217results about How to "Good charge and discharge cycle performance" patented technology

The negative electrode for a non-aqueous electrolyte secondary battery of the present invention includes a conductive porous substrate, and a conductive material and an active material filled in pores of the porous substrate. The active material contains at least one of a metal element and a semi-metal element capable of reversibly absorbing and desorbing lithium.

A cylindrical lithium secondary battery includes a positive electrode (1) having a positive electrode mixture layer disposed on a surface of a positive electrode current collector made of a conductive metal foil and containing a positive electrode active material, and a negative electrode (2) having a negative electrode mixture layer disposed on a surface of a negative electrode current collector made of a conductive metal foil and having a negative electrode active material containing silicon particles and/or silicon alloy particles. The amount of the positive electrode active material is 50 mg or less per 1 cm² of the positive electrode, the average particle size of the silicon particles and/or silicon alloy particles is from 5 μm to 15 μm, and the theoretical electrical capacity ratio of the negative electrode to the positive electrode is 1.2 or greater.

A positive active material is provided which can inhibit side reactions between the positive electrode and an electrolyte even at a high potential and which, when applied to a battery, can improve charge/discharge cycle performance without impairing battery performances even in storage in a charged state. Also provided are: a process for producing the active material; a positive electrode for lithium secondary batteries which employs the active material; and a lithium secondary battery which has improved charge/discharge cycle performance while retaining intact battery performances even after storage in a charged state and which can exhibit excellent charge/discharge cycle performance even when used at a high upper-limit voltage. The positive active material comprises: base particles able to dope and release lithium ions; and an element in Group 3 of the periodic table present on at least part of that part of the base particles which is able to come into contact with an electrolyte. It is produced by, e.g., a process which comprises: producing base particles containing lithium and able to dope and release lithium ions; and then imparting an element in Group 3 of the periodic table to the base particles so that the element can be present on at least part of that part of the base particles which is able to come into contact with an electrolyte.

The invention provides a grapheme-coated sulfur/porous carbon composite material and a preparation method thereof, and relates to a grapheme-coated sulfur/porous carbon composite material used as the positive electrode material of a lithium-sulfur secondary battery and a preparation method thereof. The grapheme-coated sulfur/porous carbon composite positive electrode material provided by the invention can be used for solving the technical problem that the existing grapheme-coated sulfur-containing composite material used as the positive electrode material of a lithium-sulfur battery is low in electrochemical properties. The external surface of each of the particles of the grapheme-coated sulfur/porous carbon composite material provided by the invention is evenly covered with a graphene sheet, and a graphene conductive network is formed between the particles; the obtained grapheme-coated sulfur/porous carbon composite material has a hierarchical core-shell structure. The preparation method of the grapheme-coated sulfur/porous carbon composite material is obtained by adding a sulfur/porous carbon composite material to graphene slurry which is stable for a long time and in which graphene sheets are highly dispersed in water for mixing and coating. The positive electrode material has high specific capacity, long cycle life and excellent high-rate performance. Besides, the grapheme-coated sulfur/porous carbon composite material can be used as the positive electrode material of a lithium secondary battery.

A lithium secondary battery has a positive electrode, a negative electrode, and a non-aqueous electrolyte. The negative electrode has a negative electrode current collector and a negative electrode mixture layer containing a negative electrode conductive agent, a negative electrode binder, and negative electrode active material particles made of a material containing silicon. The negative electrode mixture layer is sintered and disposed on the negative electrode current collector. The negative electrode active material particles have an average particle size of from 5.0-15.0 μm before being charged. The negative electrode conductive agent is made of a graphite material having an average particle size of from 2.5-15.0 μm. The amount of the graphite material added is from 3-20 mass % with respect to the negative electrode active material. The theoretical electrical capacity ratio of the positive electrode to the negative electrode is 1.0 or less.

At least two metallic materials containing element such as silicon and tin, which has ability of insertion and desertion of lithium element, and optionally another metallic material containing element such as copper are molten to prepare a melt. The melt is rapidly cooled by strip-cast method at a cooling rate of more than 2×10³ ° C./sec and no more than 10⁴ ° C./sec to be cast. Further, the cast is milled and classified into alloy powder having an average particle size of 0.1 μm to 50 μm. The alloy powder and conductive agent are laminated with binder onto a collector to obtain a negative electrode for a secondary battery. The negative electrode is employed to obtain a lithium secondary battery having high electric charge and discharge capacity, and good property of charge and discharge cycle.

The invention relates to manganese department positive electrode material of a lithium secondary battery, which can combine with electrolyte solution or solid electrolyte, and negative electrode active material to form lithium secondary battery. Its characteristics are: the positive electrode material of lithium secondary battery is LiMn1-x-y NixMyO2(x is not less than 0.2 and not larger than 0.8, y is not less than 0 and not larger than 0.6, and x+y is not larger than 1.), M is chosen from Li, Mg, Co, Ni, Fe, Al, Cr. The manufacturing method for manganese department positive electrode material of the lithium secondary battery, includes preparation of usher containing Mn; decorate to the covering of usher particle containing Mn; mix with lithium salt and prepare particle; sintering and other steps. By decoration of the surface of particle to usher 6 of positive electrode containing Mn or active material itself, state of material or apparent condition of material can be changed and its capacity of powerful charge and discharge, cycle performance and thermal stability can be raised. The invention has notable advantages including low cost, capacity of powerful charge and discharge, super-long cycle performance, excellent safety, super-long circulation property and resistance to overcharge .

The invention provides a hydrothermal preparation method of a graphene-coated sulfur/porous carbon composite material and relates to a preparation method of the graphene-coated sulfur/porous carbon composite material for a positive electrode material of a lithium-sulfur storage battery. The hydrothermal preparation method is used for solving the technical problem that the electrochemical property of the positive electrode material of an existing lithium-sulfur battery, namely a graphene-coated sulfur-containing composite material, is low. The hydrothermal preparation method comprises the steps of mixing and scattering the sulfur/porous carbon composite material with graphene slurry or oxidized graphene slurry, carrying out hydrothermal synthesis to prepare a hydrogel column, and drying to obtain the graphene-coated sulfur/porous carbon composite material. According to the graphene-coated sulfur/porous carbon composite material prepared by utilizing the hydrothermal preparation method, the outer surfaces of the graphene sheet layers are coated with sulfur/porous carbon composite material particles, a graphene conduction network is generated among the particles, and the obtained graphene-coated sulfur/porous carbon composite material is in a hierarchical core-shell structure; the positive electrode material has the high specific capacity, the long cycle life and the good rate capability; the composite positive electrode material can be used as a positive electrode material in a lithium secondary battery.

The invention provides a process for preparing lithium cobalt oxide of lithium-ion secondary battery cathode materials. The process includes that cobalt oxide or hydroxyl cobalt oxide powders and lithium carbonate powders are mixed according to a lithium/cobalt molar ratio of 1.0-1.1 and calcined in an atmosphere containing oxygen at the temperature of 850-1100 DEG C; obtained mixture is calcined for 5-55 hours in the atmosphere containing oxygen at the temperature of 850-1100 DEG C; calcined products are naturally cooled to reach room temperature and then grinded; laser scattered grain size distribution measuring device is used for classifying; lithium cobalt oxide semi-finished products are obtained by selecting an average grain diameter D50 of 8-20 micrometers; and a device with high-speed shear strength function is used for conducting coating composition treatment process on the surfaces of the lithium cobalt oxide semi-finished products. The process has the advantages of low raw material cost, high volume energy density, good safety, fine charge-discharge cycle performance, high pressurizing density and superior productivity.

The invention relates to a polyvinylpyrrolidone modified graphene coated sulfur/porous carbon composite anode material and a preparation method thereof, which relates to a sulfur/carbon composite material applied to a lithium-sulfur secondary battery anode material and a preparation method of the composite material, and solves the technical problem of the existing lithium-sulfur battery anode material graphene-coated sulfur-containing composite material that the electrochemical property is low. The polyvinylpyrrolidone modified graphene coated sulfur/porous carbon composite material is characterized in that the outer surface of a sulfur/porous carbon composite material particle is uniformly coated with a polyvinylpyrrolidone modified graphene slab layer, a graphene conductive network is formed between every two adjacent particles, and a grading core-shell structure is formed. The preparation method comprises the steps of adding the sulfur/porous carbon composite material into graphene slurry modified by the polyvinylpyrrolidone, and mixing the sulfur/porous carbon composite material with the graphene slurry, and coating the sulfur/porous carbon composite material with the graphene slurry modified by the polyvinylpyrrolidone. The anode material is high in specific capacity, long in cycle life and good in high-rate performance.

The invention provides a flaky titanium carbide-loaded manganese dioxide composite material, which is mainly applied to a super capacitor electrode material, and belongs to the field of composite materials and the technical field of super capacitors. With Ti<3>AlC<2> powder as a raw material, Ti<3>C<2>T<x> with a two-dimensional flaky structure is formed after Al is etched away through HF; and in-situ growth is carried out on a two-dimensional layered titanium carbide surface by potassium permanganate and the Ti<3>C<2>T<x>, thereby obtaining the composite material loaded with a manganese dioxide thin film and a few of manganese dioxide particles on the flaky titanium carbide surface. The composite material is excellent in capacitive performance; the measured specific capacity can reach 256F/g in 0.5M K<2>SO<4> electrolyte; the specific capacity retention rate reaches 92% after 1,000 cycles; and meanwhile, an AC impedance test demonstrates that the material is extremely low in impedance, has the advantages of good safety, high reliability, sufficient energy and the like and has a broad commercial application prospect.

Charge-discharge cycle performance is improved in a lithium secondary battery utilizing a material containing silicon as a positive electrode active material. A lithium secondary battery includes a negative electrode (2) containing silicon as a negative electrode active material, a positive electrode (1) containing a lithium-transition metal composite oxide, and a non-aqueous electrolyte. Lithium carbonate is added in the positive electrode (1), and carbon dioxide is dissolved in the non-aqueous electrolyte.

The invention consists of benzotriazole compounds and an electrode comprising at least one of vinyl ethylene carbonate, vinylene carbonate, cyclic sulfonic acid, and cyclic sulfite. It is for use in forming a thin and dens passive film to reduce the gas production rate at process of cell forming, and to decrease corrosion of copper foil and aluminum foil of current collector, and to reduce the impedance of battery.

The invention provides a lithium-rich antiperovskite oxide composite electrolyte. The materials of the lithium-rich antiperovskite oxide composite electrolyte comprise a polymer, a lithium salt and afiller, and the filler is lithium-rich antiperovskite oxide; the structural formula of the lithium-rich antiperovskite oxide is Li3-xHxOA1-yBy, wherein A and B are halogen elements, x is not more than1 and not less than 0, and y is not more than 1 and not less than 0. By using the lithium-rich antiperovskite oxide electrolyte as the filler, the ionic conductivity and electrochemical window of thecomposite polymer electrolyte can be improved, the mechanical property of the composite electrolyte can be increased, the interface impedance between the electrolyte and the lithium-based negative pole can be reduced, and thus the acquired composite electrolyte has the relatively high lithium ion conductivity, good bending mechanical property, and relatively high interface stability.

The invention discloses a long-service-life lithium ion battery and a manufacture method thereof. The long-service-life lithium ion battery comprises an anode material, a cathode material, a diaphragm and electrolyte. The long-service-life lithium ion battery provided by the invention has the advantages of excellent charge and discharge circulating performances, good low-temperature and high-temperature discharge characteristics, wide use temperature range and good safety, and can be used for storing and converting clean energy as an energy storage system.

A lithium secondary battery having high capacity and good charge-discharge cycle performance is provided. The lithium secondary battery includes a negative electrode (2) containing silicon as a negative electrode active material, a positive electrode (1) containing a positive electrode active material, and a non-aqueous electrolyte. The positive electrode active material is a lithium-transition metal composite oxide including a layered structure represented by the chemical formula Li_aNi_xMn_yCO_zO₂, where a, x, y, and z satisfy the expressions: 0≦a≦1.3, x+y+z=1, 0<x, 0≦y≦0.5, and 0≦z.), and the theoretical electrical capacity ratio of the positive electrode to the negative electrode (positive electrode/negative electrode) is 1.2 or less.

The invention relates to a microwave synthesis method for a multi-element lithium manganate-doped positive electrode material of a lithium ion battery. The method comprises the following steps: adding deionized water into raw materials comprising lithium carbonate micropowder, industrial pure electrolytic manganese dioxide micropowder, analytical pure magnesium oxide micropowder, nickelic trioxide micropowder and chromic oxide micropowder to perform wet combination; mixing the raw materials with a ball mill; drying; mixing and sieving the dried products to serve as crude materials; shaping the crude materials into green bodies, and putting the green bodies into a microwave oven for sintering; and after the sintering is finished, taking the materials out, crushing and sieving the materials to obtain the lithium manganate-doped positive electrode material of the lithium ion battery. The material serving as a positive electrode active material can be used for preparing a positive plate of the lithium ion battery. The method has the characteristics of simpleness, energy saving and consumption reduction, low cost and contribution to industrial production; and the assembled lithium ion battery has the advantages of high initial discharge capacity and high charge and discharge cycling performance. The lithium manganate-doped positive electrode material of the lithium ion battery obtained by the method can be applied to electric automobiles, mobile phones, laptops and other equipment.

The invention belongs to the technical field of lithium ion battery positive electrode materials and discloses a carbon-coated lithium-rich positive electrode material as well as a preparation method thereof. The surface-coated lithium-rich material comprises a principal phase Li[LiaNi(1/2-3a/2)M(n1/2+a/2)]O2 (a being greater than 0 and less than 1/3) as well as a coated carbon layer. The preparation method of the material comprises the following steps: a step of preparing an intermediate phase of the lithium-rich material, namely Li[LiaNi(1/2-3a/2)M(n1/2+a/2)]O2 (a being greater than 0 and less than 1/3), a step of uniformly mixing the lithium-rich intermediate phase and a carbon source, and a step of quickly and thermally treating at a high speed. The lithium ion battery positive electrode material prepared by the preparation method disclosed by the invention greatly improves charging and discharging performances of the material under high multiplying power and can satisfy high-power development requirements. Moreover, the carbon-coated lithium-rich positive electrode material is low in material cost, simple in process, high in cost performance and suitable for industrial production.

The invention provides a lithium ion battery and electrolyte thereof. The electrolyte of the lithium ion battery comprises a non-aqueous organic solvent, a lithium salt dissolved in the non-aqueous organic solvent, and an additive dissolved in the non-aqueous organic solvent, wherein the additive comprises FEC (fluoroethylene carbonate) which accounts for 1-15 mass percent of the electrolyte, 1,3-propane sultone (PS) which accounts for 0.5-10 mass percent of the electrolyte, and oxalate which has a structure in a formula I (which is as shown in the description) and contains two double bonds; the oxalate accounts for 0.01-5 mass percent of the electrolyte; n in the formula I is selected from integer of 0-4. The lithium ion battery comprises a positive pole piece, a negative pole piece, an isolating membrane isolated between the positive pole piece and the negative pole piece adjacent to each other, and the electrolyte. The lithium ion battery has excellent charging and discharging cycle performance under high temperature and high voltage. (img file= 'DDA0000455073110000011.TIF' wi= '1320' he= '208' /).