CN205177621U - Lithium ion ultracapacitor system inner core structure - Google Patents

Abstract

The utility model relates to an inner core structure of a lithium-ion supercapacitor, comprising a negative electrode, a diaphragm, and more than two positive electrodes, wherein the positive electrode and the negative electrode are assembled together in a half-winding and half-stacked manner to obtain a half-core containing more than three positive electrodes. Winding lithium-ion supercapacitor structure. The utility model assembles the positive electrode, the negative electrode and the diaphragm through the half-laminated and half-winding structure, which not only can reduce the internal resistance of the battery, but also can use a higher positive electrode with poor flexibility, so that the lithium-ion supercapacitor has a higher energy density. .

Description

A lithium-ion supercapacitor core structure

technical field

The utility model relates to an electrochemical energy storage device, in particular to a lithium ion supercapacitor structure.

Background technique

As a type of supercapacitor, lithium-ion supercapacitor has the advantages of both supercapacitor and lithium-ion battery. It not only has high power density, good safety, high cycle stability, but also has certain energy density and low self-discharge. It is a type of energy storage device that has better application prospects in the fields of mobile communication, starting power supply, and backup power supply.

Lithium-ion capacitors include positive electrodes, negative electrodes, diaphragms, electrolytes, and casings. Generally, two assembly methods are used. 1. Winding type. The positive electrode, the negative electrode, and the separator each have only one piece, and after overlapping each other in parallel, they are wound into a cylindrical or flat columnar structure in one direction (such as clockwise). The battery with this structure has compact structure, low internal resistance, and high battery power density, but the battery with this structure has high requirements on the uniformity and flexibility of the electrodes. In fact, the flexibility and uniformity of high-load electrodes are difficult to meet the requirements in terms of technology. 2. Lamination type. There are many pieces of positive and negative electrodes, and each layer has a positive and negative electrode in the structure. The membrane can be one piece as a whole, or one piece per layer structure. Through repeated folding of each layer structure, a flexible packaging battery is formed. This structure has lower requirements on the uniformity of the electrode, because the battery can be assembled by selecting a more uniform electrode, and at the same time, there is no requirement on the flexibility of the electrode, and a sufficiently high-load electrode can be used, but the disadvantage is that the electrode structure is not good. Tight, the internal resistance of the battery is high.

In summary, there are advantages and disadvantages in the battery structures of the above two methods.

Utility model content

The purpose of the utility model is to propose a new lithium-ion supercapacitor battery assembly method to overcome the shortcomings of the above two assembly methods.

To achieve this purpose, the utility model intends to take the following technical solutions:

The utility model provides an inner core structure of a lithium-ion supercapacitor, including a negative electrode, a diaphragm, and more than two positive electrodes, which are assembled according to the following placement process,

1) The horizontally placed diaphragm is folded in half from right to left for the first time at 180 degrees to form two symmetrical upper and lower parts that are superimposed on each other, and the negative electrode is placed between the upper and lower parts that are folded in half;

2) placing the first positive electrode on the upper surface of the upper separator, and aligning the right edge of the first positive electrode with the right edge of the upper separator;

Fold the separator and its internal negative electrode to the right for the second time along the left edge of the first positive electrode, and the surface of the upper part of the separator is closely attached to the upper surface of the first positive electrode; obtain a half of the positive electrode Winding lithium-ion supercapacitor structure;

3) placing the second positive electrode on the upper surface of the lower separator, and aligning the left edge of the second positive electrode with the left edge of the lower separator;

Fold the separator and its internal negative electrode to the left along the right edge of the second positive electrode for the third time 180 degrees, and the surface of the lower part of the separator is closely attached to the upper surface of the second positive electrode; obtain half of the two positive electrodes Winding lithium-ion supercapacitor structure;

4) When there are more than 3 positive poles, the odd-numbered positive poles are operated and placed according to the process of step 2), and the even-numbered positive poles are placed according to the process of step 3), that is, a half-coil containing more than 3 positive poles is obtained Li-ion supercapacitor structure.

Two or more sheet-shaped positive electrodes are parallel to each other.

In step 2), the right edge of the first positive electrode is aligned with the right edge of the upper separator, that is, the right edge of the first positive electrode and the right edge of the upper separator are in the same vertical plane.

In step 3), the left edge of the second positive electrode is aligned with the left edge of the lower separator, that is, the left edge of the second positive electrode and the left edge of the lower separator are in the same vertical plane.

The widths of the positive electrode and the negative electrode in the front-rear direction or the vertical direction are smaller than the width of the separator in the vertical direction.

Both the positive and negative electrodes have a sheet-like structure, and there are active material layers on both sides of the positive and negative electrodes; the active material of the positive electrode is activated carbon, and the active material of the negative electrode is lithium titanate, graphite, silicon, tin and other materials with the ability to intercalate and extract lithium ions. One or two or more of them.

The width of the negative electrode in the left and right direction is less than or equal to the width of the separator in the left and right direction.

The positive and negative electrodes are prepared by mixing active materials, conductive agents, and adhesives according to conventional processes (including but not limited to coating, rolling, and spraying). The surface density of the active material is: 0.1-100mgcm ^-2 , the preferred one is 1-30mgcm ^-2 , the surface density of the activated carbon is: 0.01-20mgcm ^-2 , the preferred one is 0.1-10mgcm ^-2 , the adhesive The areal density is 0.01-20mgcm ^-2 , and the preferred one is 0.1-10mgcm ^-2 .

The diaphragm can be polyethylene diaphragm, polypropylene diaphragm, polyethylene, polypropylene composite diaphragm, cellulose diaphragm, glass cellulose diaphragm, ceramic membrane, etc.

Compared with the prior art, the beneficial result of the utility model is: the utility model assembles the positive electrode, the negative electrode and the diaphragm through the structure mode of half lamination and half winding, which not only can reduce the internal resistance of the battery, but also can use higher and less flexible batteries. positive electrode, thus Li-ion supercapacitors have higher energy density.

Description of drawings

Fig. 1 is a sectional view of the assembly of the lithium-ion supercapacitor of the present invention.

Among them, 1. Positive pole; 2. Negative pole; 3. Diaphragm.

detailed description

Example 1

The positive electrode of the lithium-ion supercapacitor is prepared according to the following method: first, mix activated carbon, conductive agent, sodium carboxymethyl cellulose, and styrene-butadiene rubber according to the mass ratio of 8.5:1:0.25:0.25, add a certain amount of deionized water, The solid content of the electrode slurry was 30%. The evenly mixed electrode slurry was coated on the aluminum foil current collector, dried at 50°C for 12 hours, dried in vacuum, and set aside.

The positive electrode of the lithium-ion supercapacitor is prepared according to the following method: first, lithium titanate, conductive agent, and polyvinylidene fluoride are mixed evenly according to the mass ratio of 8:1:1, and a certain amount of deionized water is added. The solid content of the electrode slurry is 15%, the uniformly mixed electrode slurry is coated on the aluminum foil current collector, dried at 70 degrees Celsius for 12 hours, dried in vacuum, and set aside.

The solvent in the electrolyte used in lithium-ion supercapacitors is propylene carbonate and dimethyl carbonate (volume ratio 1:1), salt 1 is LiPF6, salt 1 concentration is 1molL-1, salt 2 is tetrafluoroborate tetra Ethylammonium, the concentration of salt 2 is 1molL-1.

Assemble the positive and negative electrodes of the lithium-ion supercapacitor in a half-wound and half-laminated manner: 1) Fold the horizontally placed separator 180 degrees from right to left for the first time to form two symmetrical upper and lower parts that are superimposed on each other, The negative electrode is placed between the upper and lower parts folded in half, 2) the first positive electrode is placed on the upper surface of the upper part of the diaphragm, and the right edge of the first positive electrode is aligned with the right edge of the upper part of the diaphragm; again the diaphragm and The negative electrode inside it is folded 180 degrees to the right for the second time along the left edge of the first positive electrode, and the surface of the upper part of the separator is closely attached to the upper surface of the first positive electrode; a half-wound lithium battery with a positive electrode is obtained Ionic supercapacitor structure; 3) place the second positive electrode on the upper surface of the lower part of the diaphragm, and the left edge of the second positive electrode is aligned with the left edge of the lower part of the diaphragm; The right edge of the two positive electrodes is folded 180 degrees to the left for the third time, and the surface of the lower part of the separator is closely attached to the upper surface of the second positive electrode; a half-wound lithium-ion supercapacitor structure with two positive electrodes is obtained; 4 ) when there are more than 3 positive poles, the positive poles of the odd numbered plates are operated and placed according to the process of step 2), and the positive poles of the even numbered plates are operated and placed according to the process of step 3), that is, a half-wound type containing more than 3 positive poles is obtained. Li-ion supercapacitor structure.

After the positive and negative electrodes are assembled and packaged, the electrolyte is injected, and the mass ratio of the injected electrolyte to activated carbon is 4:1. seal. That is, the battery preparation is completed.

Claims (7)

1. a lithium ion super capacitor core arrangement, comprises negative pole, barrier film, the positive pole of more than 2, it is characterized in that: it carries out assembling by following put procedure and obtains,

1) by the barrier film of horizontal positioned from right to left first time 180 degree two parts up and down that are folded to form the symmetry be superimposed with each other, negative pole is placed in up and down between two parts of doubling;

2) first positive pole is placed in the upper surface of upper part barrier film, and the right side edge of first positive pole is alignd with the right side edge of upper part barrier film;

Again the negative pole of barrier film and inside thereof is carried out second time 180 degree to the right along the left side edge of first positive pole to fold, and the surface of upper part barrier film and first positive pole upper surface fit tightly; Obtain half coiled lithium ion supercapacitor structures of 1 positive pole;

3) second positive pole is placed in the upper surface of lower part barrier film, and the left side edge of second positive pole is alignd with the left side edge of lower part barrier film;

Again the negative pole of barrier film and inside thereof is carried out third time 180 degree left along the right side edge of second positive pole to fold, and the surface of lower part barrier film and second positive pole upper surface fit tightly; Obtain half coiled lithium ion supercapacitor structures of 2 positive poles;

4) just very more than 3 time, the positive pole of odd number sheet is by step 2) process carry out operator placement, the positive pole of even number sheet is by step 3) process carry out operator placement, namely obtain containing half coiled lithium ion supercapacitor structures of more than 3 positive poles.

2. according to lithium ion super capacitor core arrangement described in claim 1, it is characterized in that: the sheet-like anode of more than 2 is parallel to each other.

3. according to lithium ion super capacitor core arrangement described in claim 1, it is characterized in that: step 2) in the right side edge of first positive pole align with the right side edge of upper part barrier film, namely the right side edge of first positive pole and the right side edge of upper part barrier film are in same perpendicular.

4. according to lithium ion super capacitor core arrangement described in claim 1, it is characterized in that: step 3) in and the left side edge of second positive pole align with the left side edge of lower part barrier film, namely the left side edge of second positive pole and the left side edge of lower part barrier film are in same perpendicular.

5. according to lithium ion super capacitor core arrangement described in claim 1, it is characterized in that: the width of positive pole and negative pole fore-and-aft direction or above-below direction is all less than the width of barrier film above-below direction.

6. according to lithium ion super capacitor core arrangement described in claim 1, it is characterized in that: positive pole and negative pole are laminated structure, positive pole and negative pole both side surface are equipped with active material layer.

7. according to lithium ion super capacitor core arrangement described in claim 1, it is characterized in that: the width of negative pole left and right directions is less than or equal to the width of barrier film left and right directions.