31results about How to "Reduce the risk of lithium analysis" patented technology

The invention discloses an electrode plate and a manufacturing method thereof, and an electrochemical device. The electrode plate comprises a current collector and further comprises active substance layers symmetrically arranged on the upper surface and the lower surface of the current collector respectively, and second active material layers respectively arranged on the first active material layers; and the current collector at the edges of the second active material layers forms a tab. By changing a traditional coating mode, two materials with different properties are coated on the current collector in a layered manner, so that the surface layer of the current collector has the capability of quickly removing and embedding lithium ions, the risk of lithium precipitation on the surface ofa pole piece is reduced, the safety performance of the battery is improved, the service life of the battery is prolonged, and the power performance of the battery is also improved.

The invention relates to a water-based high-viscosity glued diaphragm, a preparation method thereof and an application of the diaphragm in a battery. The water-based high-viscosity glued diaphragm comprises a base membrane, and a positive polymer layer and a negative polymer layer which are respectively arranged at two sides of the base membrane, wherein a positive ceramic layer is arranged between the base membrane and the positive polymer layer, and/or a negative ceramic layer is arranged between the base membrane and the negative polymer layer; a binder in the positive polymer layer and a battery positive electrode piece is the same type of binder, and a binder in the negative polymer layer and a battery negative electrode piece is the same type of binder. The diaphragm disclosed by theinvention has the characteristics of small coating amount of coatings on two sides, light and thin coatings, high cohesiveness and the like, so the shaping effect of a battery cell is optimal, and module boxing is facilitated; meanwhile, a module limiting effect is achieved. Moreover, the risk of hole blockage of the diaphragm is low, so the internal resistance of the battery cell is stable and controllable, the lithium precipitation risk is reduced, and the cycle life and safety performance of the battery cell are ensured.

The invention discloses a lithium ion battery intermediate tab roll core. The lithium ion battery intermediate tab roll core comprises an intermediate tab cathode plate, an intermediate tab anode plate and a diaphragm, two blank sections are arranged in the middle of a cathode material layer, a cathode tab is fixed at one blank section, the intermediate tab anode plate comprises an anode materiallayer, an anode tab is fixed at the blank section, and the intermediate tab cathode plate, the intermediate tab anode plate and the diaphragm are spirally wound and adhered together; and the anode material layer of the intermediate tab anode plate is wound and adhered with the cathode material layer of the intermediate tab cathode plate in a gapless manner through the diaphragm. According to the invention, the anode material layer of the intermediate tab anode plate is wound and attached to the cathode material layer of the intermediate tab cathode plate in a gapless manner through the diaphragm, namely the anode tab and the cathode material layer are avoided, the surface of the cathode material layer of the intermediate tab cathode plate, which faces the anode tab, is provided with a corresponding groove, and the anode tab is partially accommodated in the groove of the cathode material layer, so that the lithium separation risk caused by no anode at the welding position is avoided.

The invention discloses a negative prelithiated electrode. The negative prelithiated electrode comprises a metal current collector, and an active substance layer, a lithium supplementing layer and a functional polymer film protection layer which sequentially coat the surface of the metal current collector, wherein a functional polymer is a polymer containing a lithium-philic polar functional group. The invention discloses a preparation method of the negative prelithiated electrode. The preparation methodcomprises the following steps: S1, coating the surface of the metal current collector withthe active substance, and carrying out prelithiation treatment to obtain an intermediate electrode; and S2, mixing and stirring the functional polymer and an organic solvent for 6-10h, conducting standing for 12-24h, uniformly coating the surface of the intermediate electrode with a formed supernatant, and performing vacuum drying at 45-85 DEG C to obtain the negative prelithiated electrode. The risk that the lithium supplementing layer of the prelithiated electrode is oxidized can be effectively reduced, and the initial efficiency, the energy density, the cycling stability and the safety performance of a lithium ion battery are improved.

The invention provides an electrochemical device which comprises an electrode assembly composed of a first pole piece, a second pole piece and a diaphragm arranged between the first pole piece and the second pole piece, the first pole piece comprises a current collector, a tab and an active substance layer, the active substance layer is composed of a main body area and an edge area, the width of the edge area and the width of the main body area are w1 and w2 respectively, and w1/w2 is larger than 0 and smaller than or equal to 5%, the thicknesses of the edge area and the main body area are t1 and t2 respectively, t1 and t2 satisfy the relation equation that and 95% < = t1/t2 < = 100%. The edge area with the parameters is beneficial to improving the energy density of the electrochemical device, reducing the lithium precipitation risk and improving the safety of the electrochemical device. In addition, the invention also provides an electronic device.

The invention discloses a square coiled battery pole piece as well as a preparation method and a square soft package battery thereof. The preparation method comprises the following steps: coating, namely carrying out double-faced intermittent coating on a current collector by adopting battery slurry, so as to form more than two of slurry coating areas which are sequentially distributed at intervals in the length direction of the current collector, and reserving a blank area uncoated with the battery slurry at the tail part of each slurry coating area, wherein coating areal density of any slurry coating area is 90-160g/m<2>; and rolling and punching, namely after the double-faced intermittent coating is completed, carrying out rolling and punching treatment on the current collector coated with more than two slurry coating areas, thus the required square coiled battery pole piece is obtained. The scheme of the invention can overcome the defects of large polarization effect, poor batteryperformance and poor use security and realizes the beneficial effects of small polarization effect, good battery performance and good use security.

The preparation method specifically comprises the following steps: uniformly mixing a core-shell structure magnetic nano template which takes polyaniline as a shell and Fe3O4 as a core with a negative electrode material, a binder, a conductive agent and a solvent water to prepare negative electrode slurry, coating the surface of a current collector with the negative electrode slurry, and drying to obtain the lithium battery negative electrode plate. The preparation method comprises the following steps: preparing a thick electrode from magnetic nano Fe3O4, directionally assembling the magnetic nano Fe3O4 on the surface of a current collector by loading a magnetic field, recycling the magnetic nano Fe3O4 in the thick electrode through microwave heating and a magnetic recycling device, and constructing a three-dimensional network channel with high conductivity in the thick electrode to effectively improve the conductivity of the electrode, shorten ion and electron migration paths and improve the conductivity of the electrode. A multi-dimensional open permeation channel is provided, the wettability of an electrolyte is enhanced, the electrode tortuosity is reduced, the gradient porosity is generated, a molecular-level channel beneficial to lithium ion transportation is formed, and high-speed conduction of lithium ions is promoted.

The invention provides a thick electrode structure of a lithium ion battery. The thick electrode structure comprises a coating machine die head, and a gap between a coating die head lip and a current collector is formed between the coating machine die head and a negative current collector; the coating machine die head is provided with a plurality of coating machine die head cavities, and the cavities are not communicated with one another; negative electrode slurry with different components is extruded from a slit of the coating machine die head lip, so that negative electrode slurry with different components can be formed, the current collector is wet-coated with the negative electrode slurry with different components at the same time; two sides of a dressing layer of a rolled electrode roll are respectively provided with a non-tab side blank space and a tab side blank space, and electrode thickness direction grooves are arranged along an electrode thickness direction; groove gaps are formed between the electrode thickness direction grooves, and the electrode thickness direction grooves are formed in the surface of each electrode piece. According to the thick electrode structure of the lithium ion battery, the infiltration of electrolyte from the surface of the dressing layer to the current collector is facilitated, the binding power between the dressing layer and the current collector and the rate and cycle performance of the thick electrode battery are improved, and the lithium precipitation risk under high-rate charge and discharge is reduced.

The invention provides an electrochemical device and an electronic device. The electrochemical device comprises a positive pole piece, a negative pole piece and an isolating membrane arranged between the positive pole piece and the negative pole piece. The electrochemical device satisfies at least one of the following conditions (a)-(d): (a) a protective coating layer is provided on the surface of at least one side of the separator, the protective coating layer including a blocking agent; (b) the isolating membrane comprises a blocking agent; (c) the negative pole piece comprises a negative active material layer, and a protective coating is arranged on the surface of the negative active material layer; (d) the negative electrode active material layer comprises core-shell structure particles, the shells of the core-shell structure particles comprise at least one of an inorganic material or a polymer, and the cores of the core-shell structure particles comprise the blocking agent. The blocking agent comprises at least one of red phosphorus, sulfur, iodine or selenium. According to the embodiment of the invention, the lithium precipitation risk can be reduced, and the cycle performance and safety performance of the electrochemical device are improved.

The invention provides a battery charging method, which comprises the following steps: in a first stage, charging a battery to a first stage voltage in a first charging mode or a second charging mode; and in the second stage, chaging the battery to a second-stage voltage in a third charging mode, wherein the second-stage voltage is larger than the first-stage voltage, and the third charging mode adopts the first charging mode or the second charging mode. The invention further provides an electronic device and a storage medium. According to the charging method provided by the invention, the charging speed of the battery in the charging process can be improved, and the total charging time is shortened.

The invention discloses a manufacturing method of a battery roll core and a battery roll core. The manufacturing method of the battery roll core comprises the following steps that: step S10, a negative electrode current collector, a positive electrode current collector and at least two diaphragms are provided, the negative electrode current collector is coated with negative electrode slurry, the negative electrode slurry forms at least two convex parts on at least one side surface of the negative electrode current collector, and two adjacent convex parts are distributed at intervals along the extension direction of the negative electrode current collector, so that a negative electrode plate can be obtained, the positive electrode current collector is coated with positive electrode slurry, so that a positive electrode plate can be obtained; and step S20, the positive electrode plate, the diaphragm, the negative electrode plate and the diaphragm are overlapped, the first end of the positive electrode plate is wound, so that a flat roll core can be formed, and the convex parts cover the arc-shaped structure surface of the roll core on the negative electrode plate. According to the manufacturing method of the battery roll core and the battery roll core, more lithium embedding space can be provided for the negative electrode plate, so that the risk of lithium precipitation of the battery roll core is reduced.

The invention provides a silicon-carbon negative electrode material with an artificial SEI film and a preparation method and application of the silicon-carbon negative electrode material, and the preparation method comprises the following steps: mixing a perfluoromethyl vinyl ether/maleic anhydride/2-vinyl-1H-benzimidazole copolymer and a silicon-carbon negative electrode material to obtain a mixed solution, and drying the mixed solution to obtain the silicon-carbon negative electrode material with the artificial SEI film, wherein the perfluoromethyl vinyl ether/maleic anhydride/2-vinyl-1H-benzimidazole copolymer is an artificial SEI film coated on the surface of the silicon-carbon negative electrode material. The copolymer plays a role of an artificial SEI film, has a good lithium ion transmission mechanism, and can reduce the risk of lithium separation, effectively reduce the irreversible capacity of the lithium ion battery and improve the first coulombic efficiency of the lithium ion battery; and the artificial SEI film has high thermal stability, and can greatly improve the stability of high-temperature storage and high-temperature circulation of the silicon negative electrode material.

The invention provides a negative plate and a battery comprising the negative plate. The negative plate comprises a negative current collector, an electrolyte supplementing layer and a negative active material layer, the electrolyte supplementing layer is positioned on the surface of one side or two sides of the negative electrode current collector, and the negative electrode active material layer is positioned on the surface of the electrolyte supplementing layer; the negative electrode active material layer is provided with a first orientation hole. By using the negative plate, the rate capability and the energy density of the battery can be improved at the same time, and the lithium separation risk is reduced, the utilization rate of the electrode plate is improved and the energy density is improved by constructing an orientation hole rapid ion channel on the surface of the electrode plate.