Inorganic Compounds

Abstract

The invention relates to a chemical compound of the formula Ni b M1 c M2 d (O) x (OH) y , wherein M1 denotes at least one element from the group consisting of Fe, Co, Mg, Zn, Cu and/or mixtures thereof, M2 denotes at least one element from the group consisting of Mn, Al, B, Ca, Cr and/or mixtures thereof, wherein b≦0.8, c≦0.5, d≦0.5, and x is a number between 0.1 and 0.8, y is a number between 1.2 and 1.9, and x+y=2. A process for the preparation thereof, and the use thereof as a precursor for the preparation of cathode material for secondary lithium batteries are described.

1 . Chemical compound of the formula
   Ni b M1 c M2 d (O) x (OH) y      wherein   M1 denotes at least one element from the group consisting of Fe, Co, Mg, Zn, Cu and mixtures thereof,   M2 denotes at least one element from the group consisting of Mn, Al, B, Ca, Cr and mixtures thereof,   b≦0.8   c≦0.5   d≦0.5, and   x is a number between 0.1 and 0.8,   y is a number between 1.2 and 1.9, and x+y=2.   
   
   
       2 . Chemical compound according to  claim 1 , wherein
 0.3≦b≦0.6   0.1≦c≦0.4   0.1≦d≦0.4.   
   
   
       3 . Chemical compound according to  claim 1 , wherein
 x is a number between 0.2 and 0.7 and   y is a number between 1.3 and 1.8 and x+y=2.   
   
   
       4 . Chemical compound according to  claim 1 , wherein
 x is a number between 0.3 and 0.6 and   y is a number between 1.4 and 1.7.   
   
   
       5 . Chemical compound according to  claim 1 , characterized in that it contains no gamma-oxyhydroxide structures. 
   
   
       6 . Chemical compound according to  claim 1 , characterized in that it contains no alpha-hydroxide structures. 
   
   
       7 . Chemical compound according to  claim 1 , characterized in that the content of sodium is less than 2,000 ppm. 
   
   
       8 . Chemical compound according to  claim 1 , characterized in that the content of sodium is less than 1,000 ppm. 
   
   
       9 . Powder comprising the chemical compound according to  claim 1 . 
   
   
       10 . Powder according to claim 1 , characterized in that it has a tap density, measured in accordance with ASTM B 527, of greater than 1.7 g/cm 3 . 
   
   
       11 . Powder according to claim 1 , characterized in that it has a tap density, measured in accordance with ASTM B 527, of greater than 1.9 g/cm 3 . 
   
   
       12 . Powder according to claim 1 , characterized in that it has an average particle size, measured in accordance with ASTM B 822, of 2-30 μm. 
   
   
       13 . Powder according to claim 1 , characterized in that it has an average particle size, measured in accordance with ASTM B 822, of 3-15 μm. 
   
   
       14 . Powder according to  claim 1 , characterized in that the powder particles have a spherical shape. 
   
   
       15 . Powder according to  claim 1 , characterized in that the powder particles have a shape factor of greater than 0.7. 
   
   
       16 . Powder according to  claim 1 , characterized in that the powder particles have a shape factor of greater than 0.9. 
   
   
       17 . Powder according to claim 1 , wherein the standardized width of the particle size distribution, defined according to formula (1), is less than 1.8
   D90−D10     D50  (1)   wherein D denotes the diameter of the powder particles.   
   
   
       18 . Powder according to  claim 1 , wherein the standardized width of the particle size distribution, defined according to formula (1), is less than 1.2
   D90−D10     D50  (1)   wherein D denotes the diameter of the powder particles.   
   
   
       19 . Process for the preparation of the chemical compound according to  claim 1 , comprising the following steps:
 a. co-precipitation of spherical mixed metal hydroxides from corresponding metal salt solutions,   b. partial oxidation of the precipitation products (mixed metal hydroxides) using an oxidizing agent,   c. separating off of the co-precipitated partly oxidized mixed metal hydroxide from the suspension,   d. washing and drying of the partly oxidized mixed metal hydroxide.   
   
   
       20 . Process according to  claim 19 , wherein the chemical compound is a partly oxidized mixed metal hydroxide. 
   
   
       21 . Process according to  claim 19 , characterized in that the partial oxidation is carried out in a suspension. 
   
   
       22 . Process according to  claim 19 , characterized in that the oxidizing agent is an oxidizing agent from the group consisting of air, oxygen, hydrogen peroxide, sodium peroxydisulfate, potassium peroxydisulfate and/or mixtures thereof. 
   
   
       23 . Process according to  claim 19 , characterized in that the reaction temperature of the suspension during the partial oxidation is 25-65° C. 
   
   
       24 . Process according to  claim 19 , characterized in that the reaction temperature of the suspension during the partial oxidation is 30-60° C. 
   
   
       25 . Process according to  claim 19 , wherein the pH of the suspension is 7-13. 
   
   
       26 . Process according to  claim 19 , wherein the pH of the suspension is 8-12. 
   
   
       27 . Process according to  claim 19 , characterized in that the partial oxidation of the co-precipitated mixed hydroxide lasts 1 to 10 hours. 
   
   
       28 . Process according to  claim 19 , characterized in that the partial oxidation of the co-precipitated mixed hydroxide lasts 2 to 8 hours. 
   
   
       29 . Process according to  claim 19 , characterized in that the partial oxidation of the co-precipitated mixed hydroxide lasts 4 to 6 hours. 
   
   
       30 . Process for the preparation of active materials for positive electrodes of secondary batteries, comprising the following steps:
 mixing of a chemical compound according to  claim 1  with a lithium-containing component,   calcining and sieving of the mixture.   
   
   
       31 . Process for the preparation of active materials for positive electrodes of secondary batteries according to  claim 29 , comprising the steps:
 provision of a powder of the chemical compound,   conversion of the powder into a chemical compound Li a Ni b M1 c M2 d (O) 2 , wherein M1 denotes at least one element chosen from the group consisting of Fe, Co, Mg, Zn, Cu and mixtures thereof, and/or M2 denotes at least one element chosen from the group consisting of Mn, Al, B, Ca, Cr and mixtures thereof, characterized in that the conversion takes place with retention of the shape of the secondary particles and/or particle size distribution.   
   
   
       32 . Process for the preparation of active materials for positive electrodes of secondary batteries according to  claim 29 , comprising the following steps:
 mixing of a chemical compound with a lithium-containing component,   calcining and sieving of the mixture.   
   
   
       33 . Process according to  claim 29 , wherein the lithium-containing component is lithium carbonate, lithium hydroxide, lithium nitrate and/or mixtures thereof. 
   
   
       34 . Process according to  claim 29 , wherein the calcining temperature is greater than 600° C. 
   
   
       35 . Process according to  claim 29 , wherein the calcining temperature is greater than 700° C. 
   
   
       36 . Process for the preparation of the chemical compound according to  claim 1 , comprising the following steps:
 a. co-precipitation of spherical mixed metal hydroxides from corresponding metal salt solutions,   b. separating off of the co-precipitated mixed metal hydroxide from the suspension,   c. washing of the mixed metal hydroxide,   d. drying and simultaneous partial oxidation of the mixed metal hydroxide under an oxygen-containing atmosphere at a temperature of greater than 80° C. for at least 3 hours.   
   
   
       37 . Use of the chemical compound according to  claim 1  as a precursor in the preparation of cathode material for lithium secondary batteries.