421results about How to "Increase gram capacity" patented technology

The invention provides a single-crystal lithium nickel manganese cobalt positive electrode material. The single-crystal lithium nickel manganese cobalt positive electrode material comprises a substrate, wherein the substrate is a compound shown as a formula I of LiNi<x>Co<y>Mn<1-x-y>M<z>O<2>, x is more than or equal to 0.3 but less than or equal to 0.75, y is more than or equal to 0.2 but less than or equal to 0.3, z is more than or equal to 0 but less than or equal to 0.1, and a coating layer is coated on a surface of the substrate and is one or more of Li2ZrO3, Li2SnO3, LiNbO3, Li4Ti5O12 and LiAlO2. Compared with the prior art, a fast ion conductor is coated on the surface, thus, the rate performance of a single-crystal material is improved, the gram capacity of the single-crystal material is improved, the cycle performance of the material is further improved, the internal resistance can also be reduced, the polarization loss is reduced, and the cycle lifetime of a battery is prolonged; and meanwhile, the advantage of large compaction of a single-crystal ternary material is maintained, a particle broken phenomenon caused by rolling particles similar to secondary particles during battery fabrication can be prevented due to relatively high compaction, and the cycle performance is improved.

The invention relates to a preparation method of a power and energy storage lithium-ion battery. A negative active substance of the power and energy storage lithium-ion battery comprises soft carbon, hard carbon, a mixed material of soft carbon and graphite and a mixed material of hard carbon and graphite. The designing method of the battery comprises the steps of designing the gram volume of the negative active substance as the primary lithium-embedding gram volume, designing the gram volume of the positive active substance as the primary lithium-removal gram volume, designing the ratio of the capacity of the positive electrode and the capacity of the negative electrode to be (1: 1) to (1.5: 1). By adopting the designing method, the capacity and comprehensive performance of the battery can be remarkably improved, and excellent lithium-embedding and lithium-removal capacity of the soft carbon material and the hard carbon material can be adequately exerted. Compared with the existing lithium battery technology, the prepared power lithium battery has long service life, high multiplying power, high safety performance and excellent low-temperature performance and can be widely applied to the fields such as electric tools, various portable devices, spaceflight, starting power supply and the like.

The invention discloses a method for recycling a positive material from a water-system waste lithium iron phosphate battery. The method comprises the following steps: elaborately disassembling fully-discharged waste lithium iron phosphate battery to obtain an undamaged positive plate, separating a positive active material from a current collector in a way of immersing through deionized water, and drying and ball-milling the active material to obtain a lithium iron phosphate positive material to be recycled; respectively testing carbon content and ratio of Li, Fe and P elements of the lithium iron phosphate positive material to be recycled, adding a lithium source and an iron source, adjusting a mole ratio of Li to Fe to P to be (1.0-1.1):1:1, further adding the lithium source, the ion source and the phosphate source according to a ratio of 1:1:1 and adjusting C content ratio in the material; and performing ball milling, low-temperature pre-sintering and high-temperature sintering on the material of which ratio of the elements is adjusted to obtain the recycled lithium iron phosphate positive material. The recycled material has the advantages that 0.1C discharging capability can reach up to 156mAh/g, 2C discharging capability can reach up to 120mAh/g, the retention ratio of 0.1C discharging capability after 50 times of recycling is greater than 99% and various electrochemical properties are excellent. The method disclosed by the invention is low in cost and simple in process; the secondary pollution is avoided.

The invention belongs to the field of electrode material synthesis, and relates to a sodium-titanium phosphate/carbon composite material and a preparation method and use thereof. The sodium-titanium phosphate/carbon composite material comprises secondary particles formed by clustering primary particles, the primary particles comprise sodium-titanium phosphate particles and carbon layers coated on the surfaces of the sodium-titanium phosphate particles, and the carbon layers are prepared through two times of carbon coating. According to the sodium-titanium phosphate/carbon composite material and the preparation method and use thereof, by means of preparing a precursor of the sodium-titanium phosphate and then adopting a spray drying method to carry out primary carbon coating and secondary carbon coating, the sodium-titanium phosphate/carbon composite material having a uniform and compact coating carbon layer is prepared, and the problem that the coating carbon layer obtained by the primary carbon coating is not uniform is solved. The composite material is good in stability, electrodes prepared from the sodium-titanium phosphate/carbon composite material and assembled batteries have excellent electrochemical properties, the discharge capacity is above 115mAh/g, and the capacity retention ratio is above 95% after 500 weeks of circulation.

The invention discloses a negative plate of a secondary nickel-iron battery, a preparation method of the negative plate and a secondary nickel-iron battery of using the negative plate and belongs to the technical field of negative electrode materials for secondary nickel-iron batteries. According to the main points of the technical scheme, a negative active material in the negative plate of the secondary nickel-iron battery comprises an additive zinc-based multilayered hydroxide [ZnxMyM'z(OH)2].[(A<a->)n.mH2O]. The invention further particularly discloses a preparation method of the negative plate of the secondary nickel-iron battery and the secondary nickel-iron battery of using the negative plate. By adopting the novel negative plate of the secondary nickel-iron battery, the energy density and the rate capability of the secondary nickel-iron battery can be greatly improved and the cycle life of the secondary nickel-iron battery can be greatly prolonged.

The invention discloses a graphite material at the negative pole of a lithium ion battery, which comprises interphase graphite and artificial graphite in mass ratio of 90:10 to 20:80. The graphite material has the advantages of highly compacted density, small specific surface area, high discharge capacity, long circulating life, high charge-discharge efficiency and high product performance-price ratio. The invention also provides a method for preparing the graphite material, which has the advantages of simple, convenient and feasible technology, wide raw material sources and lower cost.

The invention provides a nickel-cobalt-manganese precursor, a preparation method of a nickel-cobalt-manganese ternary material and a lithium ion battery. Starting from the preparation of the precursorof the high nickel ternary material, the high nickel ternary positive electrode material with internal voids in the secondary particles and gradient layers of transition metal ions in the primary particles is prepared by using organic polymer particles as a pore-forming agent and its carbonized substance in lithium sintering as a reducing agent. A new method is developed to fabricate a porous high nickel ternary positive electrode material with the gradient layers of transition metal ions. The method is simple and feasible and easy to industrialize on a large scale. The gram capacity, cyclicstability and structural stability of the lithium ion battery using the porous high nickel ternary material containing transition metal ion gradient layers as the positive electrode material have beenimproved significantly.

The invention provides a lithium ion battery negative electrode single-side pre-lithiation method using a three-dimensional foil. The method comprises the following steps: 1, coating a three-dimensional current collector with a negative electrode slurry, and performing rolling to obtain a rolled electrode sheet; 2, performing pre-lithiation compounding on the electrode sheet: carrying the following two pre-lithiation processes according to the difference of lithium metal raw materials: uniformly spraying or coating one side of the rolled electrode sheet with lithium metal powder through a lithium metal powder pre-lithiation process or bonding and compounding one side of the rolled electrode sheet with a lithium foil under a certain pressure by adopting a lithium foil pre-lithiation process; and 3, assembling a positive electrode, a diaphragm and the negative electrode obtained after the pre-lithiation compounding is completed in order to form a battery cell, and performing electrolyteinjection and formation on the battery cell. The lithium ion battery negative electrode single-side pre-lithiation method using the three-dimensional foil solves the problems of swelling peeling, short life and low capacity of a silicon carbide/graphite electrode; and two-side pre-lithiation is simplified into single-side pre-lithiation, so the pre-lithiation efficiency is improved.

The invention provides low temperature electrolyte for lithium ion batteries, consisting of basal solvent, low viscosity carbonic esters, low viscosity and low melting point addition agent and lithium salts, by studying on main parameters of the electrolyte such as the melting point, the boiling point, the viscosity and the dielectric constant, etc., proper components and rates of the solvent are selected, and the particular addition agent of the low temperature electrolyte is selected, which obtains the electrolyte having desirable high temperature and low temperature charge-discharge performances and low temperature multiplying factor performance. The low temperature electrolyte for lithium ion batteries has the advantages of reasonable ratios of components, desirable normal temperature and low temperature charge-discharge performances, good normal temperature cyclical stability and good low temperature multiplying factor performance, and is applied to the industrialized production and can also be used as a renewal product for the low temperature electrolyte of the prior lithium ion batteries.

The invention relates to a preparation method for nickel-manganese-cobalt compound hydroxide and a reaction kettle for preparing the nickel-manganese-cobalt compound hydroxide. The preparation method comprises the following steps: 1) dissolving a nickel salt, a manganese salt, a cobalt salt and an M-salt to obtain a multi-metal salt solution; and 2) introducing a complexing agent solution, an alkali solution and the multi-metal salt solution into the reaction kettle through a complexing agent tube, an alkali solution tube and a main salt solution tube respectively, heating, stirring, performing nucleation in a system in which pH is between 12.5 and 14, performing nucleus growth in a system in which the pH is between 10 and 12, and adjusting the flow proportion of a main salt solution tube to a branch salt solution tube if a granularity distribution width is detected to be over large in the nucleus growth process in order to control the granularity distribution width. In the preparation method for the nickel-manganese-cobalt compound hydroxide provided by the invention, a nucleating process and the nucleus growth process are separated through control of the two-segment pH values, and narrow-granularity distribution nickel-manganese-cobalt compound hydroxide is obtained finally through adjustment of new crystal nucleuses and a growth speed in the nucleus growth process.

The invention relates to a graphite composite anode material and a preparation method thereof. The graphite composite anode material is of a core-shell structure and comprises an inner core and an outer shell, wherein the inner core is graphite; the outer shell is a nitrogen and phosphorus-doped composite material layer; the nitrogen and phosphorus-doped composite material layer is formed by adding the graphite serving as a raw material into nitrogen-containing ionic liquid in which a phosphorus-containing organic compound, a surfactant and lithium salt are dispersed and sintering; the mass ratio of the phosphorus-containing organic compound to the surfactant to the lithium salt to the nitrogen-containing ionic liquid is (10-50):(1-5):(1-5):200. The graphite composite anode material provided by the invention has the advantages that the transmission rate of lithium ions under the condition of high magnification can be improved, and the compatibility of the graphite composite anode material with an electrolyte can also be improved, so that the cycle performance is improved; the lithium salt in the outer shell can provide sufficient lithium ions, so that the first-time efficiency and the cycle performance are improved.

The invention discloses a method for preparing a cathode material of lithium iron phosphate for a lithium ion battery. The method comprises the following steps: firstly, adding a certain amount of deionized water into a ball mill, and adding lithium dihydrogen phosphate and ionic compound with good conductivity into the ball mill for stirring and ball milling at a high speed; secondly, adding iron oxide for stirring and ball milling at a high speed, and adding a certain amount of anhydrous ethanol as a dispersing agent; and finally, adding superfine conductive carbon black for full mixing and stirring to obtain evenly mixed powder by spray drying at a high speed, adding the powder into a mixing roll for mixing and granule crushing, and pressing the mixed powder into a block to improve the density of materials once again. After being preserved and sintered for 2 to 6 hours at 600 to 800 DEG C in a non-oxidizing sintering furnace and cooled below 50 DEG C, the materials after tablet pressing and granulation are discharged, crushed, refined and sifted, and the powder is dried so as to obtain lithium iron phosphate powder with no impurities, single structure and small granule size distribution. In addition, the preparation process method through improvement significantly reduces the cost for preparing the lithium iron phosphate and has little pollution.

The invention relates to a preparation method of a novel all-solid-state lithium ion battery, belonging to the technical field of lithium ion batteries. The preparation method comprises the steps of:mixing and uniformly dispersing a cathode active substance, a conductive agent and Li3OX as a cathode ingredient; mixing and uniformly dispersing an anode active substance, the conductive agent and Li3OX as an anode ingredient; mixing and uniformly dispersing a main body solid electrolyte and Li3OX as a solid electrolyte layer ingredient; coating the cathode ingredient on a cathode current collector, coating the anode ingredient on the anode current collector, stacking the anode current collector, the anode ingredient, the solid electrolyte layer ingredient, the cathode ingredient and the cathode current collector in order layer by layer to form a solid battery laminated cell, performing sintering of the solid battery laminated cell at a temperature of 282-400 DEG C while applying the pressure to the solid battery laminated cell, packaging the sintered solid battery laminated cell by adopting a battery membrane shell to obtain a novel all-solid-state lithium ion battery. The preparation method is simple, friendly in preparation environment, and is suitable for large-scale production.

The invention discloses a silicon-containing negative plate and a lithium ion battery comprising the same. The negative plate comprises a current collector, a first active layer and a second active layer, wherein the second active layer is arranged between the current collector and the first active layer, active substances in the first active layer are a silicon-oxygen material and graphite, and the second active layer is arranged between the first active layer and the second active layer, and the active substance in the second active layer is graphite. a contact angle between the first activelayer active substance and the non-aqueous solvent is theta 1, the porosity of the first active layer active substance is a, the contact angle between the bottom active substance and the non-aqueoussolvent is theta 2, and the porosity of the bottom active substance is b, so 100 <theta1/a<theta2/b<450 is obtained, through the above specific structure, as the silicon expands greatly during the charging and discharging process, it is beneficial to improve the porosity of the surface electrode plate so as to improve the liquid retention of the battery. and meanwhile, the silica surface containsmore functional groups, and the particles are smaller than the graphite particles, so that the energy density, the liquid retention capacity and the cycle life of the battery can be remarkably improved.