| US 7,381,498 B2 | ||
| Positive electrode active material powder for lithium secondary battery | ||
| Manabu Suhara, Chigasaki (Japan); Takuya Mihara, Chigasaki (Japan); Koichiro Ueda, Chigasaki (Japan); and Yukimitsu Wakasugi, Chigasaki (Japan) | ||
| Assigned to Seimi Chemical Co., Ltd., Chigasaki-shi (Japan) | ||
| Filed on Jun. 13, 2005, as Appl. No. 11/150,451. | ||
| Application 11/150451 is a continuation of application No. PCT/JP04/12015, filed on Aug. 20, 2004. | ||
| Claims priority of application No. 2003-208311 (JP), filed on Aug. 21, 2003. | ||
| Prior Publication US 2005/0271944 A1, Dec. 08, 2005 | ||
| Int. Cl. H01M 4/58 (2006.01); H01M 4/00 (2006.01); H01M 4/50 (2006.01); H01M 4/52 (2006.01) | ||
| U.S. Cl. 429—231.95 [429/231.1; 429/231.3; 429/223; 429/224; 429/231.5; 429/231; 423/594.4; 423/594.6; 423/599] | 9 Claims |
| 1. A positive electrode active material powder for a lithium secondary battery characterized by comprising a first granular powder having a compression breaking strength of at least 50 MPa and a second granular powder having a compression breaking strength of less than 40 MPa, formed by agglomeration of many fine particles of a lithium composite oxide represented by the formula LipNixCoyMnzMqO2-aFa (wherein M is Al, an alkaline earth metal element or a transition metal element other than Ni, Co and Mn, 0.9≤p≤1.1, 0.2≤x≤0.8, 0≤y≤0.4 0.10≤z≤0.42,y+z>0, 0≤q≤0.05, 1.9≤2-a≤2.1, x+y+z+q=1, and 0≤a≤0.02) to have an average particle size D50 of from 3 to 15 μm, in a weight ratio of the first granular powder/the second granular powder being from 50/50 to 90/10; wherein the ratio of the compression strength of the first granular powder/the compression strength of the second granular powder is from 65/30 to 200/10. |