Nonaqueous electrolyte secondary battery and method for manufacturing the same

The present invention provides a nonaqueous electrolyte secondary battery having a high capacity retention. The nonaqueous electrolyte secondary battery includes: a positive electrode containing a positive-electrode active material; a negative electrode; and a nonaqueous electrolyte. The positive-electrode active material contains a lithium-containing oxide obtained by ion-exchanging part of sodium in a cobalt-containing oxide containing lithium, sodium, and titanium with lithium.