CN201886904U - Laminated high-voltage hybrid electrochemical capacitor - Google Patents

Abstract

The utility model discloses a laminated high-voltage hybrid electrochemical capacitor, which comprises a casing, a positive lead-out end, a plurality of bipolar plates and a negative lead-out, the plurality of bipolar plates are located on the positive Between the lead end and the negative electrode lead end, there is a separator between the adjacent plates of the plurality of bipolar plates, and the plurality of bipolar plates are located in the electrolyte, and it is characterized in that the The bipolar plate is a lead plate or a lead alloy plate, the smooth side of the lead plate or lead alloy plate is coated with carbon powder as a negative electrode, and there is a lead dioxide layer on the rough side of the lead plate or lead alloy plate As a positive electrode, the lead plate or lead alloy plate itself constitutes a separator between two adjacent capacitors. Because the polar plates of the utility model adopt bipolar design, the series connection resistance between the capacitors is reduced to the greatest extent, the power density is high, and the energy density is also significantly improved at the same time; because the positive electrode adopts a formed electrode, the cycle life of the positive and negative electrodes is improved. Get a very good match, and the capacitor has a long service life, so it has a very good application prospect.

Description

A laminated high voltage hybrid electrochemical capacitor

technical field

The utility model relates to an electrochemical energy storage device, in particular to a laminated high-voltage hybrid electrochemical capacitor.

Background technique

With the continuous development of the economy, energy, resources and the environment have become the focus of society. It is an urgent and arduous task for human society to find clean, renewable and resource-saving energy.

Currently, there are three main types of energy storage devices in the energy field: batteries, physical capacitors, and electrochemical capacitors (also known as supercapacitors). Electrochemical capacitors are a new type of green energy storage device developed in recent years between the characteristics of traditional physical capacitors and batteries. Long service life (the number of cycles can reach more than 100,000 times), wide operating temperature range (between -40°C and 75°C). Based on these unique properties, electrochemical capacitors have very good application prospects.

According to different energy storage mechanisms, electrochemical capacitors can be divided into two categories: electric double layer capacitors and Faraday quasi-capacitors. Electric double layer capacitors use the interfacial electric double layer capacitance formed between electrodes and electrolytes to store energy, and their electrodes usually use porous carbon materials with high specific surface areas. Faraday quasi-capacitance capacitor refers to the underpotential deposition of electrode active materials on the surface of the electrode or in the bulk phase in a two-dimensional or quasi-two-dimensional space, so that a fast and reversible chemical adsorption/desorption or oxidation/reduction reaction occurs, thereby It produces a higher specific capacity than electric double layer capacitors, and its electrode materials are mainly metal oxides and conductive polymers.

In order to obtain higher energy density and power density at the same time, a new type of asymmetric electrochemical capacitor (also known as hybrid electrochemical capacitor) has been developed in recent years, that is, one pole of the capacitor is an electric double layer electrode, and the other pole is Faraday quasi capacitive electrodes. The asymmetric electrochemical supercapacitor combines the advantages of the two types of electrochemical capacitors, and can better meet the overall requirements of the load for the energy density and power density of the power supply system in practical applications.

In various metal oxide/carbon asymmetric electrochemical capacitors, PbO ₂ /C system, due to low material price and PbO ₂ The electrode manufacturing technology is mature, which is very suitable for the manufacture of large-capacity energy storage devices; at the same time, because sulfuric acid aqueous solution is used as the electrolyte, it has the highest conductivity, so the internal resistance of the capacitor is very low; in addition, the electrochemical window of the system is 2.20~0.80V, only Second to organic systems, it is very suitable for the manufacture of high-power energy storage devices.

In actual use, as an auxiliary power supply, single capacitors must be connected in series and parallel to achieve a suitable capacitance and working voltage, usually using an external connection. Due to the existing PbO ₂ /C asymmetrical electrochemical capacitor has high power density and long cycle life, but its energy density is low. Therefore, after the capacitor is combined, it has a larger volume and lower energy density, which cannot reach the auxiliary power of electric vehicles and hybrid electric vehicles. The requirements of the power supply and the failure to meet the requirements of the auxiliary power supply of the energy storage battery of the solar and wind power stations greatly limit the application range of the capacitor.

Contents of the invention

The purpose of the utility model is to provide a laminated high-voltage hybrid electrochemical capacitor assembly which is not only small in size, high in energy density and long in cycle life, but also has a significantly improved power density, so as to meet the needs of electric vehicles and hybrid vehicles. And auxiliary power requirements for energy storage devices in solar and wind power plants.

The technical scheme of the utility model is: a laminated high-voltage hybrid electrochemical capacitor, including a shell, a positive terminal, a plurality of bipolar plates and a negative terminal, and the multiple bipolar plates are located at Between the positive electrode lead-out end and the negative electrode lead-out end, there are separators between the adjacent plates of the plurality of bipolar plates, and the plurality of bipolar plates are located in the electrolyte, and the features That is, the bipolar plate is a lead plate or a lead alloy plate, and the smooth side of the lead plate or lead alloy plate is coated with carbon powder as a negative electrode, and there are two electrodes on the rough side of the lead plate or lead alloy plate. The lead oxide layer serves as the positive electrode, and the lead plate or lead alloy plate itself constitutes a separator between two adjacent capacitors.

Preferably, there are 3-6 bipolar plates.

Preferably, the electrolyte is a colloidal electrolyte.

Preferably, the electrolyte is dilute sulfuric acid.

Preferably, the positive terminal, the plurality of bipolar plates and the negative terminal are all fixed by injection molded frames, and the frames are assembled by resin bonding or hot-melt.

Preferably, the separator is an AGM (glass fiber wool) separator.

Preferably, the separator has a thickness of 1.0-1.5mm and a strength of 10Kpa.

Preferably, the structure of the laminated high-voltage hybrid electrochemical capacitor is a liquid-filled structure or a valve-controlled sealed structure.

The utility model has the advantages of:

1. The hybrid electrochemical capacitor provided by the utility model adopts bipolar plates, and two adjacent capacitors are connected in series with the shortest path and the smallest connection resistance, so the capacitor combination has higher power density and energy density, Smaller size.

2. The positive electrode described in the utility model adopts a formed electrode with very small internal resistance; once the active material of the positive electrode softens and falls off, the surface of the formed electrode will be oxidized to form a new active material layer, so it has an extremely long cycle life. It can match the life of the negative electrode.

3. Because the utility model adopts the sulfuric acid aqueous solution with high conductivity as the electrolyte, it has extremely high power charging and discharging characteristics. It can fully meet the requirements of electric vehicles and hybrid vehicles power batteries and the requirements of auxiliary power supplies for energy storage devices of solar and wind power stations.

Description of drawings

Below in conjunction with accompanying drawing and embodiment the utility model is further described:

Fig. 1 is the main sectional view of the utility model laminated high-voltage hybrid electrochemical capacitor monomer;

Fig. 2 is the bipolar plate schematic diagram in the utility model laminated high-voltage hybrid electrochemical capacitor;

Fig. 3 is the sectional view of the bipolar polar plate in the laminated high-voltage hybrid electrochemical capacitor of the present invention;

Fig. 4 is the sectional view of the lead-out positive plate in the laminated high-voltage hybrid electrochemical capacitor of the present invention;

Fig. 5 is a cross-sectional view of the lead-out negative plate in the laminated high-voltage hybrid electrochemical capacitor of the present invention;

Fig. 6 is a main sectional view of an assembly composed of five monomers connected in series in the utility model laminated high-voltage hybrid electrochemical capacitor;

Among them: 1. Positive lead-out terminal; 11. Positive lead collector; 2. Negative lead-out; 21. Negative lead collector; 3. Separator; 4. Bipolar plate; 41. Lead collector; 42. Carbon Powder material; 43. Lead dioxide film; 5. Shell; 6. Plate plastic frame.

Detailed ways

Embodiment 1: A laminated high-voltage hybrid electrochemical capacitor as shown in Fig. 1, a positive terminal 1, four bipolar plates 4 and a negative terminal 2 are packaged in the casing 5 arranged in sequence , the separator 3 between adjacent plates is a commercial AGM separator (thickness 1.0mm 10KPa); and the perfused electrolyte is dilute sulfuric acid (density 1.28g/cm ³ ). The positive and negative terminals are respectively used as the positive and negative terminals of the capacitor.

As shown in Fig. 2 and Fig. 3, the structure of the bipolar plate 4 is that a lead plate or a lead alloy plate is used as a lead collector: a lead plate or a lead alloy plate is embedded in a plastic box 6, and the front side is a negative electrode, and the lead plate is coated with Capacitive electrode material 42; the opposite side is the positive electrode, and the roughened surface forms a lead dioxide film 43 in the form of anodic electrochemical oxidation during the initial charging process; at the same time, the lead plate or lead alloy plate itself is the capacitor of two adjacent capacitors. Separators with electrochemical properties.

As shown in FIG. 4 , the lead-out end of the positive electrode is a single electrode of the bipolar plate 4 , that is, the positive electrode. The lead plate or lead alloy plate is drawn from the top, and the negative electrode is removed to form a positive electrode lead collector 11 .

As shown in FIG. 5 , the lead-out end of the negative electrode in this embodiment is a single electrode of the bipolar plate 4 , that is, the negative electrode. The lead plate or lead alloy plate is drawn from the top, and the positive electrode is canceled to form a negative electrode lead collector 21 .

In this embodiment, the lead plate or lead alloy plate is made of a lead-tin alloy with a tin content of 0.6% and rolled into a thin plate with a thickness of about 1.0-1.5 mm, and then cut into a rectangular shape. The surface roughening treatment method can be knurled directly on the surface during the rolling process, or it can be made into a thin plate after rolling and polished with a copper wire roller.

The weight ratio of the capacitor electrode material components described in this example is as follows: 70% of activated carbon, 15% of graphite powder, 5% of acetylene black, and 10% of PVDF. ² /g, commercial activated carbon with a mesoporosity greater than 40% and a particle size of 5-10 μm. First, dry-mix activated carbon, graphite powder and acetylene black for 5 minutes, add PVDF N-methylpyrrolidone (NMP) solution, then use an appropriate amount of N-methylpyrrolidone to make a slurry, and stir 1-2 hours, mix well.

In this embodiment, the plastic frame of the positive terminal 1, the negative and positive terminal 2, and the bipolar plate 4 is injection-molded with engineering plastics (ABS). During assembly, the plastic square frame is bonded with epoxy and then fit into the capacitor case.

Example 2:

For the laminated high-voltage hybrid electrochemical capacitor shown in Figure 6, five five-unit capacitors are combined in series in a capacitor case with five cells. The cells are connected by through-wall welding, and other implementations are the same as in Embodiment 1.

The above descriptions are only preferred embodiments of the utility model, and various changes made by those skilled in the art without departing from the scope of the claims of the utility model shall fall within the protection scope of the utility model.

Claims (8)

1. stacked high voltage hybrid electrochemical capacitor, comprise housing, anodal exit, polylith double polarity plate and negative pole exit, described polylith double polarity plate is between described anodal exit and described negative pole exit, between the adjacent plate of described polylith double polarity plate dividing plate is arranged, described polylith double polarity plate is arranged in electrolyte, it is characterized in that, described double polarity plate is stereotype or lead alloy plate, the one side that described stereotype or lead alloy plate are smooth is coated with carbon dust as negative electrode, the titanium dioxide lead layer is arranged as positive electrode on the coarse one side of described stereotype or lead alloy plate, described stereotype or lead alloy plate self constitute the slider of adjacent two capacitors.

2. stacked high voltage hybrid electrochemical capacitor according to claim 1 is characterized in that, described double polarity plate is 3-6.

3. stacked high voltage hybrid electrochemical capacitor according to claim 1 is characterized in that described electrolyte is colloidal electrolyte.

4. stacked high voltage hybrid electrochemical capacitor according to claim 1 is characterized in that described electrolyte is dilute sulfuric acid.

5. stacked high voltage hybrid electrochemical capacitor according to claim 1, it is characterized in that, described anodal exit, polylith double polarity plate and negative pole exit all adopt molded plastic frame to fix, and cohere mode or hot melting way assembling with resin between the frame.

6. stacked high voltage hybrid electrochemical capacitor according to claim 1 is characterized in that, the structure of described stacked high voltage hybrid electrochemical capacitor is pregnant solution type structure or valve-regulated sealed structure.

7. stacked high voltage hybrid electrochemical capacitor according to claim 1 is characterized in that described dividing plate is the glass fibre cotton dividing plate.

8. stacked high voltage hybrid electrochemical capacitor according to claim 8 is characterized in that, described block board thickness 1.0-1.5mm, and intensity is 10Kpa.

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