Abstract: An electrochemical device, including a cell and a shell enclosing the cell; the cell includes a jelly roll including a first electrode and a second electrode spaced from each other, a separator is disposed between the first electrode and the second electrode, the first electrode and the second electrode are wound to form the cell; the first electrode includes a first current collector, the first current collector includes a first surface and a second surface disposed oppositely; the first surface faces the shell, and includes a coated region coated with a first active material and an uncoated region; the uncoated region includes a first uncoated region disposed at an end of the jelly roll, and the first uncoated region includes alternating bent portions and straight portions; and the bent portions are provided with an insulating layer.

Abstract: A method for improving cycling performance of a battery includes, in a first stage, charging the battery with a first-stage current until a voltage of the battery reaches a first-stage voltage value and in a second stage, charging the battery with a second-stage current until the voltage of the battery reaches a second-stage voltage value. The second-stage voltage value is greater than the first-stage voltage value, and the second-stage current is less than the first-stage current.

Abstract: A cell, formed by winding or stacking a first electrode and a second electrode which are arranged at an interval, and a separator is disposed between the first electrode and the second electrode. The first electrode includes a first current collector, and the first current collector includes a coated region coated with a first active material and an uncoated region without the first active material; the uncoated region is at least partially provided with an insulating layer. The adhesion between the insulating layer and the first current collector is not less than about 0.5 N/m.

Abstract: The present application relates to an electrochemical device. Specifically, the present application provides a cell, wherein the cell is formed by winding or stacking a first electrode and a second electrode which are arranged at an interval, and a separator is disposed between the first electrode and the second electrode. Wherein the first electrode includes a first current collector, and the first current collector includes a coated region coated with a first active material and an uncoated region without the first active material; the uncoated region is at least partially provided with an insulating layer. The adhesion between the insulating layer and the first current collector is not less than about 0.5 N/m. The electrochemical device provided by the present application has improved safety performance.

Abstract: An electrochemical device includes a positive electrode plate, a negative electrode plate, a separator, and an electrolytic solution. The positive electrode plate includes a positive active material having lithium transition metal oxide particles represented by a chemical formula LiaCoxM1yM2zO2, where 0.95?a?1.05, 0.05<x<1, 0?y?0.9, 0<z?0.2, x+y+z=1, an M1 is one or two selected from the group consisting of Ni and Mn, and an M2 is at least one selected from the group consisting of Mg, Al, Ti, La, Y, and Zr. The separator includes a porous substrate and a polymer adhesive layer. The polymer adhesive layer is disposed between the porous substrate and the positive electrode plate. An adhesive force of the polymer adhesive layer between the positive electrode plate is 3 N/m to 100 N/m.

Abstract: A method for enhancing battery cycle performance is applied in a battery and includes the following steps: charging, at a first stage, the battery at a first-stage current until reaching a first-stage voltage; and charging, at a second stage, the battery at a second-stage current until reaching a second-stage voltage. The second-stage voltage is greater than the first-stage voltage. The second-stage current is less than the first-stage current. The battery includes an electrolytic solution containing an additive. The additive includes a nitrile compound. A mass percent of the nitrile compound in the electrolytic solution is 0.5% to 5%. This application further provides an electronic device. The method and electronic device according to this application can enhance high-temperature cycle performance of the battery, reduce a high-temperature storage expansion rate, and enhance hot-oven safety performance.

Abstract: A method for enhancing battery cycle performance. The method is applied in a battery and includes: charging, at a first stage, the battery at a first-stage current until reaching a first-stage voltage; and charging, at a second stage, the battery at a second-stage current until reaching a second-stage voltage. The second-stage voltage is greater than the first-stage voltage, and the second-stage current is less than the first-stage current. The battery includes an electrolytic solution containing an organic solvent. The organic solvent includes a chain carboxylate compound. A weight percent of the chain carboxylate compound in the organic solvent is 10% to 70%. This application further provides an electronic device. The method can enhance high-temperature cycle and storage performance of the battery.

Abstract: An electrochemical device, including a cell and a shell enclosing the cell; the cell includes a jelly roll including a first electrode and a second electrode spaced from each other, a separator is disposed between the first electrode and the second electrode, the first electrode and the second electrode are wound to form the cell; the first electrode includes a first current collector, the first current collector includes a first surface and a second surface disposed oppositely; the first surface faces the shell, and includes a coated region coated with a first active material and an uncoated region; the uncoated region includes a first uncoated region disposed at an end of the jelly roll, and the first uncoated region includes alternating bent portions and straight portions; and the bent portions are provided with an insulating layer.

Abstract: The present application relates to an electrochemical device. Specifically, the present application provides an electrochemical device, including a cell and a shell enclosing the cell; the cell includes a jelly roll including a first electrode and a second electrode spaced from each other, a separator is disposed between the first electrode and the second electrode, the first electrode and the second electrode are wound to form the cell; the first electrode includes a first current collector, the first current collector includes a first surface and a second surface disposed oppositely; the first surface faces the shell, and includes a coated region coated with a first active material and an uncoated region; the uncoated region includes a first uncoated region disposed at an end of the jelly roll, and the first uncoated region includes alternating bent portions and straight portions; and the bent portions are provided with an insulating layer.

Abstract: A method for improving cycling performance of a battery includes, in a first stage, charging the battery with a first-stage current until a voltage of the battery reaches a first-stage voltage value and in a second stage, charging the battery with a second-stage current until the voltage of the battery reaches a second-stage voltage value. The second-stage voltage value is greater than the first-stage voltage value, and the second-stage current is less than the first-stage current.

Abstract: A charging method is proposed to include the steps of: in a first stage of charging, charging a battery with a first-stage current until a voltage of the battery reaches a first-stage voltage value; and in a second stage of charging, charging the battery with a second-stage current until the voltage of the battery reaches a second-stage voltage value which is greater than the first-stage voltage value. The second-stage current is smaller than the first-stage current.

Abstract: The present application relates to an electrochemical device. Specifically, the present application provides a cell, wherein the cell is formed by winding or stacking a first electrode and a second electrode which are arranged at an interval, and a separator is disposed between the first electrode and the second electrode. Wherein the first electrode includes a first current collector, and the first current collector includes a coated region coated with a first active material and an uncoated region without the first active material; the uncoated region is at least partially provided with an insulating layer. The adhesion between the insulating layer and the first current collector is not less than about 0.5 N/m. The electrochemical device provided by the present application has improved safety performance.

Abstract: The present application relates to an electrode sheet, a battery cell and a battery. The electrode sheet includes a current collector and a protective layer. The current collector includes a coated region provided with an active material layer and an uncoated region without being provided with the active material layer. The protective layer is provided on at least a part of a surface of the uncoated region, and has a porosity of 0% to 95%. For the electrode sheet according to the present application, by providing the current collector with the protective layer, the contact resistance may be increased when the electrode sheet is short-circuited, and the discharge power and the thermal runaway probability of the battery cell may be reduced when the battery cell is internally short-circuited, thereby improving the safety performance of the battery cell.

Abstract: The present application relates to an electrochemical device. Specifically, the present application provides an electrochemical device, including a cell and a shell enclosing the cell; the cell includes a jelly roll including a first electrode and a second electrode spaced from each other, a separator is disposed between the first electrode and the second electrode, the first electrode and the second electrode are wound to form the cell; the first electrode includes a first current collector, the first current collector includes a first surface and a second surface disposed oppositely; the first surface faces the shell, and includes a coated region coated with a first active material and an uncoated region; the uncoated region includes a first uncoated region disposed at an end of the jelly roll, and the first uncoated region includes alternating bent portions and straight portions; and the bent portions are provided with an insulating layer.

Abstract: An electrode assembly and a battery are disclosed. The electrode assembly includes a first current collector including a first section and a second section, a second current collector including a third section and a fourth section, and a first protective layer. An outer surface of the first section is provided with an active material layer, and none of an outer surface and an inner surface of the second section, an inner surface of the first section, an outer surface of the third section, and an inner surface of the fourth section is provided with the active material layer. The outer surface of the third section faces the inner surface of the first section and the inner surface of the second section, and the inner surface of the fourth section faces the outer surface of the second section.

Abstract: An embodiment of the present application provides a negative electrode and a lithium ion battery including the negative electrode, the negative electrode includes a negative electrode current collector, and a negative electrode active material layer arranged on the negative electrode current collector, wherein the negative electrode active material layer includes a negative electrode active material and a dispersant, and the dispersant includes lithium carboxymethylcellulose, wherein the mass ratio of the negative electrode active material to the dispersant being ?18.74. The present application greatly reduces the DC resistance of the lithium ion battery and the charge transfer resistance at the interface without losing the energy density of the lithium ion battery, without affecting the cycle life of the lithium ion battery or causing cyclic expansion, which avoids the lithium precipitation phenomenon of the lithium ion battery during the cycle of charge and discharge.

Abstract: A charging method is proposed to include the steps of: in a first stage of charging, charging a battery with a first-stage current until a voltage of the battery reaches a first-stage voltage value; and in a second stage of charging, charging the battery with a second-stage current until the voltage of the battery reaches a second-stage voltage value which is greater than the first-stage voltage value. The second-stage current is smaller than the first-stage current.

Abstract: Embodiments of the present application provide a method of battery charging, which relates to the field of battery charging and is capable of effectively improving safety performance of the battery. The method includes: obtaining an anode open circuit voltage curve, an anode impedance curve, a lithium deposition potential threshold and a state of charge, corresponding to a battery; determining a current anode open circuit voltage according to the anode open circuit voltage curve and the state of charge; determining a current anode impedance according to the anode impedance curve and the state of charge; determining a current charging current according to the current anode open circuit voltage, the current anode impedance and the lithium deposition potential threshold; and charging the battery according to the current charging current. Embodiments of the present application are applicable to a rapid battery charging process.

Abstract: Embodiments of the present application provide a method of battery charging, which relates to the field of battery charging and is capable of effectively improving safety performance of the battery. The method includes: obtaining an anode open circuit voltage curve, an anode impedance curve, a lithium deposition potential threshold and a state of charge, corresponding to a battery; determining a current anode open circuit voltage according to the anode open circuit voltage curve and the state of charge; determining a current anode impedance according to the anode impedance curve and the state of charge; determining a current charging current according to the current anode open circuit voltage, the current anode impedance and the lithium deposition potential threshold; and charging the battery according to the current charging current. Embodiments of the present application are applicable to a rapid battery charging process.

Abstract: The present application discloses a lithium-ion secondary battery. By using an adhesive containing an active group in a positive electrode and/or a negative electrode, and using a coupling agent solution containing an amino or epoxy group to treat the surface of a separator, an interface between the separator and an electrode react chemically to be connected with a covalent bond, thus improving the deformation of the lithium-ion secondary battery during a cycle.