Non-aqueous electrolyte secondary battery, method of manufacturing same, and non-aqueous electrolyte secondary battery system
Provided are a non-aqueous electrolyte secondary battery excellent in reliability and productivity, a method for manufacturing the same, and a system including the non-aqueous electrolyte secondary battery. A non-aqueous electrolyte secondary battery of the present invention includes a positive electrode, a negative electrode, a separator, and a non-aqueous electrolyte. The positive electrode includes a positive electrode mixture layer in which a lithium-containing composite oxide is used as a positive electrode active material. In a charged state, the negative electrode includes an aluminum foil or an aluminum alloy foil and a Li—Al alloy formed by reaction with Li ions deintercaleted from the positive electrode. The Li—Al alloy has a Li content of 7 to 29 atomic % with respect to 100 atomic % of a total of Li and Al at the end of charge.
1. A non-aqueous electrolyte secondary battery, comprising:
a positive electrode;
a negative electrode;
a separator; and
a non-aqueous electrolyte,
wherein the positive electrode comprises a positive electrode mixture layer in which a lithium-containing composite oxide is used as a positive electrode active material,
the negative electrode consists of an aluminum foil or an aluminum alloy foil,
in a charged state, the negative electrode comprises the aluminum foil or the aluminum alloy foil and a Li—Al alloy formed by reaction with Li ions deintercaleted from the positive electrode, and
the Li—Al alloy has a Li content of 7 to 29 atomic % with respect to 100 atomic % of a total of Li and Al at the end of charge.
2. The non-aqueous electrolyte secondary battery according to claim 1 , wherein the Li content with respect to 100 atomic % of the total of Li and Al is 7 to 25 atomic % at the end of charge.
3. The non-aqueous electrolyte secondary battery according to claim 1 , wherein a thickness of the aluminum foil or the aluminum alloy foil in a portion of the negative electrode that does not face the positive electrode mixture layer is 40 μm or more.
4. The non-aqueous electrolyte secondary battery according to claim 1 , wherein the separator comprises a nonwoven fabric.
5. The non-aqueous electrolyte secondary battery according to claim 1 , wherein the separator has a porosity of 55% or more.
6. A method for manufacturing the non-aqueous electrolyte secondary battery according to claim 1 ,
wherein the aluminum foil or the aluminum alloy foil having a thickness of 40 μm or more is used for the negative electrode.
7. A non-aqueous electrolyte secondary battery system, comprising:
the non-aqueous electrolyte secondary battery according to claim 1 ; and
a charging circuit for charging the non-aqueous electrolyte secondary battery,
wherein in the charging circuit, an end-of-charge condition is set so that the Li content with respect to 100 atomic % of the total of Li and Al in the negative electrode of the non-aqueous electrolyte secondary battery is 7 to 29 atomic % at the end of charge.