METHOD FOR PREPARING FLEXIBLE MEMBRANE-FREE AND WIRE-SHAPED FUEL CELT

Abstract

A method for preparing a flexible membrane-free and wire-shaped fuel cell is provided. A carbon nanotube sheet is twisted and loaded with a catalyst to obtain a (CNT)@Fe.sub.3[Co(CN).sub.6].sub.2 cathode electrode; the carbon nanotube sheet is twisted and coated with a nickel powder to obtain a CNT@nickel particle anode electrode; and the (CNT)@Fe.sub.3[Co(CN).sub.6].sub.2 cathode electrode, the CNT@nickel particle anode electrode, and a fuel electrolyte of H.sub.2O.sub.2 are integrated in a silicone tube to obtain a flexible membrane-free and wire-shaped fuel cell. The flexible membrane-free and wire-shaped fuel cell of the present invention can generate an open-circuit voltage of 0.88 V, while having very good flexibility, and can be woven into textiles such as clothes, thereby having great application prospects in the field of portable energy supply.

Claims

1. A method for preparing a flexible membrane-free and wire-shaped fuel cell, comprising the following steps: (1) weighing reagents of FeSO.sub.4.7H.sub.2O and K.sub.3[Co(CN).sub.6] and formulating the reagents into aqueous solutions of FeSO.sub.4.7H.sub.2O and K.sub.3[Co(CN).sub.6] respectively, mixing the aqueous solutions to obtain a suspension under a magnetic stirring, filtering the suspension to obtain a precipitate, washing the precipitate using deionized water, and performing a low-temperature drying under vacuum on the precipitate to obtain a catalyst Fe.sub.3[Co(CN).sub.6].sub.2; (2) drawing a carbon nanotube sheet out from a carbon nanotube forest, and stacking a first number of layers of the carbon nanotube sheet, rolling the first number of lavers of the carbon nanotube sheet into a cylindrical shape, formulating the catalyst Fe.sub.3[Co(CN).sub.6].sub.2 in step (1) and an ethanol solution into a catalyst solution with a predetermined concentration, and then uniformly drip-coating the catalyst solution onto the first number of layers of the carbon nanotube sheet with the cylindrical shape, before twisting the first number of lavers of the carbon nanotube sheet with the cylindrical shape into a uniform (CNT)@Fe.sub.3[Co(CN).sub.6].sub.2 cathode electrode yarn by means of a motor; (3) spreading a second number of layers of the carbon nanotube sheet on a glass sheet, and then ultrasonically dispersing a nickel nanopowder in a dimethylformamide (DMF) solution to prepare a dispersion, and then uniformly drip-coating the dispersion onto the second number of layers of the carbon nanotube sheet, before twisting the second number of layers of the carbon nanotube sheet into a CNT@nickel particle anode electrode yarn by means of the motor; (4) after the CNT@nickel particle anode electrode yarn is naturally dried, by means of two synchronous motors, coating a layer of polypropylene (PP) monofilament on a surface of the CNT@nickel particle anode electrode yarn to obtain a CNT@nickel@PP electrode; (5) weighing a hydrogen peroxide solution, a perchloric acid solution, and a sodium chloride salt solution to formulate a fuel electrolyte; and (6) twisting and placing the (CNT)@Fe.sub.3[Co(CN).sub.6].sub.2 cathode electrode yarn and the CNT@nickel@PP electrode together, into a silicone tube, and injecting the fuel electrolyte to the silicone tube, so as to obtain a flexible membrane-free and wire-shaped hydrogen peroxide fuel cell.

2. The method according to claim 1, wherein in step (1), the aqueous solutions of FeSO.sub.4.7H.sub.2O and K.sub.3[Co(CN).sub.6] have concentrations of 0.2 mol/L and 0.15 mol/L, respectively; the mixing of the aqueous solutions is performed at a volume ratio of 1:1, and the magnetic stirring is performed at a rotational speed of 240 revolutions per minute; the low-temperature drying under vacuum is performed for a time of 6 to 10 hours at a temperature of 40° C.

3. The method according to claim 1, wherein in step (2), the carbon nanotube sheet has a length of 15 cm and a width of 2.5 cm, and the first number of layers of the carbon nanotube sheet is 10; the predetermined concentration of the catalyst solution is 5 mg/ml, and an amount of the catalyst solution added dropwise is 1 ml; the twisting by means of the motor is performed at a rotational speed of 100 revolutions per minute for a time of 1 min.

4. The method according to claim 1, wherein in step (3), the carbon nanotube sheet has a length of 15 cm and a width of 2.5 cm, and the second number of layers of the carbon nanotube sheet is 10; in the dispersion, a concentration of the nickel nan.opowder is 20 mg/ml, and an amount of the dispersion added dropwise is 2 ml; the twisting by means of the motor is performed at a rotational speed of 100 revolutions per minute for a time of 1 min.

5. The method according to claim 1, wherein in step (4), the two synchronous motors have a rotational speed of 50 revolutions per minute, and the PP monofilament has a diameter of 100 micrometers.

6. The method according to claim 1, wherein in step (5), a concentration of the hydrogen peroxide solution is 0.03 mol/L, a concentration of the perchloric acid solution is 0.15 mol/L, a concentration of the sodium chloride salt solution is 0.1 mol/L, and the hydrogen peroxide solution, the perchloric, acid solution, and the sodium chloride salt solution are mixed at a volume ratio of 1:1:1.

7. The method according to claim 1, wherein the silicone tube in step (6) has an inner diameter of 0.1 mm and a length of 10 to 20 cm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] FIG. 1 is a scanning electron microscopy (SEM) image of an anode electrode prepared in the present invention.

[0026] FIG. 2 is an SEM image of a cathode electrode prepared in the present invention.

[0027] FIG. 3 is a schematic diagram of a wire-shaped fuel cell prepared in the present invention.

[0028] FIG. 4 is a photograph of devices of the wire-shaped fuel cell prepared in the present invention.

[0029] FIG. 5 is a graph showing performances of the wire-shaped fuel cell prepared in the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] In order to make the aforementioned objectives, features, and advantages of the present invention comprehensible, the present invention will be described in further detail below in conjunction with the drawings and specific embodiments.

[0031] As used herein, references to “one embodiment” or “embodiments” are to be understood as describing particular features, structures, or characteristics included in at least one implementation of the present invention. Expressions “in one embodiment” appearing at different places of this description do not all refer to the same embodiment, or embodiments exclusive from other embodiments alone or alternatively. In addition, it should be noted that the mass fraction purity of FeSO.sub.4.7H.sub.2O, K.sub.3[Co(CN).sub.6], and NaCl is 99.99% wt, and the concentration of perchloric acid and ethanol (Analytical Reagent, AR)/hydrogen peroxide is 30% wt. DMF represents N-methyl pyrrolidone (Analytical Reagent, AR).

Example 1

[0032] (1) FeSO.sub.4.7H.sub.2O and K.sub.3[Co(CN).sub.6] reagents are weighed and formulated into 20 ml of a 0.2 mol/L aqueous solution and 20 ml of a 0.15 mol/L aqueous solution, respectively. The FeSO.sub.4.7H.sub.2O aqueous solution is slowly added to the K.sub.3[Co(CN).sub.6] aqueous solution to obtain a suspension under magnetic stirring at 240 revolutions per minute. The suspension is filtered to leave a precipitate, and the precipitate is centrifugally washed 3 to 5 times using deionized water, and then is dried for 8 h in a vacuum oven at 40° C. to obtain a catalyst Fe.sub.3[Co(CN).sub.6].sub.2.

[0033] (2) A carbon nanotube sheet is drawed out from a carbon nanotube forest, the carbon nanotube sheet has a length of 15 cm and a width of 2.5 cm, and 10 layers of the carbon nanotube sheet are stacked, and then rolled into a cylindrical shape. The catalyst in step (1) and an ethanol solution are formulated into a certain amount of a 5 mg/mL solution, and then 1 ml of the catalyst solution is measured and uniformly drip-coated onto the cylindrical carbon sheet which then is twisted for 1 min by means of a motor at 100 revolutions per minute to obtain a uniform (CNT)@Fe.sub.3[Co(CN).sub.6].sub.2 cathode electrode yarn.

[0034] (3) The carbon nanotube sheet is spread on a glass sheet, the carbon nanotube sheet has a length of 15 cm and a width of 2.5 cm, and 10 layers of the carbon nanotube sheet are stacked. Then, a nickel nanopowder is ultrasonically dispersed in a DMF solution to prepare a 20 mg/ml dispersion, then 2 ml of the dispersion is weighed and uniformly drip-coated onto the nano carbon sheet which then is twisted for 1 min by means of a motor at 100 revolutions per minute to obtain a CNT@nickel particle anode electrode yarn.

[0035] (4) After the CNT@nickel particle yarn is naturally dried, by means of two synchronous motors at a rotational speed of 50 revolutions per minute, a polypropylene (PP) monofilament having a diameter of 100 micrometers is coated on a surface of the CNT@nickel particle yarn to obtain a CNT@nickel@PP electrode.

[0036] (5) 0.3 mol/l hydrogen peroxide, 0.15 mol/l perchloric acid, and 0.1 mol/l sodium chloride are weighed and formulated into a mixed aqueous solution, where the three solutions are mixed at a volume ratio of 1:1:1, obtaining a fuel electrolyte.

[0037] (6) The (CNT)@Fe.sub.3[Co(CN).sub.6].sub.2 and the CNT@nickel@PP electrode are twisted together and placed into a silicone tube, and the electrolyte is injected thereto, so as to obtain a flexible wire-shaped hydrogen peroxide fuel cell.

Example 2

[0038] (1) FeSO.sub.4.7H.sub.2O and K.sub.3[Co(CN).sub.6] reagents are weighed and formulated into 20 ml of a 0.20 mol/L aqueous solution and 20 ml of a 0.15 mol/L aqueous solution, respectively. The FeSO.sub.4.7H.sub.2O aqueous solution is slowly added to the K.sub.3[Co(CN).sub.6] aqueous solution to obtain a suspension under magnetic stirring at 240 revolutions per minute. The suspension is filtered to leave a precipitate, and the precipitate is centrifugally washed 3 to 5 times using deionized water, and then is dried for 8 h in a vacuum oven at C to obtain a catalyst Fe.sub.3[Co(CN).sub.6].sub.2.

[0039] (2) A carbon nanotube sheet is drawed out from a carbon nanotube forest, the carbon nanotube sheet has a length of 15 cm and a width of 3 cm, and 15 layers of the carbon nanotube sheet are stacked, and then rolled into a cylindrical shape. The catalyst in step (1) and an ethanol solution are formulated into a certain amount of a 5 mg/mL solution, and then 1 ml of the catalyst solution is measured and uniformly drip-coated onto the cylindrical carbon sheet which then is twisted for 2 min by means of a motor at 100 revolutions per minute to obtain a uniform (CNT)@Fe.sub.3[Co(CN).sub.6].sub.2 cathode electrode yarn.

[0040] (3) The carbon nanotube sheet is spread on a glass sheet, the carbon nanotube sheet has a length of 15 cm and a width of 3 cm, and 10 layers of the carbon nanotube sheet are stacked. Then, a nickel nanopowder is ultrasonically dispersed in a DMF solution to prepare a 20 mg/ml dispersion, then 2 ml of the dispersion is weighed and uniformly drip-coated onto the nano carbon sheet which then is twisted for 1 min by means of a motor at 100 revolutions per minute to obtain a CNT@nickel particle anode electrode yarn.

[0041] (4) After the CNT@nickel particle yarn is naturally dried, by means of two synchronous motors at a rotational speed of 25 revolutions per minute, a polypropylene (PP) monofilament having a diameter of 100 micrometers is coated on a surface of the CNT@nickel particle yarn to obtain a CNT@nickel@PP electrode.

[0042] (5) 0.3 mol/l hydrogen peroxide, 0.15 mol/l perchloric acid, and 0.1 mol/l sodium chloride are weighed and formulated into a mixed aqueous solution, where the three solutions are mixed at a volume ratio of 1:1:1, obtaining a fuel electrolyte.

[0043] (6) The (CNT)@Fe.sub.3[Co(CN).sub.6].sub.2, and the CNT@nickel@PP electrode are twisted together and placed into a silicone tube, and the electrolyte is injected thereto, so as to obtain a flexible wire-shaped hydrogen peroxide fuel cell.

Example 3

[0044] (1) FeSO.sub.4.7H.sub.2O and K.sub.3[Co(CN).sub.6] reagents are weighed and formulated into 20 ml of a 0.20 mol/L aqueous solution and 20 ml of a 0.15 mol/L aqueous solution, respectively. The FeSO.sub.4.7H.sub.2O aqueous solution is slowly added to the K.sub.3[Co(CN).sub.6] aqueous solution to obtain a suspension under magnetic stirring at 240 revolutions per minute. The suspension is filtered to leave a precipitate, and the precipitate is centrifugally washed 3 to 5 times using deionized water, and then is dried for 8 h at room temperature to obtain a catalyst Fe.sub.3[Co(CN).sub.6].sub.2.

[0045] (2) A carbon nanotube sheet is thawed out from a carbon nanotube forest, the carbon nanotube sheet has a length of 15 cm and a width of 4 cm, and 15 layers of the carbon nanotube sheet are stacked, and then rolled into a cylindrical shape. The catalyst in step (1) and an ethanol solution are formulated into a certain amount of a 5 mg/mL solution, and then 1 ml of the catalyst solution is measured and uniformly drip-coated onto the cylindrical carbon sheet which then is twisted for 1.5 min by means of a motor at 100 revolutions per minute to obtain a uniform (CNT)@Fe.sub.3[Co(CN).sub.6].sub.2 cathode electrode yarn.

[0046] (3) The carbon nanotube sheet is spread on a glass sheet, the carbon nanotube sheet has a length of 15 cm and a width of 4 cm, and 10 layers of the carbon nanotube sheet are stacked. Then, a nickel nanopowder is ultrasonically dispersed in a IMF solution to prepare a 20 mg/ml dispersion, then 2 ml of the dispersion is weighed and uniformly drip-coated onto the nano carbon sheet which then is twisted for 1 min by means of a motor at 100 revolutions per minute to obtain a CNT@nickel particle anode electrode yarn.

[0047] (4) After the CNT@nickel particle yarn is naturally dried, by means of two synchronous motors at a rotational speed of 50 revolutions per minute, a polypropylene (PP) monofilament having a diameter of 100 micrometers is coated on a surface of the CNT@nickel particle yarn to obtain a CNT@nickel@PP electrode.

[0048] (5) 0.3 mol/l hydrogen peroxide, 0.15 mol/l perchloric acid, and 0.1 mol/l sodium chloride are weighed and formulated into a mixed aqueous solution, where the three solutions are mixed at a volume ratio of 1:1:1, obtaining a fuel electrolyte.

[0049] (6) The (CNT)@Fe.sub.3[Co(CN).sub.6].sub.2 and the CNT@nickel@PP electrode are twisted together and placed into a silicone tube, and the electrolyte is injected thereto, so as to obtain a flexible wire-shaped hydrogen peroxide fuel cell.

[0050] The difference between the three examples lies in that different widths and different numbers of layers ensure different distributions of the loading and different mass ratios of the loading, where Example 1 is the most preferred example.

[0051] From FIGS. 1 and 2, it can be seen that the loaded catalyst is uniformly coated on the carbon nanotube yarn. FIG. 3 is a schematic diagram of the prepared fuel cell, from which structural parts of the device can be seen. FIG. 4 is a photograph of devices of the actually manufactured wire-shaped fuel cell. FIG. 5 is a graph showing performances of the finally obtained device. From FIG. 5, it can be seen that the wire-shaped fuel cell can provide a stable voltage of 0.89 V and a power density as high as 6.2 mW cm.sup.−2.