Abstract: A secondary battery includes a positive electrode plate, a negative electrode plate, an electrolyte, and a separator. The separator includes a base film, where a pore size distribution of the base film is a bimodal distribution. A pore size on a side of the base film facing the negative electrode plate is larger than a pore size on a side of the base film facing the positive electrode plate. The pore size on the side of the base film facing the negative electrode plate is 60 nm to 500 nm, and the pore size on the side of the base film facing the positive electrode plate is 5 nm to 55 nm. This can improve the fast charging performance of the secondary battery and alleviate lithium precipitation.

Abstract: A separator and a lithium-ion battery. The separator includes a porous substrate, and a first coating layer arranged on at least one surface of the porous substrate, wherein the first coating layer includes an aromatic polyamide. An aramid coating layer is used; the aromatic polyamide in the aramid coating layer swells or plasticizes under the action of a solvent and a lithium salt in the electrolyte at high temperature or normal temperature, to increase the elongation of the separator, while improving the safety performance of the lithium-ion battery by interaction between the aramid coating layer and the electrode active material or the binder.

Abstract: A separator including a porous substrate and a porous layer. The porous layer is disposed on a surface of the porous substrate and includes inorganic particles and a binder. The porous substrate has an absolute plastic deformation rate in a first direction ranging from about 40% to about 1800%. By using the separator provided in the present application, the safety performance of lithium ion batteries is improved.

Abstract: A separator including a porous substrate and a porous layer. The porous layer is disposed on a surface of the porous substrate and includes inorganic particles and a binder. The porous substrate has an absolute plastic deformation rate in a first direction ranging from about 40% to about 1800%. By using the separator provided in the present application, the safety performance of lithium ion batteries is improved.

Abstract: The present application relates to a separator and an electrochemical device. The present application provides a separator comprising: a porous substrate and a porous layer, wherein the porous layer is disposed on a surface of the porous substrate and comprises inorganic particles and a binder. The porous substrate has an absolute plastic deformation rate in a first direction ranging from about 40% to about 1800%. By using the separator provided in the present application, the safety performance of lithium ion batteries is improved.

Abstract: The present application relates to a separator and an electrochemical device. The present application provides a separator comprising: a porous substrate and a porous layer, wherein the porous layer is disposed on a surface of the porous substrate and comprises inorganic particles and a binder. The porous substrate has an absolute plastic deformation rate in a first direction ranging from about 40% to about 1800%. By using the separator provided in the present application, the safety performance of lithium ion batteries is improved.

Abstract: The present invention provides a separator and a lithium-ion battery. The separator comprises a porous substrate, and a first coating layer arranged on at least one surface of the porous substrate, wherein the first coating layer comprises an aromatic polyamide. An aramid coating layer is used in the present invention, the aromatic polyamide in the aramid coating layer swells or plasticizes under the action of a solvent and a lithium salt in the electrolyte at high temperature or normal temperature, to increase the elongation of the separator, while improving the safety performance of the lithium-ion battery by interaction between the aramid coating layer and the electrode active material or the binder.

Abstract: The present disclosure provides a separator and a lithium ion battery. The separator includes a porous substrate; and a porous layer disposed on at least one surface of the porous substrate. The porous layer includes inorganic particles and a binder, and an iron content in the porous layer is not more than 2100 ppm.