17results about How to "Improve high temperature cycle performance" patented technology

The invention relates to the technical field of preparation of lithium ion battery positive electrode materials, in particular to an in-situ composite perovskite positive electrode active material and a preparation method and application thereof. The preparation method of the in-situ composite perovskite positive electrode active material comprises the following steps: mixing a lithium compound, a phosphate compound, a carbon source, a rare earth metal compound, a cobalt compound and / or a nickel compound with an iron compound or an iron compound and a manganese compound in a solvent to obtain mixed slurry; carrying out spray drying on the mixed slurry to obtain composite precursor powder; and sequentially carrying out pre-sintering treatment and formal sintering treatment on the composite precursor powder to prepare the in-situ composite perovskite positive electrode active material. Through the solution mixing and co-sintering process, the in-situ compounding of the perovskite phase and the positive electrode base material at the atomic scale is realized, the interface bonding and ion transmission efficiency between the perovskite phase and the positive electrode base material are remarkably enhanced, and the cycling stability is remarkably improved while the high capacity of the obtained positive electrode active material is maintained.

In order to overcome the existing technology of non-aqueous electrolytic lithium salt using lithium bis(fluorosulfonyl)imide, the battery stability, cycle performance and safety performance are deteriorated, the application provides a non-aqueous electrolyte and a lithium ion secondary battery, the non-aqueous electrolyte comprises electrolyte lithium salt, additive and organic solvent, wherein the electrolyte lithium salt comprises lithium hexafluorophosphate LiPF6 and lithium bis(fluorosulfonyl)imide, the additive comprises unsaturated phosphate ester compound, by adjusting the molar concentration Ca, Cb of lithium hexafluorophosphate LiPF6 and lithium bis(fluorosulfonyl)imide in the non-aqueous electrolyte and the mass percentage Mp of the unsaturated phosphate ester compound in the non-aqueous electrolyte, and satisfying the relationship formula, the non-aqueous electrolyte prepared can effectively inhibit the corrosion of lithium bis(fluorosulfonyl)imide to the battery electrode, and further improve the high-temperature cycle performance, initial capacity and safety performance of the lithium ion secondary battery.

The application provides a semi-solid battery and a preparation method thereof. The semi-solid battery comprises a positive electrode sheet, a negative electrode sheet, a separator and a semi-solid electrolyte. The positive electrode sheet comprises a positive electrode material layer, and the positive electrode material layer comprises a positive electrode active material. The semi-solid electrolyte comprises a gel polymer and an electrolyte solution. The gel polymer comprises monomer units from a polymerization monomer and a crosslinking agent, wherein the polymerization monomer is selected from at least one of the compounds shown in formula I. The semi-solid battery satisfies: A / B / C > 1, wherein A is the area density of the positive electrode active material, mg / cm 2 ; B is the mass percentage of the gel polymer based on the mass of the semi-solid electrolyte, %; and C is the residual amount of the polymerization monomer in the semi-solid electrolyte, %. The semi-solid battery has high room temperature cycle performance and high temperature cycle performance.

This application relates to a high-nickel cathode material and its preparation method, and a lithium-ion battery. The chemical formula of the high-nickel cathode material is Li. σ Ni a Co b Mn c M1 x M2 y M3 z O 2+α Wherein, 0.80<σ<1.20, a+b+c+x+y+z=1, 0.7<a<1.0, 0<b<0.05, 0<c<0.3, 0<x<0.3, 0<y<0.3, 0<z<0.3, 0<α<0.1, M1, M2, and M3 are each independently including at least one of Al, Co, Zr, Ti, Mg, Y, La, Sr, Ba, W, Mo, Nb, and Si, and M1, M2, and M3 are all different; the high-nickel cathode material includes a high-nickel material matrix and a coating layer. Cu-Kα rays are used to perform XRD measurements on the high-nickel material matrix and the high-nickel cathode material, respectively. The intensity of the (104) diffraction peak appearing in the diffraction angle range of 44-45° is recorded as I. b (High-nickel material matrix) and I c (High-nickel cathode material), the unit of diffraction peak intensity is counts, let the diffraction peak intensity difference P = I c -I b 0 < P < 1000. The high-nickel cathode material provided in this application has better high-temperature cycling performance and a low DC internal resistance growth rate.

The invention provides an electrolyte and a secondary battery, the electrolyte comprises a solvent, an additive and an electrolyte, the solvent comprises fluoroethylene carbonate, a compound as shown in a formula I and a compound as shown in a formula II, the mass ratio of fluoroethylene carbonate to fluorochain ester is 1: (0.33-4), the mass ratio of the compound as shown in the formula I to the compound as shown in the formula II is 1: (0.33-3), and the additive and the electrolyte are used for preparing the electrolyte. Based on the mass of the electrolyte, the mass percentage A of the fluorinated solvent is more than or equal to 20% and less than or equal to 80%; the additive comprises tetraethylene silane, based on the mass of the electrolyte, the mass percentage of the tetraethylene silane is M, and M is larger than or equal to 0.02% and smaller than or equal to 3%. Through the arrangement, the fluoroethylene carbonate, the compound as shown in the formula I, the compound as shown in the formula II and the tetraethylene silane have a synergistic effect, so that the electrolyte has proper viscosity and relatively high oxidation resistance, and meanwhile, the negative influence of defluorination on a positive electrode can be improved; therefore, the high-temperature cycle performance and the high-temperature storage performance of the secondary battery under the high-pressure condition are improved.

The application provides a battery, a battery pack and a power utilization device, the battery comprising a negative electrode sheet, the negative electrode sheet comprising a negative electrode current collector and a negative electrode active material layer arranged on at least one side of the negative electrode current collector; the negative electrode active material layer comprising a negative electrode active material; the negative electrode active material comprising a negative electrode active substance and a coating layer existing on the surface of the negative electrode active substance, the coating layer comprising amorphous carbon; and a SEI film existing on the surface of at least part of the negative electrode active material of the negative electrode active material layer, the SEI film containing fluorine elements and oxygen elements, and the atomic ratio of the oxygen elements to the fluorine elements in the SEI film being (1.5-7.5):1. The application can improve the fast charging performance, high-temperature storage and high-temperature cycle performance of the battery.

This invention discloses a high-nickel ternary cathode material, its preparation method, and a lithium battery, relating to the field of lithium battery technology. A coating layer is formed on a high-nickel ternary cathode material substrate using fluorinated liquid crystal molecules. These fluorinated liquid crystal molecules have a lower melting point, making it easier to form an ideal coating layer compared to traditional coating agents. Furthermore, the liquid crystal molecules exhibit better solvent and electrolyte corrosion resistance, significantly improving the high-temperature cycling performance of the cathode material.

This invention discloses an electrolyte and its lithium-ion battery, comprising a lithium salt, an organic solvent, and an additive; the additive includes at least compound A, the content of which is 0.5% to 8% of the total weight of the electrolyte; the general structural formula of compound A is as follows: In formula I, at least one of R1, R2, and R3 is an alkoxyalkyl group with 1 to 20 carbon atoms, at least one of which is O-TMS, and the remaining one is selected from one of an alkoxyalkyl group with 1 to 20 carbon atoms, CN-, -CH2C, -CH2CH2CN, -CH2CH2CH2CN, -CH2CH2CH2CH2CN, and O-TMS, wherein TMS is Si-(CH3)3. In this invention, compound A is added to the electrolyte, and the PF5 generated from LiPF6 in the electrolyte reacts with trace amounts of water to generate HF. The HF is cleared by the siloxane functional groups in compound A, wherein the fluoride (F... ‑ ) is captured by silicon (Si) to generate TMSF, H + It is also captured by oxygen (O) to form HPO, thereby improving high-temperature cycling performance and high-temperature storage performance under high voltage.

The application provides an electrolyte, a battery, a battery pack and a power utilization device, the electrolyte comprising a quinoline additive, the quinoline additive having a quinoline ring structure, and at least one isocyanate group being directly covalently bonded to a carbon atom of the quinoline ring structure. The application can efficiently remove trace moisture and acidic substances inside the battery, inhibit electrode-electrolyte interface side reactions, and thus improve long-term stability of the electrolyte and high-temperature cycle performance of the battery.

This invention provides a battery comprising an electrolyte and a negative electrode, wherein the negative electrode active material comprises a silicon-containing material; the electrolyte comprises a first additive and a second additive, the first additive comprising fluoroethylene carbonate, and the second additive comprising a compound having a structure of Formula 1, wherein R1-R3 are each independently selected from substituted or unsubstituted C1-C10 alkyl, substituted or unsubstituted C2-C10 alkenyl, or substituted or unsubstituted C2-C10 alkynyl groups, and at least one unsaturated group is included in R1-R3. The battery provided by this invention uses silicon material as the negative electrode and exhibits excellent room temperature and high temperature cycling performance, as well as high temperature storage performance.

The invention provides a secondary battery and electric equipment. The secondary battery comprises a positive pole piece and an electrolyte, the positive pole piece comprises a positive current collector and a positive active material layer arranged on at least one surface of the positive current collector, the positive active material layer comprises a positive active material, the positive active material comprises lithium iron phosphate, and the lithium iron phosphate comprises secondary particles formed by gathering primary particles. The average particle size of the primary particles is D nm, the specific surface area of the lithium iron phosphate is BET m < 2 > / g, and D / BET is greater than or equal to 2 and less than or equal to 30; the electrolyte comprises an additive and an organic solvent, the additive comprises lithium fluorosulfonate, the mass percentage of the lithium fluorosulfonate in the electrolyte is a%, 0.05 < = a < = 0.5, the organic solvent comprises ethyl propionate, and the mass percentage of the ethyl propionate in the organic solvent is greater than or equal to 30%. The low-temperature discharge performance, the high-temperature storage performance and the high-temperature cycle performance of the secondary battery are improved by matching the proper positive electrode active material and the electrolyte.

The application provides a cyano-containing phosphite salt additive, characterized in that the additive has a structure as shown in formula (I) and / or formula (II). The cyano-containing phosphite salt additive with a specific structure and composition designed by the application is used as a lithium ion battery lithium supplement agent, is used for supplementing active lithium lost in the first cycle of lithium ion battery self-sacrifice charging and discharging, improves the first cycle coulomb efficiency, and after the end of delithiation, the phosphorous acid and -CN functional groups of the cyano-containing phosphite salt additive are dissolved in electrolyte, participate in the formation of an SEI film, inhibit the decomposition of electrolyte, and improve the high-temperature cycle performance of the battery. In addition, the phosphite salt organic lithium supplement agent has high water oxygen stability, and solves the problem of harsh use and storage conditions of traditional positive electrode lithium supplement agents.

The application discloses a secondary electrolyte injection method and an alkali metal ion battery thereof, and the secondary electrolyte injection method comprises the following steps: injecting a first electrolyte into a semi-finished product battery cell and sealing, aging, standing and forming, wherein the first electrolyte comprises an electrolyte salt, a non-aqueous solvent and a basic additive; continuously injecting a second electrolyte, and obtaining an alkali metal secondary battery after secondary sealing and capacity distribution; the second electrolyte comprises the first electrolyte, a first additive and a second additive; the first additive is lithium fluorosulfonate or sodium fluorosulfonate, and the second additive is at least one of a fluorine-containing pyridine compound shown in the following formula (I) or a fluorine-containing imidazole compound shown in the following formula (II), and the specific structure is referred to the description. Through the secondary injection of the first additive and the second additive, the high-temperature cycle performance, the high-temperature storage performance and the low-temperature cycle performance of the battery can be improved, the rate discharge performance of the battery is improved, and the power of the battery is improved.

The invention relates to a lithium ion battery, which comprises a positive plate, a negative plate and an electrolyte, the electrolyte comprises a first additive anhydride additive, a second additive mannitol carbonate sulfate and ethyl propionate; a negative active material in the negative plate comprises silicon carbon; the lithium ion battery meets the following relational expression: S1 / 0.2 < 150A1 + 120A2 + 13A3 < S1 / 0.06; wherein S1 is the mass percentage of ethyl propionate in the solvent, A1 is the mass percentage of the first additive in the electrolyte, A2 is the mass percentage of the second additive in the electrolyte, and A3 is the mass percentage of silicon carbon in the negative electrode active material, and the lithium ion battery has good high-temperature cycle performance and good storage performance.

The invention provides an electrolyte and a secondary battery. The electrolyte comprises a solvent, an electrolyte and an additive, wherein the additive comprises a first component and a second component; the first component is selected from fluoroethylene carbonate, the second component is selected from a compound shown as a formula I, based on the mass of the electrolyte, the mass percentage content of the first component is a, a is more than or equal to 5% and less than or equal to 20%, the mass percentage content of the second component is b, and b is more than or equal to 0.1% and less than or equal to 2%. The synergistic effect of the first component and the second component can improve the high-temperature cycle performance, the high-temperature storage performance and the low-temperature discharge performance of the secondary battery and reduce the impedance.

The invention provides an electrolyte and a battery. The electrolyte is used for a battery containing a lithium supplement agent, and the lithium supplement agent can be decomposed to generate active oxygen; the electrolyte comprises an additive shown in the formula 1, in the formula 1, R1 and R2 independently comprise a substituted or unsubstituted C1-C4 alkyl group, a C2-C4 alkenyl group, a C2-C4 alkynyl group and a substituted or unsubstituted phenyl group, and R3 comprises a C1-C4 alkyl group. The problems of reducing the expansion rate of the battery and inhibiting lithium precipitation can be solved, and the high-temperature cycle performance and the storage performance of the battery are improved.

This invention relates to the field of secondary battery technology and discloses a wound battery. The negative electrode sheet contains silicon-based material with a silicon content of ≥3% by mass. The negative electrode sheet has multiple negative electrode tabs. The arc segment of the positive electrode sheet has a first groove. The arc segment of the negative electrode sheet has a first concave-convex structure including a first protrusion and a first recess, and the projection of the first protrusion is at least partially located within the first groove. This invention reduces internal resistance and uniforms current distribution through the multi-tab structure; mitigates heat generation from lithium desorption through the first groove; releases expansion stress through the first concave-convex structure; and effectively suppresses heat accumulation in the arc region by forming a heat dissipation space through the cooperation of the first protrusion and the first groove, thereby improving the rate performance and high-temperature cycle performance of the battery.