Nonaqueous electrolyte secondary battery
AssigneeToyota Jidosha Kabushiki Kaisha
InventorYutaka Oyama
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Abstract
A nonaqueous electrolyte secondary battery proposed herein is configured such that a positive-electrode active material layer includes graphite particles and a gas generant. Further, an electrolyte solution includes an α solute. Here, a relationship between an upper limit electric potential X of a positive electrode in a predetermined normal use area, an electric potential Y at which an amount of the α solute in the electrolyte solution begins to decrease due to the graphite particles, and an electric potential Z at which the gas generant begins to generate gas is X<Y<Z.
Claims13
A nonaqueous electrolyte secondary battery comprising:
- a battery outer case;
- an electrode body accommodated in the battery outer case, where the electrode body includes a positive current collector and a positive-electrode active material layer held by the positive current collector, the positive-electrode active material layer includes graphite particles and a gas generant in a solid content, and the gas generant is cyclohexylbenzene;
- and
- an electrolyte solution accommodated in the battery outer case, where the electrolyte solution includes an α solute, and the α solute is selected from the group consisting of imidazolium salt, pyridinium salt, and pyrrolidinium salt,
- wherein the nonaqueous electrolyte secondary is configured such that an electrical potentials relationship of X<Y<Z is satisfied when the nonaqueous electrolyte secondary is in use, where X is an upper limit electric potential of a positive electrode in a predetermined normal use area, Y is an electric potential at which an amount of the α solute in the electrolyte solution begins to decrease due to the graphite particles, Z is an electric potential at which the gas generant begins to generate gas, the electric potentials are based on an equilibrium potential (vs. Li/Li+) of metallic lithium, and X is from 3.9 to 4.3 V;
- an amount of the gas generant in the nonaqueous electrolyte secondary battery is equal to or larger than 3.0 wt % and less than 7.0 wt % relative to the electrolyte solution;
- and
- the positive-electrode active material layer includes at least one third of the gas generant included in the nonaqueous electrolyte secondary battery.
A nonaqueous electrolyte secondary battery comprising:
- a battery outer case;
- an electrode body accommodated in the battery outer case, where the electrode body includes a positive current collector and a positive-electrode active material layer held by the positive current collector, the positive-electrode active material layer includes graphite particles and a gas generant in a solid content, and the gas generant is cyclohexylbenzene;
- and
- an electrolyte solution accommodated in the battery outer case, where the electrolyte solution includes an α solute, and the α solute is selected from the group consisting of imidazolium salt, pyridinium salt, and pyrrolidinium salt,
- wherein the nonaqueous electrolyte secondary is configured such that an electrical potentials relationship of X<Y<Z is satisfied when the nonaqueous electrolyte secondary is in use, where X is an upper limit electric potential of a positive electrode in a predetermined normal use area, Y is an electric potential at which an amount of the α solute in the electrolyte solution begins to decrease due to the graphite particles, Z is an electric potential at which the gas generant begins to generate gas, the electric potentials are based on an equilibrium potential (vs. Li/Li+) of metallic lithium, and X is 3.9 to 4.3 V;
- and
- an additive amount of the α solute in the electrolyte solution is less than 5 mol/L.
Dependencies are inferred from the claim text.