Rechargeable electrochemical battery cell

Abstract

Rechargeable lithium battery cell having a housing, a positive electrode, a negative electrode and an electrolyte containing a conductive salt, wherein the electrolyte comprises SO2 and the positive electrode contains an active material in the composition LixM′yM″z(XO4)aFb, wherein M′ is at least one metal selected from the group consisting of the elements Ti, V, Cr, Mn, Fe, Co, Ni, Cu and Zn, M″ is at least one metal selected from the group consisting of the metals of the groups II A, III A, IV A, V A, VI A, IB, IIB, IIIB, IVB, VB, VIB and VIIIB, X is selected from the group consisting of the elements P, Si and S, x is greater than 0, y is greater than 0, z is greater than or equal to 0, a is greater than 0 and b is greater than or equal to 0.

1 . A battery cell, comprising:
 a housing, a positive electrode, a negative electrode and an electrolyte,   wherein the electrolyte comprises SO 2  and a conductive salt,   wherein the positive electrode comprises a compound of the formula Li x M′ y (XO 4 ) a F b  (I), which compound is optionally doped, wherein   M′ is at least one metal selected from the group consisting of the elements Ti, V, Cr, Mn, Fe, Co, Ni, Cu and Zn,   X is selected from the group consisting of the elements P, Si and S,   x is greater than 0,   y is greater than 0,   a is greater than 0 and   b is greater than or equal to 0,   wherein the sum of positive charges in the compound equals the sum of negative charges,   wherein the positive electrode further comprises a current collector having a first portion comprising a porous metal which has a first and second surface and a thickness located there between and comprises a plurality of pores containing the compound that extend at least partially through the thickness, wherein at least some of the pores have void spaces accessible to the electrolyte and   wherein the battery cell is a rechargeable lithium ion battery cell.   
     
     
         2 . A battery cell, comprising:
 a housing, a positive electrode, a negative electrode and an electrolyte,   wherein the positive electrode comprises LiFePO 4  which is optionally doped,   wherein the electrolyte comprises SO 2  and a conductive salt,   wherein the positive electrode further comprises a current collector having a first portion comprising a porous metal which has a first and second surface and a thickness located there between and comprises a plurality of pores containing the compound that extend through the thickness, wherein at least some of the pores have void spaces accessible to the electrolyte and   wherein the battery cell is a rechargeable lithium ion battery cell.   
     
     
         3 . A battery cell, comprising:
 a housing, a positive electrode, a negative electrode and an electrolyte,   wherein the positive electrode comprises LiFePO 4  which is optionally doped, the electrolyte comprises SO 2  and a conductive salt, wherein the SO 2  is in an amount greater than 40 weight percent of the weight of the electrolyte and   wherein the battery cell is a rechargeable lithium ion battery cell.   
     
     
         4 . A battery cell comprising a housing, a positive electrode, a negative electrode and an electrolyte,
 wherein the positive electrode comprises LiFePO 4  which is optionally doped,   wherein the electrolyte comprises SO 2  and a conductive salt, wherein organic material is in an amount less than 60 weight percent of the weight of the electrolyte and   wherein the battery cell is a rechargeable lithium ion battery cell.   
     
     
         5 . A battery cell comprising a housing, a positive electrode, a negative electrode and an electrolyte,
 wherein the positive electrode comprises LiFePO 4  which is optionally doped,   wherein the electrolyte comprises SO 2  and a conductive salt, wherein the electrolyte comprises at least 3 moles SO 2  per mole of conductive salt, and   wherein the battery cell is a rechargeable lithium ion battery cell.   
     
     
         6 . The battery cell according to  claim 1 , wherein after the first 100 cycles of charging and discharging following formation, the cell discharge capacity does not decrease by more than 25 percent over the next 250 cycles, wherein the cell is charged at a current of 0.5 C until the cell potential reaches 3.6 V at which time the potential of 3.6 V is held constant until the current reaches 0.1 C, at which time the charging is stopped and after a delay of approximately 10 minutes, the cell is discharged at a current of 0.5 C and the discharging is stopped when the cell potential reaches 2.5 V, and wherein after a delay of approximately 60 minutes after the discharging is stopped, (1) and (2) are repeated for the next cycle, wherein the charge and discharge cycles are carried out at approximately 20 C and approximately 1 bar (ambient) pressure. 
     
     
         7 . The battery cell of  claim 1 , wherein the plurality of pores further contain a compound selected from the group consisting of a conductive agent, a binding agent, and a lithium halogenide. 
     
     
         8 . The battery cell of  claim 1 , wherein the plurality of pores extend through the entire thickness. 
     
     
         9 . The battery cell of  claim 1 , wherein the current collector further comprises a connector portion in conductive contact with the porous current collector. 
     
     
         10 . The battery cell of  claim 1 , wherein the positive electrode has a thickness of at least 0.25 mm. 
     
     
         11 . The battery of cell of  claim 1 , wherein the positive electrode has a thickness of from 0.25 mm to 1.0 mm. 
     
     
         12 . The battery cell according  claim 1 , wherein the positive electrode comprises a quantity of active material per unit area of at least 30 mg/cm 2 . 
     
     
         13 . The battery cell according  claim 1 , wherein the positive electrode comprises a quantity of active material per unit area of from 30 mg/cm 2  to 180 mg/cm 2 . 
     
     
         14 . The battery cell according to  claim 1 , wherein the positive electrode is porous and has a porosity of no more than 50% 
     
     
         15 . The battery cell according to  claim 1 , wherein the negative electrode has a thickness of at least 0.2 mm. 
     
     
         16 . The battery cell according to  claim 1 , wherein the negative electrode has a thickness of from 0.2 mm to 0.8 mm. 
     
     
         17 . The battery cell according to  claim 1 , wherein the positive electrode comprises a binding agent in an amount of no more than 10 wt. % of the active material. 
     
     
         18 . The battery cell according to  claim 1 , wherein the negative electrode comprises carbon for inserting lithium ions. 
     
     
         19 . The battery cell according to  claim 1 , wherein the negative electrode comprises a quantity of active material of at least 10 mg/cm 2 . 
     
     
         20 . The battery cell according to  claim 1 , wherein the negative electrode comprises a quantity of active material per unit area of from 10 mg/cm 2  to 100 mg/cm 2 . 
     
     
         21 . The battery cell according to  claim 1 , wherein the negative electrode is porous and its porosity is no more than 50%. 
     
     
         22 . The battery cell according to  claim 1 , wherein the negative electrode comprises a porous metal portion and binding agent contained therein and the binding agent is in an amount of no more than 5 wt. % of the weight of the porous metal portion of the negative electrode. 
     
     
         23 . The battery cell according to  claim 1 , wherein the electrolyte comprises at least 3 moles SO 2  per mole of conductive salt. 
     
     
         24 . The battery cell according to  claim 1 , wherein the electrolyte comprises from 3 to 220 moles SO 2  per mole of conductive salt. 
     
     
         25 . The battery cell according to  claim 1 , wherein the conductive salt comprises lithium tetrachloroaluminate. 
     
     
         26 . The battery cell according to  claim 1 , wherein the positive electrode has a current carrying capacity of at least 10 mA/cm 2 . 
     
     
         27 . The battery cell according to  claim 1 , wherein the positive electrode has an ampacity per unit area of from 10 mA/cm 2  to 150 mA/cm 2    
     
     
         28 . The battery cell according to  claim 1 , wherein lithium chloride is mixed with active metal of the positive electrode. 
     
     
         29 . The battery cell according to  claim 1 , wherein the positive and/or negative electrode is treated to reduce covering layers by means of applying a surface coating to the electrode. 
     
     
         30 . A method for producing a positive electrode for a lithium ion rechargeable battery, comprising:
 providing a paste mass comprising LiFePO 4 , optionally with admixture of a binding agent or a conductivity-improving material;   homogeneously incorporating the paste mass into a three-dimensional porous metal current collector; and   pressing the three-dimensional metal current collector comprising the paste mass in such a manner that its thickness is reduced.   
     
     
         31 . An electrode produced according to the method of  claim 23 . 
     
     
         32 . The battery cell of  claim 1 , wherein the electrolyte comprised therein will not ignite or combust when a battery comprising the cell is placed above a Bunsen burner and contacted with the tip of a blue flame of the Bunsen burner for at least 10 minutes. 
     
     
         33 . A motor vehicle power supply, comprising the battery cell of  claim 1 . 
     
     
         34 . An energy storage system, comprising the battery cell of  claim 1 .