78results about How to "Reduce residual alkali" patented technology

The invention discloses a composite modification method for a positive electrode material. The method comprises the following steps: 1) removing impurities from a positive electrode material precursorto obtain a cleaned and impurity-removed positive electrode material precursor; 2) mixing the clean and impurity-removed positive electrode material precursor obtained in step 1) with a lithium source; 3) sintering the above obtained mixture to obtain a positive electrode material matrix; 4) dispersing and dissolving the source substance and the coating aid of a coating material in a solvent to obtain a dispersion system, adding the positive electrode material matrix obtained in step 3) to the dispersion system, performing stirring, then performing solid-liquid separation to obtain a coated solid substance, and finally performing heat treatment to obtain a material having a coating material layer; and 5) washing and drying the material obtained in step 4) to obtain a composite modified lithium ion battery positive electrode material. The high-nickel positive electrode material with a good stability is prepared through the method, and can be washed to effectively reduce residual alkaliwhile keeping the structure stable without causing deterioration of performances.

The invention relates to a preparation method of a low-surface-residual-alkali nickel cobalt manganese ternary positive electrode material and belongs to the field of chemical energy storage batteries. The preparation method includes that boric acid or citric acid is dissolved in alcohol, so that a certain amount of free-state hydrogen ions are contained in a solution; a nickel cobalt manganese ternary positive electrode material is added then, acid-alkali neutralization reaction between H+ and material surface residual alkali is utilized, and reaction intensity is regulated through stirring time, so that the residual alkali on the surface of the material can be reduced effectively, and pH value of the surface of the material is lowered; an alcohol solution is used for flushing then, so that the surface of the material is ensured to be free of residual borate ions or citrate ions; alcohol molecules probably left on the surface are removed through a two-time calcining method, so that uniformity and stability of the material are improved.

The invention discloses a double layer clad lithium ion battery cathode material and a preparation method thereof. The cathode material takes a lithium nickel cobalt manganese oxide ternary material as a matrix, and the surface of the matrix is clad with silicon lithium salt cladding and metal oxide cladding. The silicon lithium salt cladding is formed through the following steps: mixing silicon weak acid with the matrix, and carrying out a neutralization reaction on the silicon weak acid and residual alkali on the surface of the matrix to generate a layer of silicon lithium salt with which the matrix is clad. The metal oxide is mixed with the matrix which is clad with the silicon lithium salt, and the matrix is clad with a layer of the metal oxide cladding through physical cladding. The double layer clad lithium ion battery cathode material reduces the amount of the residual alkali on the surface of the lithium nickel cobalt manganese oxide matrix material, and prevents a side reaction of an electrolyte and the matrix material. Furthermore, the cathode material has high rate performance, high specific capacity and good cycle performance. In addition, the method is simple and is easy in operation and large scale production.

The invention belongs to the technical field of lithium batteries, and provides a Y/La-doped Co/B co-coated nickel-cobalt-manganese ternary positive electrode material and a preparation method thereof. According to the present invention, the cycle performance and the safety performance are improved by doping a small amount of Y<3+> ions and La<3+> ions, wherein Y<3+>/La<3+> and Ni<3+> have the same valence state, the doped Y<3+>/La<3+> can enter the metal Ni<3+> position, the Y<3+>/La<3+> does not produce the valence change during the charge and discharge, is electrochemically inert, and doesnot produce the valence state change during the charge and discharge so as not to produce the volume change, such that the Y<3+>/La<3+> can act as the skeleton, stabilize the crystal structure, and improve the cycle life and the safety performance of the material; and under the high voltage, the Co/B co-coated positive electrode material can effectively improve the cycle performance and the electronic conductivity of the battery, reduce the residual alkali, and reduce the flatulence, such that the co-coated nickel-cobalt-manganese ternary positive electrode material can effectively prevent theoccurrence of side reactions so as to improve the cycle performance and the electrochemical performance of the lithium battery.

The invention provides a method for preparing doped and modified nickel-cobalt lithium aluminate anode materials. The method includes (1), preparing first mixed liquor with nickel salt and cobalt salt; (2), preparing second mixed liquor with aluminum salt, complexing agents and compounds with doped metal elements; (3), combining flow of the first mixed liquor, flow of the second mixed liquor, flow of alkali liquor and flow of ammonia water solution with one another to obtain mixed flow, adding the mixed flow into a reaction kettle, carrying out reaction at the temperatures of 50-80 DEG C for 36-64 h, filtering, washing and drying obtained materials after the reaction is completely carried out so as to obtain doped and modified nickel-cobalt-aluminum precursors; (4), uniformly mixing the doped and modified nickel-cobalt-aluminum precursors and lithium source compounds with one another to obtain mixtures, heating the mixtures in oxygen atmosphere at the speed of 4-10 DEG C/min until the temperatures of the mixtures reach 700-800 DEG C, calcining the mixtures under heat-insulation conditions for 10-20 h, carrying out reaction, then naturally cooling obtained materials until the temperatures of the materials reach the room temperature and smashing and sieving the obtained materials to obtain the doped and modified nickel-cobalt lithium aluminate anode materials. A molar ratio of nickel metal ions to cobalt metal ions to aluminum metal ions in the reaction kettle is 0.80:0.15:0.05. The method has the advantage that the doped metal elements and host elements can be mixed with one another on atomic scales.

The invention belongs to the technical field of lithium secondary batteries and discloses a positive electrode sheet preparation method and a lithium ion secondary battery with a positive electrode sheet. Prepared positive electrode sheet paste contains an additive in a molecular formula (1), and the additive can be phosphorous acid or phosphite ester. By adding of the appropriate quantity of phosphorous acid and/or phosphite ester into the positive electrode sheet paste, the problem of powder shedding of the positive electrode sheet can be improved, adhesiveness between a positive electrode sheet coating and an aluminum foil is improved, a positive electrode material particle coating effect is achieved, and accordingly battery gas-producing expansion is remarkably inhibited while batterycycle stability is improved.

The invention belongs to the technical field of dissolving pulp preparation and relates to a stewing method for preparing bamboo wood dissolving pulp, which comprises the following steps of: (a) introducing vapor to a boiler: preparing bamboo wood raw materials into slice materials, conveying the slice materials to a digester, and introducing low pressure vapor to the digester while conveying theslice materials; (b) vapor heating and pre-hydrolyzing: heating through the vapor after introducing the vapor to the boiler to pre-hydrolyze the slice materials; (c) neutralizing through white liquor: neutralizing the slice materials and vapor condensed water in the digester through the white liquor in a hot white liquor tank; (d) replacing through hot black liquor: replacing the neutralization liquid waste in the digester through the hot black liquor in a hot black liquor tank; (e) heating and stewing in a temperature control manner to prepare virgin pulp of the bamboo wood dissolving pulp; (f) replacing the washing black liquor, washing and cooling the virgin pulp; and (g) discharging at a low temperature. The invention has the advantages of reducing the production cost, increasing the production efficiency, effectively utilizing the stewing heat and improving the yield and the quality of the bamboo wood dissolving pulp.

The invention discloses a preparation method of a high-nickel positive electrode material, which comprises the following steps: uniformly mixing up a Ni-containing hydroxide, a lithium-containing compound and a doping element, and calcining to obtain a base material A after the mixing operation; adding the base material A into a washing solution, controlling the temperature of the washing solution, washing away residual lithium carbonate and lithium hydroxide on the surface, adding a lithium-containing compound into the washing solution, and drying the washed base material to obtain a mixtureB; uniformly mixing the mixture B, a coating element and a lithium-containing compound, calcining, and crushing to obtain the finally modified high-nickel positive electrode material. The high-temperature stability of the nickel material is improved through doping. The residual lithium carbonate and lithium hydroxide on the surface are reduced through washing. The water absorption and processing performance of the material is improved. The damage to the surface of the material during washing can be repaired through coating. The direct contact between the positive electrode material and the electrolyte can be reduced, so that the high-temperature characteristic and long-cycle performance of the battery cell are improved.

The invention discloses a lithium-based high-temperature carbon-absorbing material-modified positive electrode material and a preparation method and application thereof in a lithium-ion battery. The lithium-based high-temperature carbon-absorbing material-modified positive electrode material is prepared from a positive electrode material and a lithium-based high-temperature carbon-absorbing material; and specifically, the lithium-based high-temperature carbon-absorbing material coats the positive electrode material to form primary particles, the primary particles are bridged to form secondaryparticles, and the secondary particles are coated to form the modified positive electrode material. The modified positive electrode material is in a multi-layer coating form, the coating effect generated by the structure is excellent and the conductivity is obviously strengthened; and when the modified positive electrode material is applied to the battery, one part of lithium in the lithium-basedhigh-temperature carbon-absorbing material is deintercalated to enter a negative electrode, so that the lithium consumed for generation of an SEI film of the negative electrode is compensated and theutilization rate of the lithium is improved. Volume changes in charge and discharge processes are effectively reduced through multi-coating, formation of microcracks of the positive electrode materialis reduced, meanwhile, side reaction of the positive electrode material and an electrolyte is effectively blocked, and the safety performance and the cycle performance of the material are improved.

The invention provides a positive electrode material, and a preparation method thereof and a lithium ion battery. The positive electrode material comprises a substrate and a coating layer coating the substrate, the substrate is a high-nickel ternary material, and the coating layer is a composite oxide coating layer containing Al, Co and Mn. The preparation method comprises the following steps: 1) mixing a matrix precursor with a lithium source, and calcining to obtain a matrix material; (2) mixing an aluminum source, a cobalt source and a manganese source in a dissolving agent, adding a coprecipitator, standing for reaction, and then carrying out solid-liquid separation to obtain a coating material; and 3) mixing the base material and the coating material, and performing heat treatment to obtain the positive electrode material. The positive electrode material provided by the invention can well solve the safety problem and the cycle stability problem of a high-nickel ternary material, reduces the residual alkali amount on the surface of the positive electrode material, and has the advantages of low residual alkali, low mixing degree, high conductivity, high capacity, high cycle efficiency and the like.

The invention provides a ternary positive electrode material, a preparation method thereof and a lithium ion battery. The ternary positive electrode material comprises a core and a composite coating layer coating the core, the core is a high-nickel ternary material, and the composite coating layer comprises a boron-containing compound and a phosphorus-containing compound. The method comprises the following steps: mixing a boron source, a phosphorus source and a high-nickel ternary material, and sintering in an oxidizing atmosphere to obtain the ternary positive electrode material. According to the ternary positive electrode material provided by the invention, through the high-nickel ternary material core and the composite coating layer including the boron-containing compound and the phosphorus-containing compound, the residual alkali amount is low, and the rate discharge capacity and the cycle performance are good.

The invention provides a positive electrode material of a high-nickel lithium ion battery, a preparation method thereof and a lithium ion battery, wherein, the method comprises the following steps: (1) a metal oxide is coated on the surface of the electrode material by a mixing or spray drying method to obtain a coated electrode material; The mass ratio of metal oxide to electrode material is (0.1-2): 100; (2) adding the coating electrode material obtained in the step (1) into water for stirring, wherein the mass ratio of the coating electrode material to water is (0.5-10): 1; Dehydration anddrying. The invention also provides a high-nickel lithium ion battery positive electrode material prepared by the method and a lithium ion battery using the positive electrode material. The method ofthe invention not only effectively reduces the residual alkali on the surface of the layered high-nickel positive electrode material, but also minimizes the destruction of the surface structure and the cycle performance of the material during the alkali reduction process. The layered high nickel positive electrode material prepared by the method has low residual alkali content, high reversible capacity and excellent cycling performance.

The invention discloses a single crystal ternary positive electrode material with good dispersibility, lithium-nickel mixed arrangement and low residual alkali, and a preparation method and an application thereof. In the preparation process of the single crystal ternary positive electrode material, the raw materials comprise a cationic additive, and the cationic additive is any one or a combination of at least two of an iridium source, an yttrium source, a tellurium source, an indium source and a gallium source. By adding the cationic additives such as Ir<3+>, Y<3+>, Te<4+>, In<3+> and Ga<3+>,the surface energy of the ternary material can be promoted to be reduced on the one hand, so that the sintering temperature of the material is reduced, and the volatilization of lithium salt is reduced; and on the other hand, the lithium-nickel mixed arrangement can be reduced, the directional growth of the crystal face of the material is controlled, and the adsorption effect and reaction activity of the crystal face and CO2 and H2O in the air are inhibited, so that residual alkali on the surface of the ternary material is reduced, the processing performance of the material is improved, and the rate discharge capacity and cycle performance of the single crystal ternary material are improved.

The invention is applicable to the technical field of a lithium battery, and provides an aluminium and erbium coated high-nickel lithium-ion cathode material and a preparation method thereof. The method comprises the steps of: preparing aluminium and erbium coating liquid; dispersing a lithium-ion cathode material into water, regulating pH into an alkaline state, in a stirring state, firstly adding erbium coating liquid and then adding the aluminium coating liquid, and continuously stirring to obtain suspension; and filtering the suspension, and drying, roasting and sieving precipitates to obtain the aluminium and erbium coated lithium-ion cathode material. According to the method provided by the invention, metal aluminium and erbium ions can be well dissolved in solution and are uniformlycoated on the surface of the cathode material so as to fulfill the aim of integrating washing with coating. Residual alkali of the high-nickel lithium-ion cathode material is efficiently reduced in the aspect of physical and chemical performance, reaction of the cathode material and electrolyte is inhibited, normal temperature and high temperature cycle performance of the high-nickel cathode material are improved, and flatulence is reduced.

The invention relates to the field of lithium ion battery positive electrode materials, in particular to a preparation method of a high-capacity ternary material and application of the high-capacity ternary material in a lithium ion battery positive electrode material. The method comprises the following steps: (1) preparing precursor mixed raw stock; (2) preparing a precursor; (3) preparing precursor and lithium source mixed slurry; (4) preparing a ternary material; the ternary material prepared by the method is narrow in particle size distribution, uniform in particle morphology, high in energy density and excellent in electrochemical performance. Compared with the prior art, the material has the advantages that no organic solvent is used, and the influence of the pH value is avoided;andthe operation method has the advantages of simplicity, feasibility, environmental friendliness, low production cost, high yield, excellent electrochemical performance and the like.

The invention relates to a washing method of a high-nickel positive electrode material and a product and application thereof, and the washing method comprises the following steps: mixing the high-nickel positive electrode material with a phosphate solution with the concentration of 0.1-1mol/L, reacting and sintering to obtain the washed high-nickel positive electrode material. In the washing process, phosphate reacts with residual alkali on the surface of the high-nickel positive electrode material to generate lithium phosphate precipitate to be attached to the surface of the high-nickel positive electrode material, a lithium phosphate coating layer is formed through subsequent sintering, and part of lithium phosphate can permeate into the surface layer of the material and deep positions of the surface to fill lattice gaps of the material to modify the surface, so that coating is tighter; therefore, the structural stability and the thermal stability of the positive electrode material are improved, and the dual effects of washing to remove residual alkali and improving the stability of the material are achieved; furthermore, the reaction process of washing can be carried out at normal temperature, the washing process is simple to control, the energy consumption is low, the cost is low, and the washing effect is obviously improved.

The invention provides a lithium ion secondary battery cathode material and a preparation method thereof, belongs to the technical field of lithium ion batteries, and aims to effectively improve Li/Nimixed arrangement caused by a low-cobalt material in a sintering process by reasonably designing doped coating elements and utilizing a synergistic effect or further reaction among the elements. According to the invention, the rate capability of the low-cobalt material is improved, meanwhile, element dissolution is reduced, the cycle performance is improved, the technical effect which cannot be brought by doping and coating of a single element is overcome, and the problems of poor dynamic performance and poor element dissolution and cycle performance of the low-cobalt material are improved.

The invention relates to a positive electrode slurry and an application thereof, the positive electrode slurry comprises a high-nickel positive electrode material and an additive, and the additive comprises at least one of LiPF6, boric acid, oxalic acid, citric acid, tartaric acid, tetraethyl silicate, LiPO2F2 and HPF6; the additive can react with residual alkali on the surface of a high-nickel positive electrode material to reduce the alkalinity of positive electrode slurry and improve the stability and processability of the positive electrode slurry, so that the gas production of a battery prepared from the additive in the use process is reduced, the safety of the battery is improved, the application of the waterless high-nickel positive electrode material is facilitated, and the cost ofthe battery is reduced; meanwhile, the preparation process of the positive electrode slurry is simple to operate, and industrialization is easy to realize.

The invention provides a preparation method of a modified nickel-cobalt-manganese ternary cathode material, comprising the following steps: 1) preparation of the modified nickel-cobalt-manganese and 2) preparation of the niobium doped nickel-cobalt-manganese ternary cathode material. The invention also discloses a modified nickel-cobalt-manganese ternary cathode material prepared according to thepreparation method of the modified nickel-cobalt-manganese ternary cathode material and a lithium ion battery using the modified nickel-cobalt-manganese ternary cathode material as the cathode material. Compared with the traditional Ni-Co-Mn ternary cathode material in the prior art, the modified Ni-Co-Mn ternary cathode material prepared by the invention has the advantages of lower production cost, higher gram capacity, higher cycle stability and energy density, more excellent electrochemical performance, longer cycle service life, higher first charge-discharge efficiency, and safer and environmentally friendly use.