| US 7,601,463 B2 | ||
| Nonaqueous electrolyte secondary battery | ||
| Hiroki Inagaki, Kanagawa (Japan); Hideaki Morishima, Chiba (Japan); Yoshinao Tatebayashi, Kanagawa (Japan); Yuji Sato, Kanagawa (Japan); and Norio Takami, Kanagawa (Japan) | ||
| Assigned to Kabushiki Kaisha Toshiba, Tokyo (Japan) | ||
| Filed on Jun. 09, 2005, as Appl. No. 11/148,169. | ||
| Claims priority of application No. 2004-250461 (JP), filed on Aug. 30, 2004. | ||
| Prior Publication US 2006/0046155 A1, Mar. 02, 2006 | ||
| Int. Cl. H01M 4/58 (2006.01) | ||
| U.S. Cl. 429—231.1 [429/231.3; 429/231.5; 429/221; 429/223; 429/224; 429/218.1; 429/232; 429/332; 429/330; 429/331] | 13 Claims |
| 1. A nonaqueous electrolyte secondary battery, comprising:
an outer housing;
a nonaqueous electrolyte which fills the outer housing, the nonaqueous electrolyte comprising a nonaqueous solvent of diethyl
carbonate and at least one of ethylene carbonate or propylene carbonate, the nonaqueous electrolyte having a diethyl carbonate
content of 80 to 95% by volume;
a positive electrode housed in the outer housing, the positive electrode comprising a positive electrode active substance
having a positive electrode potential in the fully charged state of 4.4 V or higher with respect to a potential of metallic
lithium;
a negative electrode housed in the outer housing, the negative electrode comprising a negative electrode active substance,
which is at least one of a lithium titanium complex oxide or a lithium iron complex sulfide, having a negative electrode potential
in the fully charged state of 1.0 V or higher with respect to the potential of metallic lithium; and
a separator disposed between the negative electrode and the positive electrode, the separator being impregnated with the nonaqueous
electrolyte, wherein
the positive electrode active substance comprises at least one material selected from the group consisting of LiCoO2, LiMnO2, LiMn2O4, LiNiO2, LiAlO2, LiNi1/3Mn1/3Co1/3O2, LiNi0.75Co0.20Al0.05O2, LiNi0.5Mn0.5O2, LiN1−yCoyO2, LiMnyCo1−yO2, and Li1−xMn1.5−yNi0.5−zMy+zO4, where
y for LiNi1−yCoyO2 and LiMnyCo1−yO2 satisfies 0<y<1, and
M for Li1−xMn1.5−yNi0.5−zMy+zO4 is at least one element selected from the group consisting of Mg, Al, Ti, Fe, Go, Ni, Cu, Zn, Ga, Nb, Sn, Zr and Ta; 0≤x≤1
and 0≤y+z≤0.15.
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