Lithium secondary battery and method for manufacturing battery-incorporating device
Provided is a secondary lithium battery including: a positive electrode plate that is a sintered lithium complex oxide plate; a negative electrode containing carbon and styrene butadiene rubber (SBR); and an electrolytic solution containing lithium borofluoride (LiBF 4 ) in a non-aqueous solvent composed of γ-butyrolactone (GBL), or composed of ethylene carbonate (EC) and γ-butyrolactone (GBL).
1. A secondary lithium battery, comprising:
a positive electrode plate that is a lithium complex oxide sintered plate and contains no binder;
a negative electrode containing graphite and styrene butadiene rubber (SBR); and
an electrolytic solution containing lithium borofluoride (LiBF 4 ) in a non-aqueous solvent composed of γ-butyrolactone (GBL), or composed of γ-butyrolactone (GBL) and ethylene carbonate (EC);
wherein the non-aqueous solvent has an EC:GBL volume ratio of 0:1 to 1:3, and
wherein the electrolyic solution has a LiBF 4 concentration of 0.5 to 2 mol/L.
2. The secondary lithium battery according to claim 1 , further comprising a separator made of polyimide, polyester, or cellulose.
3. The secondary lithium battery according to claim 2 , wherein the separator is made of polyimide.
4. The secondary lithium battery according to claim 1 , wherein the electrolytic solution further comprises vinylene carbonate (VC), and/or fluoroethylene carbonate (FEC), and/or vinyl ethylene carbonate (VEC).
5. The secondary lithium battery according to claim 1 , having a thickness of 0.45 mm or less.
6. The secondary lithium battery according to claim 1 , wherein the lithium complex oxide is lithium cobaltate.
7. The secondary lithium battery according to claim 1 , wherein the lithium complex oxide sintered plate includes a plurality of primary grains composed of the lithium complex oxide, and is an oriented positive electrode plate in which the plurality of primary grains is oriented with a mean orientation angle of more than 0° to 30° to a plate face of the positive electrode plate.
8. The secondary lithium battery according to claim 1 , wherein the secondary lithium battery is intended to be mounted on a substrate by a process involving heating at 110° C. to lower than 260° C.
9. The secondary lithium battery according to claim 8 , wherein the process involving heating is hot lamination or reflow soldering.
10. A method for manufacturing a battery-incorporating device, comprising the steps of:
providing the secondary lithium battery according to claim 1 ; and
mounting the secondary lithium battery on a substrate by a process involving heating at 110° C. to lower than 260° C.
11. The method according to claim 10 , wherein the process involving heating is hot lamination or reflow soldering.
12. The method according to claim 11 , wherein the process involving heating is hot lamination, and the battery-incorporating device is a battery-incorporating smart card.