Abstract:
A cell system using air as a positive-electrode active material and a metal substance as a negative-electrode active material includes a thin film of the metal substance, a pair of reels, each end being connected to the thin film, an electrode positioned in a vicinity of a path of the thin film between each of the reels, and a molten solution that is positioned downstream of the electrode and melts the metal substance oxidized when power is generated. The metal substance may include, for example, magnesium, aluminum, zinc, lithium and iron, the electrode may include a copper electrode, and the molten solution may include a hydrochloric acid solution, a sulfuric acid solution and an acetic acid solution. The cell system includes the pair or reels to which the thin film is connected, where the pair of reels may be configured by a cartridge type.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to a cell system and, in particular, relates to a cartridge-type magnesium battery and a system. 
       BACKGROUND ART 
       [0002]    Patent Literature 1 discloses a power generating apparatus including two systems, one of which generates hydrogen gas by hydrolysis and generates electric power by a hydrogen demanding unit and the other generates electric power by an oxidation-reduction chemical reaction involving electrodes and ions. This power generating apparatus configures: hydrogen releasing means by a hydrogen generating container in which a functional material is mounted within the container or in which a functional material is mounted on a negative electrode and a positive electrode and a battery element formed of electrolyte is provided within the container; hydrogen generating means comprising a liquid container for generating hydrogen gas both by hydrolysis through which the functional material is reacted with water or an aqueous solution (an electrolyte solution) and by bonding of hydrogen atoms that are fixed among crystals due to a change in properties of the functional material by the hydrolysis; first electrogenic means for allowing the battery element in the hydrogen generating container to generate electricity; second electrogenic means in which the hydrogen demanding unit generates electricity by utilizing the generated hydrogen gas in the hydrogen generating container; and control means for controlling the amount of the hydrogen gas generated by the hydrogen generating means according to the amount of current flowed through the load of a load device with which the electric power generated in the first electrogenic means is electrified. 
       CITATION LIST 
     Patent Literature 
       [0003]    Patent Literature 1: International Publication No. WO 2008/015844 
       SUMMARY OF INVENTION 
     Technical Problem 
       [0004]    However, the power generating apparatus disclosed in Patent Literature 1 is large-scale and the field of application is limitative. 
         [0005]    Here, the objective of the present invention is to provide a cell system with a simple structure. 
       Solution to Problem 
       [0006]    The present invention includes a cell system using air as a positive-electrode active material and a specific substance as a negative-electrode active material, the cell system including:
       a thin film of the specific substance;   a pair of reels, each end being connected to the thin film; and   an electrode positioned in a vicinity of a path of the thin film between each of the reels.       
 
         [0010]    A container that is positioned downstream of the electrode and includes a molten solution that melts the specific substance oxidized when power is generated may be included. Furthermore, as one example, the specific substance may include magnesium, zinc, lithium, iron, carbon, sodium, beryllium, aluminum, cadmium, sulfur, lead and the like; the electrode may include copper, carbon, manganese dioxide, aluminum, gold, silver, beryllium and magnesium; and a component of the molten solution may include hydrochloric acid, sulfuric acid, acetic acid, nitric acid, stearic acid, formic acid, citric acid, aqueous ammonia, sodium hydroxide, calcium chloride, sodium carbonate, ammonium chloride, ethanol, benzyl alcohol, cyclohexanol, ethylene glycol, acetone, benzene, aniline, toluene, cyclohexanone, carbon tetrachloride, trichlorethylene, castor oil, synthetic detergent and the like. 
         [0011]    Furthermore, the magnesium battery of the present invention includes the pair of reels to which the thin film is connected, where the pair of reels may be configured by a cartridge type. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0012]      FIG. 1  is a drawing showing a schematic configuration of a magnesium cell system according to the embodiment of the present invention. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0013]    Hereinafter, one embodiment of the present invention will be described with reference to the drawing. 
         [0014]      FIG. 1  is a drawing showing a schematic configuration of a magnesium cell system  1000  according to the embodiment of the present invention.  FIG. 1  shows a first reel  10 , a magnesium thin film  20 , guides  31 - 40 , a support  50 , an electrode  60 , a container  70 , a molten solution  80 , a second reel  90  and a cartridge  100  that are described below. 
         [0015]    The first reel  10  is wounded with a magnesium thin film  20 . The first reel  10  is rotatably configured about an axis (not shown). The first reel  10  may be, for example, resinous such as plastics. 
         [0016]    The magnesium thin film  20  is a negative-electrode active material in a magnesium battery, and one end thereof is connected to the first reel  10  and the other end is connected to the second reel  90 . The magnesium thin film  20  has an arbitrary thickness, width and length according to the size of the cartridge  100  or the size of the space where the cartridge  100  is attached and/or detached. Several examples of the manufacturing method of the magnesium thin film  20  are shown below but the examples are not limitative. 
         [0017]    First, the magnesium thin film  20  can be manufactured by applying magnesium on both sides or one side of a film. The film can penetrate the molten solution  80 ; however, as long as a material does not react with the molten solution  80 , any material is preferable (for example, Ultra High Molecular Weight Polyethylene (UHMWPE)). Then, by allowing the film to have strength, even if the magnesium of the magnesium thin film  20  disappears by a reaction, the film per se remains, thereby the rupture of the magnesium thin film  20  per se can be prevented. 
         [0018]    Second, the two sides of magnesium foil may be laminated with the film to manufacture the magnesium thin film  20 . Then, in addition to the advantage of the above-mentioned first case, magnesium hydroxide and magnesium oxide are retained between the film membranes; thus, the reaction product of the magnesium thin film  20  is easily collected. 
         [0019]    Furthermore, the magnesium per se that configures the magnesium thin film  20  may freely be obtained. As one example, the magnesium may be produced by desorption of oxygen from magnesium oxide by irradiating a laser to a mixture or compound such as of magnesium oxide and carbon. 
         [0020]    The guides  31 - 40  define proceeding positions of the magnesium thin film  20 . Any material may be used for the guides  31 - 40  as long as the material does not damage the magnesium thin film  20 . More specifically, when the magnesium thin film  20  is configured by a film on which magnesium is applied, slidability may preferably be provided such that the magnesium does not separate from the film. The guides  31 - 40  may be, as one example, stainless steel and the surface thereof may be processed for improving the slidability if necessary. 
         [0021]    The support  50  sandwiches the magnesium thin film  20  with the electrode  60 . Any material may be used for the support  50  as long as the material does not damage the magnesium thin film  20 . The support  50  may be, as one example, copper. Then, the support  50  has an electrode effect, thereby the generation efficiency increases. 
         [0022]    The electrode  60  generates power in cooperation with magnesium of the magnesium thin film  20  and oxygen in the air, which is a positive-electrode active material. A drive member (not shown) moves the electrode  60  in a horizontal direction in the drawing. More specifically, the electrode  60  moves towards the support  50  side when generating power and moves towards the half-valley side of that the rest of the time including the time of the exchange of the cartridge  100 . The drive member can be, as one example, a wind-up spring and can utilize the electrode  60  using a process of restoring from the wound-up position to the original position. The electrode  60  may be, for example, copper; however, as long as the electrode  60  can react with magnesium for generating power, the material is not limited to copper, but carbon, manganese dioxide and the like may be used. In this case, the material of the support  50  may also be changed depending on the material of the electrode  60 . 
         [0023]    The container  70  may contain the molten solution  80 . For example, the container  70  may be glass. However, as long as the container  70  does not dissolve in the molten solution  80 , the material is not limited to the glass. 
         [0024]    The molten solution  80  can react with the magnesium thin film  20  on which surface is oxidized by generation of power, that is, magnesium oxide. The molten solution  80  may be dilute hydrochloric acid solution, dilute sulfuric acid solution, acetic acid solution and the like. When the dilute hydrochloric acid solution is used for the molten solution  80 , the molten solution  80  generates oxygen, hydrogen, water and magnesium chloride. 
         [0025]    The second reel  90  reels up the magnesium thin film  20 . The second reel  90  is rotatably configured about an axis (not shown). The second reel  90  may be, for example, resinous such as plastics. 
         [0026]    The cartridge  100  contains the first reel  10 , the magnesium thin film  20 , the guides  31 - 40 , the support  50 , the container  70 , the molten solution  80  and the second reel  90 . The cartridge  100  may be, for example, resinous such as plastics. The object to be contained in the cartridge  100  is not limited to the matters shown in  FIG. 1 , and, for example, the container  70  and the molten solution  80  may be provided at a side that the cartridge  100  is attached, that is, the electrode  60  side. 
         [0027]    Next, the principle of the magnesium cell system  1000  of the present embodiment is explained. 
         [0028]    First, the following chemical reaction occurs by the magnesium thin film  20  adjacent to the electrode  60  and oxygen in the air. 
         [0000]      2 Mg+O 2 →2MgO
 
         [0029]    Therefore, the magnesium thin film  20  partially becomes a magnesium oxide thin film downstream of the electrode  60 . 
         [0030]    As the magnesium thin film  20  contacts with a dilute hydrochloric acid solution that is the molten solution  80  in the container  70 , the following chemical reaction occurs. 
         [0000]      MgO+2HCl→MgCl 2 +H 2 O
 
         [0031]    Furthermore, as the magnesium thin film  20  contacts with the dilute hydrochloric acid solution that is the molten solution  80  in the container  70  and the portion that was not oxidized contacts with the dilute hydrochloric acid solution that is the molten solution  80  in the container  70 , the following chemical reaction occurs. 
         [0000]      Mg+2HCl→MgCl 2 +H 2  
 
         [0032]    The reason for positioning the container  70  with the molten solution  80  downstream of the electrode  60  is to prevent reduced generation efficiency caused by hydrogen embrittlement that is generated as the H 2  gas contacting the copper that is the electrode  60 . In the present embodiment, not required, but the container  70  and the electrode  60  are isolated from each other using a separator material (not shown). 
         [0033]    Next, with an example of the length and the like of the magnesium thin film  20 , a rotational speed and the like of the second reel  90  is explained. 
         [0034]    When the magnesium cell system  1000  of the present embodiment is used as a fuel cell system of a vehicle, the magnesium thin film  20  may have a thickness of a several tens of micrometers to a several hundreds of micrometers, a width of 5 to 10 centimeters and a length of 100 to 200 meters. 
         [0035]    Furthermore, regarding the magnesium thin film  20  under the condition of such thickness and length, the relational expression, a radius of the magnesium thin film 20 squared×3.14=a thickness×a length of a tape, is established. Therefore, in a form that the first reel  10  is reeled, the radius is about 8 cm and the size is extremely small compared to that of the conventional fuel cell system for a vehicle. 
         [0036]    When one would like run an ordinary vehicle for about 500 km, theoretically four cartridges  100  comprising a magnesium thin film  20  having a length of 100 μm, a width of 10 cm and a 200 m length need to be prepared. The reason thereof is as follows. First, for the 500 km run, energy of about 100 kWh is required. This can be expressed as 360 MJ by multiplying 100 kW by one hour, that is, 3600 seconds. 
         [0037]    On the other hand, the heat generated by magnesium is 25 kJ/g. Then, the amount of magnesium required for the 500 km run is 14.4 kg, which is a value obtained by dividing 360 MJ by 25 kJ. 
         [0038]    Then, the amount of magnesium for the magnesium thin film  20  having a thickness of 100 μm, a width of 10 cm and a length of 200 m is 3.4 kg; thus, as described above, four cartridges  100  comprising a magnesium thin film  20  with these features need to be prepared. 
         [0039]    However, the conversion efficiency is not necessary 100%; thus, when one would like to run an ordinary vehicle for about 500 km, assumingly, approximately six to eight cartridges  100  should be prepared. 
         [0040]    Furthermore, when the magnesium cell system  1000  of the present embodiment is used as a fuel cell system of a vehicle, the take-up speed of the magnesium thin film  20  regarding the second reel  90  may be approximately 5 mm/sec. The reason thereof is, if a vehicle runs 500 km at 50 km per hour, for example, the running time is 10 hours, thereby the magnesium thin film  20  having a length of 200 m is reeled in 10 hours. 
         [0041]    However, as all of the magnesium of the magnesium thin film  20  does not react just once passing around the electrode  60 , the magnesium thin film  20  may be configured to be reeled from the second reel  90  side to the first reel  10  side so that the magnesium thin film  20  passes through several times. In this case, the container  70  with the molten solution  80  may also be provided between the electrode  60  and the first reel  10 . 
         [0042]    Furthermore, when the magnesium thin film  20  is reciprocatably configured to the electrode  60  in this way, the take-up speeds of the magnesium thin film  20  regarding the first reel  10  and the second reel  90  may be twice or three times faster than the above-mentioned example. 
       INDUSTRIAL APPLICABILITY 
       [0043]    The present invention is applicable in the filed of batteries for vehicles. 
       REFERENCE SIGNS LIST 
       [0000]    
       
           10  First reel 
           20  Magnesium thin film 
           31 - 40  Guides 
           50  Support 
           60  Electrode 
           70  Container 
           80  Molten solution 
           90  Second reel 
           100  Cartridge 
           1000  Magnesium cell system