Abstract:
A device for infusing liquid into material samples includes a container assembly configured to contain multiple material samples submerged in liquid. The material samples have pores containing air or gas. A pressure source and a vacuum source are both operatively connectable to the container assembly and alternately communicable with the container assembly to force the liquid to at least substantially fill the pores. The samples are thus ready for further processing, testing or use. A method of filling pores in material samples with liquid includes supporting multiple material samples within liquid in an airtight container assembly. The method further includes alternately applying a vacuum source and a pressure source to the container assembly, thereby replacing air with liquid in the pores of the material samples.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of United States Provisional Application No. 61/393,451 filed Oct. 15, 2010, which is hereby incorporated by reference in its entirety. 
     
    
     TECHNICAL FIELD 
       [0002]    The invention relates to a device for infusing liquid into pores of material samples, and a method for the same. 
       BACKGROUND 
       [0003]    Some materials are initially formed with pores. The pores may be permeated by surrounding air, thereby becoming air pockets. In certain applications, a gas other than air may fill the pores. In some instances, the pores must be filled with liquid in order for the material to be used for a desired purpose. For example, a number of anode and cathode materials used in batteries are initially formed with air pockets. The air pockets must be filled with electrolyte in order for the material to function efficiently within a battery. Existing processes for filling air pockets in this manner are time consuming, and are generally limited to processing only one material sample at a time. For example, electrolyte may be placed in a syringe with the material sample. The atmosphere in the syringe is placed under vacuum by manually pulling on the syringe plunger to remove air entrapped within the pellet. The atmosphere in the syringe is then placed under pressure by pushing on the syringe plunger to force the electrolyte into the now open air pockets (i.e., free of air that would otherwise provide resistance to the liquid entering the air pockets). The pressurizing and vacuuming process is repeated a number of times until it is determined that the pellet of material is sufficiently soaked in the liquid (i.e., the pores are sufficiently full of liquid). The pellets may sink in the liquid within the syringe when sufficiently soaked, which may serve to indicate that the soaking process is complete. Another existing method involves the use of a re-sealable plastic storage bag, such as a ZIPLOC® bag in which material samples and liquid are contained. ZIPLOC® is a registered trademark of S.C. Johnson &amp; Son, Inc., 1525 Howe Street Racine Wis. 53403. By squeezing the ZIPLOC® bag, pressure within the bag is increased and some liquid may be forced into the pores of the material sample. This method is limited to applying pressure only (no vacuum). The pressure range is also limited to the strength of the seal on the ZIPLOC® bag. 
         [0004]    The current syringe soaking process described above has several disadvantages. The existing procedure requires significant time, averaging 10-15 minutes per single pellet to manually operate the syringe to remove air from the pellet pockets and replace the air with electrolyte. The current procedure is also known to yield inconsistent results. Depending on the syringe used and the strength of the user, both the level of vacuum and the pressure level generated within the syringe can vary significantly. This can lead to inconsistent and/or subpar battery performance (in terms of capacity, charging rates, cycle life, etc). The existing syringe procedure also limits pellet size, as appropriate syringes may not be available for relatively large pellet sizes. Changes in the syringe size also have adverse effects on internal pressures achievable; as the diameter of the syringe goes up, the internal pressure range becomes less extreme, decreasing the effectiveness of air removal. Sizes of commercially-available syringes are also limiting. 
       SUMMARY 
       [0005]    A device for infusing liquid into pores of material samples includes a container assembly configured to contain multiple material samples submerged in liquid. A vacuum source is selectively operatively connectable to the container assembly and is operable to apply a vacuum to the liquid. A pressure source is selectively operatively connectable to the container assembly and is operable to apply pressurized gas to the liquid. The vacuum source and the pressure source are configured to be alternately communicable with the container assembly to force air or gas from the pores and force the liquid to at least substantially fill the pores. The samples are thus soaked in the liquid and prepared for further testing or use. The device is especially useful for preparing anode and cathode material samples by forcing electrolyte into pores of the material samples. 
         [0006]    A method of infusing liquid into pores of material samples includes supporting multiple material samples within liquid in an at least substantially airtight container assembly. The method further includes alternately applying a vacuum source and a pressure source to the container assembly, thereby replacing air with liquid in the pores of the material samples. 
         [0007]    The pressure source and the vacuum source provide consistent pressure and vacuum levels so that the material samples are more consistently filled with liquid than with previous material soaking apparatuses and methods. Furthermore, the container assembly is configured to support multiple material samples so that the method may be accomplished at a relatively high throughput rate. The size of the container assembly may be selected to allow a relatively large number of material samples to be processed simultaneously. Because the vacuum source and pressure source can be controlled at consistent vacuum and pressure levels, respectively, the method permits more efficient and consistent processing of the material samples. 
         [0008]    The above features and advantages and other features and advantages of the present invention are readily apparent from the following detailed description of the best modes for carrying out the invention when taken in connection with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a schematic side view illustration of a liquid infusion device; 
           [0010]      FIG. 2  is a schematic fragmentary cross-sectional illustration of a portion of the liquid infusion device of  FIG. 1  showing material samples within the device; 
           [0011]      FIG. 3  is a schematic side view illustration of one of the material samples of  FIG. 2 ; and 
           [0012]      FIG. 4  is a flow diagram of a method of infusing liquid into material samples. 
       
    
    
     DETAILED DESCRIPTION 
       [0013]    Referring to the drawings, wherein like reference numbers refer to like components throughout the several views,  FIG. 1  shows a liquid infusion device  10  configured to consistently and efficiently infuse liquid into multiple material samples on a high-throughput basis. The liquid infusion device  10  includes a container assembly  11  with an outer container  12 , also referred to herein as a first container. The outer container  12  includes a well portion  14  and a lid  16 . The lid  16  is secured to the well portion  14  by at least one fastener  18  with a seal  20  to close the outer container  12  so that it is at least substantially and preferably completely airtight and leak-free under a predetermined pressure range. In another embodiment, the lid  16  has external threads and the well portion  14  has internal threads so that the lid  16  can be screwed onto the well portion  14 . In the embodiment shown, the lid  16  is removable by removing the fasteners  18  in order to open the container  12  to place material samples  38 , shown in  FIG. 2 , within the well portion  14 , as further discussed below. 
         [0014]    Referring to  FIG. 2 , the well portion  14  of the outer container  12  is shown in partial cross-sectional view to reveal an inner container  24  of the container assembly  11 . The inner container  24  is also referred to as a second container. The inner container  24  is suspended within an interior cavity  26  defined by the outer container  12 . The inner container  24  may be connected to and suspended by gas flow tubing  28  into liquid  32  that at least partially fills the cavity  26 , or may be otherwise mounted within the interior cavity  26  of the outer container  12 . 
         [0015]    The inner container  24  has a basket portion  25  that is a wire mesh material that defines apertures  30 . The apertures  30  permit the liquid  32  that at least partially fills the cavity  26  to also enter an interior space  34  defined by the inner container  24 . The inner container  24  may have a wire mesh lid  36  that is hinged to the basket portion  25  and that is openable and closable to permit material samples  38  to be placed within the interior space  34 . The wire mesh lid  36  is shown in an open position  41 , pivoted about hinge  42 . In other embodiments, it may be desirable for the entire lid of the inner container  24  to be removable. The apertures  30  are smaller than the material samples  38  placed in the basket portion  25 , so that the material samples are retained within the basket portion  25 . 
         [0016]    As an alternative to wire mesh, the inner container  24  may be any material and construction that has apertures that are sized to permit liquid  32  to enter the inner container  24  but that are small enough to prevent material samples  38  from exiting the inner container  24 . The material samples  38  may all be of the same material, or may be different materials processed simultaneously. 
         [0017]    Referring to  FIG. 3 , a representative material sample  38  is shown. The material sample  38  is compressed as a pellet. Even though compressed, the material sample  38  still defines pores  40  that may be referred to as recesses or air pockets. The size of the pores  40  is exaggerated for purposes of illustration in  FIG. 3 . In one representative example, the material samples  38  may be anode or cathode material for use in a battery, and the liquid  32  may be electrolyte. Anode and cathode materials provide a better performance in a battery if electrolyte fills any pores  40  remaining after compression of the samples  38 . The liquid infusion device  10  may be used for infusing a wide array of material samples  38  with a wide variety of liquids  32  for which it is determined to be desirable to fill the pores  40  with liquid  32  by driving air or other gas out of the pores  40 . As shown in  FIG. 2 , the material samples  38  may float to the top of the basket  25  before the method  100  described below is completed (i.e., before the pores  40  are filled with liquid  32 ). 
         [0018]    The liquid infusion device  10  is configured to fill the pores  40  of  FIG. 3  in the material samples  38  with liquid  32  in a consistent and efficient manner. Referring again to  FIG. 1 , the liquid infusion device  10  includes tubing, valves, and pressure and vacuum sources that provide the desired infusing operation. Specifically, a gas pressure source  50  containing pressurized gas, such as air, is in selective fluid communication with the material samples  38  through tubing  28 , by opening a pressure shutoff valve  52 . Pressurized gas is provided to the container assembly  11  through the tubing  28  from the pressure source  50  when the pressure shutoff valve  52  is open. A pressure regulator valve  54  is positioned downstream of the pressure source  50  and upstream of the pressure shutoff valve  52  so that the pressurized gas may be controlled to a predetermined pressure or pressure range. For example, the controlled gas pressure range could be between 0 and 150 pounds per square inch (psi). The pressurized gas pushes the liquid  32  to force it into the pores  40  of  FIG. 3 . 
         [0019]    Furthermore, a vacuum source  56 , such as a vacuum pump, is in selective fluid communication with the material samples  38  through the tubing  28 , by opening a vacuum shutoff valve  58 . When the vacuum shutoff valve  58  is open, a vacuum is applied to the container assembly  11 , which tends to remove the air or gas from the pores  40  of  FIG. 3 . By alternating the opening and closing of the pressure shutoff valve  52  with the opening and closing of the vacuum shutoff valve  58 , gas or air is repeatedly drawn from the pores  40  by the vacuum source  56 , with liquid  32  being forced by the pressure source  50  to fill the pores  40  in place of the withdrawn air or gas. 
         [0020]    The liquid infusion device  10  also includes a pressure relief valve  60 . When the pressure relief valve  60  is open, the tubing  28  is in fluid communication with the surrounding atmosphere at an open end  62  of the tubing  28 . Any pressure or vacuum within the tubing  28  and the interior cavity  26  will be relieved. The pressure relief valve  60  is opened when cycling of the vacuuming and pressurizing is complete, prior to removing the material samples  38  from the container assembly  11 . The samples may then be removed by opening the lid  16  of the outer container  12 , and then opening the lid  40  of the inner container  24 . 
         [0021]    Referring to  FIG. 4 , a method  100  of infusing material samples with liquid is described with respect to the liquid infusion device  10  of  FIGS. 1 and 2  and the material samples  38  of  FIGS. 2 and 3 . The method  100  begins with optional block  102 , in which material samples  38  are compressed into pellets. Alternately, the material samples  38  may be provided in a pre-compressed state, or may not be compressed, depending on the expected use of the material samples  38  and the composition of the material samples  38 . 
         [0022]    In block  104 , the material samples  38  are supported in liquid  32  in an airtight container assembly  11 . Block  104  includes blocks  106 ,  108  and  110 . In block  106 , an outer container  12  of the container assembly  11  is at least partially filled with liquid  32 . In block  108 , multiple material samples  38  are then placed within the inner container  24  of the container assembly  11 . In block  110 , the inner container  24  and the outer container  12  are then closed by closing the lids  36  and  16 , respectively. 
         [0023]    The material samples  38  are now ready for processing in blocks  112  and  118 . Specifically, in block  112  a vacuum source  56  is applied to the container assembly  11 . Block  112  may include block  114 , in which a vacuum shutoff valve  58  is opened to establish fluid communication between the container assembly  11  and the vacuum source  56 . Block  112  may also include block  116 , in which the vacuum shutoff valve  58  is then closed so that the vacuum source  56  is no longer in communication with the container assembly  11 . 
         [0024]    In block  118 , a pressure source  50  is then applied to the container assembly  11 . Alternately, the block  118  may initially be carried out prior to block  112  before alternating between the blocks  112 ,  118 . Block  118  may include block  120 , in which a pressure shutoff valve  52  is opened. Block  118  may also include block  122 , in which the pressure shutoff valve  52  is then closed. The method  100  may cycle back and forth between blocks  112  and  118  a number of times until it is expected that the material samples  38  are in a desired condition for use or further testing, specifically with the pores  40  completely or substantially filled with liquid  32 . This may be indicated by the material samples  38  tending to sink in the liquid  32  in the inner container  24 . 
         [0025]    After cycling through blocks  112  and  118 , a pressure relief valve  60  is opened in block  124  to bring the pressure of the container assembly  11  and tubing  28  to that of the surrounding atmosphere. The outer container  12  is then opened in block  126 . The inner container  24  can then be opened in block  128 . The material samples  38  are then removed in block  130 . The container assembly  11  can then be reused for processing additional like material samples  38 , or material samples of a different material either with the same liquid  32  or with a different liquid if liquid  32  is removed from the container assembly  11 . 
         [0026]    The container assembly  11  and method  100  provide high-throughput liquid infusion of material samples  38 , filling pores  40  with liquid  32 . The regulated pressure from pressure source  50  and the vacuum of vacuum source  56  provide consistent processing of the material samples  38  to ensure that the pores  40  are filled completely or to a desired amount. Furthermore, the liquid infusion is accomplished for multiple material samples  38  simultaneously. The size of the container assembly  11  may be selected so that a very large number of material samples  38  may be simultaneously processed on a high-throughput basis. 
         [0027]    While the best modes for carrying out the invention have been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention within the scope of the appended claims.