33results about How to "Reduce charge and discharge polarization" patented technology

The invention discloses a preparation method of a lithium manganous silicate cathode material with a mesoporous structure, belonging to the field of lithium ion batteries. The method comprises two processes of liquid-phase reaction and high-temperature solid-phase sintering, wherein the process of liquid-phase reaction comprises the following steps of: performing ultrasonic dispersion of the mixture of a silicon-based molecular sieve or silicon dioxide and a carbon-containing template agent into an aqueous solution of lithium salt to obtain a dispersion; dissolving manganese salt in an organic solvent to obtain a solution 1; and mixing and stirring the dispersion and the solution 1, and performing hydrothermal or oil-bath reaction, washing, filtration and vacuum drying to obtain a precipitate 2; and the process of high-temperature solid-phase sintering comprises the following steps of: performing mechanical ball milling of the precipitate 2 for 2-5 hours, and calcining in a tubular furnace in an atmosphere of argon to obtain a final product, namely the lithium manganous silicate cathode material with a mesoporous structure. Through the lithium manganous silicate cathode material with a mesoporous structure, the specific surface area of the product is larger than that of the lithium manganous silicate prepared by a conventional method.

The invention relates to a core-shell structure electric catalyst material for lithium air batteries and a preparation method thereof. The electric catalyst material comprises a core layer formed by a transition metal oxide and a shell layer formed by a transition metal nitride, the core layer is a hollow or solid core, the inner diameter of the core layer is 0-50nm, the outer diameter of the core layer is 30-500nm, the thickness of the shell layer is 10-200nm, and the mass of the shell layer accounts for 10-40% of the mass of the electric catalyst material. The preparation method includes that the hollow or solid transition metal oxide is prepared by adopting a liquid phase method. On the basis, transition metal salt is nitrogenized directly to be covered on the surface of the transition metal oxide by adopting a nitriding sintering method, and the core-shell material is prepared by covering the transition metal nitride on the transition metal oxide. The core-shell material has good electrical conductivity and stability, can effectively reduce charging and discharging polarization of the lithium air batteries, reduces internal resistance of the batteries, has good discharging capacity simultaneously, is simple in preparation process method, convenient to operate and low in cost, and achieves large-scale production easily.

The invention relates to a nano iron nitride-carbon composite catalyst for a lithium-air battery and a preparation method of the composite catalyst. The method comprises the steps of feeding iron salt, organic ligand and a surface active agent into a solvent, and carrying out heating reflux; mixing the obtained nano-sized mesoporous metal organic framework complex and a nitrogenous organic compound, and carrying out heat treatment on the mixture in the presence of ammonia gas to realize carbonization and nitridation by one step. The catalyst is formed by compounding nanoscale primary iron nitride particles and carbon material; carbon covers and partly covers the surfaces of the nanoscale primary iron nitride particles; rich mesoporous gaps exist among the stacked nanoscale primary iron nitride particles. The rich mesoporous structure of a precursor is maintained by the catalyst, the catalyst has large specific surface area and high porosity, and is beneficial to diffusing oxygen molecules into the catalyst material particles, so that the contact between oxygen and the catalyst is promoted, and the utilization rate of the catalyst is increased; the electrical conductivity is effectively improved by the carbon material on the surfaces of the particles; the nano iron nitride-carbon composite catalyst is good in stability, so that the catalytic performance is well exerted. The charge and discharge polarization of the lithium-air battery is effectively reduced; furthermore, the method is simple and convenient, the operation is easy, the cost is low, and large-scale production can be easily implemented.

The invention discloses an anode material of a lithium-sulfur battery and a preparation method thereof. The anode material is formed by the compounding of elementary sulfur and porous three-dimensional grading carbon. The preparation method comprises the steps of preparing a precursor compound of the porous three-dimensional grading carbon with a solvothermal method, carbonizing to obtain the porous three-dimensional grading carbon, then compounding with the sulfur to obtain the anode material of the lithium-sulfur battery. The preparation method is simple and low in cost, the prepared anode material of the lithium-sulfur battery has high sulfur containing capability, and high ion transmission capability and conductivity, and can improve the high-rate capability and the high cycle performance of the lithium-sulfur battery.

The invention relates to a carbon-based composite positive electrode material for a lithium-air battery and a preparation method of the carbon-based composite positive electrode material. The carbon-based composite positive electrode material comprises a carbon material, a protection layer and precious metal particles, wherein the protection layer wraps the surface of the carbon material and is composed of an ionic liquid, and the precious metal particles are dispersed in the ionic liquid in a nanoparticle form so as to modify the surface of the carbon material.

The application provides an electrolyte solution and a lithium ion battery, which belong to the technical field of batteries. The electrolytic solution includes an organic solvent, lithium salt dissolved in the organic solvent, and an auxiliary agent. The auxiliary agent is selected from one or more of S element, B element, P element and reducing compounds that can release specific negative ions in the electrolyte, and the specific negative ion is selected from one or more of S negative ions, B negative ions and P negative ions kind. Lithium ion batteries include this electrolyte. Specific types of additives can effectively reduce the potential of lithium-containing compounds when they decompose; the way of adding additives to the electrolyte ensures that the battery has better cycle stability and has good applicability in the battery production process.

The invention relates to an application of a porous carbon material in a lithium-air cell, which is characterized in that the carbon material has a mutually communicated graded pore structure distribution, and the pore structure is a mesopore structure suitable for depositing discharge products and a macropore structure suitable for transmission of oxygen and an electrolyte. The carbon material as the lithium-air cell material can greatly increase the space utilization rate of the carbon material during a charge and discharge process at maximum limit, specific discharge capacity, voltage platform and multiplying power discharge capability of the cell can be effectively increased, so that lithium-air cell energy density and power density can be effectively increased. The porous carbon material used for anode of lithium-air cell has the advantages that the preparation technology is simple, the material source is wide, the pore structure of the graded aperture carbon material enables regulation and control, and the regulation and control modes are various, and the doping of metal and metal oxide is easy to realize.

The present invention relates to an application of a graded pore structure porous carbon material in a lithium-air battery. The porous carbon material is characterized in that the porous carbon material has interconnected graded pore structure distribution, wherein the interconnected graded pore structure distribution comprises a mesopore structure for discharge product deposition and a macropore structure for oxygen and electrolyte transmission. According to the present invention, with application of the carbon material as the lithium-air battery electrode material, the space utilization rate of the carbon material during the charge-discharge process can be increased at a maximum, and the discharge specific capacity, the voltage platform and the rate discharge capability of the battery can be effectively increased so as to increase the energy density and the power density of the lithium-air battery; and the preparation process is simple, the material source is wide, the pore structure of the graded pore carbon material can be regulated, the regulation manner is diverse, and the metal / metal oxide doping can be concurrently and easily achieved.

The present invention relates to a nitrogen-doped porous carbon material for a lithium-air battery positive electrode. The nitrogen-doped porous carbon material is characterized in that the nitrogen-doped porous carbon material has an interconnected graded pore structure, N is uniformly doped in the C skeleton, N accounts for 0.2-15% of the carbon material atomic ratio, the graded pores comprise mass transfer pores and deposition holes, the deposition holes account for 40-95% of the total pore volume, and the mass transfer pores account for 4-55% of the total pore volume. According to the present invention, with application of the carbon material as the lithium-air battery electrode material, the space utilization rate of the carbon material during the charge-discharge process can be increased at a maximum, and the energy density and the power density of the lithium-air battery can be effectively increased; and the preparation process is simple, the material source is wide, the pore structure of the graded pore carbon material can be regulated, the regulation manner is diverse, and the nitrogen doping manner is easily achieved.