Novel pressure sensor based on solid electrolyte and preparation method thereof

Abstract

The invention discloses a novel pressure sensor based on a solid electrolyte and a preparation method thereof, the pressure sensor comprises a sensing element, the sensing element comprises the solid electrolyte, a working electrode, a counter electrode, a current collector and a flexible polymer film, and the current collector, the working electrode, the solid electrolyte, the counter electrode and the current collector are sequentially arranged from top to bottom; and the flexible polymer film is used for packaging. According to the pressure sensor, the working electrode deforms under the action of pressure, ions on a contact interface of the working electrode and the solid electrolyte are caused to migrate, potential change is generated, and the change of external pressure is sensed. The sensor is simple in design, easy to integrate with an electronic system, convenient to integrate into various electronic devices, good in chemical stability, capable of being applied to various working environments, not prone to corrosion, high in sensitivity, rapid in response and low in energy consumption.

Description

Technical Field

[0001] The present invention belongs to the technical field of pressure sensors, and in particular relates to a new type of pressure sensor based on solid electrolyte and a preparation method thereof. Background Art

[0002] With the rapid development of smart industry, pressure sensors as windows for information exchange have become increasingly important. Existing sensors mainly include piezoresistive sensors, capacitive sensors, and piezoelectric sensors. However, with the continuous expansion of application scenarios, the requirements for sensor performance have become increasingly stringent. For example, sensors need to have higher sensitivity, wider pressure detection range, and lower detection frequency. However, none of the above sensors have the ability to detect low-frequency signals (<5Hz). The fundamental reason is that these sensors usually rely on electronic transmission for signal acquisition, and the high-speed transmission of electrons makes it difficult for them to effectively capture low-frequency signals. To meet this challenge, a new type of ion-based pressure sensor has emerged. This type of sensor uses ions as the information transmission medium, making full use of the slower ion transport speed than electronic transmission, so that it can match the low-frequency pressure signal on a time scale. This matching mechanism enables the new pressure sensor to effectively detect low-frequency pressure signals, meeting the needs for low-frequency signal detection in specific application scenarios. This type of sensor has broad application prospects in fields such as smart manufacturing, medical monitoring, and environmental testing that require long-term, low-frequency pressure monitoring.

[0003] However, the electrolyte systems used in existing pressure sensors based on this principle are mostly liquid, which has the disadvantages of being difficult to encapsulate, easy to volatilize and leak, resulting in decreased sensor performance, and insufficient sensitivity. These disadvantages not only affect the performance of the sensor, but may also cause pollution to the surrounding environment. In addition, the application of such sensors in specific environments such as high temperature, high pressure, and strong magnetic field is limited, which increases the difficulty and cost of manufacturing the sensor.

[0004] Therefore, preparing a pressure sensor with high safety, good stability and stable chemical properties is a technical problem to be solved. Summary of the invention

[0005] The purpose of this section is to summarize some aspects of embodiments of the present invention and to briefly introduce some preferred embodiments.

[0006] Solid electrolytes mainly include oxides, sulfides, solid polymers (excluding gel polymers) and composite materials composed of the above materials. Sensors based on solid electrolytes can adapt to different packaging requirements due to their good processability, which helps to maintain the integrity of the packaging structure and reduce the risk of leakage. At the same time, solid electrolytes have high chemical stability and can effectively resist corrosion from chemical substances in the external environment, further reducing the risk of leakage, thereby meeting the needs of sensors and other devices in complex working environments.

[0007] The present invention provides a new type of pressure sensor based on solid electrolyte and a preparation method thereof, which is designed based on the working characteristics of existing pressure sensors and the structure of the pressure sensor. The pressure sensor provided by the present invention deforms under the action of the pressure to be measured, causing the migration of ions at the contact interface with the solid electrolyte, generating a potential change, and sensing the change of external pressure, thereby converting the external pressure energy into electrical energy, and the external pressure has a corresponding relationship with the generated real-time voltage, and the real-time voltage is measured, and then the real-time voltage is converted into the corresponding pressure according to the corresponding relationship.

[0008] To achieve the above object, according to one aspect of the present invention, a pressure sensor based on a solid electrolyte of a carbon nanotube film is provided, the pressure sensor comprising a sensing element, the sensing element is used to convert the pressure energy of the pressure to be measured into electrical energy, and the sensing element comprises a solid electrolyte, a working electrode, a counter electrode, a current collector and a flexible polymer film; the current collector, the working electrode, the solid electrolyte, the counter electrode, and the current collector are arranged in sequence from top to bottom; the flexible polymer film is used for packaging;

[0009] The pressure sensor senses changes in external pressure based on the deformation of the working electrode under pressure, which causes ions at the contact interface with the solid electrolyte to migrate and produce potential changes.

[0010] Furthermore, the flexibility of the solid electrolyte should be greater than 1.0×10 -12 Pa -1 .

[0011] Furthermore, the working electrode material includes but is not limited to carbon nanotubes, graphene, and activated carbon.

[0012] Furthermore, the solid electrolyte includes but is not limited to a sulfide solid electrolyte, an oxide solid electrolyte, a solid polymer electrolyte (excluding gel polymer) and a composite material composed of the above materials.

[0013] Furthermore, the flexible polymer film material includes but is not limited to polyoxymethylene methyl acrylate film, polydimethylsiloxane film, and polystyrene film.

[0014] Furthermore, in the novel pressure sensor based on solid electrolyte, the current collector includes but is not limited to copper foil, aluminum foil, nickel, and stainless steel.

[0015] Furthermore, in the novel pressure sensor based on solid electrolyte, the working electrode and the counter electrode are completely covered by the solid electrolyte.

[0016] According to another aspect of the present invention, a method for preparing a new type of pressure sensor based on a solid electrolyte is provided, characterized in that the manufacturing method comprises the following steps: firstly fixing a working electrode and a counter electrode on two current collectors respectively, then placing a solid electrolyte between the working electrode and the counter electrode, and finally encapsulating the above components with a flexible polymer film.

[0017] Furthermore, the new pressure sensor based on solid electrolyte, wherein: the new pressure sensor based on solid electrolyte can form a pressure sensor array to sense distributed pressure.

[0018] In general, compared with the prior art, the above technical solution conceived by the present invention provides a new type of pressure sensor based on solid electrolyte, which has the following beneficial effects:

[0019] 1. The pressure sensor senses changes in external pressure based on the deformation of the working electrode under pressure, which causes the migration of ions at the contact interface between the working electrode and the solid electrolyte, resulting in changes in electric potential. The pressure sensor can obtain the current pressure based on the relationship between the current corresponding to the electric energy converted from the pressure and the corresponding pressure, thereby realizing real-time monitoring of the pressure to be measured. The pressure sensor does not require an external power supply when working, which reduces the consumption of electric energy. It has a large working range, high sensitivity, and fast response speed. It can be used in a variety of environments and has good environmental adaptability.

[0020] 2. The pressure sensor based on solid electrolyte solves the shortcoming of pressure sensors based on liquid electrolytes that are prone to volatile leakage, resulting in degradation of sensor performance, and reduces possible pollution to the surrounding environment.

[0021] 3. The pressure sensor based on solid electrolyte solves the shortcoming of difficult packaging of pressure sensors based on liquid electrolyte, reduces the manufacturing difficulty and cost of the sensor, has a simple structure, and has great prospects for industrial production and application.

[0022] 4. The solid electrolyte-based pressure sensor has good processability, enabling it to adapt to different scenario requirements.

[0023] 5. The pressure sensor based on solid electrolyte can work in a low temperature environment of -40°C. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solution of the embodiment of the present invention, the following briefly introduces the drawings required for describing the embodiment, wherein:

[0025] Figure 1 It is a structural schematic diagram of a sensing element of a pressure sensor of the present invention;

[0026] Figure 2 is the response of the sensor to pressure at room temperature and -40°C;

[0027] Figure 3 is the response of the sensor to 10Pa pressure in -40℃ environment;

[0028] Figure 4 The response of the sensor of comparative example 1 to 1 kPa pressure at -20°C;

[0029] Figure 5 The response of the sensor of comparative example 2 to 1 kPa pressure at -20°C.

[0030] Figure 1 Middle: 1-flexible polymer film, 2-working electrode, 3-counter electrode, 4-solid electrolyte, 5-signal lead, 61-current collector, 62-current collector. DETAILED DESCRIPTION

[0031] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with specific embodiments.

[0032] Embodiment 1:

[0033] See also Figure 1 and Figure 2 The present invention provides a novel pressure sensor based on a solid electrolyte and a manufacturing method thereof. The pressure sensor comprises a sensing element, the sensing element comprises a solid electrolyte, a working electrode, a counter electrode, a current collector and a flexible polymer film, which are arranged from top to bottom as a current collector, a working electrode, a solid electrolyte, a counter electrode and a current collector; the flexible polymer film is used for packaging; the flexibility of the solid electrolyte is 2.8×1O -12 Pa -1 .

[0034] The pressure sensor is based on the deformation of the working electrode under the action of pressure, which causes the migration of ions at the contact interface with the solid electrolyte and produces a change in electric potential, thereby sensing changes in external pressure.

[0035] In this embodiment, the solid electrolyte is lithium lanthanum zirconium oxide (LLZO, Li7La3Zr2O 12) solid electrolyte; the flexible polymer film is polyoxymethylene methyl acrylate film; the electrode is made of carbon nanotube film.

[0036] According to experiments, the solid electrolyte of the present invention is also applicable to other lithium lanthanum zirconium oxygen solid electrolytes. The key point is that the flexibility of the solid electrolyte should be greater than 1.0×10 -12 Pa -1 .

[0037] The present invention also provides a novel pressure sensor based on solid electrolyte and a preparation method thereof, such as Figure 1 , Figure 2 , the preparation method comprises the following steps:

[0038] (1) First, fix the working electrode and the counter electrode on two current collectors respectively.

[0039] (2) Then place the solid electrolyte between the working electrode and the counter electrode.

[0040] (3) The flexible polymer film is used for encapsulation, and the structure is arranged from top to bottom as current collector, working electrode, solid electrolyte, counter electrode, and current collector.

[0041] In order to characterize the performance of the pressure sensor, the following performance tests were performed on the pressure sensor:

[0042] See also Figure 2 , the sensor's response to pressures in the range of 83 kPa to 496 kPa at room temperature and -40 °C. At room temperature, as the pressure increases from 83 kPa to 496 kPa, the sensor's output signal increases from 0.34 mA / cm 2 Increased to 1.46mA / cm 2 At -40℃, as the pressure increases from 83kPa to 496kPa, the output signal of the sensor increases from 0.28mA / cm 2 Increased to 1.05mA / cm 2 .

[0043] See also Figure 3 , the sensor's response to a 10Pa pressure in a -40°C environment. When a 10Pa pressure is applied to the sensor, the sensor's open circuit voltage increases by 0.2mV.

[0044] Embodiment 2:

[0045] In this embodiment, the solid electrolyte is a lithium titanium phosphate (LATP) solid electrolyte; the flexible polymer film is a polydimethylsiloxane film; the flexibility of the solid electrolyte is greater than 1.0×10 -12 Pa -1; The electrode is made of a carbon nanotube array, and the sensor preparation method is the same as that in Example 1.

[0046] Embodiment 3:

[0047] In this embodiment, the solid electrolyte is a lithium phosphorus sulfur chloride (LiPSCl) solid electrolyte; the flexible polymer film is a polystyrene film; the flexibility of the solid electrolyte is greater than 1.0×10 -12 Pa -1 ; The electrode is made of graphene film, and the sensor preparation method is the same as that in Example 1.

[0048] Comparative Example 1:

[0049] In this embodiment, the electrolyte is a gel electrolyte, and this embodiment uses a polyvinyl alcohol-hydroxymethyl cellulose gel electrolyte; the flexible polymer film is a polyoxymethylene methyl acrylate film; the electrode is made of a carbon nanotube film, and the sensor preparation method is the same as that of Example 1.

[0050] See also Figure 4 The pressure sensor based on polyvinyl alcohol-hydroxymethyl cellulose gel electrolyte has an operating temperature of -20°C, a pressure detection lower limit of 1kPa, a signal change value of -30nA to 60nA, and an unstable output.

[0051] The pressure sensor prepared with gel electrolyte has insufficient sensitivity and unstable signal.

[0052] Comparative Example 2:

[0053] In this embodiment, the electrolyte is Li7La3Zr2N b 0.1 O 12 Solid electrolyte, the flexibility of solid electrolyte is 7.4×10 -13 Pa -1 ; The flexible polymer film is a polyoxymethylene methyl acrylate film; the electrode is made of a carbon nanotube film, and the sensor preparation method is the same as that in Example 1.

[0054] See also Figure 5 , based on Li7La3Zr2Nb 0.1 O 12 The operating temperature of the solid electrolyte pressure sensor is -20℃, the lower limit of pressure detection is 1kPa, the signal strength gradually decays, the maximum change value is 3nA, the minimum change value is 0.9nA, and the output is unstable. This shows that the flexibility of the solid electrolyte needs to be controlled within a reasonable range, otherwise it may cause problems such as insufficient sensitivity of the pressure sensor.

[0055] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A new type of pressure sensor based on solid electrolyte, characterized in that: The pressure sensor includes a sensing element, which is used to convert the pressure energy of the pressure to be measured into electrical energy. The sensing element includes a solid electrolyte, a working electrode, a counter electrode, and a current collector; the structural arrangement is in the order of current collector, working electrode, solid electrolyte, counter electrode, and current collector.

2. The novel pressure sensor based on solid electrolyte according to claim 1 is characterized in that: A flexible polymer film is also included for encapsulating the pressure sensor.

3. The novel pressure sensor based on solid electrolyte according to claim 1 or 2, characterized in that: The flexibility of the solid electrolyte is greater than 1.0×10 -12 Pa -1 .

4. The novel pressure sensor based on solid electrolyte according to claim 1 or 2, characterized in that: The material of the working electrode includes one or more of carbon nanotubes, graphene, and activated carbon.

5. The novel pressure sensor based on solid electrolyte according to claim 1 or 2, characterized in that: The solid electrolyte includes one or more of a sulfide solid electrolyte, an oxide solid electrolyte, and a solid polymer electrolyte.

6. The novel pressure sensor based on solid electrolyte according to claim 2 is characterized in that: The material of the flexible polymer film includes one or more of polyoxymethylene methyl acrylate film, polydimethylsiloxane film and polystyrene film.

7. The novel pressure sensor based on solid electrolyte according to claim 1 or 2, characterized in that: The current collector includes one or more of copper foil, aluminum foil, nickel, stainless steel, and platinum foil.

8. The novel pressure sensor based on solid electrolyte according to claim 1 or 2, characterized in that: It also includes signal lead-out lines respectively connected to the current collector on one side of the working electrode and the current collector on one side of the counter electrode.

9. The novel pressure sensor based on solid electrolyte according to claim 1 or 2, characterized in that: The working electrode and the counter electrode are completely covered by the solid electrolyte.

10. The method for preparing a new type of pressure sensor based on solid electrolyte according to claim 2, characterized in that: First, the working electrode and the counter electrode are fixed on two current collectors respectively, and then the solid electrolyte is placed between the working electrode and the counter electrode to obtain a pressure sensor, which is finally encapsulated with a flexible polymer film.

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