Nonaqueous electrolyte secondary battery and production method thereof
According to the embodiment, there is provided a nonaqueous electrolyte secondary battery comprising a positive electrode; a negative electrode including a negative electrode active material layer; and a nonaqueous electrolyte. The negative electrode active material layer contains carbon dioxide and releases the carbon dioxide in the range of 0.01 ml to 3 ml per 1 g when heated at 400° C. for 1 minute. The nonaqueous electrolyte contains carbon dioxide of 50 ml/L to 1000 ml/L.
1. A nonaqueous electrolyte secondary battery, comprising:
a positive electrode;
a negative electrode comprising a negative electrode active material layer; and
a nonaqueous electrolyte;
wherein:
the negative electrode active material layer comprises carbon dioxide and releases the carbon dioxide in the range of 0.01 ml to 3 ml per 1 g of the negative electrode active material layer when heated at 400° C. for 1 minute;
the nonaqueous electrolyte comprises carbon dioxide in the range of 50 ml to 1000 ml per 1 L; and
the nonaqueous electrolyte comprises carbon monoxide in the range of 5 ml to 100 ml per 1 L.
2. The battery according to claim 1 , wherein the negative electrode active material layer comprises a lithium titanium composite oxide.
3. The battery according to claim 2 , wherein the nonaqueous electrolyte comprises propylene carbonate and diethyl carbonate.
4. The battery according to claim 1 , wherein the nonaqueous electrolyte comprises propylene carbonate and diethyl carbonate.
5. A method for producing a nonaqueous electrolyte secondary battery, the method comprising:
washing a negative electrode active material powder with water;
drying the washed negative electrode active material powder under heating in an inert gas atmosphere;
preparing a slurry containing the negative electrode active material powder after the heating, in an atmosphere of a dew point of −15° C. or less;
producing a negative electrode by using the slurry, in an atmosphere of a dew point of −15° C. or less;
dissolving carbon dioxide in a nonaqueous electrolyte at a concentration of 50 ml/L to 1000 ml/L; and
assembling a nonaqueous electrolyte secondary battery by using the negative electrode, the nonaqueous electrolyte in which carbon dioxide is dissolved, and a positive electrode, in an atmosphere of a dew point of −15° C. or less.
6. The method according to claim 5 , further comprising dissolving carbon monoxide in the nonaqueous electrolyte at a concentration of 5 ml/L to 100 ml/L.
7. The method according to claim 6 , wherein the heating temperature for the washed negative electrode active material powder is in the range of 450° C. to 750° C.
8. The method according to claim 7 , further comprising an aging treatment by assembling a nonaqueous electrolyte secondary battery and maintaining the battery at a temperature range of 10° C. to 65° C. for a period of one hour to one week.
9. The method according to claim 6 , further comprising an aging treatment by assembling a nonaqueous electrolyte secondary battery and maintaining the battery at a temperature range of 10° C. to 65° C. for a period of one hour to one week.
10. The method according to claim 5 , wherein the heating temperature for the washed negative electrode active material powder is in the range of 450° C. to 750° C.
11. The method according to claim 10 , further comprising an aging treatment by assembling a nonaqueous electrolyte secondary battery and maintaining the battery at a temperature range of 10° C. to 65° C. for a period of one hour to one week.
12. The method according to claim 5 , further comprising an aging treatment by assembling a nonaqueous electrolyte secondary battery and maintaining the battery at a temperature range of 10° C. to 65° C. for a period of one hour to one week.
13. The method according to claim 5 , wherein the negative electrode active material powder consists of a powder of lithium titanium oxide.