Provided are electrochemical cells including separators permeable to some materials and impermeable to other materials in electrolytes. Also provide are methods of forming such separators. The selective permeability of a separator is achieved by its specific pore diameter and a narrow distribution of this diameter. Specifically, a species responsible for ion transport in an electrochemical cell are allowed to pass through the separator, while another species is blocked thereby preventing degradation of the cell. For example, a species containing lithium ions is allowed to pass in rechargeable cells, while one or more species containing transition metals are blocked. In some embodiments, a separator may include a membrane layer with at least 90% of pores of this having a diameter of between about 0.1 nanometers and 1.0 nanometer. The membrane layer may be a standalone layer or supported by a membrane support.

Provided is a honeycomb type lithium ion battery that makes it possible to suppress a short circuit. The honeycomb type lithium ion battery has an anode, a cathode, and a separator layer, wherein the anode has a plurality of through holes extending in one direction, the separator layer has Li ion permeability, and physically isolates the anode and the cathode from each other, at least inner walls of the through holes being covered with the separator layer, the cathode is disposed at least inside the through holes via the separator layer, the separator layer has a first layer with which the inner walls of the through holes are covered, and a second layer disposed between the first layer and the cathode, and the solubility of a binder contained in the first layer is lower than that contained in the second layer.

A porous film has a porous substrate and, on at least one surface of the porous substrate, porous layer that contains particles A. The particles A have a mixture containing a polymer that includes fluorine-containing (meth)acrylate monomers and a polymer that includes monomers having two or more reactive groups per molecule, or the particles A have a copolymer containing fluorine-containing (meth)acrylate monomers and monomers that have two or more reactive groups per molecule. The monomers having two or more reactive groups per molecule are contained in the particles A in an amount ranging from greater than 10% by mass to not more than 30% by mass, where all components of the particles A are assumed to constitute 100% by mass.

A porous film has a porous substrate and, on at least one surface of the porous substrate, porous layer that contains particles A. The particles A have a mixture containing a polymer that includes fluorine-containing (meth)acrylate monomers and a polymer that includes monomers having two or more reactive groups per molecule, or the particles A have a copolymer containing fluorine-containing (meth)acrylate monomers and monomers that have two or more reactive groups per molecule. The monomers having two or more reactive groups per molecule are contained in the particles A in an amount ranging from greater than 10% by mass to not more than 30% by mass, where all components of the particles A are assumed to constitute 100% by mass.

Provided is a lithium metal secondary battery, including: a positive electrode; a negative electrode current collector; an electrolyte layer provided between the positive electrode and the negative electrode current collector; an intermediate layer provided between the positive electrode and the negative electrode current collector and including an expandable and contractible, three-dimensional structure; and an ionic liquid held within the expandable and contractible, three-dimensional structure.

A separator for an electrochemical device including a porous polymer substrate; and a porous coating layer formed on at least one surface of the porous polymer substrate, wherein the porous coating layer comprises inorganic particles and a binder polymer positioned on at least a part of a surface of individual inorganic particles to connect and fix the inorganic particles with one another. The binder polymer comprises a first block having repeating units and a second block having repeating units. A method for manufacturing the same is also provided. The separator shows low resistance, improved adhesion to an electrode and improved swelling property with a solvent.

Disclosed are a composition, a composite separator and a preparation method therefor, and a lithium ion battery. The composition includes 10-100 parts of a polymer resin, 0.5-10 parts of a polymer adhesive. 0-50 parts of an inorganic nanoparticle powder, and 0-40 parts of nanowires. The polymer resin includes a low melting point polymer and a high melting point polymer, wherein the low melting point polymer and the high melting point polymer are the same substance: the weight ratio of the low melting point polymer to the high melting point polymer is (5-90): (10-95), the melting point of the low melting point polymer is 145° C. or less, and the melting point of the high melting point polymer is in the range of 146-500° C.

Provided is a separator for a secondary battery including a porous substrate and a coating layer disposed on at least one surface of the porous substrate. The coating layer includes a first fluorine-based binder including a vinylidene fluoride (VDF)-derived unit and a hexafluoropropylene (HFP)-derived unit, and a second fluorine-based binder including vinylidene fluoride (VDF)-derived unit and a tetrafluoroethylene (TFE)-derived unit, the hexafluoropropylene (HFP)-derived unit is included in an amount of less than or equal to 5 mol % based on 100 mol % of the first fluorine-based binder, the tetrafluoroethylene (TFE)-derived unit is included in an amount of greater than 10 mol % and less than or equal to 40 mol % based on 100 mol % of the second fluorine-based binder.

Provided is a separator for a secondary battery including a porous substrate and a coating layer disposed on at least one surface of the porous substrate. The coating layer includes a first fluorine-based binder including a vinylidene fluoride (VDF)-derived unit and a hexafluoropropylene (HFP)-derived unit, and a second fluorine-based binder including vinylidene fluoride (VDF)-derived unit and a tetrafluoroethylene (TFE)-derived unit, the hexafluoropropylene (HFP)-derived unit is included in an amount of less than or equal to 5 mol % based on 100 mol % of the first fluorine-based binder, the tetrafluoroethylene (TFE)-derived unit is included in an amount of greater than 10 mol % and less than or equal to 40 mol % based on 100 mol % of the second fluorine-based binder.

Implementations of the present disclosure generally relate to separators, high performance electrochemical devices, such as, batteries and capacitors, including the aforementioned separators, and methods for fabricating the same. In one implementation, a method of forming a separator for a battery is provided. The method comprises exposing a metallic material to be deposited on a surface of an electrode structure positioned in a processing region to an evaporation process. The method further comprises flowing a reactive gas into the processing region. The method further comprises reacting the reactive gas and the evaporated metallic material to deposit a ceramic separator layer on the surface of the electrode structure.