64results about How to "Reduce local current density" 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.

The invention discloses a composite lithium metal negative electrode based on an MXene aerogel and a synthesis method thereof, which belong to the field of lithium batteries. The composite lithium metal negative electrode comprises metal lithium and the MXene aerogel, wherein the MXene aerogel is assembled by cross-linking of two-dimensional MXene sheets and has a three-dimensional hierarchical porous structure; the MXene aerogel pores are filled with the metal lithium; and the thickness of the MXene aerogel is 300 mum to 800 mum. According to the composite lithium metal negative electrode prepared in the invention, rich pro-lithium functional groups on the surface of the MXene aerogel can be specifically combined with the lithium ions, uniform nucleation of lithium is thus realized, formation of lithium dendrites is suppressed, and the coulombic efficiency, the safety and the cycle life of the lithium metal negative electrode are effectively improved.

The invention discloses a metal electrode with a three-dimensional structure. The metal electrode comprises a substrate, wherein at least one surface of the substrate is provided with an embedded layer with a netlike structure; the substrate is selected from metal lithium, sodium, magnesium or aluminum, or an alloy consisting of at least two of the metal lithium, sodium, magnesium and aluminum; the embedded layer with the netlike structure is of a single-layer or multi-layer structure, and is selected from at least one of a metal layer, a polymer layer, a semiconductor layer and an insulator layer; the netlike structure is a planar netlike structure or a three-dimensional netlike structure; and the embedded layer is made of a material different from the material of the substrate. Through adoption of the metal electrode with the three-dimensional structure provided by the invention, the aims of restraining dendritic crystal growth and reducing volume expansion can be fulfilled, thereby increasing the coulombic efficiency of a battery and prolonging the service life the battery.

The invention belongs to the field of high-specific-energy lithium metal batteries, and particularly discloses a lithium metal secondary battery based on a porous ceramic composite lithium metal negative electrode and a preparation method of the lithium metal secondary battery. The porous ceramic lithium metal negative electrode is composed of a porous ceramic skeleton, a conductive layer and lithium metal, and compared with a traditional lithium sheet negative electrode, the porous ceramic lithium metal negative electrode disclosed by the invention has the advantages that the porosity of theporous ceramic skeleton can provide sufficient storage space for the lithium metal; the rigidity of the porous ceramic skeleton can maintain the structural stability of the lithium metal negative electrode; the large specific surface area attribute of the porous ceramic skeleton can effectively reduce the local current density of the lithium metal negative electrode and relieve the growth problemof lithium dendrites. Based on the advantages, the porous ceramic lithium metal composite negative electrode can be used for preparing a high-specific-energy lithium metal secondary battery. Meanwhile, the preparation method is simple, and large-batch manufacturing can be realized.

The invention relates to a magnetic lithium metal battery copper magnetic composite electrode material and a preparation method and application thereof and belongs to the technical field of magnetic batteries. The preparation method comprises 1), removing oxides on the surface of a copper substrate and carrying out cleaning and drying, and 2), preparing a magnetic layer structure containing a magnetic metal on the surface of the copper substrate treated by the step 1), wherein the magnetic metal includes iron, cobalt, nickel and platinum and the magnetic layer structure includes a magnetic plating layer structure, non-magnetic micro-nano-structure doped magnetic particles, magnetic micro-nano-structure doped magnetic particles and a magnetic micro-nano-structure.

The invention discloses a preparation method of a porous graphene/silver nanoparticle composite lithium metal secondary battery negative current collector. The method includes the following steps: 1,dispersing graphene oxide in an aqueous solution to form a uniform graphene oxide solution; 2, adding silver nanoparticles into a micro/nano microsphere template solution, and fully stirring under theirradiation of ultraviolet light to uniformly load the silver nanoparticles on template microspheres; 3, mixing the solutions obtained in the steps 1 and 2, and performing ultrasonic treatment in anultrasonic cleaning machine; 4, performing vacuum filtration on the mixed solution obtained in the step 3 to obtain graphene oxide, micro/nano template microsphere and silver nanoparticle composite materials; and 5, processing the composite material obtained in the step 4, removing the micro/nano template microspheres to obtain a porous graphene oxide/silver nanoparticle material, and finally carrying out sintering to obtain the required porous graphene/silver nanoparticle composite material. The material can be directly used in a negative electrode of a lithium metal secondary battery.

The invention relates to the field of lithium metal air batteries, in particular to a copper magnetic current collector, a preparation process thereof and a magnetic lithium air battery containing thesame. Surface modification is performed on a material with the permanent magnetic property to obtain a negative electrode material of a lithium air battery with large specific surface and high catalytic activity. According to the invention, the mass transfer process of oxygen is enhanced through the micro magnetic field, the concentration of active oxygen on the positive electrode surface is improved by the paramagnetic property of oxygen, the magnetohydrodynamics effect, the magnetization force effect and the like produce disturbance on the electrolyte, so that the reaction activity of the gas-liquid-solid three-phase interface is increased, the polarization is reduced, non-uniform deposition of the negative electrode metal lithium is improved, and the lithium dendrites are inhibited; the catalytic activity of the bifunctional catalyst is increased and the over-potential is reduced by the electric field generated by the copper layer structure; by the structure field energy, the volume change stress is released, the expansion space is provided, a uniform reaction active site and the like are provided, and the overall electrochemical performance is fully improved.

The invention discloses a lithium-loaded composite framework material and a preparation method and application thereof.The lithium-loaded composite framework material is of a thin film packaging structure internally packaged with a plurality of hollow thin-wall carbon nanospheres, low-lithium-precipitation overpotential nano particles are compounded on the inner walls of the hollow thin-wall carbon nanospheres, a thin film is a high-lithium-precipitation overpotential film layer, and the hollow thin-wall carbon nanospheres are arranged on the inner walls of the hollow thin-wall carbon nanospheres. The film layer is a single layer or a plurality of layers and is selected from a carbon layer, a polymer film layer, a solid electrolyte film layer, an oxide film layer or an ion/electron mixed conductor film layer; the low lithium precipitation overpotential nanoparticles are defined as simple substances or compounds with the reaction potential with lithium being greater than 0V; the high-precipitation lithium overpotential film layer is defined as a film layer in which the electrodeposition potential of lithium on the surface thereof is less than 0V. Compared with a thin film, the inner wall of the lithium-loaded composite framework material has lower lithium precipitation potential, so that lithium ions can only penetrate through the carbon wall and are preferentially nucleated and deposited in the hollow carbon sphere, and packaging and continuous and uniform deposition/dissolution of lithium metal are realized.

The invention discloses a lithium metal-based battery taking copper selenide in-situ coated foamy copper as a lithium metal carrier and a preparation method of the lithium metal-based battery. The preparation method comprises the following specific steps: (1) dissolving selenium dioxide in an aqueous solution; (2) immersing the purified foamy copper into a solution; (3) putting the soaked modifiedfoamy copper into a vacuum drying oven for drying; (4) carrying out lithium metal loading and electrochemical performance characterization on the copper selenide in-situ coated foamy copper current collector obtained after modification. According to the invention, liquid-phase selenylation is adopted to carry out surface lithium-affinity modification on low-price foamy copper, the foamy copper iscompounded with lithium metal, and the chemical composition, multi-dimensional interpenetrating structure and good conductivity of the foamy copper and the lithium affinity of a surface layer are utilized to achieve the effects of accommodating and uniformizing lithium nucleation, inhibiting lithium dendritic crystal growth and improving the performance of the lithium ion battery. And finally, the coulombic efficiency and the cycle performance of the lithium metal negative electrode are improved. The method has the advantages of short production period, simple process, low production cost andhigh cycling stability.

The invention discloses a method for preparing a three-dimensional metal lithium negative electrode by using an MOFs derivative. Preparing a metal organic framework material; mixing the pretreated three-dimensional porous skeleton with a metal organic framework material, so that the metal organic framework material uniformly grows on the three-dimensional porous skeleton; transferring into a muffle furnace for carbonization; and pouring the molten liquid metal lithium into the whole framework to obtain the novel three-dimensional metal lithium negative electrode. The electrode can be applied to a liquid lithium battery and a high-energy-density lithium-oxygen and lithium-sulfur solid-state battery, the local current density is effectively reduced, the growth of lithium dendrites is inhibited, the safety of the battery is improved, and the service life of the battery is prolonged. The method can effectively cope with the volume expansion of the lithium negative electrode, improve the interface stability of the electrode/electrolyte, the electrochemical performance of the electrode and the like, can also be applied to metal batteries with higher energy density, such as three-dimensional metal sodium negative electrode, zinc negative electrode, potassium negative electrode and the like, and further promotes the research, development and practice pace of high-safety power batteries.

The invention discloses a contact system, and the system includes at least one contact pair and a flexible contact support. The contact pair includes a fixed contact piece connected to a first conductor rail and a moveable contact piece. The flexible contact support includes first and second spring limbs connected to each other via a connection. An end of the first spring limb connected to a second conductor rail and the moveable contact piece attached on the second spring limb. The opposing first and second spring limbs extending from the connection form a sharp angle V-shaped configuration.The contact support may be formed of a single piece or of a multi-piece design. The contact support may, in the connection area, be formed of two spring limbs arranged in parallel above one another and connected to each other.

The invention relates to the technical field of electrochemistry and new energy materials, in particular to a heteroatom in-situ doped porous carbon composite lithium negative electrode and a preparation method and application thereof. The heteroatom in-situ doped porous carbon composite lithium negative electrode comprises the following raw materials: a porous carbon material and lithium, the porous carbon material comprises a carbon framework containing a pore structure, the carbon framework is uniformly doped with heteroatoms, and the heteroatoms comprise at least one of nitrogen, oxygen, phosphorus and sulfur. According to the scheme, the technical problem that the battery performance is difficult to improve due to the fact that an existing lithium negative electrode and a preparation method thereof cannot effectively improve the deposition-dissolution behavior of lithium is solved. According to the scheme, the three-dimensional porous carbon framework containing the electronegative functional group is used, the deposition-dissolution behavior of lithium is directionally regulated and controlled, and the prepared heteroatom in-situ doped porous carbon composite lithium negative electrode has a wide application prospect in the fields of liquid lithium ion batteries and solid lithium batteries.

The invention discloses a uniformly-distributed three-dimensional lithium alloy negative electrode and a preparation method thereof. The preparation method comprises the following steps: (1) smelting metal lithium and other metals at high temperature to obtain an alloy material; (2) rolling the alloy material through a roller to obtain an alloy belt, and performing roughness treatment on the alloy belt; (3) the pure lithium strip is subjected to surface roughness treatment after being subjected to surface polishing; (4) the treated alloy strip and the pure lithium strip are subjected to composite rolling, the grooves and the protrusions are embedded, and then roller rolling is carried out to obtain a composite strip; and (5) carrying out heat treatment on the rolled composite strip to obtain the uniformly distributed three-dimensional lithium alloy negative electrode material. The cycle life of the three-dimensional lithium alloy negative electrode material prepared by the method is obviously prolonged, and the lithium dendrite problem is obviously improved, so that the safety performance of the battery is greatly improved.

The invention belongs to the technical field of lithium metal battery materials, and particularly discloses a Cu3P@P-doped mesoporous carbon composite framework, and a preparation method and application thereof. The Cu3P@P-doped mesoporous carbon composite framework comprises thin-wall mesoporous carbon frameworks which are mutually crosslinked, cavities which are mutually communicated, Cu3P nanoparticles which are compounded on the inner sides of the cavities of the mesoporous carbon frameworks, and phosphorus-containing functional groups which are doped on the mesoporous carbon frameworks; a large number of cavities are contained in the mesoporous carbon frameworks, and the cavities are of a three-dimensional networked structure communicated through pore channels; the Cu3P nanoparticles are doped on the inner sides of the cavities of the mesoporous carbon frameworks in situ; and the phosphorus-containing functional groups are uniformly distributed on the surfaces of the mesoporous carbon frameworks. The Cu3P@P-doped mesoporous carbon composite framework material provided by the invention has a relatively large specific surface area, and can effectively reduce the local current density; due to the mutually communicated cavity structures, the transmission of lithium ions can be accelerated, and the reaction kinetics can be optimized; the Cu3P nanoparticles and the phosphorus-containing functional groups are used for inducing the deposition behavior of lithium, and selective deposition is realized; and the constructed lithium metal negative electrode has excellent electrochemical performance, and the coulombic efficiency and the cycling stability are greatly improved.

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.

The invention discloses a preparation method of a flexible self-supporting iron-doped porous carbon nanofiber lithium metal negative electrode framework material, and belongs to the field of lithium metal battery materials. The nanofiber is prepared by taking cheap ferric acetylacetonate, polyacrylonitrile and polymethyl methacrylate as raw materials through electrostatic spinning and high-temperature heat treatment. The lithium metal negative electrode framework prepared by the preparation method has a relatively large specific surface area, an electric field can be uniform, and local current density can be reduced, so uniform lithium deposition is caused, and formation of lithium dendrites is effectively avoided; the three-dimensional porous main body can provide open pores so as to adapt to volume change and lithium ion transmission; the nitrogen and oxygen doped carbon main body can strongly interact with lithium atoms, so that lithium nucleation becomes easier and more uniform; meanwhile, the material is simple in preparation method, relatively low in cost, green and efficient, can be produced on a large scale, can be used as an ideal high-performance lithium metal negative electrode framework material, and has a very good practical prospect.