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Positive Electrode Material For Rechargeable Lithium Ion Batteries
Abstract: A bimodal lithium transition metal oxide based powder mixture for a rechargeable battery, comprising: -a first lithium transition metal oxide based powder, comprising particles of a material A having a layered crystal structure consisting of the elements Li, a transition metal based composition M and oxygen, the first powder having a particle size distribution characterized by a (D90- D10)/D50 <1.0; and -a second lithium transition metal oxide based powder, comprising a material B having single crystal particles, said particles having a general formula Li +b N" -b O 2, wherein -0.03=b=0.10, and N"=Ni x M" y Coz Ed, wherein 0.30=x=0.92 0.05=y=0.40, 0.05=z=0.40 and 0=d=0.10, with M" being 10 either one or both of Mn or Al, and with E being a dopant different from M", the first powder having an average particle size D50 between 10 and 40 µm, the second powder having an average particle size D50 between 2 and 4 µm; and wherein the weight ratio of the second powder in the bimodal mixture is between 15 and 60 wt%.
Notices, Deadlines & Correspondence
Patent Information
Applicants
UMICORE
UMICORE KOREA LTD.
Inventors
1. KIM, Dae-Hyun
2. PAULSEN, Jens
3. KUMAKURA, Shinichi
4. LEE, YuRi
5. ZHU, Liang
6. YANG, TaeHyeon
Specification
We Claim:
1. A bimodal lithium transition metal oxide based powder mixture for a rechargeable battery,
comprising:
- a first lithium transition metal oxide based powder, comprising particles of a material A having a layered crystal structure consisting of the elements Li, a transition metal based composition M and oxygen, the first powder having a particle size distribution characterized by a (D90-D10)/D50<1.0;and
- a second lithium transition metal oxide based powder, comprising a material B having single crystal particles, said particles having a general formula Lii+bN'i-b02, wherein -0.0320um, and wherein M' is either one or more metals of the group consisting of Al, Ca, Si, Ga, B, Ti, Mg, W, Zr, Cr and V, and wherein the weight ratio of the second powder in the bimodal mixture is between 15 and 25 wt%.
3. The bimodal powder mixture of claim 1 or 2, wherein the material A is polycrystalline and has particles having a general formula Lii+a'Mi-a'02, with -0.033.2 g/cm3, wherein the first corrected pressed density is calculated with the formula PD/100x(100+ID10); wherein PD is the pressed density under a pressure of 200MPa and ID10 is the increase of the D10 value in the particle size distribution of the bimodal powder calculated as follows:
D10 after PDM - D10 before PDM
ID1° = "—n«n , r T^T, x 10° (in %)
DW before PDM
wherein (D10 after PDM) and (D10 before PDM) are respectively the D10 values after and
before the application of a pressure of 200MPa.
9. The bimodal powder mixture of any one of claims 1 to 8, wherein the bimodal powder has a
second corrected pressed density >3.0 g/cm3, wherein the second corrected pressed density is
calculated with the formula PD/100x(100-IB); wherein PD is the pressed density under a
pressure of 200MPa and IB is the increase of the specific surface area BET of the bimodal
powder calculated as follows:
BET after PDM - BET before PDM
BET before PDM y J
wherein (BET after PDM) and (BET before PDM) are respectively the BET values after and before the application of a pressure of 200MPa.
10. The bimodal powder mixture of any one of claims 3 or 4, wherein the particles of the powder mixture have a surface layer comprising an intimate mixture of the elements of M, LiF and AI2O3.
11. A positive electrode mixture for a rechargeable battery comprising the bimodal powder mixture of any one of claims 1 to 10, a binder and a conductive agent, wherein the weight ratio of the bimodal powder mixture in the positive electrode mixture is at least 90wt% and wherein the positive electrode mixture has a density of at least 3.65 g/cm3 when pressed under 1765.2 N.