40results about How to "Improve capacity play" patented technology

The invention belongs to the field of sodium ion batteries, and particularly discloses a positive electrode material and a preparation method and application thereof. The positive electrode material is carbon nitride coated fluorine-doped pyrophosphate sodium manganese iron phosphate, the chemical formula of the positive electrode material is NaaFe3-bMnb (PO4-x) 2F4xP2O7 / C3N4, a is larger than or equal to 3.95 and smaller than or equal to 4.1, b is larger than or equal to 0.3 and smaller than or equal to 2.4, and x is larger than or equal to 0.005 and smaller than or equal to 0.05. The sodium ferromanganese pyrophosphate is subjected to fluorine doping and carbon nitride coating, so that the electronic conductivity and the structural stability of the sodium ferromanganese pyrophosphate can be improved, the capacity of the sodium ferromanganese pyrophosphate can be well exerted, and the capacity and the voltage platform of the sodium-ion battery are improved.

The invention relates to the technical field of lithium batteries, in particular to a composite binder aqueous solution, a silicon-based negative pole piece and a preparation method and application of the silicon-based negative pole piece. The preparation method of the composite binder aqueous solution comprises the following steps: dissolving a water-based polymer binder and a micromolecular physical crosslinking agent in water, adding pyrrole, stirring, adding an initiator, and mixing to obtain the composite binder aqueous solution. A small molecule physical cross-linking agent is introduced into the water-based polymer binder, and a large number of hydrogen bond binding sites are increased, so that the mechanical property of the binder is remarkably enhanced, and the machinability of the pole piece is further improved. Meanwhile, polypyrrole can be generated in the binder through in-situ polymerization, and the polypyrrole can be tightly coated on the surfaces of the silicon particles through strong interaction between the binder and the silicon particles to form a stable conductive network, so that the charge transfer capability of the electrode is remarkably improved. In addition, the composite binder is also beneficial to formation of a solid electrolyte layer rich in Li-N and participates in formation of a solid electrolyte interface layer, so that the lithium ion transmission capability of the composite binder is further improved.

The invention provides a positive active material and a preparation method thereof, a positive pole piece, a battery and electric equipment, the change rate d of the characteristic peak interplanar spacing of the positive active material (104) is greater than or equal to 0.05% and less than or equal to 0.5%, d = (d before-d after) / d before * 100%, d before is the interplanar spacing of the characteristic peak of the positive active material (104) measured by an X-ray diffractometer before circulation, and d after is greater than or equal to 0.05% and less than or equal to 100%. And d, measuring the interplanar spacing of the characteristic peak of the positive electrode active material (104) by an X-ray diffractometer at 45 DEG C after circulation for 80 weeks. Therefore, the interplanar spacing change rate of the positive electrode active material before and after circulation is small, which shows that the crystal structure stability of the positive electrode active material is good, the positive electrode active material is not easy to pulverize in the long-term circulation process of the battery, and the cycle performance of the battery can be improved.

The invention relates to the field of new energy batteries, in particular to an oxyhalide solid electrolyte composite material, a preparation method thereof and a battery, the oxyhalide solid electrolyte composite material comprises a core particle and a coating layer coating the surface of the core particle; wherein the inner core particle comprises LiaMObXc, the coating layer material comprises LiaMObXc-dFd, a is greater than or equal to 0.1 and less than or equal to 5w, and d is greater than or equal to 0.1 and less than or equal to 0.5 w; b < = 2, 2 < = c < = 6, 0lt; d < = 2; m is selected from at least one of Hf, Zr, Nb, Ta and Ti, and X is selected from at least one of Cl, Br and I. The oxyhalide solid electrolyte composite material disclosed by the invention is relatively low in fluorine content in a main body, so that the negative influence of over-low conductivity caused by high overall fluorine content of the material is reduced, and the electrolyte material is promoted to have excellent electrochemical oxidation potential and air stability while maintaining high ionic conductivity.

The invention provides a positive electrode material as well as a preparation method and application thereof, and relates to the technical field of lithium ion batteries. The particle size distribution curve of the positive electrode material is bimodal distribution, the positive electrode material is composed of large-particle-size secondary spherical particles and small-particle-size secondary spherical particles, the large-particle-size secondary spherical particles are composed of small-particle-size primary spherical particles, the small-particle-size secondary spherical particles are composed of large-particle-size primary spherical particles, and the large-particle-size primary spherical particles are composed of small-particle-size primary spherical particles. The D50 of the large-particle-size secondary sphere particles is 8.0-12.0 [mu] m, the D50 of the small-particle-size secondary sphere particles is 2.0-4.0 [mu] m, the maximum diameter of the small-particle-size secondary sphere particles is not more than 5 [mu] m, and the minimum diameter of the large-particle-size secondary sphere particles is not less than 5 [mu] m. Compared with the prior art, the invention provides the positive electrode material matched with two secondary spherical particles with different primary spherical particle sizes, so that the compaction density and the cycling stability of the positive electrode material are improved.

The invention discloses a sodium-ion battery positive electrode material and a preparation method thereof, a positive plate and a negative-electrode-free sodium-ion battery, and relates to the technical field of sodium-ion batteries. According to the sodium battery positive electrode material provided by the invention, the inner layer is the layered oxide, the outer layer is the sodium-lanthanum-zirconium-oxygen coating layer, and the dissolution phenomenon of Fe < 3 + > in the layered oxide material can be relieved by utilizing the sodium-lanthanum-zirconium-oxygen coating layer; the sodium lanthanum zirconium oxide material belongs to a solid electrolyte and is a fast ion conductor of sodium ions, so that the injection amount of the electrolyte can be reduced, the growth of dendritic crystals can be reduced, the safety performance of the battery can be improved, and the capacity exertion of the active material can be improved. Based on the advantages, the sodium battery positive electrode material provided by the invention can improve the safety and the cycle life of the battery.

The invention relates to a 3D printing composite positive pole piece, a preparation method thereof and a solid-state battery, the 3D printing composite positive pole piece comprises 90-97wt% of a positive active material, 10-15wt% of a conductive agent, 10-15wt% of a binder, 10-15wt% of a plasticizer and 10-15wt% of a polymer monomer; the proportion of the conductive agent is 1 to 3.5 weight percent; the plasticizer accounts for 0 to 1.5 wt%; the binder accounts for 1 to 5 weight percent; the proportion of the polymer monomer is 1 to 5 weight percent. The method has the advantages that the raw materials are printed on the positive electrode current collector in a 3D printing mode, the printed electrode has high integration and high material utilization rate, compared with a coating mode, the battery manufacturing time and cost can be effectively reduced, monomers in the electrode and an electrolyte precursor solution are polymerized, the combination degree between the solid electrolyte and the electrode is improved, and the battery performance is improved. And electrode / solid electrolyte integration is realized, so that the interface impedance between the electrolyte and the electrode is reduced, the lithium ion interface transmission is accelerated, and the capacity exertion and rate capability of the positive electrode material are improved.

The invention relates to a lithium cobalt oxide positive electrode material with an O2 phase structure and a preparation method and application thereof, the chemical general formula of the lithium cobalt oxide positive electrode material is Li1 + a (CocMd) (1 + a) / (1 + a + b) O2. Xb (CocM'd) b / (1 + a + b) O2,-1 < a < = 0.1, 0 < b < = 1, 0 < c < = 1, 0 < = d < = 0.5,-1 < a + b < = 1.1, X comprises at least one of Na, K, Rb, Cs or B, and M and M'are selected from at least one of Ni, Mn, A l, Mg, Co, Cu, Ca, Zn, Zr, B, Nb, Fe, Cr, Y, La, Ce, Cd or Al; the space group is P63mc; according to an XRD (X-Ray Diffraction) test, diffraction characteristic peaks exist at the same time at the diffraction angles of 18.3 to 18.9 degrees, 37.9 to 38.4 degrees, 46.7 to 47.3 degrees and 16.0 to 16.5 degrees.

The invention provides a fluorinated alcohol electrolyte, a preparation method and application in a lithium ion battery, the electrolyte contains a fluorinated alcohol additive, the structural formula is R-OH, R is CF < x > H < 2-x >, CF < x > H < 3-x > CF < x > H < 2-x >, CF < x > H < 3-x > CHCFF < x > H < 3-x >, and CF < x > H < 3-x > CFCFF < x > H < 3-x >; compared with the prior art, the development of the fluoroalcohol additive is beneficial to exerting the performance of the battery, and fluoroalcohols can quickly react to form a film on a negative electrode to form a protective layer, namely, the fluoroalcohols can effectively gather on the surface of the negative electrode to form a fluorine-containing SEI film. By adopting the electrolyte of the fluorinated alcohol additive, the electrochemical performance of the lithium ion battery is improved. And comparing the performance of the battery containing the fluorinated alcohol additive with the performance of the battery without the fluorinated alcohol additive. Results show that compared with a battery without the additive, the battery containing the additive has the advantages that the capacity exertion and utilization are obviously improved, and the cycle performance is improved.

The invention discloses a precursor for a polyanionic sodium ion battery positive electrode material and a preparation method of the precursor. The chemical general formula of the precursor is NaxMyHzOa (POb) c.mH2O, wherein M is a transition metal element Fe and / or Mn; the relationship among x, y, z, a, b and c is x + 3y + z-2a + 5c-2b * c = 0, and the value range of m is greater than or equal to 0. The precursor for the polyanionic sodium ion battery positive electrode material and the preparation method thereof have the characteristics of high phase purity, high compaction density, excellent electrochemical performance, low cost and wide system applicability.

The invention discloses a high-conductivity sodium ion battery positive electrode material / organic conductive polymer composite material and a preparation method thereof, and the preparation method comprises the following steps: S1, preparation of a chain product: adding water into an organic conductive polymer monomer for dissolving, adjusting the pH value of the solution to be acidic, adding an oxidizing agent, and stirring to obtain the chain product; inducing an organic conductive polymer monomer to generate a polymerization reaction to form a chain product; s2, preparation of precursor slurry: adding a sodium source, an iron source and a sulfur source into the solution for forming the chain product, and fully dissolving to form uniform precursor slurry; s3, preparation of precursor powder: drying the precursor slurry to realize solid-liquid separation so as to obtain dried precursor powder; and S4, high-temperature sintering: calcining the precursor powder in a protective atmosphere, and naturally cooling to obtain the Na < 2 + x > Fe < 2-x > (SO4) 3 / organic conductive polymer composite positive electrode material. The preparation method has the characteristics of high electronic conductivity, low specific surface area, high compaction density and excellent electrochemical performance.

The invention belongs to the technical field of lithium ion batteries, and relates to a high-load positive pole piece, a preparation method and a high-specific-energy battery. The positive pole piece is an electrode of a double-layer structure and comprises a current collector, a first electrode layer and a second electrode layer, wherein the first electrode layer and the second electrode layer are far away from the current collector. The specific gravity of the active substance small-particle single crystal ternary material of the first electrode layer is smaller than that of the large-particle polycrystalline ternary material, and the specific gravity of the active substance small-particle single crystal ternary material of the second electrode layer is larger than that of the large-particle polycrystalline ternary material. According to the dual-structure electrode plate, Li < + > migration paths are distributed in a tortuous gradient mode, large and small particles have a synergistic effect, a rapid electrolyte diffusion channel and a rapid lithium ion diffusion channel are achieved, the first electrode layer serves as a rapid transmission layer, the second electrode layer serves as a reaction balance layer, the concentration polarization problem in a thick electrode is effectively solved, the positive electrode capacity can be brought into play, and the service life of the electrode plate is prolonged. The battery energy density is improved. Meanwhile, the prepared positive electrode slurry is heated, high solid content is achieved, the use amount of a solvent is reduced, cracking of a high-load pole piece during coating is prevented, simultaneous coating and integrated preparation of the first electrode layer and the second electrode layer are achieved through the double-layer coating die head, and the interface internal resistance is reduced.

The present invention relates to a Mo-doped polyanion positive electrode material, a preparation method and an application. The chemical general formula of the Mo-doped polyanion positive electrode material is: Na b Mn x T i y Mo a M z (PO4)3; M is an element co-doped with Mo, including: Fe 3+ , Zn 2+ ,Mg 2+ , Ni 2+ , Li + , Al 3+ , Si 4+ , Zr 4+ ,Cr 3+ , Nb 5+ , Sc 3+ One or more of; the valence state of the element Mo is +6, where Mo 6+ The doping of Na + The migration barrier of the Mo-doped polyanion cathode material is Na + The Mn element migrates through three pathways, including: from the Na1 position to the Na2 position in the NAS I CON structure, through the gap between the PO4 tetrahedron and the MO6 octahedron, and across the channel between adjacent MO6 octahedrons, thereby causing the valence state of the Mn element used for charge compensation in the process of sodium insertion and extraction in the positive electrode material to be in the Mn 2+ ‑Mn 3+ ‑Mn 4+ Transition between.

The invention belongs to the field of solid electrolytes of all-solid-state lithium ion batteries, and particularly relates to a fluoride solid electrolyte, a preparation method of the fluoride solid electrolyte and application of the fluoride solid electrolyte in all-solid-state lithium ion batteries and composite positive electrodes of the all-solid-state lithium ion batteries, and the fluoride solid electrolyte is obtained by one-step synthesis of LiCl, Li2O and FeF3 through high-energy ball milling reaction; the ionic conductivity of the fluoride solid-state electrolyte reaches 2.8 mS cm <-1 >, and the fluoride solid-state electrolyte is used as a positive electrode supporting electrolyte in an all-solid-state lithium battery, so that the energy density of an electrode layer is improved; the fluoride solid electrolyte material has reversible capacity exceeding 250 mAh g <-1 > at the same time; when the fluoride solid electrolyte capable of contributing capacity is used as a positive electrode supporting electrolyte to be matched with a ternary positive electrode material, the specific capacity of the positive electrode layer of the all-solid-state lithium battery is improved by 20% or above, the energy density is improved by 15% or above, and the cycling stability of the all-solid-state lithium battery under high cut-off voltage is remarkably improved.

The present application belongs to the field of battery material technology, and specifically relates to a dry high-load composite positive electrode sheet with gradient distribution and a preparation method thereof, wherein the conductive carbon material, multi-size oxide solid electrolyte particles, and positive electrode active material are pre-mixed and dispersed at high speed to obtain a first powder; a binder is added to the first powder, and a low-temperature and low-speed dispersion treatment is performed to obtain a second powder; the second powder is subjected to a heat preservation treatment to obtain a pre-fiberized second powder; the binder is fiberized and other components are uniformly dispersed to form a third powder; the third powder is subjected to a multi-stage hot rolling treatment to obtain a first electrode membrane; steps 1-5 are repeated to adjust the component ratio to prepare a second electrode membrane; the first and second electrode membranes and the carbon-coated aluminum foil current collector are stacked and rolled in sequence to obtain a high-load composite positive electrode sheet with gradient distribution. The present application realizes gradient distribution preparation, improves the lithium ion diffusion rate, uniform electric field distribution, improves the rate performance of thick electrodes and the adhesion of the electrode sheet, and prevents shedding.

This invention relates to a method for improving the consistency of battery cell sorting based on DC internal resistance time-domain response subdivision. The method includes: performing a DC internal resistance test on the battery cells to be sorted, the DC internal resistance test including constant current discharge of the battery cells to be sorted, and collecting voltage and current time series data of the battery cells to be sorted during the constant current discharge process. A time reference is determined for the constant current discharge to reach a target current steady state, and multiple response time intervals are determined based on the time reference. Using the EIS principle, a reference voltage value before constant current discharge and the interval voltage value corresponding to each response time interval are determined. Multiple time-domain segmented equivalent impedance parameters of the battery cells to be sorted are calculated. The battery cells to be sorted are then sorted according to the multiple time-domain segmented equivalent impedance parameters. This method can improve the consistency of DC load response among battery cells in the same group and is beneficial for improving the capacity utilization, power output, temperature rise dispersion, and cycle aging consistency after battery cell grouping.

This application proposes a layered cathode material, its preparation method, and a lithium-ion battery. The layered cathode material includes a lithium source, a manganese source, and a grain refiner. By adding a grain refiner to the raw materials, the layered cathode material has a larger half-maximum width at half-maximum (FWHM) and a smaller grain size, or an I(010) / I(021) intensity ratio in the range of 0.3 to 0.85. This shortens the lithium-ion diffusion path, which is beneficial for lithium-ion diffusion, thereby improving the rate performance, capacity utilization, and cycle stability of the material. The layered cathode material of this application is a primary particle and a single-crystal material. Compared with conventional polycrystalline materials, single-crystal materials do not have the anisotropic stress problem of polycrystalline materials. The stress distribution of single-crystal materials is uniform, and the mechanical stress is stable. Therefore, it has less expansion stress and less volume deformation during charge and discharge, which can reduce the generation of particle cracks and effectively delay the occurrence of failure.

This invention relates to a Cr and Br dual-element doped polyanionic sodium-ion battery cathode material, sodium iron phosphate pyrophosphate, its preparation method, and its application, belonging to the field of sodium-ion battery technology. The general chemical formula of the cathode material of this invention is: Na₄Fe₂O₃. 3‑x Cr x (PO4)2P2O7Br y Where 0 < x < 0.5, 0 < y < 0.7; the precursor wet gel is obtained through a sol-gel process, dried, and then sintered. This invention relates to a Cr- and Br-doped polyanionic sodium-ion battery cathode material, sodium iron phosphate pyrophosphate. The Cr dopant enhances bulk stability, while the gradient distribution of Br forms a fast ion conduction layer on the surface. The two elements together improve the rate capability and cycle performance of the sodium-ion battery. This provides a modification strategy of significant reference value for cathode materials that suffer from low discharge specific capacity and poor cycle performance at high rates due to electron conductance differences.

The invention provides a ternary positive electrode material and a preparation method thereof, a positive electrode and a lithium ion battery, belongs to the technical field of lithium ion batteries, and can at least partially solve the problem that the capacity exertion of the existing ternary positive electrode material is limited. The preparation method of the ternary positive electrode material comprises the following steps: performing first sintering on a first sintering raw material to obtain a first sintering product; the first sintering raw material comprises a ternary precursor, a main lithium source and lithium sulfate, and the ternary precursor comprises a nickel element, a cobalt element and a manganese element; carrying out second sintering on the second sintering raw material to obtain a second sintering product, and preparing the ternary positive electrode material by using the second sintering product, the second sintering raw material comprises the first sintering product.

The invention provides an all-solid-state battery capacity grading method which comprises the following steps: placing a battery in a capacity grading cabinet, and controlling the internal temperature of the capacity grading cabinet to reach a first preset temperature; performing low-current discharging operation on the battery at the first preset temperature, so that the voltage of the battery is reduced to a first preset voltage; low-current charging operation is carried out on the battery, so that the voltage of the battery is increased to a second preset voltage, and the second preset voltage is larger than the first preset voltage; the internal temperature of the capacity grading cabinet is controlled to be reduced to a second preset temperature, large-current charging operation is carried out on the battery, the voltage of the battery is made to be increased to a third preset voltage, and the third preset voltage is larger than the second preset voltage; controlling the internal temperature of the capacity grading cabinet to rise to a first preset temperature, discharging the battery, and reducing the voltage of the battery to a first preset voltage; and charging the battery to enable the voltage of the battery to meet the preset K value test voltage, and ending the capacity grading operation. By applying the method, the internal polarization degree of the battery in the charge-discharge process during capacity grading can be reduced, and the capacity grading process time is shortened.

The invention relates to the technical field of lithium ion batteries, in particular to a phosphate positive electrode material and a preparation method and application thereof. Provided is a phosphate-based positive electrode material having a minimum particle diameter of 80 nm or more and a particle diameter dispersion coefficient (PDI) of less than 0.4. The minimum particle size of particles of the phosphate positive electrode material is controlled to be greater than or equal to 80nm, so that fine powder particles less than 80nm cannot appear in the particles, and the stability of a crystal structure of the material is improved, so that the overall thermal stability and cycle performance of the material are improved; the particle size dispersion coefficient PDI is further controlled to be less than 0.4, and when the particle size dispersion coefficient is smaller, the distribution of the positive electrode material is more uniform, so that the phosphate positive electrode material with narrow particle size distribution and uniform particle size is obtained, the processing performance of the material is effectively improved, and the rate cycle stability is improved.

This invention discloses a composite anode material for an all-solid-state lithium-ion battery, its preparation method, and the all-solid-state lithium-ion battery itself, relating to the field of all-solid-state lithium-ion battery technology. The composite anode material comprises a silicon skeleton and multiple functional coating layers sequentially covering the outer surface of the silicon skeleton. The pore size and porosity of the silicon skeleton gradually increase from the inside out. The multiple functional coating layers, from the inside out, sequentially include a carbon layer, an ion-conducting layer, and an interface protection layer, wherein the ion-conducting layer is a composite material of a sulfide solid electrolyte and a lithium-containing compound. The silicon skeleton of this invention has a non-uniform pore distribution. This pore distribution structure allows the loose outer layer of the skeleton to effectively absorb stress, thereby more effectively protecting the structural integrity of the core region. This application achieves a synergistic effect of stress buffering, ion transport, and interface stabilization through multiple functional coating layers, suppressing the possibility of silicon anode failure and effectively extending the cycle life of the battery.

The invention provides a composite positive electrode plate, a composite positive electrode structure, an all-solid-state battery cell and an all-solid-state battery. The composite positive electrode plate comprises a positive electrode layer and a solid electrolyte layer coated on one surface of the positive electrode layer; the positive electrode layer is prepared by rolling a material comprising a positive electrode active material by a dry method; and the solid electrolyte layer is prepared by coating one surface of the positive electrode layer with a wet method. According to the invention, the high-load positive electrode layer prepared by a dry method is coated with a layer of uniform ultrathin solid electrolyte slurry by a wet method, so that the composite positive electrode plate is formed, the performance advantages of an all-solid-state battery can be exerted, and relatively high energy density can be achieved.

In order to solve the problem that an existing positive electrode active material is insufficient in interface stability and conductivity, the invention provides a positive electrode material which comprises positive electrode particles and a graphene coating layer located on the outer sides of the positive electrode particles, and the graphene coating layer is a lithium carbonate and boron doped graphene composite layer. Meanwhile, the invention also discloses a preparation method of the positive electrode material, and a battery and an electric device comprising the positive electrode material. The positive electrode material provided by the invention has relatively excellent cycling stability, electronic conductivity and ion diffusion performance, and is beneficial to enhancing capacity exertion under high-rate charge and discharge conditions.

The invention discloses an alkaline secondary battery current collector base band and application thereof.The current collector base band comprises a metal base band, a plurality of burr units are evenly distributed on the metal base band in an array mode, and each burr unit is composed of front trapezoid burrs and back trapezoid burrs which are symmetrically arranged; long bottom plates of the front trapezoid burrs and long bottom plates of the back trapezoid burrs are adjacent and parallel to each other, front trapezoid burr long bottom edges formed by the front trapezoid burrs are connected with the metal base band, front trapezoid burr short bottom edges form front trapezoid burr ends, and back trapezoid burr long bottom edges formed by the back trapezoid burrs are connected with the metal base band. And the reverse trapezoidal burr short bottom edge forms a reverse trapezoidal burr end part. The current collector base band adopting a specific trapezoidal burr bidirectional arrangement mode effectively improves the conductivity of the polar plate and reduces the battery resistance, so that the assembled alkaline secondary battery has high rate performance, long cycle service life and other electrical properties and high specific energy, and meanwhile, the requirements of high power and high specific energy of the battery are met.

The present application discloses a ternary positive electrode active material and a preparation method thereof, a secondary battery, a battery module, a battery pack and an electric device containing the same. The ternary positive electrode active material comprises a nickel-rich layered oxide positive electrode active material, the surface of which is co-coated with an oxygen ion conductor and an oxide additive; the chemical composition of the nickel-rich layered oxide positive electrode active material is LiNi x Co y A z O2, wherein A = Mn or Al, 0.6 ≤ x < 1, 0 < y ≤ 0.2, z = 1-x-y. In the technical solution of the embodiment of the present application, the high-nickel ternary layered oxide positive electrode active material is co-coated and modified by synergistically introducing oxides and oxygen ion conductors to improve the material interface stability, improve the capacity loss problem, and make the battery exhibit excellent electrochemical performance.

The invention discloses a fast-filling type ternary precursor material and a preparation method and application thereof, the precursor material is spherical or sphere-like particles, the chemical formula of the precursor material is NixCoyMnz (OH) 2 or NixCoyMnzCO3, x is more than or equal to 0.1 and less than or equal to 0.8, y is more than or equal to 0.1 and less than or equal to 0.3, z is more than or equal to 0.1 and less than or equal to 0.8, and x + y + z = 1; the nitrogen element content in the precursor material is distributed at each part of the material in a gradient concentration manner from low to high from inside to outside, the core represents the precursor material when the particle size D50 reaches 50% of the target D50, the nitrogen content of the core is 0.11-0.52 wt%, and the nitrogen content of the shell is 0.61-1.92 wt%. The ternary precursor material and the lithium source are mixed and sintered to form the positive electrode material, so that the positive electrode material has a core-shell structure with a compact inner part and a low specific surface and a loose outer part and a high specific surface, and the structure has good resistance to stress deformation generated by high-voltage charging and discharging; meanwhile, the loose shell structure with the high specific surface area is beneficial for increasing the wettability of the material and an electrolyte and lithium battery active sites, so that the fast charging performance and the cycling stability of the material are improved.

The invention relates to the technical field of preparation of current collectors of lithium metal batteries, in particular to a preparation method of a current collector of a lithium metal battery, which comprises the following steps of: 1, preparing a vertical channel current collector by adopting a phase inversion method; and 2, preparing the vertical channel porous current collector by using the Kirkendall effect by taking the vertical porous current collector as a template. Through the Kirkendall effect, the mutual diffusion effect between two metal atoms with different diffusion rates and diffusion coefficients is achieved, and through long-term diffusion, a large number of Kirkendall holes can be formed in the contact surface of the two metals; the three-dimensional porous vertical current collector prepared by simply heating the diffusion couple has cavities which penetrate through the interior of the copper foil and are connected with each other, the three-dimensional porous vertical current collector has more advantages when being used as a current collector of a lithium metal battery, side reactions between lithium metal and electrolyte are greatly reduced, and the current density is also reduced due to the fact that the electrode area is increased for a three-dimensional structure of the three-dimensional porous vertical current collector.

The present invention provides a composite lithium iron phosphate positive electrode material and a preparation method and application thereof. The preparation method comprises the following steps: (1) mixing lithium ferrite powder and ferrous phosphide and performing a primary granulation treatment to obtain first particles, and performing a one-step roasting treatment to obtain a precursor A; (2) mixing lithium ferrite powder and a carbon source and performing a secondary granulation treatment to obtain second particles, and performing a two-step roasting treatment to obtain a precursor B; (3) compounding the precursor A and the precursor B, adding a carbon source, and performing a calcination treatment to obtain the composite lithium iron phosphate positive electrode material. The lithium iron phosphate positive electrode material of the present invention has a high compaction density of the pole piece, excellent rate performance under low temperature conditions, effectively improving the LFP capacity while improving the material stability, and the preparation method is simple in process, low in production cost, energy-saving and high-efficiency, and suitable for industrial production.

The invention discloses a cylindrical battery and a power utilization device, and belongs to the technical field of new energy materials. By adopting an in-situ polymerization technology, a compact and continuous quasi-solid electrolyte network is constructed in the cylindrical roll core, so that the safety pain points that a traditional liquid lithium ion battery is easy to leak and inflammable and explosive are fundamentally solved, and meanwhile, the technical bottlenecks that a solid-solid interface of a solid-state battery is poor in contact and large in impedance are overcome; according to the battery system, atomic-scale close contact of the electrolyte and the electrode particles is realized, the intrinsic safety and the energy density of the battery are remarkably improved while high ionic conductivity is ensured, and the battery system is particularly suitable for the power and energy storage fields with extremely high safety requirements.