6results about How to "Improve high temperature cycle performance" patented technology

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.

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.

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 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.