Lithium ion secondary battery and method for manufacturing the same
AssigneeNEC Energy Devices, Ltd.
InventorYoshimasa YAMAMOTO
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Abstract
There is provided a lithium ion secondary battery comprising a positive electrode containing, as a positive electrode active material, a lithium nickel composite oxide having a layered rock salt structure, a negative electrode containing a negative electrode active material capable of occluding and releasing lithium ions, an electrolyte, and an outer package, wherein the lithium nickel composite oxide is represented by the composition formula LiNixM1-xO2 (x represents a numerical value of 0.75 to 1, and M represents at least one metal element occupying nickel sites other than Ni), and has a crystal phase having, in a full charge state, an interplanar spacing d(003) larger than an interplanar spacing d(003) in a complete discharge state.
Claims11
A lithium ion secondary battery, comprising:
- a positive electrode comprising, as a positive electrode active material, a lithium nickel composite oxide having a layered rock salt structure;
- a negative electrode comprising a negative electrode active material capable of occluding and releasing lithium ions;
- an electrolyte;
- and an outer package,
- wherein the lithium nickel composite oxide is represented by the composition formula LiNixM1-xO2 where x represents a numerical value of 0.75 to 1, and M represents at least one metal element occupying nickel sites other than Ni;
- and
- the lithium nickel composite oxide has a crystal phase having, in a full charge state, an interplanar spacing d(003) larger than an interplanar spacing d(003) in a complete discharge state.
A method for manufacturing a lithium ion secondary battery comprising:
- a positive electrode comprising, as a positive electrode active material, a lithium nickel composite oxide having a layered rock salt structure;
- a negative electrode comprising a negative electrode active material capable of occluding and releasing lithium ions;
- an electrolyte;
- and an outer package, the method comprising:
- forming the positive electrode;
- forming the negative electrode;
- accommodating the positive electrode, the negative electrode and the electrolyte in the outer package,
- wherein the lithium nickel composite oxide is represented by the composition formula LiNixM1-xO2 where x represents a numerical value of 0.75 to 1, and M represents at least one metal element occupying nickel sites other than Ni;
- and
- interplanar spacings d(003) of the lithium nickel composite oxide in charge voltages in a range including a lower limit voltage and an upper limit voltage are measured by X-ray analysis, and the upper limit voltage is set in a range in the charge voltages where a crystal phase having an interplanar spacing d(003) larger than an interplanar spacing d(003) in a complete discharge state is present.
Dependencies are inferred from the claim text.