36results about How to "Improve nail penetration safety performance" patented technology

The present application relates to the field of batteries, in particular, to a positive electrode sheet and an electrochemical device. The positive electrode sheet of the present application includes a current collector and an electrode active material layer disposed on at least one surface of the current collector, wherein the current collector includes a support layer and a conductive layer disposed on at least one surface of the support layer, the The thickness D2 of one side of the conductive layer satisfies: 30nm≤D2≤3μm, the material of the conductive layer is aluminum or aluminum alloy, and the density of the conductive layer is 2.5g / cm 3 ~2.8g / cm 3 , the electrode active material layer includes an electrode active material, a binder and a conductive agent, and the binder in the electrode active material layer has a non-uniform distribution in the thickness direction, wherein based on the total weight of the electrode active material layer , the weight percent of the binder in the inner region of the electrode active material layer is higher than the weight percent of the binder in the outer region of the electrode active material layer.

The invention relates to a battery, comprising a positive electrode sheet, a diaphragm, a negative electrode sheet and an electrolyte, wherein the positive electrode sheet includes a positive electrode current collector and at least two layers of positive electrode active material layers coated on at least one surface of the positive electrode current collector, The lower positive electrode active material layer in contact with the positive electrode current collector comprises the first positive electrode active material, the first polymer material and the first conductive material, based on the total weight of the lower positive electrode active material layer, the weight percentage of the first positive electrode active material is A%, the weight percentage of the first macromolecular material is B%, the weight percentage of the first conductive material is C%, and the upper positive electrode active material layer that is in contact with the lower positive electrode active material layer and away from the positive electrode current collector contains the second Two positive electrode active materials, the second polymer material and the second conductive material, based on the total weight of the upper positive electrode active material layer, the weight percentage of the second positive electrode active material is A '%, the weight percentage of the second polymer material The content is B'%, the weight percentage of the second conductive material is C'%, where A% <a′％，b％>B′%, C%≧C′%, and the first polymer material includes polyvinylidene fluoride and / or polyvinylidene chloride polymer material. The battery has good safety and improved electrical properties, and the normal temperature viscosity of the electrolyte is ≤4cp.< / a′％，b％>

The present application relates to the field of batteries, in particular, to an electrode sheet and an electrochemical device. The electrode sheet of the present application includes a current collector, an electrode active material layer disposed on at least one surface of the current collector, and an electrical connection member electrically connected to the current collector, and the electrode active material layer is disposed on the current collector The main part of the main body, this area is called the diaphragm area, and the electrical connection member is welded to the current collector at the edge of the current collector. This welding area is called the transfer welding area, and the diaphragm area and the transfer The transition area of ​​the current collector that is not coated with the electrode active material layer between the welding areas is called the extension area, the current collector is a composite current collector, and the electrode pole piece also includes a thermally conductive coating, and the thermally conductive coating is in the The transfer welding area covers at least a part of the electrical connection member.

The present application relates to the field of batteries, in particular, to a positive electrode sheet and an electrochemical device. The positive electrode sheet of the present application includes a current collector and an electrode active material layer disposed on at least one surface of the current collector, wherein the current collector includes a support layer and a conductive layer disposed on at least one surface of the support layer, the The single-side thickness D2 of the conductive layer satisfies: 30nm≤D2≤3μm, the thickness D1 of the support layer satisfies: 1μm≤D1≤30μm, and the support layer is a polymer material or a polymer composite material; the electrode active material layer includes Electrode active material, binder and conductive agent, the total thickness D of the electrode active material layer 总 is no more than 170 μm, and the sheet resistance of the electrode active material layer is 0.1 ohms to 10 ohms. The electrochemical device comprising the positive electrode sheet has high energy density, good safety performance (especially nail penetration safety performance) and electrochemical performance.

The invention relates to a positive pole piece and an electrochemical device. The positive electrode sheet includes a metal current collector, a positive electrode active material layer, and a safety coating disposed between the metal current collector and the positive electrode active material layer, the safety coating includes a polymer matrix, a conductive material and an inorganic filler, and the high The molecular matrix is ​​polyvinylidene fluoride and / or polyvinylidene chloride polymer matrix, based on the total weight of the safety coating, the weight percentage of the polymer matrix is ​​35wt%-75wt%, and the weight percentage of the conductive material is 5wt%-25wt%, the weight percentage of the inorganic filler is 10wt%-60wt%, and the breaking elongation δ of the metal current collector satisfies 0.8%≤δ≤4%. The positive electrode sheet can quickly disconnect the circuit when the electrochemical device (such as a capacitor, a primary battery or a secondary battery, etc.) is under high temperature conditions or an internal short circuit occurs due to nail penetration, thereby improving the high temperature safety of the electrochemical device.

The invention relates to a positive pole piece and an electrochemical device. The positive electrode sheet includes a current collector, a positive electrode active material layer and a safety coating disposed between the current collector and the positive electrode active material layer, wherein: the safety coating comprises a polymer matrix, a conductive material and an inorganic filler. When the coating layer and the positive electrode active material layer are collectively referred to as the membrane layer, the elongation of the membrane layer is equal to or greater than 30%. The positive electrode sheet can improve the safety performance of piercing nails of electrochemical devices (such as capacitors, primary batteries or secondary batteries, etc.).

The invention relates to a battery, comprising a positive electrode sheet, a separator and a negative electrode sheet, wherein the positive electrode sheet comprises a positive electrode current collector and at least two layers of positive electrode active material layers coated on at least one surface of the positive electrode current collector, and the positive electrode current collector is connected with the positive electrode current collector. The lower positive electrode active material layer in fluid contact comprises a first positive electrode active material, a first polymer material and a first conductive material, and based on the total weight of the lower positive electrode active material layer, the weight percentage of the first positive electrode active material is A%, The weight percentage of the first polymer material is B%, and the weight percentage of the first conductive material is C%. material, the second polymer material and the second conductive material, based on the total weight of the upper positive electrode active material layer, the weight percentage of the second positive electrode active material is A'%, and the weight percentage of the second polymer material is B '%, the weight percentage of the second conductive material is C'%, of which A% <a′％，b％>B'%, C%≥C'%, and the first polymer material includes an oily polymer material whose solubility in NMP at 130°C within 5 minutes is less than 30% of that of PVDF under the same conditions. The battery has good safety and improved electrical properties.< / a′％，b％>