45results about How to "Improve Lithophilicity" patented technology

The invention discloses a preparation method of a three-dimensional conductive skeleton/metal nitride composite lithium metal negative electrode current collector, which is used for solving the technical problem of poor practicability of the existing preparation method of the lithium metal negative electrode current collector. According to the technical scheme, a precursor with a specific nanostructure grows on a three-dimensional conductive skeleton by using a hydrothermal synthesis method, and the nitride-modified three-dimensional conductive skeleton current collector is obtained through high-temperature nitridation. The conversion reaction between the metal nitride and the lithium metal endows the three-dimensional skeleton with excellent lithium affinity, so that uniform deposition/stripping of lithium is induced, and meanwhile, the conductive skeleton with the spatial three-dimensional structure effectively alleviates the problem of volume expansion of the lithium metal in the circulation process. The synergistic effect of the two protects the stability of a solid electrolyte membrane and effectively inhibits the growth of lithium dendrites. The lithium metal negative electrode of the three-dimensional current collector prepared by the method has excellent coulombic efficiency, ultra-long cycle life, low voltage lag and good practicability.

Melamine resin pellets are obtained through one-step condensation of melamine and formaldehyde, the melamine resin pellets used as templates are coated with polypyrrole by using pyrrole as a nitrogensource and a carbon source and ammonium persulfate as a catalyst; the melamine resin pellets are gradually decomposed in the roasting process by controlling roasting to obtain nitrogen-doped porous hollow carbon spheres; and finally, the material is used in a lithium ion battery negative electrode. By using the melamine resin pellets instead of traditional silicon dioxide pellets, the problem of environmental pollution caused by etching of a silicon dioxide hard template with use of toxic reagents such as hydrofluoric acid in a traditional hard template method is avoided. Because the melamineresin pellets can generate a large amount of gas in the decomposition process, pores can be further formed in the pore walls of the hollow carbon spheres. Because the material is uniform in morphology, large in specific surface area and of a hollow structure, volume expansion can be relieved, and high specific capacity and cycle stability are shown in the lithium ion battery.

The invention relates to an amorphous hollow carbon nanotube and a preparation method thereof. The amorphous hollow carbon nanotube has an inner diameter of 50 to 100 nm, a thickness of 10 to 20 nm and a tube length of 1 to 5 [mu]m; the carbon wall of the amorphous hollow carbon nanotube is of a porous amorphous structure; and a plurality of nanoparticles are attached to the inner wall of the amorphous hollow carbon nanotube. The amorphous hollow carbon nanotube is obtained by using zinc oxide as a template and phenolic aldehyde amine resin as a carbon source through low-temperature heat treatment and hydrochloric acid etching. According to the invention, the lithium/sodium affinity of metal nanoparticles is utilized to guide lithium/sodium metals; the deposition and stripping processes ofthe lithium/sodium metals are limited in the cavity of a carbon tube; the effects of inhibiting dendritic crystal growth, limiting volume change generated in the deposition and stripping processes ofthe lithium/sodium metals and stabilizing negative electrode/electrolyte interfaces are achieved; and important application values are achieved for constructing stable and highly-efficient lithium/sodium metal batteries.

The invention discloses a flexible three-dimensional layered MXene@indium composite film and a preparation method and application thereof. The flexible composite film is prepared by depositing metal indium (In) with a low melting point onto a flexible self-supporting MXene film by a simple and industrial electrodeposition method, wherein indium can be subjected to alloying reaction with metal lithium, and indium has excellent lithium affinity, so nucleation barriers can be effectively reduced, the actual current density in the lithium deposition and dissolution process is reduced, the reduction of deposition dissolution overpotential is facilitated, the uniformity of deposition is improved, the preparation method is simple, the internal lithium ion transmission rate is increased, the lithium deposition direction can be changed, and the battery safety problem caused by the fact that the lithium dendrites pierce the diaphragm is relieved; the composite material has an excellent effect ofinhibiting the growth of the lithium dendrites, the electrodeposition operation is simple and convenient, and large-scale production can be realized, so that the preparation method has the great application value and scientific research value.

The invention provides a Li-Ti3C2-rGO composite thin film material and a preparation scheme thereof. The Li-Ti3C2-rGO composite thin film material is prepared by the following steps that step 1, a GOdispersion solution and a Ti3C2 dispersion solution are prepared, the concentration of the GO dispersion solution and the Ti3C2 dispersion solution is 1-4mg/mL, after the GO dispersion solution and the Ti3C2 dispersion solution are mixed, stirring is carried out, and then ultrasonic treatment is carried out; step 2, the solution obtained in the step 1 is subjected to vacuum filtration in batches;step 3, a Ti3C2-GO thin film filtered by the step 2 is subjected to air drying naturally, a contact heat table is torn off from the filter film, so that the Ti3C2-GO thin film becomes a multihole Ti3C2-rGO thin film; and step 4, the multihole Ti3C2-rGO thin film in the step 3 is in contact with a molten lithium metal. According to the thin film prepared by the preparation scheme, the electrode hasgood flexibility, and is very useful for wearable electrode design; and the uniform and rapid combination of the lithium metal with the composite material can be realized, the lithium content of thethin film material is high, and the superstrong protection for the lithium metal can be realized.

The invention discloses a three-dimensional porous material containing a lithium alloy skeleton network and a preparation method thereof, and a composite lithium negative electrode material of the three-dimensional porous material and a preparation method thereof. According to the invention, the phase separation or component segregation process of the high-temperature molten lithium-rich alloy in the three-dimensional porous material and/or on the surface of the three-dimensional porous material is controlled, the micro-nano three-dimensional lithium alloy skeleton network further divides pores of the porous material into small pores which are smaller in size and communicated with one another, and the lithium alloy micro-nano skeleton does not participate in a charge-discharge reaction; only the effects of enlarging the specific surface area, inducing uniform deposition of lithium ions and inhibiting formation of lithium dendrites are achieved, a multi-scale skeleton structure is formed with the three-dimensional porous base material, and the electrochemical performance of the negative electrode is further improved through the synergistic effect. The lithium alloy skeleton or the surface of the lithium alloy skeleton is filled with the metal lithium to form the composite lithium negative electrode material containing the lithium alloy skeleton network, which is formed by compounding lithium, the lithium alloy skeleton and the three-dimensional porous material, and the metal lithium provides reversible capacity for the charge-discharge reaction of the battery.

The invention provides a preparation method of a nano-carbon composite lithium metal lithium negative electrode, which comprises the following steps: S1, carrying out graphitization treatment on a nano-carbon material to obtain a highly graphitized nano-carbon material; and S2, fully mixing the highly graphitized nano carbon material obtained in the step S1 with molten liquid lithium, and then carrying out cooling treatment to obtain the nano carbon composite lithium metal negative electrode. According to the preparation method, other substances do not need to be introduced, the effective content of lithium metal in the composite negative electrode is effectively guaranteed, and other side reactions are avoided; and complicated modification operation is not needed, so that the preparation process of the nano-carbon composite lithium metal negative electrode is simple, and the cost is low. The invention further provides the nanocarbon composite lithium metal negative electrode, the problems of lithium dendrite growth and huge volume change of the lithium metal negative electrode in the charging and discharging process can be solved, other impurities except carbon are not introduced into the lithium metal negative electrode, the content of metal lithium is high, and the prepared negative electrode has higher specific capacity.

The invention belongs to the technical field of lithium metal batteries, and particularly discloses a preparation method of a metal oxide composite self-supporting heat-conducting carbon film. The method comprises the following steps of (1) cracking a polymer to obtain a polymer carbon material, mixing the polymer carbon material with graphene, and pressing to form a film, namely obtaining the self-supporting heat-conducting carbon film; and (2) carrying out coordination reaction on a solution containing the self-supporting heat-conducting carbon film, an M metal source and an organic ligand to obtain a metal organic framework-self-supporting heat-conducting carbon film material, and then carrying out carbonization treatment to obtain the self-supporting metal oxide composite heat-conducting carbon film. The invention also provides a negative electrode obtained by filling the metal oxide composite self-supporting heat-conducting carbon film with lithium and an application method of thenegative electrode in a lithium metal battery. The material obtained by the technical scheme provided by the invention has excellent performance, and can significantly improve the long cycle performance of the lithium metal battery.

The invention discloses a preparation method of a composite lithium metal negative electrode with a three-dimensional structure and a product of the composite lithium metal negative electrode. An inherent pore structure of carbon fiber cloth taking thin-crystal graphite flakes as pore walls not only can relieve volume change in a lithium deposition/dissolution process, but also can introduce a lithium storage mechanism through a lithium insertion/extraction path; and meanwhile, the carbon cloth has light weight and good flexible mechanical properties, and can inhibit the growth of lithium dendrites. In the lithium electrochemical deposition process, the metal lithium and the cobalt fluoride are subjected to an irreversible reduction reaction to form cobalt nanoparticles and the lithium fluoride; the cobalt nanoparticles have smaller binding energy with the lithium metal, so that nucleation sites can be increased, the nucleation overpotential of the lithium metal is reduced, and uniform diffusion of lithium ions is promoted. The lithium fluoride formed in situ has good interface contact with the carbon fiber cloth, has high mechanical modulus, high chemical stability and high interface energy with lithium, and can uniformize lithium ion flux and effectively inhibit dendritic crystal growth of lithium.

The invention particularly discloses a composite negative electrode material, a negative electrode, a lithium ion battery and a preparation method. The preparation method comprises the following steps: carbonizing foam resin of melamine or derivatives thereof to obtain a matrix, and dipping the matrix into molten lithium to obtain the composite negative electrode material. The nitrogen-containingfunctional groups are uniformly distributed in the foam carbon matrix provided by the invention, so that the foam carbon matrix has relatively strong binding energy to lithium, lithium ion flow can behomogenized in a lithium ion deposition process, uniform deposition of metal lithium is facilitated, and formation of nucleation sites for lithium dendritic crystal growth is avoided; meanwhile, thefoam carbon matrix of the three-dimensional network structure further has a high specific surface area, the local current density can be reduced, the deposition uniformity of metal lithium in the matrix is further improved, the hollow structure of the foam carbon matrix serves as an ion transmission channel, carriers are provided in the lithium deposition process, and aggregation of lithium ions/electrons is dispersed. The continuous growth of the lithium dendrites is favorably relieved, so that the effects of inhibiting the lithium dendrites and buffering the volume expansion are achieved.

The invention discloses a flexible composite lithium metal electrode, a preparation method thereof and a lithium metal battery. The flexible composite lithium metal electrode comprises a flexible substrate, the flexible substrate comprises a non-lithium-philic first conductive fiber layer, the first conductive fiber layer is provided with two opposite surfaces, and a lithium-based film layer is laminated and combined on one surface of the first conductive fiber layer; or, the flexible substrate comprises the non-lithium-philic first conductive fiber layer, a non-lithium-philic second conductive fiber layer and the lithium-based film layer, the first conductive fiber layer and the second conductive fiber layer are each provided with two opposite surfaces, and along the direction from the first conductive fiber layer to the second conductive fiber layer, the first conductive fiber layer, the lithium-based film layer and the second conductive fiber layer are sequentially laminated and combined to form a sandwich structure. The negative electrode of the lithium metal battery is the flexible composite lithium metal electrode.

The invention discloses a stannous oxide/graphene heterojunction composite material, a preparation method and application thereof and a metal lithium negative electrode taking the stannous oxide/graphene heterojunction composite material as a host. The preparation method comprises the following steps: preparing stannous oxide nanosheets through a polymer-assisted liquid-phase synthesis method; carrying out positive electricity modification on the graphene nanosheet, and inducing stannous oxide and graphene to be alternately stacked and assembled in a liquid phase environment to prepare a stannous oxide/graphene heterojunction material; uniformly coating a copper foil current collector with the heterojunction material, and controlling the lithium metal deposition reaction on the electrode to prepare the lithium metal heterojunction composite electrode. The stannous oxide/graphene heterojunction composite material obtained in the invention has good conductivity and good lithium affinity,reversible deposition and stripping of lithium metal can be realized by taking the stannous oxide/graphene heterojunction composite material as a support host material of a metal lithium negative electrode, volume expansion of metal lithium and growth of lithium dendrites are inhibited in a cyclic process, and the high-performance lithium metal negative electrode of the lithium ion battery is obtained.

The invention discloses a three-dimensional porous substrate material for a lithium metal battery negative electrode and a preparation method and application thereof, and relates to a three-dimensional porous substrate material and a preparation method and application thereof. The invention aims to solve the problems of battery safety and instability of electric circulation caused by dendritic crystal growth of a metal lithium negative electrode in a metal lithium battery in a circulation process. The invention discloses a three-dimensional porous substrate material for a lithium metal battery negative electrode. The three-dimensional porous substrate material consists of foam metal and metal carbon/nitride. The method comprises the following steps: 1, pretreating foam metal; 2, preparing a two-dimensional MXenes nano material; and 3, preparing the three-dimensional porous substrate material. The three-dimensional porous substrate material for the negative electrode of the lithium metal battery is used as a substrate material of the negative electrode of the lithium metal battery. The three-dimensional porous substrate material for the negative electrode of the lithium metal battery has huge application potential in the lithium metal battery. The three-dimensional porous substrate material for the negative electrode of the lithium metal battery can be obtained.

A lithium metal anode comprises a carbon nano tube sponge and a lithium metal material, the carbon nano tube sponge comprises a plurality of carbon nano tubes and a plurality of micropores, the surfaces of the carbon nano tubes are coated with carbon deposition layers, and the micropores are formed by the carbon nano tubes with the surfaces coated with the carbon deposition layers. And the lithium metal material is filled in the plurality of micropores and coats the carbon nanotubes coated by the carbon deposition layer. The invention also relates to a preparation method of the lithium metal anode.

The lithium battery negative electrode comprises a negative electrode current collector and a protective layer arranged on the surface of the negative electrode current collector, the protective layer comprises a doped carbon material matrix and transition metal compound particles, and at least part of the transition metal compound particles are coated by the doped carbon material matrix, doping elements in the doped carbon material matrix are cobalt element and nitrogen element. The arrangement of the protective layer is beneficial to uniform deposition of lithium ions in the negative electrode, so that lithium dendrites can be effectively prevented from growing towards the positive electrode side, and the phenomenon of short circuit of the battery is avoided.

The invention discloses a three-dimensional conductive skeleton as well as a preparation method and application thereof, and the method comprises the following steps:(1) mixing a nitrogen source and asulfur source with an aqueous solution containing NaCO3 and NaHCO3 to obtain a conductive buffer solution; (2) soaking a three-dimensional conductive skeleton matrix in an organic solvent and concentrated acid in sequence; (3) assembling a three-electrode electrolytic tank by taking the three-dimensional conductive skeleton matrix obtained in the step(2) as a working electrode, Pt as a counter electrode, Ag/AgCl as a reference electrode and a conductive buffer solution as an electrolyte; and(4) applying a voltage to the working electrode in the step(3), and then carrying out heat treatment toobtain the three-dimensional conductive skeleton. By adopting the method, the three-dimensional conductive skeleton with good lithium affinity can be obtained, so that the lithium metal with higher content can be loaded, the contact resistance between the three-dimensional skeleton and the lithium metal is reduced, and the problem of uneven current density in the charging and discharging processis improved; and the lithium metal negative electrode prepared from the three-dimensional conductive skeleton obtained by the method is higher in specific capacity, better in lithium dendritic crystalinhibition effect and better in rate capability.