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

The electrochemical device disclosed in the present application includes a wound battery cell and a casing for accommodating the battery cell. The battery cell includes a first pole piece, a second pole piece, and a film arranged in layers. The first pole piece includes a current collector, and the current collector It includes a first surface facing the inside of the battery core and a second surface facing away from the inside of the battery core; the tab is electrically connected to the current collector and protrudes from the current collector; the first active material layer is arranged on the first surface of the current collector; An active material layer includes a main coating and an edge coating. Along the first direction, the edge coating is located on the side of the main coating facing the tab, and is adjacent to or partially overlapped with the main coating; along the second direction , the main coating and the edge coating extend in a band shape, and the length of the edge coating is longer than that of the main coating; the electrochemical device has high energy density and good electrical performance.

The invention provides a method for forming a hard carbon negative electrode material lithium ion battery, belonging to the technical field of battery formation. The formation method of the present invention is to perform formation treatment on the battery that has been aged by liquid injection; the process of the formation treatment includes: charging to the designed lithium intercalation gram capacity-discharging process N times until the discharge depth reaches 100% of the target discharge depth; The designed lithium intercalation gram capacity is 350-700mAh / g, the target discharge depth is 100% of the designed lithium intercalation gram capacity; the depth of the first discharge is 10-90% of the target discharge depth, and the depth of the Nth discharge is compared to The depth of the N-1th discharge is increased by 1 to 20% of the target discharge depth; N≥2, where N is an integer. The present invention eliminates irreversible lithium in the cycle process by controlling the target discharge depth and each discharge depth, improves the lithium intercalation platform of the hard carbon negative electrode material, reduces the risk of lithium analysis, and improves the cycle stability of the hard carbon negative electrode material lithium ion battery .

The invention discloses a preparation method of a lithium-ion battery that improves high-voltage low-temperature discharge and cycle performance, and belongs to the technical field of lithium-ion batteries. The preparation method is as follows: a layer of negative electrode slurry A with a thickness of 170um~240um is coated on the paste surface of the negative electrode current collector, and the negative electrode slurry A is composed of negative electrode main material, high specific surface area conductive agent, CMC , SBR, and modified acrylic binder; a layer of negative electrode slurry B with a thickness of 170um~240um is coated on the short pasted surface of the negative electrode current collector, and the negative electrode slurry B is composed of negative electrode main material, low specific surface area Composed of conductive agent, CMC and SBR; rolling → sorting. The present invention uses two coating processes to coat different types of slurries on both sides of the negative electrode current collector to improve the bonding performance of the negative electrode active material and the current collector and the liquid absorption performance of the negative electrode sheet, especially improving the long-term coating The polarization effect between the paste surface and the negative electrode current collector improves the low-temperature discharge and cycle performance of the high-voltage battery.

The disclosure relates to a charging method for a lithium ion battery and a charging device for the lithium ion battery. The charging method of lithium-ion battery comprises: obtaining the polarization property of lithium-ion battery, and polarization property comprises the anode of lithium-ion battery and does not analyze the maximum charging current of lithium; According to the polarization property, it is determined that according to the stepwise charging sequence, the current value decreases progressively. Multi-stage charging constant current; charge the lithium-ion battery step by step with multi-stage charging constant current, and after each stage of charging, let the lithium-ion battery stand still or discharge the lithium-ion battery at a preset discharge current that is less than the maximum charging current; when the lithium-ion When the voltage of the battery reaches the constant current cutoff voltage, constant voltage charging is performed with the constant current cutoff voltage as a constant voltage. Various embodiments of the present disclosure effectively reduce the polarization of the battery, thereby reducing the full charge time of the lithium-ion battery.

The present application provides electrochemical devices and electronic devices. The electrochemical device includes a positive pole piece, a negative pole piece, and a separator disposed 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 is provided on the surface of at least one side of the isolation membrane, and the protective coating includes a blocking agent; (b) the isolation membrane Including a blocking agent; (c) the negative electrode pole piece includes a negative electrode active material layer, and the surface of the negative electrode active material layer is provided with a protective coating; (d) the negative electrode active material layer includes core-shell structure particles, and the outer shell of the core-shell structure particles includes At least one of inorganic materials or polymers, and the core of the core-shell structured particle includes the blocking agent. The blocking agent includes at least one of red phosphorus, sulfur, iodine, or selenium. The embodiments of the present application can reduce the risk of lithium precipitation and improve the cycle performance and safety performance of the electrochemical device.