Positive active material and nonaqueous electrolyte secondary battery

A nonaqueous electrolyte secondary battery comprising:

• a cathode including a positive active material;
• an anode including a negative active material;
• and
• a nonaqueous electrolyte,
• wherein,
• the positive active material includes a compound expressed by a general formula Lim,Mx,M′yM″z,O2, where M designates at least one kind of element selected from Co, Ni and Mn, M′ designates at least one kind of element selected from Al, Cr, V, Fe, Cu, Zn, Sn, Ti, Mg, Sr, B, Ga, In, Si and Ge, and M″ designates at least one kind of element selected from Mg, Ca, B and Ga, x is designated by an expression of 0.9≦x<1, y is indicated by an expression of 0.001≦y≦0.5, z is indicated by an expression of 0≦z≦0.5, and m is indicated by an expression of 0.5≦m, and
• the positive active material includes manganese-containing oxides having at least one kind of first element selected from a group having lithium, manganese, metal elements except manganese and boron and oxygen, the mole ratio of the first element relative to the manganese ‘first element/manganese’ being located within a range of 0.01/1.99 or more and 0.5/1.5 or less, and nickel-containing oxides including at least one kind of second element selected from a group having lithium, nickel and metal elements except nickel and boron and oxygen, the mole ratio of the second element relative to the nickel ‘second element/nickel’ being located within a range of 0.01/0.99 or more and 0.5/0.5 or less, the negative active material includes at least one or more kinds of materials between lithium metals, lithium alloys, or materials capable of being doped with or dedoped from lithium, and the average specific surface area of the positive active material is 0.2 m2/g or larger and 1.5 m2/g or smaller and the amount of Li2CO3 remaining in the positive active material is 5.0 wt % or lower relative to all the weight of the positive active material.

A nonaqueous electrolyte secondary battery comprising:

• a cathode including a positive active material;
• an anode including a negative active material;
• and
• a nonaqueous electrolyte,
• wherein,
• the positive active material includes a compound expressed by a general formula Lim,MxM′yM″zO2, where M designates at least one kind of element selected from Co, Ni and Mn, M′ designates at least one kind of element selected from Al, Cr, V, Fe, Cu, Zn, Sn, Ti, Mg, Sr, B, Ga, In, Si and Ge, and M″ designates at least one kind of element selected from Mg, Ca, B and Ga, x is designated by an expression of 0.9≦x<1, y is indicated by an expression of 0.001≦y≦0.5, z is indicated by an expression of 0≦z≦0.5, and m is indicated by an expression of 0.5≦m,
• the positive active material includes manganese-containing oxides having at least one kind of first element selected from a group having lithium, manganese, metal elements except manganese and boron and oxygen, the mole ratio of the first element relative to the manganese ‘first element/manganese’ being located within a range of 0.01/1.99 or more and 0.5/1.5 or less, and nickel-containing oxides including at least one kind of second element selected from a group having lithium, nickel and metal elements except nickel and boron and oxygen, the mole ratio of the second element relative to the nickel ‘second element/nickel’ being located within a range of 0.01/0.99 or more and 0.5/0.5 or less,
• the negative active material includes at least one or more kinds of materials between lithium metals, lithium alloys, or materials capable of being doped with or dedoped from lithium, and
• the average specific surface area of the negative active material is 0.5 m2/g or more and 10 m2/g or less.

A nonaqueous electrolyte secondary battery comprising:

• a cathode including a positive active material;
• an anode including a negative active material;
• and
• a nonagueous electrolyte,
• wherein,
• the positive active material includes a compound expressed by a general formula LimMx,M′yM″zO2, where M designates at least one kind of element selected from Co, Ni and Mn, M′ designates at least one kind of element selected from Al, Cr, V, Fe, Cu, Zn, Sn, Ti, Mg, Sr, B, Ga, In, Si and Ge, and M″ designates at least one kind of element selected from Mg, Ca, B and Ga, x is designated by an expression of 0.9≦x<1, y is indicated by an expression of 0.001≦y≦0.5, z is indicated by an expression of 0≦z≦0.5, and m is indicated by an expression of 0.5≦m, and
• the positive active material includes a mixed material obtained by mixing lithium manganese oxide expressed by a general formula LisMn2-tMatO4, where the value of x is expressed by 0.9≦s, the value of t is located within a range expressed by 0.01≦t≦0.5, and Ma indicates one or a plurality of elements between Fe, Co, Ni, Cu, Zn, Al, Sn, Cr, V, Ti, Mg, Ca, Sr, B, Ga, In, Si and Ge, and lithium nickel oxide expressed by a general formula LiNi1-uMbuO2, where the value of u is located within a range expressed by 0.01≦u≦0.5 and Mb indicates one or a plurality of elements between Fe, Co, Mn, Cu, Zn, Al, Sn, Cr, V, Ti, Mg, Ca, Sr, B, Ga, In, Si and Ge in the mass ratio the lithium manganese oxide of 10 wt % to 80 wt % to lithium nickel oxide of 90 wt % to 20 wt %, the negative active material includes at least one or more kinds of materials between lithium metals, lithium alloys, or material capable of doping and dedoping lithium, and the volume density of a cathode composite mixture layer including the positive active material ranges from 2.5 g/cm3 to 3.3 g/cm3.

A nonaqueous electrolyte secondary battery comprising:

• a cathode including a positive active material;
• an anode including a negative active material;
• and
• a nonaqueous electrolyte,
• wherein,
• the positive active material includes a compound expressed by a general formula LimMxM′yM″z,O2, where M designates at least one kind of element selected from Co, Ni and Mn, M′ designates at least one kind of element selected from Al, Cr, V, Fe, Cu, Zn, Sn, Ti, Mg, Sr, B, Ga, In, Si and Ge, and M″ designates at least one kind of element selected from Mg, Ca, B and Ga, x is designated by an expression of 0.9≦x<1, y is indicated by an expression of 0.001≦y≦0.5, z is indicated by an expression of 0≦z≦0.5, and m is indicated by an expression of 0.5≦m, and
• the positive active material includes a mixed material obtained by mixing lithium manganese oxide expressed by a general formula LisMn2-tMatO4, where the value of x is expressed by 0.9≦s, the value of t is located within a range expressed by 0.01≦t≦0.5, and Ma indicates one or a plurality of elements between Fe, Co, Ni, Cu, Zn, Al, Sn, Cr, V, Ti, Mg, Ca, Sr, B, Ga, In, Si and Ge, and lithium nickel oxide expressed by a general formula LiNi1-uMbuO2, where the value of u is located within a range expressed by 0.01≦u≦0.5 and Mb indicates one or a plurality of elements between Fe, Co, Mn, Cu, Zn, Al, Sn, Cr, V, Ti, Mg, Ca, Sr, B, Ga, In, Si and Ge, in the mass ratio the lithium manganese oxide of 10 wt % to 80 wt % to lithium nickel oxide of 90 wt % to 20 wt %,
• the negative active material includes at least one or more kinds of materials between lithium metals, lithium alloys, or materials capable of doping and dedoping lithium, and
• the percentage of porosity of a cathode composite mixture layer including the positive active material ranges from 20% to 40%.