Pulverulent compounds, processes for the preparation thereof and the use thereof in electrochemical applications
View Patent ↗The present invention relates to pulverulent compounds of the formula Ni b M1 c M2 d (0) x (OH) y (SO 4 ) z , a process for the preparation thereof and the use thereof as precursors for the preparation of active materials for lithium secondary batteries.
1. A pulverulent compound of the formula;
Ni b M1 c M2 d (O) x (OH) y (SO 4 ) z ,
M1 denoting at least one element selected from the group consisting of Fe, Co, Cr, Mg, Cu and mixtures thereof, M2 is Mn and
0.3≦b≦0.94, 0.02≦c≦0.5, 0≦d≦0.5, 0.01≦x≦0.9, 1.1≦y≦1.9 and 0.001≦z≦0.03, wherein secondary particles composed of a multiplicity of primary particles have a compressive strength of at least 50 MPa, and a normalized width of the particle distribution, measured according to the formula (1)
D
90
-
D
10
D
50
(
1
)
in which D denotes diameters of the secondary particles, is less than 1.4.
2. The pulverulent compound according to claim 1 , having a compressive strength of at least 100 MPa.
3. The pulverulent compound according to claim 1 , having a compressive strength of at least 150 MPa.
4. The pulverulent compound according to claim 1 , having a porosity of up to 0.05 cm 3 /g, measured according to ASTM D 4222.
5. The pulverulent compound according to claim 1 , having a porosity of up to 0.03 cm 3 /g, measured according to ASTM D 4222.
6. The pulverulent compound according to claim 1 , wherein the secondary particles of the compound have a spheroidal shape.
7. The pulverulent compound according to claim 6 , wherein the secondary particles have a shape factor greater than 0.8.
8. The pulverulent compound according to claim 1 , wherein the particles have a the D10 value, measured according to ASTM B 822, that changes by not more than 0.5 μm compared with a starting material after compression of the material at a pressure of 50 MPa.
9. The pulverulent compound according to claim 8 , having a D90 value, measured according to ASTM B 822, that changes by not more than 1 μm compared with the starting material after compression of the material at a pressure of 50 MPa.
10. The pulverulent compound according to claim 1 , having a compressed density of at least 2.4 g/cm 3 at a compression pressure of 50 MPa.
11. The pulverulent compound according to claim 1 , having a tapped density, measured according to ASTM B 527, of at least 2.0 g/cm 3 .
12. The pulverulent compound according to claim 11 , having a tapped density, measured according to ASTM B 527, of at least 2.3 g/cm 3 .
13. A secondary lithium battery containing as an active material the pulverulent compound according to claim 1 .
14. A nickel metal hydride battery containing as an active material the pulverulent compound according to claim 1 .
15. The pulverulent compound according to claim 1 , having a normalized width of the particle distribution measure according to the formula (1) is not more than 1.347.