvinylpyrrolidone and stannous chloride dehydrate to obtain a core layer spinning solution; performing coaxial electrostatic spinning on the shell layer spinning solution and the core layer spinning solution to obtain a carbon fiber precursor; and carrying out pre-oxidation and carbonization treatment to obtain the hollow porous carbon nanofiber with tin oxide loaded on the inner tube wall. Compared with porous carbon nanofiber prepared by a traditional method, the hollow porous carbon nanofiber has the advantages that the tin oxide and carbon fiber are combined to form a network skeleton, so that the carbon fiber has more active sites and higher specific capacitance, and meanwhile, controllable ion and electron transmission channels of the carbon fiber improve the charge storage stability and efficiency of the tin oxide; and the prepared hollow porous carbon nanofiber can be applied to the aspects of lithium batteries, supercapacitors and the like.

The invention discloses a carbon nanotube-containing carbon shell-coated silicon negative electrode material and a preparation method thereof. The invention belongs to the technical field of lithium ion battery anode materials. The invention aims to solve the problems that the silicon-carbon material prepared by the prior art is non-uniform in coating and the degree of graphitization is low; according to the invention, the silicon is coated in a polyhedron carbon shell covered by carbon nanotubes; the preparation method comprises the following steps: by taking cobalt nitrate hexahydrate and dimethylimidazole as raw materials and silicon as a precursor, carrying out reaction for 24 hours at room temperature by adopting a coprecipitation method to obtain a silicon-metal organic framework material; treating the obtained precursor for 3.5 h under the argon-hydrogen mixed atmosphere of 600-900 DEG C, and obtaining the carbon nanotube modified silicon-carbon negative electrode material, thecoating effect of the product is good, and excellent electrochemical performance is shown. The surface carbon layer in the material structure effectively inhibits the volume expansion of silicon, andthe carbon nanotubes on the surface of the carbon layer construct a three-dimensional conductive network, thereby improving the electronic conductivity of the material.

The invention provides a preparation method of core-shell structured Si-Li4Ti5O12 composite material. The preparation method comprises preparing outer-layer spinning liquid by mixing lithium source, titanium source, organic acid, high-molecular polymer and absolute ethanol; preparing inner-layer spinning liquid by high-molecule polymer, high-capacity anode material and anhydrous ethanol; preparing the core-shell structured Si-Li4Ti5O12 composite material by electrospinning and calcination. With the coaxial electrospinning technology, the different materials can be jet out from the inner and outer layers of solution to prepare the composite material with the coaxial structure, and a nanometer composite material with high-capacity negative electrode material as the core and the zero-strain material as the shell is formed.

The invention relates to an SnO2@PPy coaxial nanorod array structure and a preparation method of the structure. The coaxial structure grows on foamed nickel, and an SnO2 nanorod surface is coated by a polymer, namely pyrrole. A nanorod of the coaxial structure is 300-600nm in length. The preparation method of the coaxial structure comprises the following steps: 1) dispersing a pyrrole monomer in a lithium perchlorate acetonitrile solution, mixing and stirring for 30min, and 2) taking foamed nickel where an SnO2 nanorod array grows as a working electrode, Ag/AgCl as a reference electrode and a platinum electrode as a counter electrode for electro-deposition for 700s, allowing current density to be 1.6mA/cm<2>, and carrying out washing. The coaxial structure and the method have the benefit that an SnO2@PPy coaxial structure material is prepared by a method of depositing polypyrrole by a constant current timing method. The material becomes a potential application material of a lithium ion battery, meets requirements of green chemistry and facilitates marketed popularization.

The invention relates to a metal organic framework (MOF) catalytic growth carbon nanotube (CNT) coated nickel-tin alloy electrode material as well as preparation and application thereof. Stannic oxide (SnO2) is added into a Ni-MOF precursor solution to be stirred and mixed at room temperature and then to be put into a hydrothermal kettle for hydrothermal reaction so as to obtain the MOF-SnO2 composite material. The MOF-SnO2 composite material can be prepared into the CNT coated nickel-tin alloy composite material through a chemical vapor deposition (CVD) method. The surface of the nickel-tin alloy is coated with the CNT catalytically grown by the MOF, so that the ion and electron conductivity can be improved, and meanwhile, the cycling stability of the electrode material can be effectively improved due to the unique stability of the CNT. The method for growing the CNT through catalytic coating of the MOF is simple in preparation process, low in energy consumption and environmentally friendly, and is suitable for large-scale production of lithium ion batteries and supercapacitors.

The invention discloses a polypyrrole-coated sulfur-doped cobalt-based carbon nanocage material, a preparation method and application thereof, and belongs to the technical field of lithium-sulfur batteries. The method specifically includes the following steps: preparation of a precursor cobalt-based ZIF-67, preparation of sulfur-doped cobalt-based carbon nanocages, and preparation of polypyrrole-coated sulfur-doped cobalt-based carbon nanocages (PS-CNCs). By forming an internal hollow structure in the carbon nanocages, it is possible to contain more active material sulfur and restrict the volume expansion of sulfur, thereby effectively alleviating the volume expansion during a battery reaction, and extending a service life. The co-doping of sulfur and cobalt can effectively improve the interaction of the PS-CNCs and polar polysulfides in a reaction can effectively inhibit the shuttle effect of the polysulfide and improve the cycle performance of the battery. The use of the polypyrrole-coated carbon nanocages can significantly improve the conductivity of the material, reduce the impedance, inhibit polarization, and improve battery stability. The method of the invention has low cost,simple operation and an obvious effect, and is suitable for popularization.

The invention discloses a ZnS-SnS@3DC composite material and a preparation method and application thereof. The ZnS-SnS@3DC composite material is formed by embedding ZnS-SnS nanocrystals with a heterostructure into a nitrogen-doped three-dimensional porous carbon framework obtained by carbonizing a metal organic framework ZIF-8 in a composite mode; and the ZnS-SnS@3DC composite material serves as a negative electrode material of a lithium ion battery or a sodium ion battery. The ZnS-SnS heterostructure nanocrystal is embedded into the nitrogen-doped three-dimensional porous carbon, so that the volume expansion of ZnS-SnS can be better limited, the structural stability of an active substance in a lithium or sodium de-intercalation process is ensured, and the electrochemical performance is further improved.

The invention discloses a multilayer nano-composite electrode for a lithium ion battery and preparation method thereof. The multilayer nano-composite electrode is mainly composed of a copper current collector and multilayer active substances; the copper current collector is provided with a porous structure and a nano-needle structure; the multilayer active substances comprise a silicon layer and a carbon layer. The preparation method of the multilayer nano-composite electrode is as follows: (1) sintering of copper powder; (2) growing and reducing of copper oxide nanoneedle structure; (3) depositing of a silicon nanometer layer; and (4) cladding of the carbon nanometer layer. The multilayer nano-composite electrode disclosed by the invention can effectively limit the sharp change of the volume of silicon active substance in the charging/discharging process of the battery, thereby prolonging the cycle life of the battery; and meanwhile, the porous structure and the nano-needle structure of the current collector are directly and tightly contacted with the active substances, the use of each of the adhesive and the conductive additive is reduced, thereby facilitating the improvement of the reversible capacity, the coulombic efficiency, the cycle stability and other electrochemical properties of the battery.

The invention discloses a positive electrode material, a preparation method thereof and a lithium ion battery. The positive electrode material comprises a positive electrode material substrate, the surface of the positive electrode material substrate is coated with a negative thermal expansion material layer, and the surface of the negative thermal expansion material layer is coated with a tungsten-boron co-coating layer. The positive electrode material disclosed by the invention has good normal-temperature cycle performance and high-temperature cycle performance.

The invention relates to a quasi-solid electrolyte for protecting a lithium negative electrode and a preparation method of the quasi-solid electrolyte, and belongs to the technical field of lithium metal battery electrolytes. The electrolyte is a porous network structure prepared from a lithium salt, an ionic liquid, an aluminum precursor and a catalyst through sol-gel reaction. An aluminum oxideframework of the porous network structure serves as a supporting structure, and liquid electrolyte composed of lithium salt and ionic liquid is adsorbed in the framework. The preparation method comprises the following steps: adding a lithium salt into an ionic liquid in a near-oxygen-free and water-free environment, stirring to be transparent, adding an aluminum precursor, stirring to obtain a milky white uniform thick liquid, adding a catalyst, and uniformly stirring; standing for 24 to 72h in a nearly oxygen-free and water-free environment, moving out and placing in a vacuum of -70 KPa to -100KPa, and drying at 60-90 DEG C for 4-6 days to obtain the electrolyte. The electrolyte has high ionic conductivity, a wide electrochemical stability window and good thermal and chemical stability; and the lithium-ion battery has super-strong lithium affinity and is beneficial to protection of a lithium negative electrode.

The invention discloses a silicon monoxide/carbon composite negative electrode material and a preparation method and application thereof. The preparation method comprises the following steps: puttingsilicon monoxide and a modifier into a rotary crucible, heating to a certain temperature, carrying out heat preservation for a period of time to enable the modifier to fully coat the surface of silicon monoxide, and then carrying out vapor deposition carbon layer coating on the modified silicon monoxide to obtain the silicon monoxide/carbon composite negative electrode material. Through surface modification, the flowability of the silicon monoxide can be effectively improved. In the vapor deposition process, the contact between the material and pyrolysis gas can be effectively improved, the coated carbon layer is more uniform. Meanwhile, the electrochemical performance of the negative electrode material is greatly improved by modifying the surface of the silicon monoxide and further coating the silicon monoxide with the pyrolysis carbon layer, and the actual application of the silicon monoxide negative electrode material is facilitated.

The invention discloses a cobalt phosphide nanoparticle inlaid carbon nanosheet array material and a preparation and application thereof in a lithium ion battery negative electrode material. The cobalt phosphide nanoparticles are embedded into the carbon nanosheet array material, and the cobalt phosphide nanoparticles are embedded into the carbon nanosheets to form a jujube cake type composite structure; the carbon nanosheets vertically grow on a surface of the foamed nickel to form an array structure. The preparation method comprises the following steps of firstly, growing the ZIF67 nanosheetarray on the surface of the foamed nickel, and then carbonizing and phosphatizing. According to the preparation method, conductivity, structural stability, cycling stability and electrochemical activity of cobalt phosphide can be improved, so cobalt phosphide has higher charge-discharge capacity and more stable cycling performance. The cobalt phosphide nanoparticle embedded carbon nanosheet arrayhas important application value as a lithium ion battery negative electrode material.