Abstract: A method for screening a lithium ion battery is provided. A number of lithium ion batteries are galvanostatically discharged a to an inflection point voltage at an inflection point of a discharge curve at a first constant current I1. The number of lithium ion batteries are rested for a first rest time T1 to raise an open circuit voltage of the number of lithium ion batteries to U1. U1 is greater than the inflection point voltage. The number of lithium ion batteries are galvanostatically discharged to the inflection point voltage at a second constant current I2, in which I2<<I1. The number of lithium ion batteries are rested for a second rest time T2 and the batteries are screened based on a self-discharge of the number of lithium ion batteries.

Abstract: The present disclosure provides a lithium ion battery comprising a base, a winding column, a shell, a cover cap, and a cell. The winding column is disposed on the base. The cell is winded onto an outer surface of the winding column. The shell is sleeved outside an outer surface of the cell, and two ends of the shell are respectively connected to the base and the cover cap to seal the cell. The lithium ion battery further comprises a secure structure body disposed between the winding column and the cell. The secure structure body comprises an elastic layer and a plurality of acicular members disposed in the elastic layer. The plurality of acicular members has a plurality of pointed ends, and the plurality of pointed ends points to the cell.

Abstract: The present disclosure provides an electrolyte additive. The electrolyte additive comprises: maleimide derivative, bis-maleimide derivative, or combinations there of The structural formulas of maleimide derivative and bis-maleimide derivative respectively are: wherein, R1, R2 are selected from hydrogen atom and halogen atoms, R3 is selected from silicon containing group, nitrogen containing group, fluorine containing group, phosphorus containing group, and a repeating ethoxy group. The present disclosure also provides an electrolyte liquid and a lithium ion battery using the electrolyte additive.

Abstract: A method for making a cathode active material of a lithium ion battery is disclosed. In the method, LiMPO4 particles and LiNPO4 particles are provided. The LiMPO4 particles and LiNPO4 particles both are olivine type crystals belonged to a pnma space group of an orthorhombic crystal system, wherein M represents Fe, Mn, Co, or Ni, N represents a metal element having a +2 valence, and N is different from M. The LiMPO4 particles and the LiNPO4 particles are mixed together to form a precursor. The precursor is calcined to form LiMxN1-xPO4 particles, wherein 0<x<1.

Abstract: An electrode binder, a cathode electrode material and a lithium ion battery are disclosed. The cathode electrode material includes the cathode binder. The cathode binder includes a polymer obtained by polymerizing a dianhydride monomer with a diamine monomer. At least one of the dianhydride monomer and the diamine monomer includes a silicon-containing monomer. The lithium ion battery includes an anode electrode, an electrolyte, a separator, and the cathode electrode, the cathode electrode includes a cathode active material, a conducting agent, and the cathode binder.

Abstract: An anode electrode material and a lithium ion battery are disclosed. The anode electrode material includes an anode binder. The anode binder includes a polymer obtained by polymerizing a dianhydride monomer with a diamine monomer. At least one of the dianhydride monomer and the diamine monomer includes a silicon-containing monomer. The lithium ion battery includes an anode electrode, an electrolyte, a separator, and the cathode electrode, the anode electrode includes an anode active material, a conducting agent, and the anode binder.

Abstract: A composite separator is disclosed. The composite separator includes a base membrane, and a composite gel composited with the base membrane. The composite gel includes a gel polymer and a nano-barium sulfate dispersed in the gel polymer. A surface of the nano-barium sulfate is modified with lithium carboxylate group. A method for preparing the composite separator and a lithium-ion battery are also provided.

Abstract: A composite separator comprises a non-woven fabric-polymer composite separator substrate and a composite gel combined with the non-woven fabric-polymer composite separator substrate. The composite gel comprises a gel polymer and a nano-barium sulfate whose surface is modified with lithium carboxylate group. The nano-barium sulfate is dispersed to the gel polymer. The non-woven fabric-polymer composite separator substrate comprises a non-woven fabric and a soluble heat-resistant polymer. A method for making the composite separator and a lithium ion battery comprising the composite separator are also disclosed in the present disclosure.

Abstract: A composite barium sulfate diaphragm is disclosed. The composite barium sulfate diaphragm includes a base membrane, and a coating layer coated on the base membrane. The coating layer includes nano-barium sulfate. A surface of the nano-barium sulfate is modified with the lithium carboxylate group. A method for preparing the composite barium sulfate diaphragm and a lithium-ion battery are also provided.

Abstract: A method for making a lithium ion battery anode active material comprising: providing silicon particles and a silane coupling agent, wherein the silane coupling agent comprises a hydrolysable functional group and an organic functional group; mixing the silicon particles and the silane coupling agent in water to obtain a first mixture; adding a monomer or oligomer to the first mixture to obtain a second mixture, the surfaces of the silicon particles being coated with a polymer layer by in situ polymerization method to obtain silicon polymer composite material, the monomer or the oligomer reacting with the organic functional group of the silane coupling agent in a polymerization, thereby a generated polymer layer being chemically grafted on the surfaces of the silicon particles; and heating the silicon polymer composite material to carbonize the polymer layer to form a carbon layer coated on the surfaces of the silicon particles.

Abstract: A solvothermal method for making a lithium iron phosphate is disclosed. The waste liquid of a solvothermal reaction is treated synthetically by flash evaporation and a centrifugal separation to separate the water, the organic solvent, and the lithium sulfate, which is a byproduct from each other. One part of the separated organic solvent is reused as a reaction material of the solvothermal reaction to form a organic solvent recycle circuit. The other part of the separated organic solvent is mixed with the separated water to be used as a washing liquid. The washing liquid is retreated by flash evaporation and centrifugal separation to obtain the water and the organic solvent again to form a washing liquid circuit.

Abstract: A method for making a sulfur based cathode composite material is disclosed. Polyacrylonitrile and elemental sulfur are dissolved together in a first solvent to form a first solution. An electrically conductive carbonaceous material is added to the first solution to mix with the polyacrylonitrile and the elemental sulfur. An environment in which the polyacrylonitrile and the elemental sulfur are located in is changed to reduce a solubility of the polyacrylonitrile and the elemental sulfur in a changed environment to simultaneously precipitate the polyacrylonitrile and the elemental sulfur, thereby forming a precipitate having the electrically conductive carbonaceous material. The precipitate is heated to chemically react the polyacrylonitrile with the elemental sulfur. A sulfur based cathode composite material is also disclosed.

Abstract: An apparatus for making a battery slurry is disclosed. The apparatus comprises a vacuum system providing a vacuum environment, a dry powder mixing device mixing a plurality of powdery materials uniformly to obtain a dry powder, a kneading device kneading the dry powder with the first part solvent to form a doughy mixture, and a high speed dispersing device dispersing the doughy mixture to the second part solvent to form the battery slurry. The vacuum system, the dry powder mixing device, the kneading device, and the high speed dispersing device are connected to each other.

Abstract: A method for making a sulfur based cathode composite material is disclosed. Polyacrylonitrile and elemental sulfur are dissolved together in a first solvent to form a first solution. An additive is added to the first solution to mix with the polyacrylonitrile and the elemental sulfur. The additive is at least one of metal and metal sulfide. An environment in which the polyacrylonitrile and the elemental sulfur are located in is changed to reduce a solubility of the polyacrylonitrile and the elemental sulfur in a changed environment to simultaneously precipitate the polyacrylonitrile and the elemental sulfur, thereby forming a precipitate having the additive. The precipitate is heated to chemically react the polyacrylonitrile with the elemental sulfur.

Abstract: A method for making a battery slurry is disclosed. The method comprises providing a plurality of solid raw materials and at least one liquid raw material, the at least one liquid raw material is divided into a first part solvent and a second part solvent to be used; mixing the plurality of solid raw materials to obtain a dry powder; kneading the dry powder and the first part solvent to obtain a doughy mixture; and dispersing the doughy mixture to the second part solvent to obtain the battery slurry.

Abstract: An anode composite material includes an anode active material and a polymer composited with the anode active material. The polymer is obtained by polymerizing a maleimide type monomer with an organic diamine type compound. The maleimide type monomer is a maleimide monomer, a bismaleimide monomer, a multimaleimide monomer, a maleimide type derivative monomer, or combinations thereof. A method for forming the anode composite material and a lithium ion battery are also disclosed.

Abstract: A method for screening a lithium ion battery is provided. A number of lithium ion batteries are galvanostatically discharged a to an inflection point voltage at an inflection point of a discharge curve at a first constant current I1. The number of lithium ion batteries are rested for a first rest time T1 to raise an open circuit voltage of the number of lithium ion batteries to U1. U1 is greater than the inflection point voltage. The number of lithium ion batteries are galvanostatically discharged to the inflection point voltage at a second constant current I2, in which I2<<I1. The number of lithium ion batteries are rested for a second rest time T2 and the batteries are screened based on a self-discharge of the number of lithium ion batteries.

Abstract: A method of screening a lithium ion battery is provided. A number of lithium ion batteries are galvanostatically discharged to a discharge cutoff voltage V0 at a first constant current I1. The number of lithium ion batteries are rested for a first rest time T1. The number of lithium ion batteries are galvanostatically charged to a charge cutoff voltage V1 at a second constant current I2. The number of lithium ion batteries are rested for a second rest time T2, and the batteries are screened based on a self-discharge of the plurality of lithium ion batteries.

Abstract: A method for making a cathode composite material is disclosed. In the method, a maleimide-based material is provided. The maleimide-based material is a maleimide monomer, a maleimide polymer formed from the maleimide monomer, or combinations thereof. The maleimide-based material, an inorganic electrical conductive carbonaceous material, and a cathode active material are mixed to form a mixture. The mixture is heated to a temperature of about 200° C. to about 280° C. in a protective gas to obtain the cathode composite material. A cathode composite material and a lithium ion battery are also disclosed.

Abstract: A lithium metal electrode includes a lithium metal plate and a protective layer coated on a surface of the lithium metal plate. The protective layer includes an organic-inorganic hybrid polymer comprising a repeating unit. The repeating unit includes a silicon atom, a methacryloyloxy group or an acryloyloxy group, and at least two alkoxy groups. The alkoxy groups and the methacryloyloxy group or the acryloyloxy group are respectively joined to the silicon atom. A method for preparing the lithium metal electrode and a lithium ion battery is also disclosed.