840 results about "Specific discharge" patented technology

Positive electrode active materials are described that have a very high specific discharge capacity upon cycling at room temperature and at a moderate discharge rate. Some materials of interest have the formula Li_1+xNi_αMn_βCO_γO₂, where x ranges from about 0.05 to about 0.25, α ranges from about 0.1 to about 0.4, β ranges from about 0.4 to about 0.65, and γ ranges from about 0.05 to about 0.3. The materials can be coated with a metal fluoride to improve the performance of the materials especially upon cycling. Also, the coated materials can exhibit a very significant decrease in the irreversible capacity lose upon the first charge and discharge of the cell. Methods for producing these materials include, for example, a co-precipitation approach involving metal hydroxides and sol-gel approaches.

Positive electrode active materials are described that have a high tap density and high specific discharge capacity upon cycling at room temperature and at a moderate discharge rate. Some materials of interest have the formula Li_1+xNi_αMn_βCo_γO₂, where x ranges from about 0.05 to about 0.25, α ranges from about 0.1 to about 0.4, β ranges from about 0.4 to about 0.65, and γ ranges from about 0.05 to about 0.3. The materials can be coated with a metal fluoride to improve the performance of the materials especially upon cycling. Also, the coated materials can exhibit a very significant decrease in the irreversible capacity lose upon the first charge and discharge of the battery.

Lithium ion secondary batteries are described that have high total energy, energy density and specific discharge capacity upon cycling at room temperature and at a moderate discharge rate. The improved batteries are based on high loading of positive electrode materials with high energy capacity. This capability is accomplished through the development of positive electrode active materials with very high specific energy capacity that can be loaded at high density into electrodes without sacrificing performance. The high loading of the positive electrode materials in the batteries are facilitated through using a polymer binder that has an average molecular weight higher than 800,000 atomic mass unit.

Positive electrode active materials comprising a dopant in an amount of 0.1 to 10 mole percent of Mg, Ca, Sr, Ba, Zn, Cd or a combination thereof are described that have high specific discharge capacity upon cycling at room temperature and at a moderate discharge rate. Some materials of interest have the formula Li_1+xNi_αMn_β-δCo_γA_δX_μO_2−zF_z, where x ranges from about 0.01 to about 0.3, δ ranges from about 0.001 to about 0.15, and the sum x+α+β+γ+δ+μ can approximately equal 1.0. The materials can be coated with a metal fluoride to improve the performance of the materials especially upon cycling. The materials generally can have a tap density of at least 1.8 g/mL. Also, the materials can have an average discharge voltage of around 3.6 V.

The invention relates to a lithium-ion secondary battery anode material technology, in particular to a lithium-rich manganese-based anode material Li(Li(1-2x)/3Nix-aMyMn(2-x)/3-b)O2 (M is Co, Al, Ti, Mg and Cu) and a preparation method thereof. A general formula of the lithium-rich manganese-based anode material is as follows: Li(Li(1-2x)/3Nix-aMyMn(2-x)/3-b)O2 (M is Co, Al, Ti, Mg and Cu), wherein x is more than 0 and less than or equal to 0.5, when M is Co and Al, y is more than 0 and less than 2x, a is equal to b, and b is equal to y/2; when M is Ti, y is more than 0 and less than (2-x)/3, a is equal to 0, and b is equal to y; and when M is Mg and Cu, y is more than 0 and less than x, a is equal to y, and b is equal to 0. The invention has high specific discharge capacity, excellent normal temperature and high temperature cycle performance, good safety, low raw material cost and production cost, and very high cost-performance ratio.

The invention relates to a functional composite membrane for a lithium-sulfur battery and a preparation method of the functional composite membrane. The composite membrane comprises a membrane for the lithium-sulfur battery and a functional modified layer, wherein the functional modified layer is located on the membrane for the lithium-sulfur battery, and comprises an electronic conductive material and/or inorganic oxides. Compared with the lithium-sulfur battery employing an ordinary battery membrane, the lithium-sulfur battery employing the functional composite membrane with the modified layer has a relatively high specific discharge capacity; the shuttle effect of the lithium-sulfur battery can be suppressed; the coulombic efficiency of the battery is improved; and the cycle performance of the battery is improved.

The invention relates to the technical field of lithium-ion cathode material, in particular to silicon cathode material coated with graphene and a preparation method of the silicon cathode material coated with the grapheme. The preparation method comprises the following steps: A, preparing oxidized graphene suspension liquid; B, preparing nanometer silicon particle suspension liquid; and C, preparing silicon cathode material coated with grapheme. The preparation method adopts the electrostatic self-assembly synthetic technology and is wide in source of raw material, low in price, simple in synthetic method, easy for control of process conditions, strong in operability and good in repeatability. The silicon cathode material coated with grapheme is high in specific capacity and good in cycle performance and rate capability, wherein the specific discharge capacity for the first time under the electric current density of 0.01-1.2V, 200mA/g can reach 2746mAh/g, and the specific discharge capacity after 100 times of cycles can maintain 803.8mAh/g.

The invention discloses a porous silicon negative material of a lithium ion battery, and a preparation method and application of the material. The method comprises the following steps of: reacting silicon alloy powder, which is taken as a raw material, with inorganic acid to generate porous silicon particles; and washing the porous silicon particles by an HF (Hydrogen Fluoride) acid solution to eliminate surface silicon oxide, and washing and drying the washed porous silicon particles so as to obtain the porous silicon material. The porous silicon material prepared by the method has a sponge-shaped structure which is formed by linking nano silicon particles; the particle sizes of the particles of the porous silicon negative material range from 0.01 micron to 50 microns; the specific surface area of the material is 30-600cm<2>/g; the porous silicon negative material can be taken as a negative material of a lithium ion battery; and in a lithium ion battery electrolyte, the porous silicon powder shows high specific discharge capacity and charge-discharge circulation stability. The porous silicon negative material has the advantages of low cost, simplicity and convenience in method and high electrochemical property, and can be applied to production of silicon negative materials of high-performance lithium ion batteries.

The invention relates to an application of a porous carbon material with a grading pore structure in a lithium-air cell anode, and is characterized in that the carbon material has mutually communicated grading pore structure distribution which has a mesoporous structure for depositing the discharge products and a macroporous structure suitable for transmission of oxygen and an electrolyte. When the carbon material is taken as a material of the lithium-air cell anode, the space utilization rate of carbon material can be increased at maximum limitation during a charge and discharge process, specific discharge capacity, voltage platform and multiplying power discharge capability of the cell can be effectively increased, so that the energy density and power density of the lithium-air cell can be increased. The porous carbon material has the advantages that the preparation technology is simple, the material source is wide, the grading pore carbon material pore structure enables regulation and control, the regulation and control modes are various, and the doping of metal/metal oxide can be easily and simultaneously realized.

The invention provides a preparation method for a coating anode material of a lithium battery. The preparation method comprises the following specific steps: (1) weighing a coating material and monomer sulfur; weighing the coating material and the monomer sulfur according to a mass ratio, wherein the mass ratio of the coating material to the monomer sulfur ranges from 1:1 to 1:100; (2) preparing a dispersion solution of the sulfur: dissolving the monomer sulfur into a sodium polyacrylate water solution with the mass percentage of 2%-10% at a room temperature to obtain the dispersion solution of the sulfur; (3) preparing a dispersion solution of the coating material: dissolving the coating material into a surfactant water solution at 20-45 DEG C to obtain the dispersion solution of the coating material; and (4) preparing the coating anode material of the lithium battery. According to the preparation method for the coating anode material of the lithium battery, self discharge of the battery is reduced effectively and the stability of the structure in a charging/discharging process of a sulfur electrode is kept; a sulfur active material prepared by the preparation method is used as a lithium-sulfur secondary battery anode material and the prepared lithium material has a high specific discharge capacity and a good circulating performance.

The invention belongs to the technical field of lithium sulfur batteries, specifically relates to a sulfur-carbon composite material with a nitrogen-doped porous carbon nanofiber net-shaped structure, as well as a preparation method and an application of the composite material. By taking a polypyrrole net-shaped structure which is synthesized by virtue of a soft template method as a raw material, taking the potassium hydroxide as a pore forming agent, and taking the nitrogen-doped carbon nanofiber net-shaped structure which is synthesized through high-temperature carbonization under nitrogen atmosphere and is in a porous structure as a precursor, the sulphur-carbon composite material which can be used as the anode of the lithium sulfur battery can be prepared through heat treatment with elemental sulfur. The preparation method provided by the invention is simple, and good in reproducibility, and the prepared composite material is uniform in structure distribution, and can be used as the anode of the lithium sulfur battery. Due to the nitrogen doping and the tridimensional net-shaped structure, for the material, the conductivity can be improved, a transmission path of lithium ions is shortened, meanwhile, the dissolving of the sulfur and intermediate product in an electrolyte can be prevented, the electrochemistry performance of a positive material of the lithium sulfur battery is improved, good specific discharge capacity, cycle performance and rate performance can be achieved.

The invention belongs to the field of super capacitors and particularly relates to a binary metal organic framework material applied to a super capacitor and a preparation method for the binary metal organic framework material. The binary metal organic framework material is formed of two types of metal ions and an organic ligand using a solvothermal method in a self assembly coordination manner. The two types of metal ions are Co-Ni, Co-Fe, Co-Mn, Ni-Mn or Ni-Cu. The organic ligand is trimesic acid, terephthalic acid, 2,6-naphthalene acid, 4,4'-biphenyl diacid or 2-methylimidazole. The binary metal organic framework material is advantaged by having multiple holes, large specific surface area and an adjustable structure, and being varied in structure. The cooperative effect between the two types of metal ions in the binary metal organic framework material (MOFs) is utilized, so that when the binary metal organic framework material is applied to the electrode material of a super capacitor, excellent cycling stability and high specific discharge capacity are achieved.

The present invention belongs to energy material, and in particular relates to a method of using high-activity disordered iron phosphate to prepare ferrous phosphate lithium/carbon composite material. A ferrous iron source is mixed with phosphorus source solution according to stoichiometric ratio, has hydrogen peroxide added in, has pH value controlled and is stirred so as to prepare high-activity disordered iron phosphate. iron phosphate, a lithium source and a carbon source are mixed pro rata, ball-milled uniformly, spray-dried and treated via high temperature under protective atmosphere, so as to obtain high specific capacity ferrous phosphate lithium/carbon composite material of which the average particle diameter is 200-500nm, 0.25C rate specific discharge capacity reaches 145-150mAh/g, 1C rate specific discharge capacity reaches 130-140mAh/g, and 5C rate specific discharge capacity reaches 105-110mAh/g. The method is low in cost and simple in process. Prepared material is good in electrochemical performance and especially excellent in rate performance, which is applicable to battery anode material of electric vehicles and other large-scale mobile devices.

The invention discloses a preparation method of lithium-ion battery positive electrode material spherical nickel-cobalt-lithium aluminate. The preparation method comprises the following steps of: firstly dissolving aluminum salt in deionized water, and preparing AlOOH aluminum sol by adding HNO3 or ammonium hydroxide and nitric acid; preparing nickel salt and cobalt salt into uniform aqueous solution according to a certain ratio; enabling the mixed salt solution to be collectively reacted with the aluminum sol and a mixed alkali solution, adjusting the pH value to be 9 to 12, controlling the reaction temperature, carrying out the solid-liquid separation after 20 to 30h of the reaction, and washing, filtering and drying the reaction product to obtain spherical nickel-cobalt-aluminum hydroxide precursor powder; then mixing the spherical nickel-cobalt-aluminum hydroxide precursor powder with lithium, sintering the mixture, and pulverizing and grading sintered material to obtain the lithium-ion battery positive electrode material spherical nickel-cobalt-lithium aluminate. The prepared spherical nickel-cobalt-lithium aluminate particles are controllable in shape and granularity, high in compacting density, high in specific discharge capacity, good in cycling stability and low in cost.

The invention provides a functionalized ZIF type metal organic framework (MOF) porous material. A framework of the material comprises metal ions Zn<2+> or Co<2+> as well as imidazole and aminobenzimidazole. The material is excellent in physical and chemical stability and overcomes the defect that a traditional MOF porous material is sensitive to water; the material has a good CO2 adsorption property; besides, a lithium ion battery manufactured with the material as an electrode material has good electrochemical properties, and furthermore, after N cycles, the specific discharge capacity of the lithium ion battery tends to be stable, wherein N is greater than or equal to 10; as a result, the functionalized ZIF type MOF porous material has bright application prospect in the field of lithium ion batteries.

The invention relates to the technical field of battery materials, in particular to a coupled carbon nano tube-graphene composite three-dimensional network structure-coated ternary material and a preparation method thereof. According to the coupled carbon nano tube-graphene composite three-dimensional network structure-coated ternary material, a nickel-cobalt-manganese ternary material, carbon nano tubes and graphene are taken as raw materials; and the ternary material is characterized by being prepared by the following steps: with polyvinyl pyrrolidone as a dispersing agent, through a liquid-phase self-assembling method, simultaneously connecting the graphene and the carbon nano tubes with a silane coupling agent to form a three-dimensional network structure; and evenly dispersing the coupled carbon nano tube-graphene composite material and the nickel-cobalt-manganese ternary material through a physical method, coating the surface of the nickel-cobalt-manganese ternary material, and sintering the nickel-cobalt-manganese ternary material in an inert atmosphere, so as to obtain the evenly coated product. The product provided by the invention has the advantages of high specific discharge capacity, long cycle life and simplicity in preparation process; and large-scale production is easy to realize.

The invention discloses a high-temperature solid-phase synthesis method of a one-dimensional nano-sodion cell anode material NaxMnO2. The high-temperature solid-phase synthesis method comprises the following steps of 1, dissolving a sodium salt and a manganese salt in water according to a mole ratio of sodium to manganese of 0.44-0.56 to obtain a solution I, 2, dissolving citric acid in water to obtain a solution II, wherein a mole ratio of citric acid to the total metal ions is in a range 0.5-1, 3, dropwisely adding the solution I into the solution II and carrying out stirring for 10-60min, 4, carrying out heating evaporation on the mixed solution at a temperature of 60-90 DEG C to remove a solvent, heating the residues at a temperature of 120 DEG C for 6-24h, cooling the heated residues to a temperature of 10-30 DEG C, and grinding the cooled residues into powder, 5, heating the powder at a temperature of 350-500 DEG C for 3-10h, cooling the powder to a temperature of 10-30 DEG C, and grinding the cooled powder into fine powder, and 6, heating the fine powder at a temperature of 800-950 DEG C for 10-45h, and carrying out cooling to obtain the one-dimensional nano-sodion cell anode material NaxMnO2. The high-temperature solid-phase synthesis method has short synthesis time and a high yield in unit time. The one-dimensional nano-sodion cell anode material NaxMnO2 has uniform, dispersive, thin and long product morphology and good electrochemical properties (of a specific discharge capacity of 114mA.h/g at 0.1C charging-discharging multiplying power).

The present invention is microwave synthesis process of high density spherical lithium ferric phosphate as the positive electrode material of lithium ion cell, and belongs to the field of energy source material preparing technology. Spherical lithium ferric phosphate is prepared through mixing ferrous sulfate and solid phosphorus in the required Fe/P ratio; adding in certain speed into deionized water; adding alkali matter to regulate pH value to form the precursor ammonium ferrous phosphate; drying the precursor, mixing with lithium acetate in the same ratio, adding proper amount of conducting agent, and high temperature treatment at 600-800 deg.c for 3-30 hr in the protecting atmosphere. Thus prepared spherical lithium ferric phosphate has average grain size of 5-10 microns, tap density 2.0-2.3 g/cu cm, and room temperature initial specific discharge capacity of 140-160 mA/g. The process is simple, low in cost, high in yield and suitable for industrial production.

The invention discloses a preparation method of a secondary lithium-sulfur battery anode adhesive. Carbonylated beta-cyclodextrin is taken as an adhesive instead of beta-cyclodextrin, so that water dissolubility is enhanced. A secondary lithium-sulfur battery anode is obtained by the following steps of: uniformly dispersing the carbonylated beta-cyclodextrin, a sulfur-containing material and a conductive agent in water; coating the solution on current collecting fluid; drying; and tableting. A secondary lithium-sulfur battery consists of the anode and a metal lithium cathode. Charging and discharging are performed at the temperature of 0.1 DEG C. Primary specific discharge capacity is up to 822.2 mAh/g, secondary specific discharge capacity is 652.7 mAh/g and the capacity is kept at 627.5 mAh/g after 45 cycles. Therefore, capacity keeping rate is high, and the cycle performance of the battery is stable at the temperature of 55 DEG C.

The invention discloses a high-temperature type lithium manganate anode material for a power lithium ion battery. The high-temperature type lithium manganate anode material consists of a core material as shown in a formula Li1+xMn2-y-zAyQzO4, and a coating layer on the surface of the core material, wherein the coating layer is one or more of cobaltosic oxide, aluminum oxide and nickel protoxide. The anode material is excellent in high-temperature property, and is good in specific discharge capacity, capacity retention ratio and electrochemical circulation property at high temperature. In addition, the preparation method of the anode material disclosed by the invention is simple in production process, easy to achieve and low in cost, and can be applied to large-scale industrialization production.

The invention provides a positive electrode active substance, a positive electrode containing the positive active substance and a battery including the positive electrode. The positive active substance contains a crystal mixture containing a first crystal and a second crystal, wherein the first crystal is selected from one or more of compounds represented by LixxM'yy (XO4) zz, LiM'XO5, LiM'XO6, and LiM'X2O7, where the ratio of xx to zz is larger than 0 and not larger than 1, and the ratio of yy to zz is larger than 0 and not larger than 1.1; and the second crystal is one or more of compounds represented by LiDcO2, LiiNi(1-d-e)CodMneO2, LiNi(1-f-g) CofAlgO2, LixNi(1-y) CoO2 and LimMn(2-n)EnOj, where D is one element selected from B, Mg, Al, Ti, Cr, Fe, Cu, Zn, Ga, Y, La and V, c is larger than 0 and not larger than 3, i is not less than 0.9 and not larger than 1.2, d is not less than 0 and not larger than 0.5, e is larger than 0 and not larger than 0.3, f is not less than 0 and not larger than 0.5, g is not less than 0 and not larger than 0.3, x is not less than 0.9 and not larger than 1.1, y is not less than 0 and not larger than 1; E is one of B, Mg, Al, Ga and a transition metal except Mn, m is not less than 0.9 and not larger than 1.1, n is not less than 0 and not larger than 1, and j is larger than 1 and less than 6. The positive active substance has an electron conductivity of 0.001 to 10 S/cm at 25 DEG C, and can remarkably improve the specific discharge capacity and the cycle performance of the battery.

The invention discloses a preparation method of a submicron level LiniO.5MnO.5O2 cathode material, which comprises the steps of: taking soluble nickel salt and manganese salt to prepare a nickel salt water solution and a manganese salt water solution respectively, and mixing the two solutions; preparing a sodium hydroxide solution isometric to a metal ion solution, and adding ammonia as a precipitator solution; dropwise adding the metal ion solution and the precipitator solution into a water solution of surface active agents in parallel flow, and stirring the mixed solution evenly; controlling the temperature of the precipitation reaction to be 55 DEG C, and stirring at high speed, standing, vacuum filtrating, flushing, drying and grinding after the metal ion solution and the precipitator solution are completely added to obtain the powder; adding lithium hydroxide, and carrying out ball grinding to obtain a precursor. The heat treatment for the precursor comprises the following processes of: heating the precursor at 2 to 12 DEG C /min to 350 to 450 DEG C for 2 to 6 h for pre-treatment, and then continuing to heat the precursor at the speed of 2 to 12 DEG C/min to 700 to 1000 DEG C; calcinating the precursor for 8 to 20 DEG C, cooling the precursor at the speed of 2 to 12 DEG C/min down to 300 to 500 DEG C, and annealing the precursor for 2 to 4 h. In the invention, the submicron level uniformly distributed near-spherical LiniO.5MnO.5O2 material with no obvious glomeration by introducing the surface active agent into the LiniO.5MnO.5O2 cathode material prepared by the optimized coprecipitation method. The grains of the material are distributed uniformly, and the grain diameter is about 80 to 200nm; the material is in a near-spherical shape, and has higher specific discharge capacity and good cycling stability.

The invention provides a high-nickel ternary cathode material coated with a fast ion conductor and a preparation method thereof. The high-nickel ternary cathode material is spherical or spheroidic secondary particles composed of primary particles, the diameter of the high-nickel ternary cathode material is 1-30 [mu]m, and the chemical formula of the high-nickel ternary cathode material is LiNi0.8Co0.1Mn0.1O2. The preparation method comprises the following steps of: weighing raw materials for synthesizing the fast ion conductor in proportion, and uniformly dispersing the raw materials in a solvent to obtain a mixed solution; adding the high-nickel ternary precursor into the mixed solution, and then performing stirring, drying and grinding to obtain high-nickel ternary precursor powder coated with the fast ion conductor; and uniformly mixing the obtained precursor powder with a lithium salt, and performing sintering to obtain the high-nickel ternary cathode material coated with the fastion conductor. The fast ion conductor material is used as a coating substance of the ternary cathode material and can provide a fast transmission channel for lithium ion transmission, so that the purpose of reducing the internal resistance of the battery is achieved; and after coating, the cycling stability of the battery is improved under the condition that the specific discharge capacity of thebattery is not reduced.