A separator for secondary batteries that allows the amount of a dispersing resin that is used and the amount of a dispersant that is used to be reduced in order to prevent an increase in resistance after the separator is coated, which occurs in the case in which a large amount of the dispersing resin is used in order to disperse inorganic matter, and an electrochemical device having the same applied thereto. The amount of a dispersing resin is reduced, whereby it is possible to prevent an increase in resistance after a porous separator is coated, a dispersing resin having a specific weight average molecular weight is mixed, whereby physical properties and dispersivity are improved, and the use of an expensive dispersant is excluded, whereby processing costs are reduced.

High density polyethylene polymers, including high molecular weight and ultrahigh molecular weight polyethylene polymers, are disclosed that are at least partially made from bio-based feedstocks. The bio-based feedstocks are selected so as to produce high purity monomers capable of producing high density polymers for use in high purity applications, such as in producing implants and porous membranes for lithium-ion batteries.

A secondary battery for cycling between a charged and a discharged state, wherein a 2D map of the median vertical position of the first opposing vertical end surface of the electrode active material in the X-Z plane, along the length LE of the electrode active material layer, traces a first vertical end surface plot, EVP1, a 2D map of the median vertical position of the first opposing vertical end surface of the counter-electrode active material layer in the X-Z plane, along the length LC of the counter-electrode active material layer, traces a first vertical end surface plot, CEVP1, wherein for at least 60% of the length Lc of the first counter-electrode active material layer (i) the absolute value of a separation distance, SZ1, between the plots EVP1 and CEVP1 measured in the vertical direction is 1000 μm≥|SZ1|≥5 μm.

A secondary battery for cycling between a charged and a discharged state, wherein a 2D map of the median vertical position of the first opposing vertical end surface of the electrode active material in the X-Z plane, along the length LE of the electrode active material layer, traces a first vertical end surface plot, EVP1, a 2D map of the median vertical position of the first opposing vertical end surface of the counter-electrode active material layer in the X-Z plane, along the length LC of the counter-electrode active material layer, traces a first vertical end surface plot, CEVP1, wherein for at least 60% of the length Lc of the first counter-electrode active material layer (i) the absolute value of a separation distance, SZ1, between the plots EVP1 and CEVP1 measured in the vertical direction is 1000 μm≥|SZ1|≥5 μm.

A separator, a method of manufacturing the same, and a lithium secondary battery including the same are disclosed herein. In some embodiments, a separator includes a non-crosslinked polyolefin layer; and a crosslinked polyolefin layer disposed on one surface of the non-crosslinked polyolefin layer and having at least one crosslinking bond represented by the following Chemical Formula 1, wherein the separator is configured such that the non-crosslinked polyolefin layer of the separator faces a positive electrode. In some embodiments, a lithium secondary battery includes a positive electrode, a negative electrode and the separator interposed between the positive electrode and the negative electrode. The lithium secondary battery has a high melt-down temperature and shows high oxidation stability under high-voltage/high-temperature environment.

Provided is pouch battery including an electrode assembly, and a case in which the electrode assembly is sealed and housed; the electrode assembly including a stacked structure of a sheet cathode, a sheet separator, and a sheet anode; the sheet cathode including a positive electrode active material disposed on a current collector; the sheet anode is thin conductive sheet on which lithium metal reversibly deposits on a surface thereof during discharging; the sheet anode being made of a conductive material other than lithium and having a surface substantially free from lithium metal prior to charging the battery. The pouch battery design is flexible and lightweight and provides high power density, making it a suitable replacement for conventional lithium-ion primary batteries and thermal batteries in many applications. Power can be further increased by the application of external compression. Additives and formation conditions can be tailored for forming a solid-electrolyte interface (SEI).

Provided is pouch battery including an electrode assembly, and a case in which the electrode assembly is sealed and housed; the electrode assembly including a stacked structure of a sheet cathode, a sheet separator, and a sheet anode; the sheet cathode including a positive electrode active material disposed on a current collector; the sheet anode is thin conductive sheet on which lithium metal reversibly deposits on a surface thereof during discharging; the sheet anode being made of a conductive material other than lithium and having a surface substantially free from lithium metal prior to charging the battery. The pouch battery design is flexible and lightweight and provides high power density, making it a suitable replacement for conventional lithium-ion primary batteries and thermal batteries in many applications. Power can be further increased by the application of external compression. Additives and formation conditions can be tailored for forming a solid-electrolyte interface (SEI).

This application provides a secondary battery, including at least one battery unit assembly. The battery cell assembly includes a positive electrode plate, a negative electrode plate, and a separator disposed between the positive electrode plate and the negative electrode plate. An elongation rate of the separator is greater than 100%, the elongation rate of the separator includes an elongation rate in the length direction and/or an elongation rate in the width direction, a ratio of the elongation rate of the separator to a thickness of the active material layer of the positive electrode plate and/or negative electrode plate is 3.0%/.Math.m to 8.0%/.Math.m, and a ratio of the elongation rate of the separator to an elongation rate of the current collector of the positive electrode plate and/or negative electrode plate is greater than or equal to 60.

A battery manufacturing method includes: winding positive and negative electrode plates and a separator to form a wound electrode assembly; cutting unwound portions of the positive and negative electrode plates and the separator such that the separator constitutes an outermost layer of the wound electrode assembly when the winding is completed; further winding around the wound electrode assembly the cut unwound portions; fixing a part of a terminal end of the separator in a lateral direction to the wound electrode assembly; and performing heat welding on parts of both lateral ends of an outermost portion of the separator in the wound electrode assembly, which are located above an electrode active material-uncoated portion of the positive or negative electrode plate to fix the lateral ends to the wound electrode assembly.

This disclosure details exemplary immersion cooling battery array designs for use in electrified vehicle battery packs or other electrified components. An exemplary battery array design may include a battery subassembly including a compressible spacer assembly and a plurality of battery cells held by the compressible spacer assembly. The battery subassembly may be surrounded by an outer shell assembly. A non-conductive (i.e., dielectric) fluid may be received and communicated inside the outer shell assembly for thermally managing heat generated by the battery cells.