38results about How to "Improve battery cycle performance" patented technology

The present invention provides a lithium secondary battery having excellent battery characteristics such as battery cycling property, electrical capacity and storage property.

The present invention relates to a nonaqueous electrolytic solution for lithium secondary batteries in which an electrolyte salt is dissolved in a nonaqueous solvent, the nonaqueous electrolytic solution comprising a formic ester compound having a specific structure in an amount of 0.01 to 10% by weight of the nonaqueous electrolytic solution, and a lithium secondary battery using the same.

The invention discloses a preparation method of a high-capacity and high-rate lithium battery anode material, and is characterized in that the preparation method includes the following steps: stirring needle-coke and a binder in a high-speed stirrer evenly; pressing the mixture after stirring under an ultra-high pressure of an isostatic pressing machine, to obtain an initially-pressed block; heating and sintering the initially-pressed block under a nitrogen atmosphere protection, cooling, and then crushing and shaping the semi-finished block, to obtain a carbon powder; and carrying out high temperature graphitization on the carbon powder, cooling, and then carrying out iron removal screening, to obtain the graphite powder with high rate, high capacity and high compaction. The graphite anode material prepared by the preparation method has the characteristics of high capacity, high rate and good cycling performance.

Disclosed is a lithium secondary battery which is excellent in cycle characteristics, battery capacity and battery characteristics such as storage characteristics. A nonaqueous electrolyte solution for lithium secondary batteries wherein an electrolyte salt is dissolved in a nonaqueous solvent is characterized in that a formate compound having a specific structure is contained in the nonaqueous electrolyte solution in an amount of 0.01-10 weight% relative the nonaqueous electrolyte solution. A lithium secondary battery uses such a nonaqueous electrolyte solution.

A sodium-ion battery multi-element positive electrode material and a preparation method thereof are provided. The chemical general formula of the sodium-ion battery multi-element positive electrode material is Na<0.67>Mn<x>Mg<y>Ni<z>W<n>O<2-q>B<q>, 0.65 <= x <= 0.8, 0 < y < = 0.2, 0 < z < = 0.2, 0 < n < = 0.2, 0 < q < = 0.05, and x + y + z + n = 1. The preparation method comprises the following steps: adding a sodium source, a manganese source, a nickel source, a magnesium source, a tungsten source and a boron source into citric acid to generate sol, drying the sol to obtain gel, and carryingout heat treatment on the gel to obtain the sodium-ion battery multi-element positive electrode material. According to the preparation of the sodium ion battery multi-element positive electrode material, a cation or anion doping or co-doping means is utilized, so the structural stability and the conductivity of the material are enhanced. The material has good rate capability and excellent cyclingstability, the required raw materials are rich in resource and low in cost, and the preparation method is simple and controllable.

The invention belongs to the technical field of lithium ion batteries, and particularly relates to a non-aqueous electrolyte and a lithium ion battery. The invention provides an additive, the additive is a phosphate compound containing thienyl, and the phosphate compound containing thienyl has a structure shown as a formula I; the invention also discloses a non-aqueous electrolyte and a lithium ion battery; and according to the additive and the non-aqueous electrolyte provided by the invention, the technical defects that the lithium ion battery is easy to break out a fire and explode under the conditions, such as high temperature, overcharging, acupuncture penetration and extrusion, of the lithium ion battery can be solved.

Good cycle performance is obtained with a non-aqueous electrolyte secondary battery having a positive electrode, a negative electrode, and a non-aqueous electrolyte. The positive electrode contains as positive electrode active material a mixture of a lithium-manganese composite oxide and a lithium-transition metal composite oxide containing at least Ni and Mn as transition metals. The negative electrode contains as a negative electrode active material a material capable of intercalating and deintercalating lithium. Charging of the non-aqueous electrolyte secondary battery is controlled so that the end-of-charge voltage becomes higher than 4.3 V.

The invention provides a sodium ion positive electrode material with a ternary layered structure, and a preparation method for the sodium ion positive electrode material. The sodium ion positive electrode material comprises Na2/3Ni1/3TixMn(2/3-x)O2, wherein the x is greater than 0 and less than 2/3. The sodium ion positive electrode material provided by the invention is provided with the ternary layered structure; when the sodium ion positive electrode material is charged or discharged at the 0.1 C, the specific discharge capacity is greater than 120mAhg-1; and the retention rate of the specific capacity reaches greater than 90% after the sodium ion positive electrode material is charged or discharged for 100 times.

The present invention provides a lithium silicon oxide particle having a core-shell structure. The lithium silicon oxide particle comprises: an inner core particle comprising a lithium silicate compound matrix and an elemental silicon nanoparticle, wherein the molar ratio of lithium element/silicon element in the inner core particle is X, the molar ratio of oxygen element/silicon element is Y, 0.1 < = X < 2, and 0.5 < = Y < = 1.5; a silicon carbide shell layer which coats the inner core particle; and a conductive carbon layer, wherein the silicon carbide shell layer is coated with the conductive carbon layer. The lithium silicon oxide particle has the characteristics of good water resistance, low expansion rate, long cycle life, high coulombic efficiency and the like.

Separators, materials, and processes for producing electrochemical cells, for example, lithium (Li) metal batteries, and electrochemical cells produced therefrom. Such a separator includes a permeable membrane formed of a first polymer that is hydrophobic and has oppositely-disposed first and second surfaces, a second polymer that is hydrophilic and is incorporated into the first surface of the first polymer so that the first surface of the first polymer is a hydrophilic surface, and a conductive composite layer on the hydrophilic surface. The composite layer contains at least one layer of a carbonaceous material and an aqueous binder that binds the carbonaceous material together and to the hydrophilic.

The invention discloses a sodium-ion battery nickel-based precursor capable of being used for filling a conductive material and a positive electrode material. The chemical formula of the precursor is NixMyMoz (OH) 2, wherein x is greater than or equal to 0.6 and less than 1, y is greater than 0 and less than or equal to 0.2, z is greater than 0 and less than or equal to 0.2, x + y + z = 1, and M is Cr or Nb. The chemical formula of the positive electrode material is NamNixMyMozO2, wherein m is greater than or equal to 0.67 and less than or equal to 1, and the conductive material is a conductive polymer material. According to the invention, the loose and porous precursor of the sodium-ion battery is prepared by adopting an industrially mature precursor preparation process, then the loose and porous positive electrode material is synthesized by adopting a high-temperature solid-phase method, and finally, the conductive material is filled into internal gaps of the positive electrode material, so that the conductivity of the conductive material is fully exerted, mechanical stress accumulation of the positive electrode material in the charging and discharging process is buffered, and the effect of protecting the structure of the positive electrode material is achieved. The traditional manganese element is not used, the influence of structural collapse and capacity fading caused by the Jahn-Taller effect of the manganese element is reduced, meanwhile, the nickel content is increased, the nickel and Mo, Cr or Nb are coordinated, and the structural stability and electrochemical performance of the positive electrode material are further improved.

The invention discloses a preparation method of a layered quaternary cobalt-free single crystal precursor and a positive electrode material. The chemical formula of the layered single crystal precursor is Ni < x > Mn < y > Ce < m > Zr < n > (OH) < 2 >, and the chemical formula of the single crystal positive electrode material is LiNi < x > Mn < y > Ce < m > Zr < n > O < 2 >, 1, 0lt; y is less than or equal to 0.2, 0lt; m is less than or equal to 0.2, 0lt; n < = 0.1, and x + y + m + n = 1. The layered quaternary cobalt-free single crystal precursor is prepared by adopting an industrially mature precursor preparation process. And then synthesizing the layered quaternary cobalt-free single crystal positive electrode material through a segmented high-temperature method. The layered quaternary precursor is composed of internal nickel manganese hydroxide with the size of 3-4 microns and external nickel manganese cerium zirconium hydroxide with the size of 1-1.5 microns, and is different from academic and industrial core-shell structures, and the interior of the precursor and the interior of the positive electrode material are dense. The dense layered structure and the element coordination effect improve the stability of the whole single crystal material on the bulk phase on one hand and play the coordination effect among the elements on the other hand, the cerium and zirconium on the outer layer effectively reduce side reactions, side effects caused by no cobalt are reduced, and the stability and the electrochemical performance of the single crystal material are further improved.

The invention discloses a water washing method and system for a high-nickel ternary cathode material. The water washing method of the high-nickel ternary cathode material comprises the following steps of preparing a high-nickel ternary cathode material matrix; mixing the high-nickel ternary cathode material matrix with water to obtain an electrolyte solution; and electrolyzing the electrolyte solution to remove residual alkali on the surface of the high-nickel ternary cathode material matrix. According to the technical scheme, lattice lithium on the surface of the material can be inhibited from being separated out, and the generation amount of waste water is reduced.

The invention discloses a composite nanofiber lithium battery diaphragm which has a coaxial three-layer structure, the outer layer is a TiO2 nano layer, the middle layer is a polyacrylonitrile (PAN) pre-oxidized fiber layer, and the core layer is a polyimide (PI) fiber layer; the preparation method specifically comprises the following steps: by taking a PAA spinning solution as a core material and a PAN spinning solution as a shell material, preparing a PAN@PAA nanofiber membrane with a coaxial double-layer structure through coaxial electrostatic spinning; dipping the PAN@PAA nanofiber membrane in a TiOSO4 solution, taking out the PAN@PAA nanofiber membrane, and naturally airing the PAN@PAA nanofiber membrane to prepare a TiO (OH) 2 nanolayer@PAN@PAA nanofiber membrane; and carrying out heat treatment on the TiO (OH) 2 nano layer@PAN@PAA nano fiber membrane to obtain the coaxial three-layer structure TiO2@PAN pre-oxidized@PI composite nano fiber membrane. The composite diaphragm has excellent thermal stability, excellent mechanical performance, good electrochemical performance and battery cycle performance.

The invention provides a rapid and efficient lithium ion battery negative electrode homogenate stirring method. The method comprises the following steps: 1) adding a glue solution into powder while stirring; 2) continuing to add the glue solution, and stirring; (3) adding the glue solution and N-methyl pyrrolidone, and stirring; and 4) adding the butadiene styrene rubber, then adding the rest of the glue solution, and stirring. Compared with the prior art, the glue solution is divided into four parts, the mixing sequence of each step and the amount of the added glue solution are controlled, and the stirring speed and time of each step are controlled, so that uniform dispersion of the slurry is facilitated, and the fineness, stability and rheological property of the slurry and the cycle performance of a battery cell are improved.

The invention provides an application of a gallium-germanium nanowire as a lithium ion battery electrode material. The gallium-germanium nanowire comprises a simple substance germanium and a simple substance gallium, and an atomic ratio of the simple substance germanium to the simple substance gallium in the gallium-germanium nanowire is (4-9):1. The gallium-germanium nanowire as the electrode material of a lithium ion battery can improve the cell cycle performance and multiplying power performance of the lithium ion battery.

A method of manufacturing a secondary battery using lithium metal as a negative electrode, and more particularly, a method of manufacturing a secondary battery capable of removing an oxide film formed on a lithium metal by performing some initial discharges during the initial period of the activation process to thereby improve the cycling performance of the battery by allowing lithium to be uniformly precipitated. The result minimizes the reduction of ion conductivity by removing the oxide film formed on the surface of the lithium metal through the initial partial discharge and improves the battery cycle performance since the precipitation reaction of lithium becomes uniform.

The invention discloses a high-ionic-conductivity ultralow-moisture high-temperature-resistant surface-modified lithium ion battery diaphragm and a preparation method thereof.The lithium ion battery diaphragm is formed by coating of coating slurry, and the preparation method of the coating slurry comprises the following steps that firstly, a dispersing agent, water, a PTFE/CNTs nano composite material and amorphous LTO mixed powder are evenly mixed and subjected to ultrasonic treatment, and the surface-modified lithium ion battery diaphragm is obtained; according to the coating slurry, the amorphous LTO mixed powder and the PTFE/CNTs nano composite material are used for forming a mixed material, the amorphous LTO mixed powder and the PTFE/CNTs nano composite material are compounded to form brand-new slurry, the safety performance of the battery is improved, and meanwhile the cycle performance of the battery can be improved; meanwhile, the heat resistance of the lithium ion diaphragm can be effectively improved, the ionic conductivity is improved, and the moisture content of the diaphragm is reduced, so that the battery safety is improved, and the safety of an electric vehicle driven by a high-energy-density battery is further improved.