8360results about "Electrode manufacturing processes" patented technology

Systems and methods for charging and discharging a plurality of batteries are described herein. In some embodiments, a system includes a battery module, an energy storage system electrically coupled to the battery module, a power source, and a controller. The energy storage system is operable in a first operating state in which energy is transferred from the energy storage system to the battery module to charge the battery module, and a second operating state in which energy is transferred from the battery module to the energy storage system to discharge the battery module. The power source electrically coupled to the energy storage system and is configured to transfer energy from the power source to the energy storage system based on an amount of stored energy in the energy storage system. The controller is operably coupled to the battery module and is configured to monitor and control a charging state of the battery module.

The invention discloses a preparation method of a high-compaction lithium manganese iron phosphate positive electrode material, which comprises the following steps: placing a manganese source, an iron source and a phosphorus source in deionized water, stirring, carrying out primary high-speed ball milling, carrying out constant-temperature water bath, adding an oxidizing agent, stirring and oxidizing, and drying the slurry to obtain manganese iron phosphate precursor powder; carrying out primary sintering on the ferromanganese phosphate precursor powder to obtain a ferromanganese phosphate primary sintering material; putting the ferromanganese phosphate primary sintering material into deionized water, adding a lithium source and a carbon source at the same time, and performing stirring, secondary high-speed ball milling and drying to obtain lithium ferromanganese phosphate precursor powder; and carrying out secondary sintering on the lithium manganese iron phosphate precursor powder to obtain the high-compaction lithium manganese iron phosphate positive electrode material. The void ratio is well reduced and good carbon coating is realized by means of secondary grinding and secondary sintering, and compared with the prior art, the method has the advantages that good capacity can be maintained, the powder compaction density of the material can be improved, the conductivity can be improved, and the specific surface area of the material can be effectively reduced.

The invention relates to a surface-modified lithium-rich manganese-based positive electrode material, a preparation method and a lithium ion battery, and the preparation method comprises the following steps: uniformly mixing a lithium-rich manganese-based precursor, a lithium source and a metal oxide required by garnet type solid electrolyte to obtain a mixture; and performing gradient temperature calcination on the mixture in an oxidizing atmosphere to obtain the surface-modified lithium-rich manganese-based positive electrode material, the surface-modified lithium-rich manganese-based positive electrode material comprises a lithium-rich manganese-based material, a disordered spinel self-protection layer coated on the surface of the lithium-rich manganese-based material, and a garnet type solid electrolyte coated on the surface of the disordered spinel self-protection layer, the gradient temperature calcination comprises the following steps: calcining at the nucleation temperature of the lithium-rich manganese-based material, and then heating to the nucleation temperature of the garnet type solid electrolyte for calcining. The lithium-rich manganese-based positive electrode material can solve the problems of low first coulombic efficiency and poor rate capability of the lithium-rich manganese-based positive electrode material in related technologies.

The invention belongs to the technical field of batteries, and discloses a negative pole piece and a preparation method thereof, a non-negative lithium battery and a lithium battery. The negative pole piece comprises a current collector and a lithium-loving active layer, the lithium-loving active layer is arranged on at least one side of the current collector, the lithium-loving active layer comprises nanowires and conductive particles dispersed on the nanowires, and when lithium metal is deposited, the nanowires provide nucleation sites for the lithium metal. According to the negative pole piece provided by the invention, the coulombic efficiency and the cycling stability of the negative-electrode-free lithium battery can be improved.

The invention belongs to the technical field of battery materials, and particularly relates to a method for preparing a porous carbon structure containing a sub-nanoscale ionic conduction improvement layer by utilizing atomic layer deposition and application. The invention discloses a porous carbon-silicon negative electrode structure, which is characterized in that a sub-nano-scale ion conduction improvement layer is added between a porous carbon substrate and silicon particles, and the sub-nano-scale ion conduction improvement layer comprises silicon carbide, aluminum phosphide, aluminum nitride, aluminum oxide, lithium phosphate, aluminum phosphate and lithium aluminum phosphate. Meanwhile, the invention also discloses a preparation method of the porous carbon-silicon negative electrode structure, namely, a sub-nano-scale ion conduction improvement layer is deposited on the porous carbon substrate through an atomic layer deposition method, so that the binding force between the sub-nano-scale ion conduction improvement layer and silicon particles and an ion transport channel are increased, and the ion conduction of a vapor deposition silicon-carbon negative electrode material is improved; the polarization of the material is effectively reduced, so that the rate capability of the battery is improved, and the cycling stability of the porous carbon structure battery is improved.

A protective structure for use with metallic lithium (or other alkali or alkali earth metals) and its method of manufacture are provided. The protective structure may include a substantially continuous and substantially nonporous buffer layer disposed on the metallic lithium layer which is conductive to lithium ions. A substantially continuous and substantially nonporous protective layer may be disposed on the buffer layer.

The invention provides an iron-based phosphate positive electrode material as well as a preparation method and application thereof. The preparation method of the positive electrode material comprises the following steps: reacting a mixed material containing metallic iron and a phosphorus source at normal temperature to 100 DEG C to form a solid-liquid mixture containing a phosphate iron salt compound; mixing the solid-liquid mixture with an acidity regulator, a carbon source and a sodium source, and sanding to obtain slurry; performing drying treatment on the slurry to obtain a precursor material; and sintering the precursor material under a protective atmosphere condition to obtain the iron-based phosphate positive electrode material. According to the method provided by the invention, the metal iron and the phosphorus source do not need to be mixed and completely dissolved to form a solution in the reaction process, and anhydrous iron phosphate does not need to be formed firstly, so that the method for preparing the iron-based phosphate positive electrode material is short in process and relatively low in requirements on reaction conditions, and is applicable to industrial production and large-scale production.

The invention provides a titanium-doped high-nickel ternary positive electrode material and a preparation method thereof. The titanium-doped high-nickel ternary positive electrode material comprises a high-nickel ternary positive electrode material and a titanium-doped element, and the content of the titanium-doped element accounts for 0.5-5wt% of the titanium-doped high-nickel ternary positive electrode material. The preparation method comprises the following steps: preparing a nickel-cobalt-manganese hydroxide precursor; uniformly mixing the nickel-cobalt-manganese hydroxide precursor with a lithium source, sintering and cooling to obtain a high-nickel ternary positive electrode material; and mixing and sintering the high-nickel ternary positive electrode material and a reducing titanium source to obtain the titanium-doped high-nickel ternary positive electrode material. Reducing titanium is used for modifying the high-nickel ternary material, more stable Ni < 2 + > is enriched on the surface of the material through an oxidation-reduction reaction to serve as a protective layer, corrosion of electrolyte to the material is reduced, and the surface stability of the material is improved; the titanium element can enter material crystal lattices more easily compared with a common doping method; the lattice structure strength of the material is improved through a relatively strong Ti-O bond, and excellent cycling stability and rate capability are obtained.

The invention discloses a porous carbon and silicon carbon material as well as a preparation method and application thereof. The pore structure of the porous carbon comprises mesopores and micropores; in the pore structure, the pore volume ratio of mesopores is 3-20%, and the pore volume ratio of micropores is 80-97%; the adsorption and desorption isotherm of the mesopores is one or more of an H1 type hysteresis loop, an H2 type hysteresis loop and an H3 type hysteresis loop; the pore structure is filled with carbon particles, and the carbon particles are spherical carbon particles or fusiform carbon particles. By regulating and controlling the pore structure of the porous carbon, the performance of the silicon-carbon negative electrode is remarkably improved, and the double advantages of high strength and low expansion are achieved. The preparation method disclosed by the invention has obvious advantages in the aspects of cost, time and safety.

The invention relates to a preparation method of a positive pole piece of a secondary battery, the positive pole piece is prepared by a dry process, and when process parameters meet the following formula: # imgabs0 # 0.6 * S0 < = S1 < = 1.5 * S0, the prepared positive pole piece has remarkable advantages in the aspects of electrical properties and mechanical properties.

The invention provides an electrode slurry treatment device and battery production equipment. The electrode slurry treatment device comprises a container and a power source, and the container is provided with a containing cavity used for containing electrode slurry. The power supply comprises a positive electrode part and a negative electrode part which are both connected to the container, and the power supply is used for applying an electric field to the electrode slurry contained in the containing cavity. Wherein the container comprises a tank body, a stirring paddle, a first conductive part and a second conductive part, the tank body comprises a containing cavity, the stirring paddle is arranged in the containing cavity and is configured to rotate relative to the tank body, and the stirring paddle is used for stirring electrode slurry. The first conductive part and the second conductive part are both arranged in the accommodating cavity, and the first conductive part, the second conductive part and the stirring paddle are arranged at intervals. One of the positive electrode portion and the negative electrode portion is connected to the first conductive member, and the other of the positive electrode portion and the negative electrode portion is connected to the second conductive member. According to the invention, the quality of the electrode slurry can be effectively improved.

The invention belongs to the technical field of industrial control, and discloses a bottleneck prediction optimization method, device and equipment for a battery positive electrode material production line, and the method comprises the steps: collecting the spatial data and time series data of the production line in real time; synchronizing the spatial data and the time sequence data to a digital twinborn model, wherein the digital twinborn model is pre-constructed based on the production line; converting the spatial data and the time sequence data into spatio-temporal data; inputting the spatio-temporal data into a pre-trained spatio-temporal diagram convolutional network to obtain a prediction result of the bottleneck of the production line; when it is judged that a production line bottleneck exists according to the prediction result, based on the prediction result, an optimization strategy is generated according to a priority rule, the optimization strategy is operated on the digital twin model in a simulation mode, a simulation result is obtained, and if it is judged that the simulation result meets the expectation, the production line is controlled according to the optimization strategy. Efficient and stable operation of a production line can be ensured, and production efficiency and stability are improved.

The invention discloses a high-nickel ternary positive electrode material as well as a preparation method and application thereof. The chemical formula of the positive electrode material is LixNiyCozMaNbOc, M is at least one of Mn and Al, N is at least one of Ti, V, Nb, Zr, Ta, W or Mo, x is larger than or equal to 0.9 and smaller than 1.2, y is larger than or equal to 0.6 and smaller than or equal to 0.95, 0 lt, and z is larger than or equal to 0.5. Z < = 0.2, 0lt; a < = 0.2, 0 < b < = 0.02, and values of x, y, z, a, b and c accord with an electrically neutral principle; the positive electrode material has a single crystal morphology, the average size of primary particles is 0.20-1.50 microns, and the c / a ratio in lattice parameters is greater than 4.9360. The positive electrode material is applied to a positive electrode of a lithium ion battery, and shows good first coulombic efficiency and charge-discharge capacity.

The invention discloses high-compaction high-capacity positive electrode slurry based on a polyanion positive electrode material, a pole piece, a sodium ion battery and a preparation method of the sodium ion battery, and the positive electrode slurry of composite powder is prepared by simply dry-mixing polyanion positive electrode material powder and layered oxide positive electrode material powder of the sodium ion battery. Or in the slurry preparation process, sodium ion battery polyanion type positive electrode material powder and layered oxide positive electrode material powder are respectively added for slurry stirring and mixing, so that composite positive electrode slurry is obtained, the obtained slurry is coated, and the sodium ion battery is prepared. The compaction density and gram volume of the composite positive plate are regulated and controlled by controlling the adding proportion of the two positive electrode materials of the slurry and the types of the positive electrode materials.

The invention provides a composite silicon-carbon negative electrode material as well as a preparation method and application thereof. The composite silicon-carbon negative electrode material comprises a composite silicon-carbon inner core and a carbon coating layer arranged on the surface of the composite silicon-carbon inner core, the composite silicon-carbon inner core comprises a porous carbon skeleton and nano silicon particles, modified holes are formed in the porous carbon skeleton, graphite microcrystalline layers are arranged around openings of the modified holes, and the nano silicon particles are arranged on the surface of the porous carbon skeleton and in the modified holes. The modified holes are formed in the composite silicon-carbon negative electrode material, silicon particles can be properly deposited in the modified holes, and the graphite microcrystalline layer is arranged around the modified holes, so that the resistivity of the material can be greatly reduced, and the electrical property of the silicon-carbon negative electrode material is improved.

The invention discloses a lithium ion battery positive electrode material and a preparation method thereof, the lithium ion battery positive electrode material comprises an active substance, a conductive additive, a binder and a thermal stability additive, the active substance is # imgabs0 # with a layered structure, x + y + z = 1, 0.5 < = x < = 0.8, 0.1 < = y < = 0.3, 0.1 < = z < = 0.3, the conductive additive is a compound of a carbon nanotube and graphene, and the thermal stability additive is a mixture of a carbon nanotube and graphene. The binder is a mixture of polyvinylidene fluoride and sodium carboxymethyl cellulose, the thermal stability additive is a mixture of lithium phosphate and aluminum oxide, the sum of the mass fraction of the lithium phosphate and the mass fraction of the aluminum oxide in the thermal stability additive is 0.5-10%, and the mass fraction of the lithium phosphate is 0.5-5%. According to the lithium ion battery positive electrode material and the preparation method thereof, the stability of the positive electrode material at high temperature can be improved, the thermal runaway risk is reduced, and the cycle life of the battery is prolonged.

The invention relates to a hybrid scrim / paste paper material for a plate-shaped battery electrode (2, 3) of a lead-acid battery, in particular for a positive plate-shaped battery electrode (2) of a lead-acid battery (1), wherein the scrim / paste paper material is designed as a nonwoven or woven mat and comprises: - fibers made of a first material which is chemically unstable, such that the fibers made of the first material dissolve at least substantially upon contact with an electrolyte of the lead-acid battery (1), in particular during the manufacture of the lead-acid battery (1); - fibers made of a second material which is chemically stable at least to the extent that the fibers made of the second material do not dissolve, or do not dissolve substantially, upon contact with the electrolyte of the lead-acid battery (1), in particular during the manufacture of the lead-acid battery (1);and - optionally a binding agent for the fibers from the second material;

The invention provides positive electrode slurry, a positive electrode plate, a lithium ion battery and a power utilization device, a positive electrode lithium supplement agent comprises a lithium iron phosphate main material, a binder, a conductive agent and a porous additive, the conductive agent comprises conductive carbon black with a high specific surface area, and the specific surface area of the conductive carbon black is greater than or equal to 130 m < 2 > / g. The space between the lithium iron phosphate particles in the positive electrode slurry provided by the invention is filled with the porous additive with the medium aperture and the conductive carbon black with the small aperture and the high specific surface area, so that a positive electrode plate applying the positive electrode slurry not only is small in internal pore spacing, but also forms gradient pore structure matching capable of reducing tortuosity of lithium ion transmission, and the lithium ion transmission efficiency is improved. And the technical effects of improving the electrolyte wettability of the electrode, improving the quick charge capacity, the cycle life, the low-temperature discharge capacity and the like of the battery are achieved.

The invention discloses a negative pole piece and a preparation method thereof, a bipolar pole piece and a preparation method thereof, a battery and an electric device. The negative pole piece comprises a first current collector and a second current collector, wherein the first current collector comprises a first side and a second side which are opposite to each other; the first active material layer and the second active material layer are sequentially arranged on the first side in the direction away from the first current collector, the first active material layer comprises metal lithium, and the second active material layer comprises metal lithium alloy. By adopting the negative pole piece or the bipolar pole piece, the problems of continuous thickening of an SEI film, continuous growth of lithium dendrites, lithium death, penetration of the lithium dendrites to a diaphragm and the like can be avoided, so that the cycle stability of a battery applying the negative pole piece or the bipolar pole piece is favorably improved.

The invention discloses a die-cutting system and method, the system comprising: a sensor, a controller and a laser; the sensor is used for collecting the pole piece thickness data of the pole piece and sending the pole piece thickness data to the controller; the controller is used for determining the starting point of a thickness thinning zone according to the change of the pole piece thickness data, calculating the first distance from the starting point of the thickness thinning zone to the laser, calculating the die-cutting waiting time according to the first distance, and sending the die-cutting waiting time to the laser; the laser is used for die-cutting the pole piece after the die-cutting waiting time is interval to obtain a first pole ear; because the present application determines the starting point of the thickness thinning zone by the change of the pole piece thickness, and guides the laser to cut the first pole ear according to the starting point of the thickness thinning zone, the position of the thickness thinning zone can be accurately identified in the die-cutting process, and then the first pole ear can be accurately cut at the designed spacing before the thickness thinning zone in the die-cutting process, so that the thickness thinning zone is at the corner of the battery cell winding.

The invention provides an elastic current collector and a preparation method and application thereof. The elastic current collector comprises a metal foil and an elastic carbon interface layer arranged on at least one side surface of the metal foil, and the elastic carbon interface layer comprises an elastic carbon material, a conductive additive and a binder; the elastic carbon material comprises hollow carbon and / or biomass-based porous carbon, and the surface and the interior of the biomass-based porous carbon are both provided with pore structures. According to the invention, hollow carbon and / or biomass-based porous carbon are / is used as an elastic carbon material, mixed with the conductive additive and the binder, and then coated on the surface of at least one side of the metal foil to form the elastic carbon interface layer, so that the surface roughness of the current collector is increased and the interface stress is dynamically reduced without influencing the electrochemical performance of the electrode; therefore, the electrochemical stability of the electrode is effectively improved, and the preparation method is simple and suitable for large-scale application.

The invention discloses a modified nickel-cobalt-aluminum ternary positive electrode material, a preparation method thereof and a lithium battery, the modified nickel-cobalt-aluminum ternary positive electrode material provided by the invention comprises a bulk phase material and a coating layer coating the surface of the bulk phase material, the coating layer is composed of boric acid and at least one of transition metal nitride containing effective metal and aluminum-containing metal oxide. According to the invention, at least one of the binary compound containing the effective metal or the aluminum-containing metal oxide and the boric acid are used as the composite coating source for composite coating, so that the coating effect of the nickel-cobalt-aluminum ternary positive electrode material is optimized, and the ultrahigh nickel-nickel-cobalt-aluminum ternary positive electrode material with better physical and chemical properties is prepared. Meanwhile, the problems that the material is poor in structural stability, high in residual alkali content, relatively low in capacity and poor in rate and cycle performance exertion are solved.

A composite current collector for an anode-free lithium metal battery and a preparation method therefor, and an anode-free lithium metal battery. The composite current collector for an anode-free lithium metal battery comprises: a base film; an electrically conductive layer, which is arranged on at least one side surface of the base film; and a surface modification layer, which is arranged on the side surface of the conductive layer that is away from the base film, wherein the material of the surface modification layer comprises a hydroxyapatite-based compound. By means of constructing, on the surface of a composite current collector, a surface modification layer including a hydroxyapatite-based composite, the repulsion of an anode to free-state anions is effectively relieved, such that sufficient anion derivatives are generated at an electrolyte-anode interface to stabilize the electrolyte-anode interface; and the generated stable interface can reduce desolvation energy barriers of lithium ions, accelerate the transmission dynamics of the interface, and effectively suppress the generation of "dead lithium" and lithium dendrites, thereby prolonging the cycle life of a lithium metal battery.

The invention provides a composite material with an MOF structure as well as a preparation method and application thereof, the composite material comprises a main body material structure with oxygen vacancies coated with the MOF structure, the composite material is formed by in-situ growth of the MOF structure on a main body material with the oxygen vacancies, and the main body material with the oxygen vacancies is formed by in-situ growth of the MOF structure on the main body material with the oxygen vacancies. According to the MOF material, metal active sites capable of growing can be provided for the MOF structure, oxidizing gas generated by the battery under the extreme condition can be synergistically eliminated, the MOF material has Lewis acidity, the rate performance of the battery can be improved, reducing gas generated by the battery under the extreme condition can be adsorbed, and therefore the safety performance of the battery is improved.

The invention provides a positive pole piece and a preparation method thereof, a secondary battery and an electronic device. The positive pole piece comprises a positive pole current collector, a positive pole material layer and an insulating layer, the positive pole piece comprises an empty foil area and a coating area, the positive pole material layer and the insulating layer are located in the coating area, the insulating layer and the positive pole material layer are connected in the length direction of the positive pole current collector, and the insulating layer is closer to the empty foil area than the positive pole material layer; in the direction from the positive electrode material layer to the insulating layer, the positive electrode material layer comprises a first edge and a second edge which are opposite, and the first edge is close to the empty foil area; the tensile strength of the positive pole piece is tested in the direction, the fracture position of the positive pole piece is located between the first edge and the second edge, the distance between the fracture position and the first edge is x mm, and x is larger than 3 and smaller than or equal to 20. The positive pole piece provided by the invention is used for the secondary battery, so that the secondary battery has good safety performance.

The invention designs a manufacturing method of a conductive polymer protective layer poly (3, 4-ethylenedioxythiophene): poly (styrene sulfonate) (PEDOT: PSS) modified zinc negative electrode surface, and the PEDOT: PSS with good film-forming property and zinc affinity is selected and simply coated on the zinc negative electrode surface (PEDOT: PSS at Zn) to construct an integrated PEDOT: PSS at Zn dendrite-free zinc negative electrode. The PEDOT: PSS-Zn integrated electrode has excellent flexibility and adhesive force, and can still keep integrity after being bent for 1000 times. Meanwhile, the PEDOT: PSS can block direct contact between electrolyte and a zinc negative electrode interface, and corrosion reaction and by-products are inhibited. Besides, PEDOT: PSS has good conductivity, so that charge distribution on the surface of the zinc negative electrode is more uniform, rich sulfur-containing functional groups on the surface can induce uniform deposition of Zn < 2 + >, selective deposition of zinc ions is effectively avoided, and finally the purpose of inhibiting growth of zinc dendrites is achieved. The preparation method of the integrated zinc negative electrode is simple and efficient, the zinc dendritic crystal inhibition effect is obvious, a choice is provided for realizing a long-circulation water system zinc ion battery, and the preparation method has important research significance.

The present invention relates to the working principle and production methods for the pre-expansion of sulfur and / or other chalcogenides such as selenium or tellurium, and / or a mixture of any two or more. The present invention further relates an electrode / cathode comprising sulfur and / or a mixture of sulfur allotropes, for example, crystalline, glassy, amorphous, and / or polymeric (e.g., β-, γ-, and / or ω-phasic) sulfur and / or a mixture of any two or more sulfur allotropes, wherein the sulfur is photonically / electronically / thermally pre-expanded to a state where it has a density equivalent to a metal sulfide, such as Li2S. The expansion is carried out before electrode / cathode fabrication for the realization of alkali and / or alkali earth metal / ion batteries, such as LiS batteries. The resulting pre-expanded chalcogenides such as sulfur has an artificially generated internal cavities / porosity in addition to an open / external porosity, wherein the internal cavities limits and / or compensates the expansion of sulfur further or expansion partially / negligibly during chemical / electrochemical reactions, such as lithiation or sodiation, with mono, di, and trivalent metal ions. A thus fabricated electrode / cathode comprising pre-expanded sulfur and / or chalcogenides allows precise control over density and volume fluctuations and withstands the chemical and electrochemical reactions that occur during battery operation. Additionally, leads to improved performance, and longevity and offers significant potential for further technological developments in this field.

The invention relates to an electrode preparation method, an electrode prepared by the electrode preparation method and an energy storage device comprising the electrode, and the preparation method comprises the following steps: (1) preparing an electrode diaphragm: (a) mixing materials: uniformly mixing an electrode active material, a conductive additive and a non-fibrillated binder, then adding a fibrillated binder, and uniformly mixing the materials to obtain the electrode diaphragm; processing the obtained mixture to be flocculent or muddy; or uniformly mixing the electrode active material, the conductive additive, the non-fibrillated binder and the fibrillated binder, and processing the obtained mixture to be flocculent or muddy; (b) forming: forming the flocculent or muddy product obtained in the step (a) into an electrode membrane; and (2) depositing a current collector: depositing a metal layer on one surface of the electrode diaphragm obtained in the step (1) through a physical deposition method to serve as the current collector. The energy storage device provided by the invention has improved cycle performance, rate capability and first coulombic efficiency.

The invention discloses a zinc negative electrode and a preparation method and application thereof. The zinc negative electrode comprises a polycatechol coating; and the thickness is 10 nm to 1 [mu] m. The method has the advantages of being green, environmentally friendly and low in cost. Catechol has zinc affinity and can be stably combined with zinc metal to form an ultrathin protection layer, compared with other organic matter coating methods (the process is complex and raw materials are expensive), the method is simpler and rapider, no binder or expensive medicine is needed, the zinc foil only needs to make contact with a modified solution for a certain time, practicability is high, and the method is suitable for large-scale production. The application prospect of large-scale continuous preparation is realized. The added oxidizing agent has the function of accelerating reaction, other metal ions can be introduced to be chelated with catechol, the deposition behavior of zinc ions is further optimized and regulated, and the battery performance is improved. The cycle life of the modified zinc negative electrode battery can reach more than 500h.

A ternary polycrystalline positive electrode material is a secondary ball formed by agglomerating primary particles, the secondary ball is equally divided into four parts in the direction from the center to the surface of the secondary ball, the four parts are an inner core layer, a first middle layer, a second middle layer and a shell layer, and the section of the ternary polycrystalline positive electrode material is observed through a scanning electron microscope. The porosity is sequentially reduced from inside to outside. The preparation method comprises the following steps: mixing a positive electrode material precursor, a lithium source and a Li-containing polyanion compound, and sintering at a high temperature to obtain a primary sintered matrix; and washing and drying the primary sintering substrate, mixing the primary sintering substrate with a coating agent, and sintering to obtain the ternary polycrystalline positive electrode material. The invention also discloses a lithium ion battery. The porosity of the section of the positive electrode material is sequentially reduced from inside to outside, so that the positive electrode material can be in more sufficient contact with an electrolyte, more diffusion paths are formed, the transmission obstruction of lithium ions is reduced, and the transmission rate of the lithium ions is effectively improved, so that the discharge performance of the positive electrode material is improved, and the cycle performance of the material is improved.