CN104008893A - Manufacturing method of lithium ion mixed type capacitor and lithium ion mixed type capacitor - Google Patents

Abstract

A method for preparing a lithium-ion hybrid capacitor, comprising the following steps: a) stacking or winding electrode sheets and separators in the order of positive electrode/diaphragm/negative electrode to form a battery core; b) putting the battery core into an aluminum plastic In the composite film case, the top side and the first side of the aluminum-plastic composite film case are heat-sealed, and the positive and negative electrodes of the battery protrude from the top side of the aluminum-plastic composite film case; c) metal lithium electrodes Put it into the aluminum-plastic composite film shell, the metal lithium electrode is placed adjacent to the battery cell and separated by a diaphragm, and the tab of the metal lithium electrode protrudes from the second side of the aluminum-plastic composite film shell; d) to the aluminum-plastic composite film Inject excess electrolyte into the membrane casing, and then heat seal the second side of the aluminum-plastic composite membrane casing; e) Pre-embed lithium on the negative electrode with the negative electrode as the working electrode and the metal lithium electrode as the counter electrode in a constant current mode; f) Take out the metal lithium electrode, pour out the excess electrolyte, and vacuum heat seal the second side of the aluminum-plastic composite film case to obtain a lithium-ion hybrid capacitor.

Description

Preparation method of lithium-ion hybrid capacitor and lithium-ion hybrid capacitor

technical field

The invention relates to a preparation method of a lithium-ion hybrid capacitor and a lithium-ion hybrid capacitor prepared by the method.

Background technique

Lithium-ion hybrid capacitor is a new type of electrochemical energy storage device between lithium-ion batteries and electric double-layer supercapacitors. It not only has the characteristics of high power and long life of electric double-layer supercapacitors, but also has a Compared with the electric double layer supercapacitor, it has been greatly improved. The structural feature of this device is that the positive electrode can be made of carbon-based battery materials including battery positive electrode materials and capacitor materials, and the negative electrode is pre-intercalated lithium. The core of the preparation process is the pre-intercalation lithium process of the negative electrode. At present, there are mainly the following pre-intercalation lithium processes: (1) First assemble the battery with the negative electrode and metal lithium sheet, pre-intercalate lithium through external charging and discharging, then disassemble the battery, take out the negative electrode and reassemble it with the positive electrode Lithium-ion hybrid capacitors, see "Electrochimica Acta" 2014, Volume 125, pages 22-28. This method requires dismantling and reassembling the battery in an inert atmosphere, which is not convenient for mass production. (2) Make the negative electrode directly contact with the metal lithium sheet in the electrolyte, and under the drive of the potential difference, lithium enters the electrolyte from the metal lithium sheet and then embeds in the negative electrode. See "Journal of Materials Chemistry A" published in 2014 titled : A Fast and Efficient Pre-doping Approach to High Energy Density Lithium-Ion Hybrid Capacitors paper. This method also has the same problem as method (1), that is, it needs to pre-embed lithium and then assemble it into batteries and devices by lamination or winding. (3) Pre-doped lithium-rich materials in the positive electrode as a lithium source, and this part of lithium is intercalated into the negative electrode through the charging process. Chinese patent application 200710098687.7 "A Method for Pre-embedding Lithium in the Negative Electrode of Lithium Ion Supercapacitor" discloses that 3-50% of lithium cobalt oxide, nickel cobalt lithium manganese oxide, lithium manganate or Li _2.6 Co _0.4 N, etc. are prepared on the pole piece Incorporation into the positive electrode as a lithium source during the process, "Advanced Energy Materials" 2011, Volume 1, pages 1002-1006 also reported the use of Li ₂ MoO ₃ doped into the positive electrode as a lithium source. The problem with this method is that after the initial lithium intercalation, this part of the doped lithium source material no longer has electrochemical capacity or limited capacity, thereby reducing the energy density of the device. (4) Aluminum foil with through holes with 30-50% open porosity and copper foil with through-holes with 30-50% open porosity are used as current collectors for positive and negative electrodes respectively, and electrode sheets are prepared and stacked or wound Into a battery cell, the metal lithium electrode is used as the lithium source as the third electrode to pre-intercalate lithium to the negative electrode through electrochemical charge and discharge (see Chinese patent application 201310374169.9). However, the preparation of through-hole aluminum foil and copper foil requires chemical etching or mechanical processing, which will significantly increase the process cost.

Contents of the invention

The purpose of the present invention is to provide a more convenient and lower process cost lithium-ion hybrid capacitor preparation method.

In order to solve the above technical problems, the present invention adopts the following technical solutions:

A preparation method for a lithium-ion hybrid capacitor, comprising the following steps:

a) Laminate or wind the electrode sheets and separators in the order of positive electrode sheets/diaphragm/negative electrode sheets to make batteries;

b) Put the battery cell made in step a) into the aluminum-plastic composite film casing, heat seal the top edge and the first side of the aluminum-plastic composite film casing, and remove the positive and negative tabs of the cell from the The top edge of the aluminum-plastic composite film shell protrudes;

c) Put the metal lithium electrode into the aluminum-plastic composite film case, place the metal lithium electrode adjacent to the cell and separate it with a diaphragm; protrude the tab of the metal lithium electrode from the second side of the aluminum-plastic composite film case ;

d) Inject excess electrolyte into the aluminum-plastic composite film case, and then heat seal the second side of the aluminum-plastic composite film case;

e) Using the negative electrode as the working electrode and the metal lithium electrode as the counter electrode, the negative electrode is pre-intercalated with lithium by constant current discharge;

f) Cut open the aluminum-plastic composite film case, take out the metal lithium electrode; pour out the excess electrolyte, and vacuum heat seal the second side of the aluminum-plastic composite film case to obtain a lithium-ion hybrid capacitor.

The positive electrode includes a positive electrode active material and aluminum foil without through holes, and the positive electrode active material is coated on the aluminum foil; the negative electrode includes a negative electrode active material and a copper foil without through holes, and the negative electrode active material is coated on the copper foil.

The positive electrode active material is composed of a lithium ion battery positive electrode material and a carbon material with a high specific surface area. Calculated by 100 parts by mass, the lithium ion positive electrode material is 0 to 90 parts by mass, and the carbon material with a high specific surface area is The material is 10 to 100 parts by mass, the positive electrode material of the lithium ion battery is lithium nickel cobalt manganese oxide or lithium nickel cobalt aluminum oxide or lithium iron phosphate or lithium cobalt oxide, and the high specific surface area carbon material is activated carbon or activated carbon fiber or porous conductive carbon black or graphene; the negative electrode active material is at least one of artificial graphite or mesocarbon microspheres or hard carbon or soft carbon. For the positive electrode, when the active material is activated carbon, it exhibits electric double layer characteristics; with the increase in the content of the positive electrode material in the positive electrode active material, the proportion of the capacity of the lithium-ion battery decreases, while the proportion of the battery capacity of the intercalated lithium increase, or even dominate, the present invention collectively refers to these devices as lithium-ion hybrid capacitors.

The current density of the pre-intercalated lithium is 5-50 mA/g, and the current density is based on the mass of the negative electrode active material. The state of charge of the negative electrode after pre-intercalation of lithium is 50-80%. The present invention pre-intercalates lithium by adding an excessive amount of electrolyte and discharging with a small current, so that the effect of fully intercalating lithium in the negative electrode active material can also be achieved in the case of using a current collector without through holes. The discharge pre-intercalation of lithium means that lithium ions enter the electrolyte from the metal lithium electrode by means of constant current discharge, and then diffuse to the negative electrode and embed in the negative electrode active material. distributed. The metal lithium electrode is used as a lithium source for pre-intercalated lithium, and at the same time it can also function as a lithium reference electrode.

The present invention also proposes a lithium-ion hybrid capacitor prepared by the above method, the operating voltage of the lithium-ion hybrid capacitor is not higher than 4.0V, and the potential of the positive electrode is not higher than 4.2V relative to the lithium reference electrode , The potential of the negative electrode is not lower than 0.1V relative to the lithium reference electrode. Because the positive electrode active material contains carbon materials with high specific surface area, the potential higher than 4.2V relative to the lithium reference electrode will cause the decomposition of the electrolyte and the reduction of cycle life, and when the potential of the negative electrode is lower than 0.1V relative to the lithium reference electrode, High-power intercalation of lithium will cause the precipitation of metallic lithium and the growth of lithium dendrites, resulting in potential safety hazards.

Description of drawings

Fig. 1 Schematic diagram of the structure of a lithium-ion hybrid capacitor, in the figure: 1 cell, 11 positive tab, 12 negative tab, 2 aluminum-plastic composite film shell, 21 first side sealing area, 22 top side sealing area, 23 second side sealing area, 24 vacuum sealing area, 3 metal lithium electrode, 31 metal lithium electrode tab;

The charge-discharge curve of the initial 4 weeks of Fig. 2 embodiment 1 lithium-ion hybrid capacitor;

Figure 3 is the rate curve of Example 1 and Comparative Example.

Detailed ways

The preparation method of the positive electrode and the negative electrode is: after the active material, the binder and the conductive agent are uniformly mixed into a slurry in a certain proportion, the coating machine is used to coat the current collector without through holes, and after drying, it is rolled, Cutting to obtain the pole piece of the electrode.

The binders are polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), sodium carboxymethyl cellulose (CMC), styrene-butadiene rubber (SBR) and LA series water-based adhesive produced by Chengdu Yindile. binder, etc. The conductive agent is selected from conductive carbon black, conductive graphite or carbon nanotubes. The current collector of the positive electrode is aluminum foil without through holes, and the current collector of the negative electrode is copper foil without through holes. The positive electrode active material is composed of one kind of lithium ion battery positive electrode material and one kind of carbon material with high specific surface area. Calculated by 100 parts by mass, the lithium ion positive electrode material is 0-90 parts by mass, and the carbon material with high specific surface area is 10-100 parts by mass. parts by mass, the positive electrode material of lithium ion battery is lithium nickel cobalt manganese oxide (LiNi _x Co _y Mn _z O ₂ ) or lithium nickel cobalt aluminate (LiNi _x Co _y Al _z O ₂ ) or lithium iron phosphate (LiFePO ₄ ) or cobalt Lithium oxide (LiCoO ₂ ), the high specific surface area carbon material is activated carbon or activated carbon fiber or porous conductive carbon black or graphene. The negative electrode active material is at least one of artificial graphite or mesocarbon microspheres or hard carbon or soft carbon.

As shown in Figure 1, the preparation method of the lithium-ion hybrid capacitor is as follows:

1. According to the order of positive electrode/diaphragm/negative electrode, stack or wind the pole piece and diaphragm of the electrode to make a cell 1, and put the cell 1 into the aluminum-plastic composite film casing 2;

2. Heat seal the top side sealing area 22 and the first side sealing area 21 of the aluminum-plastic composite film case 2 at 180°C, and extend the positive electrode tab 11 and the negative electrode tab 12 from the top side sealing area 22 to the aluminum Plastic composite film shell 2;

3. Put the metal lithium electrode 3 into the aluminum-plastic composite film casing 2 in a glove box filled with argon or in a drying room. The metal lithium electrode 3 is placed adjacent to the battery cell 1 and separated by a diaphragm, and the metal lithium electrode The tab 31 protrudes from the aluminum-plastic composite film shell 2 from the second side sealing area 23;

4. Inject excess electrolyte into the aluminum-plastic composite film case 2, and then heat seal the second side sealing area 23 of the aluminum-plastic composite film case 2;

5. With the negative electrode as the working electrode and the metal lithium electrode 3 as the counter electrode, the negative electrode is pre-intercalated with lithium in the way of constant current discharge with the CT2001A battery tester of Wuhan Landian Company. The current density of the pre-intercalated lithium is 5-50mA/g, the current density is based on the mass of the negative electrode active material, and the state of charge of the negative electrode after the pre-intercalated lithium is 50-80%;

6. Finally, cut open the aluminum-plastic composite film shell, take out the metal lithium electrode 3 and the tab 31, pour out the excess electrolyte, and vacuum heat seal the vacuum sealing area 24 of the aluminum-plastic composite film shell 2 under vacuum conditions , remove the excess aluminum-plastic composite film to obtain a lithium-ion hybrid capacitor.

The operating voltage of the lithium-ion hybrid capacitor prepared by the preparation method of the present invention is not higher than 4.0V, and the potential of the positive electrode is not higher than 4.2V relative to the lithium reference electrode, and the potential of the negative electrode is not lower than that of the lithium reference electrode. 0.1V.

Example 1

The active material of the negative electrode is artificial graphite CAG-3MT, the binder is sodium carboxymethyl cellulose and styrene-butadiene rubber, and the conductive agent is conductive carbon black Super C45. According to artificial graphite: conductive carbon black: sodium carboxymethyl cellulose: The mass ratio of styrene-butadiene rubber = 90:5:2:3 is mixed evenly to make a slurry, which is coated on a 12-micron thick copper foil without through holes. After drying, it is rolled and cut to obtain the negative pole piece. The areal density of one side of the pole piece coating layer was 39.3 g/m ² .

The active material of the positive electrode is lithium nickel cobalt manganese oxide LiNi _0.5 Co _0.2 Mn _0.3 O ₂ , the high specific surface area carbon material is activated carbon YP50F, the binder is polyvinylidene fluoride, the conductive agent is conductive carbon black Super C45 and conductive graphite KS- 6. According to the mass ratio of activated carbon: nickel cobalt lithium manganese oxide: conductive carbon black: conductive graphite: polyvinylidene fluoride = 60: 20: 10: 2: 8, mix evenly to make a slurry, and coat it to 20 without through holes. On the micron-thick aluminum foil, after drying, it is rolled and cut to obtain the positive pole piece. The areal density of one side of the pole piece coating layer was 33.1 g/m ² .

The above-mentioned positive and negative pole pieces are used to prepare batteries, put the batteries into the aluminum-plastic composite film case, and heat seal the top side and the first side of the aluminum-plastic composite film case. Put the metal lithium electrode in the aluminum-plastic composite film shell, and there is a diaphragm between the metal lithium electrode and the battery cell, and inject an excessive amount of electrolyte in the glove box. The electrolyte is 1mol/L LiPF ₆ electrolyte, solvent It is a mixed solvent of ethylene carbonate, dimethyl carbonate and diethyl carbonate in a mass ratio of 1:1:1. Then heat seal the second side of the aluminum-plastic composite film shell. The current density of the pre-intercalated lithium is 5 mA/g, and the current density is based on the mass of the negative electrode active material. The state of charge of the negative electrode after pre-intercalation of lithium is 50%. Finally, cut open the aluminum-plastic composite film shell, take out the metal lithium electrode, pour out the excess electrolyte, and then vacuum seal to obtain a lithium-ion hybrid capacitor. Use the CT2001A battery tester of Wuhan Landian Company to test the lithium-ion hybrid capacitor in the way of constant current charge and discharge. The same test methods are used below. The operating voltage range of this embodiment is 2.5-4.0V. The potential variation range of the positive electrode and the negative electrode is measured with the metal lithium electrode as the reference electrode, and the following are the same.

Comparative example:

The same positive and negative electrode sheets as in Example 1 were used to prepare the electric core, and then the electric core was put into the aluminum-plastic composite film case, and the top edge and the first side of the aluminum-plastic composite film case were heat-sealed, and placed in the glove box Inject an appropriate amount of electrolyte, the electrolyte is 1mol/L LiPF ₆ electrolyte, and the solvent is a mixed solvent of ethylene carbonate, dimethyl carbonate and diethyl carbonate in a mass ratio of 1:1:1. Afterwards, the second side of the aluminum-plastic composite film case is vacuum-sealed to obtain a lithium-ion hybrid capacitor. The lithium ion hybrid capacitor is tested in the voltage range of 2.5 ~ 4.0V.

Figure 2 shows the charging and discharging curves of the lithium-ion hybrid capacitor in Example 1, wherein curve 1 is the potential change curve of the positive electrode relative to the lithium reference electrode, and the potential change range is 2.89 to 4.19V, and curve 2 is the lithium-ion hybrid capacitor The voltage curve of the capacitor, the voltage range is 2.5 ~ 4.0V. Curve 3 is the potential change curve of the negative electrode relative to the lithium reference electrode, and the potential change range is 0.18-0.39V.

Figure 3 shows the rate performance curves of Example 1 and Comparative Example, the abscissa is the rate (in C), the ordinate is the specific capacity based on the mass of the positive active material (in mAh/g), and curve 1 is the embodiment 1 is the rate performance curve, and curve 2 is the rate performance curve of the comparative example. It can be seen that both have good rate performance. However, after the pre-intercalated lithium process, the specific capacity was increased from 25.4mAh/g to 34.8mAh/g when charged and discharged at a current density of 25mA/g, an increase of 37%.

Embodiment 2～6

The active material of the negative electrode of embodiment 2～6 is hard carbon LN-0010, and binding agent is sodium carboxymethyl cellulose and styrene-butadiene rubber, and conductive agent is conductive carbon black Super C45, press hard carbon: conductive carbon black: carboxyl Sodium methylcellulose: styrene-butadiene rubber = 90:5:2:3 mass ratio mixed evenly to make a slurry, coated on a 12 micron thick copper foil without through holes, rolled and cut after drying Obtain the pole piece of the negative electrode. The areal density of one side of the pole piece coating layer was 47.0 g/m ² .

The active material of the positive electrode is lithium nickel cobalt manganese oxide LiNi _0.5 Co _0.2 Mn _0.3 O ₂ , the high specific surface area carbon material is activated carbon YP50F, the binder is polyvinylidene fluoride, the conductive agent is conductive carbon black Super C45 and conductive graphite KS- 6. According to the mass ratio of positive electrode active material: conductive carbon black: conductive graphite: polyvinylidene fluoride = 80:10:2:8, mix evenly to make a slurry, and coat it on a 20-micron thick aluminum foil without through holes. After drying, it is rolled and cut to obtain the positive electrode sheet. The mass ratio of the components of the positive electrode active material and the areal density of one side of the coating are shown in Table 1.

After preparing the electric core with the above-mentioned positive and negative pole pieces, put the electric core into the aluminum-plastic composite film case, heat seal the top edge and the first side of the aluminum-plastic composite film case, and seal the aluminum-plastic composite film Metal lithium electrodes are placed in the shell, and there is a diaphragm between the metal lithium electrodes and the battery core. Inject excess electrolyte into the glove box, the electrolyte is 1mol/L LiPF ₆ electrolyte, and the solvent is a mixed solvent of ethylene carbonate, dimethyl carbonate and diethyl carbonate at a mass ratio of 1:1:1. Then heat seal the second side of the aluminum-plastic composite film shell. The current density of the pre-intercalated lithium is 6 mA/g, and the current density is based on the mass of the negative electrode active material. The state of charge of the negative electrode after pre-intercalation of lithium is 60%. After taking out the metal lithium electrode, pouring out the excess electrolyte, and vacuum sealing, a lithium-ion hybrid capacitor is obtained. Lithium-ion hybrid capacitors were charged and discharged in the voltage range of 2.0-4.0V. Based on the specific capacity of the positive active material and the potential of the positive and negative electrodes relative to the lithium reference electrode, see Table 1.

Table 1

As can be seen from Table 1, the specific capacity increases significantly as the content of nickel-cobalt-lithium manganese oxide in the positive electrode active material increases, but since the capacity of the negative electrode of this group of capacitors is fixed, the lower limit of the potential of the negative electrode is significantly reduced. Example 4 The potential range of ~6 drops below 0.1V, and the cycle life is significantly reduced. The capacity retention rate of Examples 2 and 3 after 10,000 cycles of charging and discharging is above 90%, while the capacity of Examples 4 to 6 has decayed by more than 50% after 1,000 cycles of charging and discharging.

Example 7

The active material of the negative electrode of the present embodiment is made up of soft carbon and mesophase carbon microspheres in a mass ratio of 1:1, the binding agent is sodium carboxymethyl cellulose and styrene-butadiene rubber, and the conductive agent is conductive carbon black Super P Li, According to the mass ratio of active material: sodium carboxymethyl cellulose: styrene-butadiene rubber: conductive carbon black = 90:5:2:3, mix evenly to make a slurry, and coat it on a 12-micron thick copper foil without through holes , after drying, roll pressing and cutting to obtain the negative pole piece. The areal density of one side of the pole piece coating layer was 30.0 g/m ² .

The active material of the positive electrode is composed of lithium nickel cobalt aluminate, activated carbon fiber, porous conductive carbon black and few-layer graphene in a mass ratio of 1:1:1:1, and the binder is polyvinylidene fluoride. Active material: polyvinylidene fluoride = 90:10 mass ratio mixed evenly to make a slurry, coated on a 20 micron thick aluminum foil without through holes, after drying, rolled and cut to obtain the positive pole piece. The areal density of one side of the pole piece coating layer was 25 g/m ² .

After the above-mentioned positive and negative pole pieces are used to prepare the electric core, put it into the aluminum-plastic composite film case, heat seal the top edge and the first side of the aluminum-plastic composite film case, and put in the metal lithium electrode, the metal lithium battery There is a diaphragm between the pole and the battery core. Inject excess electrolyte into the glove box, the electrolyte is 1mol/L LiPF ₆ electrolyte, and the solvent is a mixed solvent of ethylene carbonate, dimethyl carbonate and diethyl carbonate at a mass ratio of 1:1:1. Then heat seal the second side of the aluminum-plastic composite film shell. The current density of the pre-intercalated lithium is 50 mA/g, and the current density is based on the mass of the negative electrode active material. The state of charge of the negative electrode after pre-intercalation of lithium is 80%. Cut open the aluminum-plastic composite film shell, take out the metal lithium electrode, pour out the excess electrolyte, and vacuum seal to obtain a lithium-ion hybrid capacitor.

Example 8

The active material of the negative electrode of the present embodiment is hard carbon LN-0010, and binding agent is sodium carboxymethyl cellulose and styrene-butadiene rubber, and conductive agent is conductive carbon black Super P Li, press hard carbon: sodium carboxymethyl cellulose : Styrene-butadiene rubber: conductive carbon black = 90:5:2:3 mass ratio mixed evenly to make a slurry, coated on a 12-micron thick copper foil without through holes, dried, rolled and cut to obtain Negative pole piece.

The active material of the positive electrode is lithium cobalt oxide, the high specific surface area carbon material is activated carbon YP80F, the binder is polyvinylidene fluoride, the conductive agent is conductive carbon black Super P Li and conductive graphite KS-15, according to activated carbon: lithium cobalt oxide: Conductive carbon black: conductive graphite: polyvinylidene fluoride = 60:20:10:2:8 mass ratio mixed evenly to make a slurry, coated on a 20 micron thick aluminum foil without through holes, and rolled after drying , cutting to obtain the positive pole piece.

The above-mentioned positive and negative pole pieces are used to prepare batteries, put the batteries into the aluminum-plastic composite film case, and heat seal the top side and the first side of the aluminum-plastic composite film case. Put the metal lithium electrode in the aluminum-plastic composite film shell, and there is a diaphragm between the metal lithium electrode and the battery cell, and inject an excessive amount of electrolyte in the glove box. The electrolyte is 1mol/L LiPF ₆ electrolyte, solvent It is a mixed solvent of ethylene carbonate and propylene carbonate at a mass ratio of 1:1. Then heat seal the second side of the aluminum-plastic composite film shell. The current density of the pre-intercalated lithium is 10 mA/g, and the current density is based on the mass of the negative electrode active material. The state of charge of the negative electrode after pre-intercalation of lithium is 60%. Cut open the aluminum-plastic composite film shell, take out the metal lithium electrode, pour out the excess electrolyte, and then vacuum seal to obtain a lithium-ion hybrid capacitor.

Example 9

The active material of the negative electrode of the present embodiment is hard carbon LN-0001, binding agent is sodium carboxymethyl cellulose and styrene-butadiene rubber, and conductive agent is conductive carbon black Super P Li, press hard carbon: sodium carboxymethyl cellulose : Styrene-butadiene rubber: conductive carbon black = 90:5:2:3 mass ratio mixed evenly to make a slurry, coated on a 12-micron thick copper foil without through holes, dried, rolled and cut to obtain Negative pole piece.

The active material of the positive electrode is lithium iron phosphate, the high specific surface area carbon material is activated carbon YP80F, the binder is polyvinylidene fluoride, the conductive agent is conductive carbon black Super P Li and conductive graphite KS-15, according to activated carbon: lithium iron phosphate: Conductive carbon black: conductive graphite: polyvinylidene fluoride = 60: 20: 10: 2: 8 mass ratio mixed evenly to make a slurry, coated on a 20 micron thick aluminum foil without through holes, and rolled after drying , cutting to obtain the positive pole piece.

The above-mentioned positive and negative pole pieces are used to prepare batteries, put the batteries into the aluminum-plastic composite film case, and heat seal the top side and the first side of the aluminum-plastic composite film case. Put the metal lithium electrode in the aluminum-plastic composite film shell, and there is a diaphragm between the metal lithium electrode and the battery cell, and inject an excessive amount of electrolyte in the glove box. The electrolyte is 1mol/L LiPF ₆ electrolyte, solvent It is a mixed solvent of ethylene carbonate, dimethyl carbonate and diethyl carbonate in a mass ratio of 1:1:1. Then heat seal the second side of the aluminum-plastic composite film shell. The current density of the pre-intercalated lithium is 10 mA/g, and the current density is based on the mass of the negative electrode active material. The state of charge of the negative electrode after pre-intercalation of lithium is 60%. Cut open the aluminum-plastic composite film shell, take out the metal lithium electrode, pour out the excess electrolyte, and then vacuum seal to obtain a lithium-ion hybrid capacitor.

Claims (4)

1. a preparation method for lithium ion hybrid capacitors, is characterized in that described preparation method comprises the following steps:

A) electrode plates and barrier film are made to battery core (1) according to the order lamination of anode pole piece/barrier film/cathode pole piece or coiling;

B) battery core (1) of step a) being made is put into aluminum-plastic composite membrane housing (2), by the top margin of aluminum-plastic composite membrane housing (2) and first side hot-seal, the positive pole ear of battery core (1) (11) and negative lug (12) are stretched out from the top margin of aluminum-plastic composite membrane housing (2);

C) metal lithium electrode (3) is put into aluminum-plastic composite membrane housing (2), metal lithium electrode (3) and battery core (1) placed adjacent also separate with barrier film; The lug of metal lithium electrode (1) is stretched out from the second side of aluminum-plastic composite membrane housing (2);

D) inject excessive electrolyte to aluminum-plastic composite membrane housing (2), then by the second side hot-seal of aluminum-plastic composite membrane housing (2);

E), taking negative pole as work electrode, taking metal lithium electrode as to electrode, carry out pre-embedding lithium with the mode anticathode of constant current discharge;

F) cut apart with a knife or scissors aluminum-plastic composite membrane housing (2), take out metal lithium electrode (3), pour out unnecessary electrolyte, by the second side Vacuum Heat sealing of aluminum-plastic composite membrane housing (2), obtain lithium ion hybrid capacitors;

Described positive pole comprises positive electrode active materials and the aluminium foil without through hole, and positive electrode active materials is coated on described aluminium foil; Described negative pole comprises negative active core-shell material and the Copper Foil without through hole, and negative active core-shell material is coated on described Copper Foil.

2. the preparation method of lithium ion hybrid capacitors according to claim 1, it is characterized in that described positive electrode active materials is made up of the material with carbon element of a kind of anode material for lithium-ion batteries and a kind of high-specific surface area, calculate by 100 mass parts, described lithium ion anode material is 0～90 mass parts, and high-specific surface area material with carbon element is 10～100 mass parts; Described anode material for lithium-ion batteries is nickle cobalt lithium manganate or nickel cobalt lithium aluminate or LiFePO4 or cobalt acid lithium, and described high-specific surface area material with carbon element is active carbon or active charcoal fiber or porous, electrically conductive carbon black or Graphene; Described negative active core-shell material is at least one in Delanium or carbonaceous mesophase spherules or hard carbon or soft carbon.

3. the preparation method of lithium ion hybrid capacitors according to claim 1, is characterized in that the current density of described pre-embedding lithium is 5～50mA/g, the quality of described current density based on negative active core-shell material; After pre-embedding lithium, the state-of-charge of negative pole is 50～80%.

4. the lithium ion hybrid capacitors making according to the preparation method described in claim 1 or 2 or 3, it is characterized in that the operating voltage of described lithium ion hybrid capacitors is not higher than 4.0V, and anodal current potential is not not less than 0.1V higher than the current potential of 4.2V, negative pole with respect to lithium reference electrode with respect to lithium reference electrode.