NONAQUEOUS ELECTROLYTE SECONDARY BATTERY AND METHOD OF PRODUCING THE SAME
A nonaqueous electrolyte secondary battery, comprising a positive electrode containing a transition metal-containing composite oxide as a positive electrode active material, a negative electrode containing a negative electrode active material allowing reversible insertion and extraction of lithium, a separator, and a nonaqueous electrolyte solution, wherein the nonaqueous electrolyte solution contains at least one additive (A) selected from the group consisting of ethylene sulfite, propylene sulfite, and propane sultone and at least one additive (B) selected from the group consisting of maleic anhydride, vinylene carbonate, vinylethylene carbonate, and LiBF 4 ; and an end voltage of charge is 4.3 to 4.5 V.
1 . A nonaqueous electrolyte secondary battery, comprising a positive electrode containing a transition metal-containing composite oxide as a positive electrode active material, a negative electrode containing a negative electrode active material allowing reversible insertion and extraction of lithium, a separator, and a nonaqueous electrolyte solution, wherein
the nonaqueous electrolyte solution contains at least one additive (A) selected from the group consisting of ethylene sulfite, propylene sulfite, and propane sultone and at least one additive (B) selected from the group consisting of maleic anhydride, vinylene carbonate, vinylethylene carbonate, and LiBF 4 ; and
an end voltage of charge is 4.3 to 4.5 V.
2 . The nonaqueous electrolyte secondary battery according to claim 1 , wherein the total content of the additives (A) and (B) in the nonaqueous electrolyte solution is 0.1 to 10 mass %.
3 . The nonaqueous electrolyte secondary battery according to claim 1 , wherein the positive electrode contains as the positive electrode active material a transition metal-containing composite oxide represented by General Formula Li x Ni 1−(y+z) Co y M z O 2 (wherein, 0.95≦x≦1.12, 0.01≦y≦0.35, 0.01≦z≦0.50, and M represents at least one element selected from the group consisting of Al, Mn, Ti, Mg, Mo, Y, Zr, and Ca) that has a specific surface area of 0.15 to 1.50 m 2 /g.
4 . The nonaqueous electrolyte secondary battery according to claim 3 , wherein M in the General Formula Li x Ni 1−(y+z) Co y M z O 2 contains Mn and at least one element selected from the group consisting of Al, Ti, Mg, Mo, Y, Zr, and Ca.
5 . The nonaqueous electrolyte secondary battery according to claim 3 , wherein the positive electrode contains LiCoO 2 additionally as the positive electrode active material.
6 . The nonaqueous electrolyte secondary battery according to claim 1 , wherein the negative electrode contains a carbon material as the negative electrode active material allowing reversible insertion and extraction of lithium.
7 . The nonaqueous electrolyte secondary battery according to claim 6 , wherein the load capacity (X/Y), a rate of the theoretical battery capacity (X) to the mass of the carbon material (Y), is 250 to 360 mAh/g.
8 . The nonaqueous electrolyte secondary battery according to claim 1 , wherein the negative electrode contains one or both of Si alone and a compound of Si and O as the negative electrode active material allowing reversible insertion and extraction of lithium.
9 . A method of producing a nonaqueous electrolyte secondary battery having a positive electrode containing a transition metal-containing composite oxide as a positive electrode active material, a negative electrode containing a negative electrode active material allowing reversible insertion and extraction of lithium, a separator and a nonaqueous electrolyte solution, wherein
the nonaqueous electrolyte solution contains at least one additive (A) selected from the group consisting of ethylene sulfite, propylene sulfite, and propane sultone and at least one additive (B) selected from the group consisting of maleic anhydride, vinylene carbonate, vinylethylene carbonate, and LiBF 4 ; and
the method comprising
an assembling step of placing an electrode assembly having the positive electrode, the negative electrode and the separator, and the nonaqueous electrolyte solution in a battery case and
a high-voltage-charging step of charging the nonaqueous electrolyte secondary battery to a voltage in the range of 4.3 to 4.5 V at least once after the assembling step.
10 . The method of producing a nonaqueous electrolyte secondary battery according to claim 9 , wherein the high-voltage-charging step includes charging to a voltage in the range of 4.3 to 4.5 V at least twice.
11 . The method of producing a nonaqueous electrolyte secondary battery according to claim 9 , further comprising a preliminary charging/discharging step of performing at least one charge/discharge cycle at an end voltage of preliminary charge of lower than 4.3 V and an end voltage of preliminary discharge of 3.0 V or higher between the assembling step and the high-voltage-charging step.
12 . The method of producing a nonaqueous electrolyte secondary battery according to claim 9 , wherein the positive electrode contains, as the positive electrode active material, a transition metal-containing composite oxide represented by General Formula Li x Ni 1−(y+z) Co y M z O 2 (wherein, 0.95≦x≦1.12, 0.01≦y≦0.35, 0.01≦z≦0.50, and M represents at least one element selected from the group consisting of Al, Mn, Ti, Mg, Mo, Y, Zr, and Ca) that has a specific surface area of 0.15 to 1.50 m 2 /g.
13 . The method of producing a nonaqueous electrolyte secondary battery according to claim 12 , wherein M in the General Formula Li x Ni 1−(y+z) Co y M z O 2 contains Mn and at least one element selected from the group consisting of Al, Ti, Mg, Mo, Y, Zr, and Ca.