A convective paper-based microfluidic fuel cell with a bent flow channel

Abstract

The present invention discloses a convective paper-based microfluidic fuel cell with a bent flow channel; it includes an anode part and a cathode part; the anode part includes an anode, an anolyte paper-based flow channel, and an anode support plate; the cathode part includes a cathode, a catholyte paper-based flow channel, and a cathode support plate; the anolyte paper-based flow channel is composed of an anolyte paper-based first flow channel and an anolyte paper-based second flow channel, and there is a bend between the anolyte paper-based first flow channel and the anolyte paper-based second flow channel; the catholyte paper-based flow channel is composed of a catholyte paper-based first flow channel and a catholyte paper-based second flow channel, and there is a bend between the catholyte paper-based first flow channel and the catholyte paper-based second flow channel; a catalytic layer is provided at the contact part between the anode and the anolyte paper-based flow channel, and between the cathode and the catholyte paper-based flow channel; an anolyte inlet and a catholyte inlet are provided at the front ends of the anolyte paper-based flow channel and the catholyte paper-based flow channel, and the tails are connected to an absorption pad; the anolyte paper-based second flow channel is in close contact with the catholyte paper-based second flow channel to form a charge transport channel inside the battery.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cells, and particularly to a convective paper-based microfluidic fuel cell with a bent flow channel. Background Art

[0002] Paper-based analysis and detection chips can effectively reduce the cost of related detection chips, achieve rapid and accurate sample analysis and detection, and have broad application prospects. However, the wide application of paper-based analysis and detection chips requires a low-cost micro power source as an important technical support.

[0003] The paper-based microfluidic fuel cell is a new type of micro power source. It utilizes the porous characteristics of the paper-based medium to achieve the passive flow of the reaction liquid, getting rid of the dependence on micropumps in traditional microfluidic fuel cells; and based on laminar flow in the paper-based channels, it realizes the natural separation of fuel and oxidant without the need to use the proton exchange membrane in traditional microbatteries, avoiding a series of membrane-related problems, and having good application prospects in paper-based analysis and detection chips. Currently, the flow mode of the reaction liquid in the developed paper-based microfluidic fuel cells is mostly parallel laminar flow. To avoid the diffusion of reactants to the opposite electrode and generate parasitic current, this fluid flow channel mode requires a large cathode-anode spacing and has strict restrictions on the length of the electrode along the fluid flow direction. The large cathode-anode spacing generates a large ohmic internal resistance, reducing the output performance of the battery; and the dimensional limitation of the electrode length brings an inherent defect of too low output power of a single cell to the paper-based microfluidic fuel cell. Summary of the Invention

[0004] The purpose of the present invention is to provide a convective paper-based microfluidic fuel cell with a bent flow channel in view of the deficiencies existing in the prior art.

[0005] The present invention is realized through the following technical solutions:

[0006] A convective paper-based microfluidic fuel cell with a bent flow channel, characterized in that the convective paper-based microfluidic fuel cell comprises: an anode part and a cathode part arranged opposite to each other; the anode part includes an anode, an anode liquid paper-based flow channel and an anode support plate; the cathode part includes a cathode, a cathode liquid paper-based flow channel and a cathode support plate; the anode liquid paper-based flow channel is composed of an anode liquid paper-based first flow channel and an anode liquid paper-based second flow channel, and there is a bend between the anode liquid paper-based first flow channel and the anode liquid paper-based second flow channel; the anode, the anode liquid paper-based first flow channel and the anode support plate are stacked in sequence from top to bottom, and the anode liquid paper-based second flow channel hangs down along the side surface of the anode support plate; the cathode liquid paper-based flow channel is composed of a cathode liquid paper-based first flow channel and a cathode liquid paper-based second flow channel, and there is a bend between the cathode liquid paper-based first flow channel and the cathode liquid paper-based second flow channel; the cathode, the cathode liquid paper-based first flow channel and the cathode support plate are stacked in sequence from top to bottom, and the cathode liquid paper-based second flow channel hangs down along the side surface of the cathode support plate; catalytic layers are arranged at the contact parts between the anode and the anode liquid paper-based flow channel and between the cathode and the cathode liquid paper-based flow channel; an anode liquid inlet and a cathode liquid inlet are respectively arranged at the front ends of the anode liquid paper-based flow channel and the cathode liquid paper-based flow channel, and the tails are connected to an absorption pad; the anode liquid paper-based second flow channel is in close contact with the cathode liquid paper-based second flow channel to form a charge transport channel inside the battery.

[0007] Specifically, in the convective paper-based microfluidic fuel cell with a bent flow channel designed by the present invention, the anode liquid paper-based flow channel and the cathode liquid paper-based flow channel are designed in a counterflow type above the anode support plate and the cathode support plate, so that the diffusion direction of the reactants at the junction of the anode liquid and the cathode liquid is opposite to the flow direction of the reaction liquid on the opposite side, which can effectively inhibit the diffusion of the reactants to the opposite electrode, and further reduce the requirement for the distance between the cathode and anode electrodes; the 90° bend at the junction of the anode liquid paper-based flow channel and the cathode liquid paper-based flow channel changes the development direction of the mixing layer at the junction of the anode liquid and the cathode liquid, and breaks the limitation of the mixing layer on the electrode size.

[0008] Furthermore, a convective paper-based microfluidic fuel cell with a bent flow channel: there is a 90° bend between the anode liquid paper-based first flow channel and the anode liquid paper-based second flow channel; there is a 90° bend between the cathode liquid paper-based first flow channel and the cathode liquid paper-based second flow channel. Specifically, the anode liquid paper-based first flow channel and the anode liquid paper-based second flow channel are interconnected; the cathode liquid paper-based first flow channel and the cathode liquid paper-based second flow channel are interconnected. It can be understood that the flow channels with 90° bends exist in the anode liquid paper-based flow channel and the cathode liquid paper-based flow channel in the present invention.

[0009] Further, a convective paper-based microfluidic fuel cell with a bent flow channel: the length of the first anolyte paper-based flow channel is greater than that of the second anolyte paper-based flow channel; the length of the first catholyte paper-based flow channel is greater than that of the second catholyte paper-based flow channel.

[0010] Further, a convective paper-based microfluidic fuel cell with a bent flow channel: the anode covers the upper surface of the first anolyte paper-based flow channel, and the side of the anode close to the cathode does not extend beyond the anode support plate.

[0011] Further, a convective paper-based microfluidic fuel cell with a bent flow channel: the cathode covers the upper surface of the first catholyte paper-based flow channel, and the side of the cathode close to the anode does not extend beyond the cathode support plate.

[0012] Further, a convective paper-based microfluidic fuel cell with a bent flow channel: both the anolyte paper-based flow channel and the catholyte paper-based flow channel are cut from cellulose chromatography filter paper.

[0013] Further, a convective paper-based microfluidic fuel cell with a bent flow channel: the anode material is palladium-loaded carbon paper, and the cathode material is platinum-loaded carbon paper.

[0014] Further, a convective paper-based microfluidic fuel cell with a bent flow channel: both the anode support plate and the cathode support plate are made of PMMA plates.

[0015] Further, a convective paper-based microfluidic fuel cell with a bent flow channel: the anolyte is a mixed solution of potassium formate and potassium hydroxide, and the catholyte is a potassium hydroxide solution.

[0016] The anolyte and the catholyte flow towards each other spontaneously and passively during the paper-based flow. The fuel on the anode side is transported to the anodic catalyst layer by convection-diffusion to undergo an oxidation reaction; oxygen in the air spontaneously diffuses through the gas diffusion layer of the cathode to the cathodic catalyst layer to undergo a reduction reaction. After the anolyte and the catholyte meet at the junction, they bend downward by 90° and flow towards the absorption pad.

[0017] Further, a convective paper-based microfluidic fuel cell with a bent flow channel: the absorption pad is composed of a porous medium with spontaneous liquid absorption ability. Specifically, the absorption pad can be made of blotting paper. When the blotting paper in the absorption pad is saturated, it needs to be replaced in time to maintain the fluid flow in the dimension.

[0018] Advantages of the present invention:

[0019] (1) The convective paper-based microfluidic fuel cell with a bent flow channel designed by the present invention: Through the counter-flow design of the anolyte paper-based flow channel and the catholyte paper-based flow channel above the pallet, the diffusion direction of the reactants at the junction of the anolyte and the catholyte is opposite to the flow direction of the reaction liquid on the opposite side, which can effectively inhibit the diffusion of the reactants to the opposite electrode, thereby reducing the requirements for the distance between the cathode and anode electrodes, reducing the ohmic loss of the system, and improving the battery performance.

[0020] (2) The present invention designs the anolyte paper-based flow channel and the catholyte paper-based flow channel into a structure with a 90° bent flow channel, which changes the development direction of the mixing layer at the junction of the anolyte and the catholyte and breaks the limitation of the mixing layer on the electrode size.

[0021] (3) The convective paper-based microfluidic fuel cell with a bent flow channel designed by the present invention: Compared with the traditional paper-based microfluidic fuel cell with parallel laminar flow of the reaction liquid, the ohmic loss of the convective paper-based microfluidic fuel cell with a 90° bent flow channel provided by the present invention is significantly reduced. The relevant results show that the development direction of the reaction liquid mixing layer is perpendicular to the electrode plane, and the increase in the electrode size will not cause the generation of parasitic current. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those skilled in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0023] Figure 1 It is a schematic structural diagram of a convective paper-based microfluidic fuel cell with a bent flow channel designed by the present invention;

[0024] Figure 2 It is a front view of a convective paper-based microfluidic fuel cell with a bent flow channel designed by the present invention.

[0025] Reference numerals in the figure: 1 Anode part, 2 Cathode part, 1-1 Anode, 1-2 Anolyte paper-based flow channel, 1-3 Anode pallet, 1-2-1 First anolyte paper-based flow channel, 1-2-2 Second anolyte paper-based flow channel, 1-2-3 Anolyte inlet, 2-1 Cathode, 2-2 Catholyte paper-based flow channel, 2-3 Cathode pallet, 2-2-1 First catholyte paper-based flow channel, 2-2-2 Second catholyte paper-based flow channel, 2-2-3 Catholyte inlet. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and in no way limits the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0027] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "top", "bottom", etc. is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. Moreover, the terms "first", "second", etc. are used to distinguish similar objects and do not necessarily have to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein.

[0028] Embodiment 1

[0029] As Figure 1-2 shown, a convective paper-based microfluidic fuel cell with a bent flow channel, characterized in that the convective paper-based microfluidic fuel cell includes: an anode part 1 and a cathode part 2 arranged oppositely; wherein: the anode part 1 includes an anode 1-1, an anode liquid paper-based flow channel 1-2 and an anode tray 1-3; the cathode part 2 includes a cathode 2-1, a cathode liquid paper-based flow channel 2-2 and a cathode tray 2-3.

[0030] The anode liquid paper-based flow channel 1-2 is formed by connecting the anode liquid paper-based first flow channel 1-2-1 and the anode liquid paper-based second flow channel 1-2-2 (the length of the anode liquid paper-based first flow channel 1-2-1 is greater than that of the anode liquid paper-based second flow channel 1-2-2), and there is a 90° bend between the anode liquid paper-based first flow channel 1-2-1 and the anode liquid paper-based second flow channel 1-2-2, forming a 90° bent flow channel in the anode liquid paper-based flow channel 1-2; the anode 1-1, the anode liquid paper-based first flow channel 1-2-1, and the anode support plate 1-3 are stacked in sequence from top to bottom, and the anode liquid paper-based second flow channel 1-2-2 hangs down along the side surface of the anode support plate 1-3 (that is, the anode liquid paper-based flow channel 1-2 in the anode part 1 covers the surface of the anode support plate 1-3 after bending, where the longer side after bending covers the upper surface of the anode support plate 1-3, and the shorter side hangs down along the side surface of the anode support plate 1-3);

[0031] The cathode liquid paper-based flow channel 2-2 is formed by connecting the cathode liquid paper-based first flow channel 2-2-1 and the cathode liquid paper-based second flow channel 2-2-2 (similarly, the length of the cathode liquid paper-based first flow channel 2-2-1 is greater than that of the cathode liquid paper-based second flow channel 2-2-2), and there is a 90° bend between the cathode liquid paper-based first flow channel 2-2-1 and the cathode liquid paper-based second flow channel 2-2-2, forming a 90° bent flow channel in the cathode liquid paper-based flow channel 2-2; the cathode 2-1, the cathode liquid paper-based first flow channel 2-2-1, and the cathode support plate 2-3 are stacked in sequence from top to bottom, and the cathode liquid paper-based second flow channel 2-2-2 hangs down along the side surface of the cathode support plate 2-3 (similarly, the cathode liquid paper-based flow channel 2-2 in the cathode part 2 covers the surface of the cathode support plate 2-3 after bending, where the longer side after bending covers the upper surface of the cathode support plate 2-3, and the shorter side hangs down along the side surface of the cathode support plate 2-3);

[0032] A catalytic layer is provided at the contact part between the anode 1-1 and the anode liquid paper-based flow channel 1-2, and a catalytic layer is also provided at the contact part between the cathode 2-1 and the cathode liquid paper-based flow channel 2-2;

[0033] An anode liquid inlet 1-2-3 and a cathode liquid inlet 2-2-3 are respectively provided at the front ends of the anode liquid paper-based flow channel 1-2 and the cathode liquid paper-based flow channel 2-2, and the tail ends are connected to the absorption pad;

[0034] The anode liquid paper-based second flow channel 1-2-2 is in close contact with the cathode liquid paper-based second flow channel 2-2-2 to form a charge transport channel inside the battery.

[0035] Preferably, in the above-described Embodiment 1, both the anolyte paper-based flow channel 1-2 and the catholyte paper-based flow channel 2-2 are made by cutting cellulose chromatography filter paper; the anode 1-1 is palladium-loaded carbon paper; the cathode 2-1 is platinum-loaded carbon paper; the absorption pad is made of absorbent paper; the anode support plate 1-3 and the cathode support plate 2-3 are made of PMMA plates.

[0036] The anolyte in the above-described Embodiment 1 is a mixed solution of potassium formate and potassium hydroxide, and the catholyte is a potassium hydroxide solution. The anolyte and the catholyte flow towards each other spontaneously and passively during the paper-based flow. The fuel on the anode side is transported to the anode catalyst layer by convection-diffusion to undergo an oxidation reaction; oxygen in the air spontaneously diffuses through the gas diffusion layer of the cathode to the cathode catalyst layer to undergo a reduction reaction. The anolyte and the catholyte meet at the junction and then bend 90 degrees downward to flow towards the absorption pad. During operation, when the absorbent paper in the absorption pad is saturated, it needs to be replaced in time to maintain the fluid flow of the dimension.

[0037] Compared with the traditional paper-based microfluidic fuel cell with parallel laminar flow of the reaction liquid, the ohmic loss of the convective paper-based microfluidic fuel cell with a 90° bent flow channel provided by the present invention is significantly reduced. The relevant results show that the development direction of the reaction liquid mixing layer is perpendicular to the electrode plane, and the increase in the electrode size will not cause the generation of parasitic current.

[0038] The above are the preferred embodiments of the present invention, which are only used to explain the present invention and are not used to limit the present invention. Any obvious changes or variations derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A convective paper-based microfluidic fuel cell with a bent flow channel, characterized in that The described convective paper-based microfluidic fuel cell includes: an anode part (1) and a cathode part (2) arranged oppositely; the anode part (1) includes an anode (1-1), an anolyte paper-based flow channel (1-2), and an anode support plate (1-3); the cathode part (2) includes a cathode (2-1), a catholyte paper-based flow channel (2-2), and a cathode support plate (2-3). The anolyte paper-based flow channel (1-2) is composed of an anolyte paper-based first flow channel (1-2-1) and an anolyte paper-based second flow channel (1-2-2), and there is a bend between the anolyte paper-based first flow channel (1-2-1) and the anolyte paper-based second flow channel (1-2-2); the anode (1-1), the anolyte paper-based first flow channel (1-2-1), and the anode support plate (1-3) are stacked in sequence from top to bottom, and the anolyte paper-based second flow channel (1-2-2) hangs down along the side surface of the anode support plate (1-3). The catholyte paper-based flow channel (2-2) is composed of a catholyte paper-based first flow channel (2-2-1) and a catholyte paper-based second flow channel (2-2-2), and there is a bend between the catholyte paper-based first flow channel (2-2-1) and the catholyte paper-based second flow channel (2-2-2); the cathode (2-1), the catholyte paper-based first flow channel (2-2-1), and the cathode support plate (2-3) are stacked in sequence from top to bottom, and the catholyte paper-based second flow channel (2-2-2) hangs down along the side surface of the cathode support plate (2-3). Catalytic layers are provided at the contact parts between the anode (1-1) and the anolyte paper-based flow channel (1-2), and between the cathode (2-1) and the catholyte paper-based flow channel (2-2). An anolyte inlet (1-2-3) and a catholyte inlet (2-2-3) are respectively provided at the front ends of the anolyte paper-based flow channel (1-2) and the catholyte paper-based flow channel (2-2), and the tails are connected to the absorption pad. The anolyte paper-based second flow channel (1-2-2) is in close contact with the catholyte paper-based second flow channel (2-2-2) to form an internal charge transport channel of the battery. There is a 90° bend between the anolyte paper-based first flow channel (1-2-1) and the anolyte paper-based second flow channel (1-2-2); there is a 90° bend between the catholyte paper-based first flow channel (2-2-1) and the catholyte paper-based second flow channel (2-2-2).

2. The convective paper-based microfluidic fuel cell with a bent flow channel according to claim 1, wherein The length of the anolyte paper-based first flow channel (1-2-1) is greater than that of the anolyte paper-based second flow channel (1-2-2); the length of the catholyte paper-based first flow channel (2-2-1) is greater than that of the catholyte paper-based second flow channel (2-2-2).

3. The convective paper-based microfluidic fuel cell with a bent flow channel according to claim 1, characterized in that, The anode (1-1) covers the upper surface of the anolyte paper-based first flow channel (1-2-1), and the side of the anode (1-1) close to the cathode (2-1) does not extend beyond the anode support plate (1-3).

4. The convective paper-based microfluidic fuel cell with a bent flow channel according to claim 1, wherein The cathode (2-1) covers the upper surface of the catholyte paper-based first flow channel (2-2-1), and the side of the cathode (2-1) close to the anode (1-1) does not extend beyond the cathode support plate (2-3).

5. A convective paper-based microfluidic fuel cell having a bent flow channel according to claim 1, characterized in that, The anode liquid paper-based flow channel (1-2) and the cathode liquid paper-based flow channel (2-2) are cut from cellulose chromatography filter paper.

6. The convective paper-based microfluidic fuel cell with a bent flow channel according to claim 1, wherein The anode (1-1) is made of palladium-loaded carbon paper, and the cathode (2-1) is made of platinum-loaded carbon paper.

7. A convective paper-based microfluidic fuel cell with a bent flow channel according to claim 1, characterized in that, The anode support plate (1-3) and the cathode support plate (2-3) are both made of PMMA plates.

8. A convective paper-based microfluidic fuel cell with a bent flow channel according to claim 1, characterized in that, The anode liquid is a mixed solution of potassium formate and potassium hydroxide, and the cathode liquid is a potassium hydroxide solution.

9. The convective paper-based microfluidic fuel cell with a bent flow channel according to claim 1, wherein The absorption pad is composed of a porous medium with spontaneous liquid absorption ability.

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