Process for the preparation of crystalline lithium-, iron- and phosphate-comprising materials

Abstract

The present application relates to a process for the preparation of compounds of general formula (I) Lia-bM 1 bFe1-cM 2 cPd-eM 3 eOx (I), wherein M 1 , M 2 , M 3 , a, b, c, d, e and x: M 1 : Na, K, Rb and/or Cs, M 2 : Mn, Mg, Ca, Ti, Co, Ni, Cr, V, M 3 : Si, S, a: 0.8-1.9, b: 0-0.3, c: 0-0.9, d: 0.8-1.9, e: 0-0.5, x: 1.0-8, depending on the amount and oxidation state of L 1 , M 1 , Fe, M 2 , P, M 3 , wherein compounds of general formula (I) are neutrally charged, comprising the following steps (A) providing an essentially aqueous mixture comprising at least one lithium-comprising compound, FeOOH as iron-comprising compound and at least one M 1 -comprising compound, if present, and/or at least one M 2 -comprising compound, if present, and/or least one M 3 -comprising compound, if present, at least one compound comprising at least one phosphorous atom and at least one reducing agent, (B) drying the mixture provided in step (A), in order to obtain a solid compound and (C) calcining the solid compound obtained from step (A) or (B) at a temperature of 300 to 950° C.

1 - 18 . (canceled) 
     
     
         19 . A process for the preparation of a compound represented by formula (I)
   Li a-b M 1   b Fe 1-c M 2   c P d-e M 3   e O x   (I),
   wherein M 1 , M 2 , M 3 , a, b, c, d, e and x:   M 1 : Na, K, Rb and/or Cs,   M 2 : Mn, Mg, Ca, Ti, Co, Ni, Cr, V,   M 3 : Si, S,   a: 0.8-1.9,   b: 0-0.3,   c: 0-0.9,   d: 0.8-1.9,   e: 0-0.5,   x: 1.0-8, depending on the amount and oxidation state of Li, M 1 , Fe, M 2 , P, M 3 ,
 wherein compounds of general formula (I) are neutrally charged, comprising 
 drying an essentially aqueous mixture comprising at least one lithium-comprising compound, FeOOH as iron-comprising compound and at least one M 1 -comprising compound, if present, and/or at least one M 2 -comprising compound, if present, and/or least one M 3 -comprising compound, if present, at least one compound comprising at least one phosphorous atom and at least one reducing agent in order to obtain a solid compound and 
 calcining the solid compound obtained from at a temperature of 300 to 950° C. 
   
     
     
         20 . The process according to  claim 19 , wherein the at least one reducing agent is water-soluble. 
     
     
         21 . The process according to  claim 19 , wherein the at least one reducing agent is selected from the group consisting of a reducing sugar, an alcohol ascorbic acid, and a compound comprising an easily oxidisable double bond, and mixtures thereof. 
     
     
         22 . The process according to  claim 19 , wherein FeOOH is selected from the group consisting of α-FeOOH, β-FeOOH, γ-FeOOH and mixtures thereof. 
     
     
         23 . The process according to  claim 20 , wherein the at least one compound comprising at least one phosphorous atom is selected from the group consisting of H 3 PO 4 , (NH 4 )H 2 PO 4 , (NH 4 ) 2 HPO 4 , (NH 4 ) 3 PO 4 , Li 3 PO 4 , LiH 2 PO 4 , Li 2 HPO 4  and mixtures thereof. 
     
     
         24 . The process according to  claim 20 , wherein the drying is conducted by spray-drying. 
     
     
         25 . A spherical particle or agglomerate comprising at least one compound represented by formula (I) obtained by the process according to  claim 19 . 
     
     
         26 . The compound represented by formula (I) as defined in  claim 19 , obtained by the process according to  claim 19 . 
     
     
         27 . A cathode for a lithium-ion battery, comprising at least one spherical particle or agglomerate according to  claim 25 . 
     
     
         28 . A cathode for a lithium-ion battery, comprising at least one compound according to  claim 26 . 
     
     
         29 . A process for the preparation of a mixture comprising at least one compound represented by formula (I) as defined in  claim 19  and at least one electrically conducting material, said process comprising
 drying an essentially aqueous mixture comprising at least one electrically conducting material or at least one precursor of an electrically conducting material, at least one lithium-comprising compound, FeOOH as the iron-comprising compound and at least one M 1 -comprising compound, if present, and/or at least one M 2 -comprising compound, if present, and/or at least one M 3 -comprising compound, if present, at least one compound comprising at least one phosphorous atom and at least one reducing agent to obtain a solid compound and 
 calcining the solid compound at a temperature of 300 to 950° C. 
 
     
     
         30 . The process according to  claim 29 , wherein the at least one reducing agent is selected from the group consisting of a reducing sugar, an alcohol ascorbic acid, and a compound comprising an easily oxidisable double bond, and mixtures thereof. 
     
     
         31 . The process according to  claim 29 , wherein the at least one compound comprising at least one phosphorous atom is selected from the group consisting of H 3 PO 4 , (NH 4 )H 2 PO 4 , (NH 4 ) 2 HPO 4 , (NH 4 ) 3 PO 4 , Li 3 PO 4 , LiH 2 PO 4 , Li 2 HPO 4  and mixtures thereof. 
     
     
         32 . The process according to  claim 29 , wherein the electrically conducting material is selected from the group consisting of carbon black, graphite, a carbon fiber, a carbon nanofiber, a carbon nanotube, an electrically conducting polymer and mixtures thereof. 
     
     
         33 . A mixture, comprising at least one compound represented by formula (I) as defined in  claim 19  and at least one electrically conducting material obtained by a process comprising
 drying an essentially aqueous mixture comprising at least one electrically conducting material or at least one precursor of an electrically conducting material, at least one lithium-comprising compound, FeOOH as the iron-comprising compound and at least one M 1 -comprising compound, if present, and/or at least one M 2 -comprising compound, if present, and/or at least one M 3 -comprising compound, if present, at least one compound comprising at least one phosphorous atom and at least one reducing agent to obtain a solid compound and 
 calcining the solid compound at a temperature of 300 to 950° C. 
 
     
     
         34 . A spherical particle or agglomerate comprising the mixture as claimed in  claim 33 . 
     
     
         35 . A cathode for a lithium-ion battery, comprising a mixture according to  claim 33 . 
     
     
         36 . A cathode for a lithium-ion battery, comprising a spherical particle or agglomerate according to  claim 34 .