Nonaqueous battery having porous separator and production method thereof
AssigneeAsahi Kasei Kabushiki Kaisha
InventorsMasaya Yamashita, Shunsuke Oki
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Abstract
Disclosed is a battery comprising a positive electrode comprising a cathode active material layer, a negative electrode comprising an anode active material layer, and a sole porous separator disposed between the positive electrode and the negative electrode, wherein the positive electrode, the negative electrode and the separator are disposed in a casing containing an electrolyte, and wherein the porous separator comprises at least one layer of an aggregate form of particles of at least one insulating substance, the layer of the aggregate form of particles having a three-dimensional network of voids which function as pores of the porous separator and which are capable of passing ions therethrough.
Claims16
A non-aqueous secondary battery comprising:
- a casing,
- a non-aqueous electrolyte contained in said casing,
- a positive electrode comprising a cathode active material layer which comprises a lithium-containing composite metal oxide selected from the group consisting of a composite metal oxide of lithium and a transition metal, and a composite metal oxide of lithium, a transition metal and a non-transition metal,
- a negative electrode comprising an anode active material layer which comprises a carbonaceous material, and
- a sole porous separator disposed between said positive electrode and said negative electrode, wherein two opposite surfaces of said sole porous separator face said cathode active material layer and said anode active material layer, respectively,
- said positive electrode, said negative electrode and said sole porous separator being disposed in said casing, operatively with said non-aqueous electrolyte,
- said sole porous separator comprising at least one layer of an aggregate form of particles of at least one insulating substance and a binder which is mixed with said particles to thereby bind said particles together, wherein said porous separator is directly formed, in an immobilized form, on at least one active material layer selected from the group consisting of said cathode active material layer and said anode active material layer, and wherein said at least one layer of the aggregate form of particles has a three-dimensional network of voids which function as pores in said porous separator and which contain therein said non-aqueous electrolyte, said voids being capable of passing ions through the non-aqueous electrolyte contained therein.
A method for producing a non-aqueous secondary battery, comprising:
- (1) individually providing a positive electrode comprising a cathode active material layer and a negative electrode comprising an anode active material layer,
- said cathode active material layer comprising a lithium-containing composite metal oxide selected from the group consisting of a composite metal oxide of lithium and a transition metal, and a composite metal oxide of lithium, a transition metal and a non-transition metal,
- said anode active material layer comprising a carbonaceous material;
- (2) coating a dispersion of a mixture of particles of at least one insulating substance and a binder for said particles in a dispersion medium on at least one active material layer selected from the group consisting of said cathode active material layer and said anode active material layer;
- (3) removing, by evaporation, the dispersion medium of said dispersion coated on said at least one active material layer to form a layer of an aggregate form of said particles, wherein said particles are bound together by means of said binder, thereby providing a porous separator formed directly, in an immobilized form, on said at least one active material layer, wherein said layer of an aggregate form of particles has a three dimensional network of voids which function as pores in said porous separator and which are capable of accommodating therein a non-aqueous electrolyte;
- and
- (4) disposing said positive electrode and said negative electrode, at least one of which has the porous separator formed on the active material layer thereof, in a casing so that said cathode active material layer and said anode active material layer are arranged, operatively with a non-aqueous electrolyte which is contained in said casing and contained in the voids of said porous separator, in a positional relationship opposite to each other through a sole separator which consists of said porous separator formed on said at least one active material layer.
Dependencies are inferred from the claim text.