Filter Cartridge for Extracting Lithium from Brine, Filter Cartridge Assembly and Apparatus

Abstract

The present invention provides a filter cartridge (1) for extracting lithium from lithium-containing brine, a filter cartridge assembly comprising a cartridge container (80) which contains such a filter cartridge (1), and an apparatus comprising a plurality of such filter cartridge assemblies (1, 80). The filter cartridge (1) at least comprises a capture electrode (47) for capturing lithium ions from the brine, a capture electrode current collector (48) for imparting a negative charge to the capture electrode, a counter electrode (51), and a counter electrode current collector (52) for imparting a positive charge to the counter electrode. Each of the capture electrode, the capture electrode current collector, the counter electrode and the counter electrode current collector comprises a brine-permeable sheet. The sheets are each in the form of a long strip, so that each sheet has an opposing pair of long edges and an opposing pair of short edges. The sheets are stacked in layers forming a stack (67) which is wound into a spiral cylinder, so that the opposing pairs of long edges of all the sheets form opposite ends of the cylinder, allowing the lithium-containing brine to flow radially through the cylinder. At least one of the capture electrode current collector and the counter electrode current collector are provided with a respective plurality of electrical contacts along a respective one of the opposing pair of long edges of the respective current collector, and the plurality of electrical contacts are electrically connected to each other and to a common electrical current connector. The apparatus comprises a plurality of the filter cartridge assemblies (1, 80) arranged in series and/or parallel with each other and sharing a common electrical supply.

1 . A filter cartridge ( 1 ) for extracting lithium from lithium-containing brine, at least comprising:
 a capture electrode ( 47 ) for capturing lithium ions from the brine;   a capture electrode current collector ( 48 ) for imparting a negative charge to the capture electrode ( 47 );   a counter electrode ( 51 ); and   a counter electrode current collector ( 52 ) for imparting a positive charge to the counter electrode ( 51 );   
       wherein:
 each of the capture electrode ( 47 ), the capture electrode current collector ( 48 ), the counter electrode ( 51 ) and the counter electrode current collector ( 52 ) comprises a brine-permeable sheet, each sheet having an opposing pair of long edges and an opposing pair of short edges and being stacked in layers forming a stack ( 67 ) wound into a spiral cylinder, such that the opposing pairs of long edges of all the sheets form opposite ends of the cylinder allowing the lithium-containing brine to flow radially therethrough; 
 at least one of the capture electrode current collector ( 48 ) and the counter electrode current collector ( 52 ) are provided with a respective plurality of electrical contacts along a respective one of the opposing pair of long edges of the respective current collector ( 48 ,  52 ); and 
 the plurality of electrical contacts are electrically connected to each other and to a common electrical current connector ( 59 ). 
 
     
     
         2 . A filter cartridge ( 1 ) according to  claim 1 , wherein the capture electrode current collector ( 48 ) is provided with a first plurality of electrical contacts along a first one of the opposing pair of long edges of the capture electrode current collector ( 48 ), and the counter electrode current collector ( 52 ) is provided with a second plurality of electrical contacts along a second one of the opposing pair of long edges of the counter electrode current collector ( 52 ), which are opposite to the first plurality of electrical contacts. 
     
     
         3 . A filter cartridge ( 1 ) according to  claim 1 , wherein a separation(s) between adjacent ones of the respective plurality of electrical contacts along the respective long edge of the respective current collector ( 48 ,  52 ) is non-uniform and is arranged such that when the stack ( 67 ) is wound into a spiral cylinder, the respective plurality of electrical contacts are aligned with each other along a radius of the cylinder. 
     
     
         4 . A filter cartridge ( 1 ) according to  claim 1 , wherein a current density per unit area of the stack ( 67 ) supplied by each one of the electrical contacts is not greater than 1 A cm −2 . 
     
     
         5 . A filter cartridge ( 1 ) according to  claim 1 , wherein at least one of the capture electrode current collector ( 48 ) and the counter electrode current collector ( 52 ) is wider along the short edge thereof than the capture electrode ( 47 ) or the counter electrode ( 51 ), respectively, is along the short edge thereof, and the respective one of the capture electrode current collector ( 48 ) and the counter electrode current collector ( 52 ) comprises a strip of electrically insulating sealant ( 104   b ) located inside and spaced apart from an exposed long edge thereof. 
     
     
         6 . A filter cartridge ( 1 ) according to  claim 1 , wherein the opposite ends of the cylinder are each provided with a respective end seal ( 72 ,  74 ) sealing against the flow of brine therethrough, and through which end seal ( 72 ,  74 ) the electrical contacts protrude. 
     
     
         7 . A filter cartridge ( 1 ) according to  claim 6 , further comprising a respective endcap ( 3 ,  12 ) enclosing the electrical contacts between the respective end seal ( 72 ,  74 ) and the respective endcap ( 3 ,  12 ) within a part of the filter cartridge ( 1 ), which, during use of the cartridge, is not perfused by brine. 
     
     
         8 . A filter cartridge ( 1 ) according to  claim 7 , wherein the common electrical current connector ( 59 ) is in electrical contact with a current connector ( 25 ,  26 ) on an exterior surface of the respective endcap ( 3 ,  12 ). 
     
     
         9 . A filter cartridge assembly comprising a filter cartridge ( 1 ) according to  claim 8  and a cartridge container ( 80 ) for containing the filter cartridge ( 1 ) therein, wherein the cartridge container ( 80 ) comprises:
 a first mating assembly ( 82 ) for electrical connection with the capture electrode current connector ( 25 ) of the filter cartridge ( 1 ); 
 a second mating assembly ( 83 ) for electrical connection with the counter electrode current connector ( 26 ) of the filter cartridge ( 1 ); 
 a capture electrode current connector ( 85 ) on an exterior of the cartridge container ( 80 ) in electrical connection with the first mating assembly ( 82 ); 
 a counter electrode current connector ( 86 ) on the exterior of the cartridge container ( 80 ) in electrical connection with the second mating assembly ( 82 ); 
 an inlet ( 2 ) for supplying lithium-containing brine to the stack ( 67 ) of the filter cartridge ( 1 ) therein; and 
 an outlet ( 13 ) for lithium-depleted brine from the stack ( 67 ) of the filter cartridge ( 1 ). 
 
     
     
         10 . A filter cartridge assembly according to  claim 9 , wherein the cartridge container ( 80 ) is adapted and arranged to allow the filter cartridge ( 1 ) to be removed from within the cartridge container ( 80 ) when loaded with lithium and replaced with a like filter cartridge ( 1 ′) containing less lithium. 
     
     
         11 . An apparatus ( 110 ) comprising a plurality of filter cartridge assemblies according to  claim 9  arranged in series with each other and sharing a common electrical supply. 
     
     
         12 . An apparatus ( 113 ) comprising a plurality of filter cartridge assemblies according to  claim 9  arranged in parallel with each other and sharing a common electrical supply.