All-polymer aqueous battery as well as preparation method and application thereof

Abstract

The invention relates to an all-polymer aqueous battery and a preparation method thereof, and belongs to the technical field of batteries. The all-polymer aqueous battery comprises a positive electrode, a negative electrode, a diaphragm and an electrolyte, the positive electrode and the negative electrode are both made of polyaniline, and the electrolyte is a mixture of a molecular crowding reagent, water and electrolyte salt. In the all-polymer aqueous battery, polyaniline is successfully used as a polymer electrode of a symmetrical battery through hole / electron doping (p / n doping). The all-polymer aqueous battery has high energy density and good cycling stability, and the electrochemical stability window of the all-polymer aqueous battery can be expanded to 3.2 V under the condition that high-concentration sodium salt is not used. Meanwhile, the all-polymer aqueous battery uses a metal-free electrode and a low-concentration electrolyte, has excellent sustainability, machinability, flexibility and recoverability, and can be used as a flexible energy storage device. And large-scale preparation of the recyclable all-polymer flexible battery with excellent mechanical flexibility is realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of batteries, and in particular relates to an all-polymer aqueous battery and a preparation method and application thereof. Background Art

[0002] With the rapid development of wearable technology, the safety of flexible batteries has attracted increasing attention. Although lithium-ion batteries have dominated the field of portable electronics in recent decades, their reliance on flammable / toxic organic electrolytes and mineral resources poses challenges in terms of safety and sustainability. Aqueous sodium-ion batteries have become an alternative to lithium-ion batteries due to their abundant sources and inherent safety, but their lack of suitable electrode materials leads to their limited energy density and poor cycling stability, which restricts their practical applications.

[0003] Organic electrode materials have rich structural designability, high capacity and sustainability, and are expected to become a substitute for inorganic electrode materials in aqueous batteries. However, due to the low redox potential of organic electrode materials, only a few carbonyl derivatives can be used as negative electrode materials for aqueous batteries, and positive electrode materials are almost limited to activated carbon and other inorganic materials, and their capacity and cycle stability are far from reaching commercial levels. On the other hand, the electrodes of flexible alkali metal ion batteries are currently limited to a few inorganic materials, and most of them are used in lithium-ion batteries, exacerbating the sustainability problem. In addition, the modern film and fiber industry has developed on the basis of the rise of polymer science. Therefore, considering the requirements of wearable batteries for flexibility and processability, it is urgent to develop an all-polymer aqueous battery based on polymer electrode materials. Summary of the invention

[0004] In view of this, one of the objects of the present invention is to provide an all-polymer aqueous battery; the second object is to provide a method for preparing an all-polymer aqueous battery; and the third object is to provide the application of the all-polymer aqueous battery in a flexible battery.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] 1. An all-polymer aqueous battery, comprising a positive electrode, a negative electrode, a separator and an electrolyte, wherein the materials of the positive electrode and the negative electrode are both polyaniline, and the electrolyte is a mixture of a molecular crowding agent, water and an electrolyte salt, wherein the mass molar mass ratio of the molecular crowding agent, water and the electrolyte salt is 3-19:1:0.5-3, kg:kg:mol.

[0007] Preferably, the number average molecular weight of the molecular crowding agent is 200-1000.

[0008] Preferably, the molecular crowding agent is one of polyethylene glycol dimethyl ether, polyethylene glycol, polypropylene glycol, polypropylene glycol dimethyl ether, glucose, urea, polyvinyl alcohol, polyacrylic acid or polyacrylamide.

[0009] Preferably, the electrolyte salt is one of NaTFSI, NaOTF, NaFSI, NaClO4, LiTFSI, LiFSI, LiOTF, LiClO4, LiBF4, KFSI, KTFSI, KClO4, KOTF, Mg(TFSI)2, Mg(FSI)2, Mg(OTF)2, Ca(TFSI)2, Ca(FSI)2, Ca(OTF)2 or Al(OTF)3.

[0010] Preferably, the separator is a non-woven fabric or a glass fiber separator.

[0011] Preferably, the electrolyte is prepared as follows: after uniformly mixing the molecular crowding reagent and water, an electrolyte salt is added and dissolved.

[0012] 2. A method for preparing an all-polymer aqueous battery, the preparation method is as follows:

[0013] S1. Preparation of electrolyte

[0014] After the molecular crowding agent and water are evenly mixed, an electrolyte salt is added and dissolved, wherein the molecular crowding agent, water and electrolyte salt have a molar mass ratio of 3-19:1:0.5-3, kg:kg:mol;

[0015] S2. Preparation of all-polymer aqueous batteries

[0016] Polyaniline is used as the positive electrode and the negative electrode respectively, and the positive electrode, the negative electrode and the separator are assembled with the electrolyte prepared in step S1.

[0017] 3. Application of the all-polymer aqueous battery in flexible batteries.

[0018] Preferably, the flexible battery is a flexible thin film planar battery.

[0019] Preferably, the flexible thin film planar battery is prepared as follows:

[0020] S1. Preparation of electrolyte

[0021] After the molecular crowding agent and water are evenly mixed, an electrolyte salt is added and dissolved, wherein the molecular crowding agent, water and electrolyte salt have a molar mass ratio of 3-19:1:0.5-3, kg:kg:mol;

[0022] S2. Preparation of flexible thin film planar batteries

[0023] Polyaniline is used as the positive electrode and the negative electrode respectively, and the separator is placed between the positive electrode and the negative electrode, and then the whole is placed in a hydrogenated styrene-butadiene block copolymer bag, and then the electrolyte prepared in step S1 is injected and sealed under vacuum, and finally further packaged with polyparaxylene.

[0024] The beneficial effects of the present invention are as follows: the present invention provides an all-polymer aqueous battery and a preparation method and application thereof, in which polyaniline is successfully used as a polymer electrode of a symmetrical battery through hole / electron doping (p / n doping), and when the intrinsic polyaniline is used as a positive electrode, two electrons can be lost through anion doping; when it is used as a negative electrode, two electrons can be obtained through cation doping, for example Figure 1 As shown, when intrinsic polyaniline is used as the positive electrode, it can be - Doping loses 2 electrons; when used as a negative electrode, Na + Doping obtains 2 electrons. On the negative electrode side, polyaniline was used as the negative electrode material of aqueous batteries for the first time; on the positive electrode side, the high-voltage stability in polyaniline aqueous polymer electrolytes was improved. The all-polymer aqueous battery has high energy density and good cycle stability, and its electrochemical stability window can be extended to 3.2V without the use of high-concentration sodium salts. At the same time, the all-polymer aqueous battery uses metal-free electrodes and low-concentration electrolytes, has excellent sustainability, as well as excellent processability, flexibility and recyclability, and can be used as a flexible energy storage device. The large-scale preparation of all-polymer flexible batteries with excellent mechanical flexibility and recyclability has been achieved.

[0025] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below in conjunction with the accompanying drawings, wherein:

[0027] Figure 1 Schematic diagram of the dual ion doping mechanism of the polyaniline symmetric electrode during charging in the present invention;

[0028] Figure 2 The electrochemical stability window test results of the two electrolytes NaTFSI-PAE and NaTFSI-H2O prepared in Example 1 are shown;

[0029] Figure 3The results of H NMR analysis of NaTFSI-PAE, NaTFSI-H2O and water prepared in Example 1 are shown in FIG.

[0030] Figure 4 The infrared test spectra of NaTFSI-PAE, NaTFSI-H2O and water prepared in Example 1 are shown;

[0031] Figure 5 The constant current charge-discharge test and cycle performance test results of the all-polymer aqueous battery prepared in Example 2 are shown in FIG. Figure 5 Figure a is the constant current charge-discharge curve of the all-polymer aqueous battery at the 20th, 50th, 500th, 1000th, and 4000th cycles. Figure 5 Middle b is the test result diagram of the charge-discharge capacity and cycle performance of the all-polymer aqueous battery;

[0032] Figure 6 The FTIR spectra of the polyaniline positive electrode and negative electrode at different charged states in the first two cycles of the constant current charge and discharge test and the cycle performance test of the all-polymer aqueous battery prepared in Example 2 are shown in FIG. Figure 6 a is the FTIR spectrum of the positive electrode. Figure 6 b is the FTIR spectrum of the negative electrode;

[0033] Figure 7 The XPS analysis diagram of the polyaniline positive electrode and negative electrode under different charged states in the first two cycles of the constant current charge and discharge test (GCD test) and the cycle performance test of the all-polymer aqueous battery prepared in Example 2, wherein: Figure 7 a is the XPS spectrum of the positive electrode. Figure 7 b is the XPS spectrum of the negative electrode;

[0034] Figure 8 The SEM images of the negative electrode surface of the all-polymer aqueous battery prepared in Example 2 after different cycles (initial, 10 cycles, 100 cycles);

[0035] Fig. 9 The XPS graphs of the negative electrode surface in the all-polymer aqueous battery prepared in Example 2 after different cycles (initial, 10 cycles, 200 cycles, 400 cycles);

[0036] Fig.10 CV test result diagram of the all-polymer aqueous battery prepared in Example 2;

[0037] Fig.11 The constant current charge-discharge test and cycle performance test results of the all-polymer aqueous battery prepared with recycled polyaniline are shown in Figure 1. Fig.11a is the constant current charge-discharge curve of the all-polymer aqueous battery at the 1st, 10th, 50th, 100th, and 200th cycles. Fig.11 Figure b is the test result of the charge-discharge capacity and cycle performance of the all-polymer aqueous battery;

[0038] Fig.12 The FTIR spectra of the polyaniline positive electrodes in the two batteries when charged to 2.2V and discharged to 0.1V during the constant current charge and discharge test and cycle performance test of the all-polymer aqueous batteries prepared in Example 2 and Comparative Example 1;

[0039] Fig.13 is a schematic diagram of a flexible thin film planar battery in Example 3;

[0040] Fig.14 This is a graph showing the test results of the cycle performance of the flexible thin film planar battery in Example 3;

[0041] Fig.15 The graph is a test result of the charge-discharge capacity and cycle performance of the all-polymer aqueous battery in Example 4;

[0042] Fig.16 The graph is a test result of the charge-discharge capacity and cycle performance of the all-polymer aqueous battery in Example 5;

[0043] Fig.17 The graph is a test result of the charge-discharge capacity and cycle performance of the all-polymer aqueous battery in Example 6;

[0044] Fig.18 The graph is a test result of the charge-discharge capacity and cycle performance of the all-polymer aqueous battery in Example 7;

[0045] Fig.19 This is a graph showing the test results of the charge-discharge capacity and cycle performance of the all-polymer aqueous battery in Example 8. DETAILED DESCRIPTION

[0046] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0047] Example 1

[0048] Preparation of electrolyte (NaTFSI-PAE)

[0049] (1) polyethylene glycol dimethyl ether with a relative average molecular weight of 250 and polyethylene glycol dimethyl ether with a relative average molecular weight of 500 are mixed in a weight ratio of 1:4 to prepare polyethylene glycol dimethyl ether with a relative average molecular weight of 450 (PEGDME450);

[0050] (2) The PEGDME450 prepared in step (1) was mixed with deionized water in a mass ratio of 47:3 to obtain a blending agent. 1 kg of the blending agent was added with 2 mol of NaTFSI and dissolved.

[0051] The stability of NaTFSI-PAE prepared in Example 1 was tested by using acetylene black (AB) as the working electrode (~0.5 mg / cm 2 ), activated carbon (AC) as the counter electrode (15-20 mg / cm 2 ), silver / silver chloride electrode (SSCE) as the reference electrode, the electrochemical stability window of the electrolyte was evaluated using a three-electrode system, and the NaTFSI-PAE prepared in Example 1 was compared with a traditional aqueous electrolyte (NaTFSI-H2O). The results are as follows: Figure 2 As shown by Figure 2 It can be seen that the electrochemical stability window of NaTFSI-PAE can be extended to 3.2 V without using high concentrations of sodium salt.

[0052] The NaTFSI-PAE prepared in Example 1 was subjected to hydrogen nuclear magnetic resonance spectroscopy ( 1 H-NMR) analysis, using a traditional aqueous electrolyte (NaTFSI-H2O) and water for comparison, the results are as follows Figure 3 As shown by Figure 3 It can be seen that in NaTFSI-PAE, the amount of H2O 1 The H chemical shift moves upfield, indicating that the electron density around the H atom of H2O increases, which can be attributed to the hydrogen bond interaction between the O atom of PEGDME and the H atom in H2O. Usually, the shielding effect of H increases due to the lengthening of the hydrogen bond between the donor and the acceptor. This change indicates that the hydrogen bond network between H2O molecules is broken, and weaker hydrogen bonds are formed between H2O and the ether chain, which reduces the activity of the H2O molecule and can inhibit the hydrogen evolution reaction of the electrolyte and the deprotonation process of the high oxidation state PANI positive electrode.

[0053] The NaTFSI-PAE prepared in Example 1 was analyzed by infrared spectroscopy (FTIR) and compared with the traditional aqueous electrolyte (NaTFSI-H2O) and water. Figure 4 As shown by Figure 4 It can be seen that the wave numbers of the typical HO stretching and bending peaks of H2O are 3300-3500 cm -1 and 1638cm -1, which changes little in 2m NaTFSI-H2O, but is obviously blue-shifted in 2mNaTFSI-PAE (3400-3600cm -1 and 1652cm -1 ). It is further proved that after adding PEGDME, the hydrogen bond network in water is destroyed and converted into free H2O molecules. The higher the light wave number absorbed by the HO bond of water indicates that the strength of the HO covalent bond is higher, which explains why the electrochemical stability of the all-polymer water-based sodium ion battery in the present invention is significantly increased, that is, a higher overpotential is required to electrochemically decompose water in the presence of the crowding reagent PEGDME.

[0054] Example 2

[0055] Preparation of all-polymer aqueous batteries

[0056] (1) Preparation of disc electrodes

[0057] The active material polyaniline (PANI), the conductive agent Ketjen black (KB) and the binder PTFE are mixed into a slurry in isopropyl alcohol (IPA) at a mass ratio of 7:2:1, and the slurry is rolled into a uniform film using a stainless steel cylinder to obtain an electrode film; the electrode film is then pressed onto a current collector (titanium mesh) to obtain an electrode sheet; finally, after vacuum drying at 80°C for 12 hours, the electrode sheet is cut into a disc electrode with a diameter of 12 mm.

[0058] (2) Assembling the battery

[0059] Take the two disc electrodes prepared in step (1), a Whatman glass fiber membrane, 2 m NaTFSI-PAE prepared in Example 1 and a CR2032 button cell, assemble them in a glove box to obtain a full polymer aqueous battery, and let it stand for more than 8 hours.

[0060] At room temperature, the all-polymer aqueous battery prepared in Example 2 was subjected to constant current charge and discharge test (GCD test) and cycle performance test on a CT-4008T (Xinwei battery test system) instrument. The results are as follows: Figure 5 As shown, Figure 5 Figure a is the constant current charge-discharge curve of the all-polymer aqueous battery at the 20th, 50th, 500th, 1000th and 4000th cycles. It can be seen from the figure that the all-polymer aqueous battery can provide a high initial discharge capacity of 139mAh / g and an energy density of 153Wh / kg at a current density of 1C. After 20, 50, 500, 1000 and 4000 cycles, the discharge capacity is 139mAh / g, 136mAh / g, 135mAh / g, 133mAh / g and 128mAh / g, respectively. Figure 5Figure b is the test results of the charge and discharge capacity and cycle performance of the all-polymer aqueous battery. It can be seen from the figure that after 4800 cycles (381 days), the battery capacity retention rate is 92.0%, and the average Coulomb efficiency (CE) is 99.5%. Its stability is much higher than that of most aqueous sodium-ion batteries and aqueous lithium-ion batteries.

[0061] In addition, in the first two cycles of the constant current charge and discharge test (GCD test) and the cycle performance test of the all-polymer aqueous battery prepared in Example 2, the redox states of the two polyaniline electrodes at different charge and discharge potentials were studied. Specifically, when charged to 2.2 V and discharged to 0.1 V, the battery was disassembled, the electrode sheets were washed and soaked with ethanol, and then dried and subjected to infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) analysis, respectively. The results are as follows: Figure 6 and Figure 7 As shown. Among them, Figure 6 a is the FTIR spectrum of the positive electrode. It can be seen from the figure that SNS (879cm -1 )、O=S=O(1051cm -1 ) and CF3(1211cm -1 ) appears periodically during charging and disappears during discharging, proving that when TFSI - When doping is performed, PANI is oxidized. Figure 7 a is the XPS spectrum of the positive electrode. It can be seen from the figure that TFSI - Reversible doping on the polyaniline positive electrode. The initial F1s peak of the positive electrode comes from the polytetrafluoroethylene (PTFE) binder in the positive electrode. When charged to 2.2V, due to TFSI - When doped with PANI positive electrode, the intensity of F1s increases significantly; when discharged to 0.1V, due to TFSI - The intensity of F1s recovered to nearly the initial value after the anion doping and de-doping was repeated in the second cycle, proving that TFSI - Reversibility of doping onto polyaniline positive electrode in the potential range of 0.1-2.2V. Figure 6 b is the FTIR spectrum of the negative electrode. It can be seen from the figure that during the charge and discharge cycle, the C=N (1290cm -1 ) to the C=N in the reduced PANI - (1305cm -1 ) has undergone a reversible displacement. Figure 7 b is the XPS spectrum of the negative electrode, which shows the reversible change of F1s intensity during two charge and discharge cycles. The XPS Na1s spectrum is further used to characterize the Na +The contribution of TFSI to the negative electrode reaction is shown in the figure. The reversible change of Na1s intensity during two charge and discharge cycles is shown in the figure. - and Na + , spectral analysis at different potentials proves that polyaniline can be used as a symmetrical electrode for aqueous batteries. Specifically, polyaniline positive electrode doped with TFSI - Oxidation occurs during the process to remove TFSI - The reduction reaction occurs during the process; the polyaniline negative electrode is doped with Na + A reduction reaction occurs during the process to remove Na + An oxidation reaction occurs during the doping process, and the doping and removal processes are reversible. Therefore, the aqueous battery using polyaniline as a symmetrical electrode can reversibly carry out charge and discharge reactions and has good cycle stability.

[0062] Scanning electron microscopy was used to observe the morphological changes of the negative electrode surface in the all-polymer aqueous battery after different cycles. Figure 8 As shown by Figure 8 It can be seen that as the number of cycles increases, the negative electrode surface becomes dense and smooth, indicating that a continuous and dense solid electrolyte interface film (SEI) is formed on the surface of the polyaniline negative electrode, which is beneficial to improve the cycle life of the battery during charge and discharge. In order to further study the formation of SEI film on the negative electrode surface in the all-polymer aqueous battery, the chemical composition of SEI was determined by X-ray photoelectron spectroscopy (XPS). The results are as follows Fig. 9 As shown in the figure, from the changes in the binding energy of C1s, O1s and Na1s in the XPS spectrum of the PANI negative electrode after different cycle times (original, 10, 200, 400 times), the peak signals of CO (286.6eV) and C=O (287.5eV) in C1s increased significantly, and the peak signals of CO (531.2eV), C=O (33.7eV) and Na-O (529.5eV) in O1s increased significantly, indicating that the main components of SEI include RCH2CH2ONa. The obvious Na-O peak signal in Na1s further confirmed the formation of SEI whose main component is RCH2CH2ONa.

[0063] The all-polymer aqueous battery prepared in Example 2 was subjected to CV testing in the range of 0.1-2.2 V at a scan rate of 0.1 mV / s on a CHI electrochemical workstation (Corrtest CS2350M). Fig.10 As shown by Fig.10It can be seen that in the first scan, two reduction peaks are shown on the CV curve, and the broad peak near 1.5V is considered to be the irreversible formation of the solid electrolyte interface (SEI). In addition to the first scan, a pair of symmetrical redox peaks can be observed at 1.15 / 1.2V, and the shape does not change much in the third to fifth scans. The all-polymer aqueous battery shows good redox reversibility.

[0064] The recyclability and reusability of the all-polymer aqueous battery of the present invention were verified. The all-polymer aqueous battery was re-prepared with the recycled polyaniline on a CT-4008T instrument, and the GCD test and cycle performance test were performed on it. The results are as follows: Fig.11 As shown, Fig.11 Figure a is the constant current charge-discharge curve of the newly prepared all-polymer aqueous battery at the 1st, 10th, 50th, 100th and 200th cycles. It can be seen from the figure that the all-polymer aqueous battery can provide a high initial discharge capacity of 140mAh / g and an energy density of 153Wh / kg at a current density of 1C. After 1, 10, 50, 100 and 200 cycles, the discharge capacity is 140mAh / g, 127mAh / g, 113mAh / g, 110mAh / g and 95mAh / g, respectively. Fig.11 Figure b is a graph showing the charge and discharge capacity and cycle performance test results of the all-polymer aqueous battery. It can be seen from the figure that the battery capacity retention rate after 200 cycles is 72.0%, and the average Coulomb efficiency (CE) is about 92%.

[0065] Comparative Example 1

[0066] Compared with Example 2, 2 m NaTFSI-PAE was replaced with 2 m NaTFSI-H2O, and button cells were assembled.

[0067] In order to study the structural changes of the polyaniline positive electrode at different voltages in 2m NaTFSI-PAE and 2m NaTFSI-H2O electrolytes, the button cells in Example 2 and Comparative Example 1 were subjected to constant current charge and discharge tests (GCD tests) and cycle performance tests. When charged to 2.2V and discharged to 0.1V, the batteries were disassembled, the electrode sheets were washed and soaked with ethanol, and infrared (FTIR) analysis was performed after drying. The results are shown in Figure 2. Fig.12 As shown by Fig.12 It can be seen that in the FTIR spectrum, 1589cm -1 and 1500cm -1 The peak corresponds to the stretching vibration of the benzene ring. During the charging process, a structural transformation occurs from the benzene (B) ring to the quinone (Q) ring, and the benzene ring stretching vibration peak changes from 1574 cm -1 Displacement to 1502cm -1 . At 1154cm-1 and 1128cm -1 There are obvious band changes at , corresponding to the in-plane deformation of Q = N = Q and B-NH-B, respectively. In 2m NaTFSI-PAE, the conversion of benzo-quinone compounds in the polyaniline cathode is highly reversible after discharge. In contrast, in 2m NaTFSI-H2O electrolyte, the PANI cathode is highly reversible with quinones (1589cm -1 and 1502cm -1 ) structure-related characteristic peaks are broader and stronger than those of the original PANI even after full discharge to 0.1 V, proving that in 2mNaTFSI-PAE, the PANI cathode can also achieve reversible charge and discharge at high voltage, while in 2m NaTFSI-H2O, the PANI cathode cannot achieve reversible charge and discharge in this voltage range.

[0068] Example 3

[0069] Preparation of flexible batteries as flexible thin film planar batteries

[0070] (1) Preparation of flexible electrodes

[0071] The active material polyaniline (PANI), the conductive agent Ketjen black (KB) and the binder PTFE were mixed into a slurry in isopropyl alcohol (IPA) in a mass ratio of 7:2:1, and the slurry was rolled into a uniform film using a stainless steel cylinder to obtain an electrode film; the 2.0 cm × 6.0 cm electrode film was pressed onto a current collector (titanium mesh) to obtain a flexible electrode.

[0072] (2) Assembling the battery

[0073] A nickel strip is attached as an electrode sheet to the edge of the flexible electrode prepared in step (1), a glass fiber membrane with a thickness of about 200 μm is placed between the two flexible electrodes, and then the whole is placed in a hydrogenated styrene-butadiene block copolymer bag, and then the NaTFSI-PAE prepared in Example 1 is injected and sealed under vacuum, and finally further encapsulated with polyparaxylene with a thickness of about 20 μm. The schematic diagram of the battery is shown in FIG. Fig.13 shown.

[0074] At room temperature, the cycle performance test of the flexible thin film planar battery prepared in Example 3 was carried out using a CT-4008T instrument. The results are as follows: Fig.14 As shown by Fig.14 It can be seen that the capacity retention rate of the flexible thin film planar battery is about 100% after 120 cycles (9.5 days), and the average coulombic efficiency is about 95%, which proves that the flexible thin film planar battery exhibits higher discharge specific capacity and coulombic efficiency.

[0075] Example 4

[0076] Preparation of all-polymer aqueous batteries

[0077] (1) Preparation of electrolyte (NaOTF-PAE)

[0078] 1) mixing polyethylene glycol dimethyl ether with a relative average molecular weight of 250 and polyethylene glycol dimethyl ether with a relative average molecular weight of 500 in a weight ratio of 1:4 to prepare polyethylene glycol dimethyl ether with a relative average molecular weight of 450 (PEGDME450);

[0079] 2) Mix the PEGDME450 prepared in step 1) with deionized water in a mass ratio of 47:3 to obtain a blending solvent, take 1 kg of the blending agent, add 2 mol NaOTF, and dissolve;

[0080] (2) Preparation of disc electrodes

[0081] The active material polyaniline (PANI), the conductive agent Ketjen black (KB) and the binder PTFE are mixed into a slurry in isopropyl alcohol (IPA) at a mass ratio of 7:2:1, and the slurry is rolled into a uniform film using a stainless steel cylinder to obtain an electrode film; the electrode film is then pressed onto a current collector (titanium mesh) to obtain an electrode sheet; finally, after vacuum drying at 80°C for 12 hours, the electrode sheet is cut into a disc electrode with a diameter of 12 mm.

[0082] (3) Take the two disc electrodes prepared in step (2), a Whatman glass fiber membrane, 2 m NaOTF-PAE prepared in step (1) and a CR2032 button battery, assemble them in a glove box to obtain a full polymer aqueous battery, and leave it for more than 8 hours.

[0083] At room temperature, the all-polymer aqueous battery prepared in Example 4 was subjected to constant current charge and discharge test (GCD test) and cycle performance test on a CT-4008T instrument. The results are as follows: Fig.15 As shown in the figure, it can be seen that under the 1C current density test condition, the discharge specific capacity of the battery is 120mAh / g, and the battery capacity retention rate after 100 cycles is 68.1%.

[0084] Example 5

[0085] The difference from Example 4 is that 2 mol NaOTF in step 2) is replaced by 2 mol NaClO4 to prepare an all-polymer aqueous battery.

[0086] At room temperature, the all-polymer aqueous battery prepared in Example 5 was subjected to constant current charge and discharge test (GCD test) and cycle performance test on a CT-4008T instrument. The results are as follows: Fig.16As shown in the figure, it can be seen that under the 1C current density test condition, the discharge specific capacity of the battery is 136mAh / g, and the battery capacity retention rate after 100 cycles is 68.6%.

[0087] Example 6

[0088] The difference from Example 4 is that 2 mol NaOTF in step 2) is replaced by 2 mol NaFSI to prepare an all-polymer aqueous battery.

[0089] At room temperature, the all-polymer aqueous battery prepared in Example 6 was subjected to constant current charge and discharge test (GCD test) and cycle performance test on a CT-4008T instrument. The results are as follows: Fig.17 As shown in the figure, it can be seen that under the 1C current density test condition, the discharge specific capacity of the battery is 147mAh / g, and the battery capacity retention rate after 100 cycles is 82.3%.

[0090] Example 7

[0091] The difference from Example 4 is that 2 mol NaOTF in step 2) is replaced by 2 mol LiTFSI to prepare an all-polymer aqueous battery.

[0092] At room temperature, the all-polymer aqueous battery prepared in Example 7 was subjected to constant current charge and discharge test (GCD test) and cycle performance test on a CT-4008T instrument. The results are as follows: Fig.18 As shown in the figure, it can be seen that under the 1C current density test condition, the discharge specific capacity of the battery is 110mAh / g, and the battery capacity retention rate after 100 cycles is 90.1%.

[0093] Example 8

[0094] Preparation of all-polymer aqueous batteries

[0095] (1) Preparation of electrolyte (NaTFSI-PPG)

[0096] A blending agent is obtained by mixing polypropylene glycol with a relative average molecular weight of 400 and deionized water in a mass ratio of 9:1. 1 kg of the blending agent is added with 2 mol of NaTFSI and dissolved;

[0097] (2) Preparation of disc electrodes

[0098] The active material polyaniline (PANI), the conductive agent Ketjen black (KB) and the binder PTFE are mixed into a slurry in isopropyl alcohol (IPA) at a mass ratio of 7:2:1, and the slurry is rolled into a uniform film using a stainless steel cylinder to obtain an electrode film; the electrode film is then pressed onto a current collector (titanium mesh) to obtain an electrode sheet; finally, after vacuum drying at 80°C for 12 hours, the electrode sheet is cut into a disc electrode with a diameter of 12 mm.

[0099] (3) Take the two disc electrodes prepared in step (2), a Whatman glass fiber membrane, 2 m NaTFSI-PPG prepared in step (1) and a CR2032 button battery, assemble them in a glove box to obtain a full polymer aqueous battery, and leave it for more than 8 hours.

[0100] At room temperature, the all-polymer aqueous battery prepared in Example 8 was subjected to constant current charge and discharge test (GCD test) and cycle performance test on a CT-4008T instrument. The results are as follows: Fig.19 As shown in the figure, it can be seen that under the 1C current density test condition, the discharge specific capacity of the battery is 141mAh / g, and the battery capacity retention rate after 50 cycles is 65.3%.

[0101] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution 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 solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. An all-polymer aqueous battery, comprising a positive electrode, a negative electrode, a separator and an electrolyte, It is characterized in that The materials of the positive electrode and the negative electrode are both polyaniline, the electrolyte is a mixture of a molecular crowding agent, water and an electrolyte salt, and the mass molar mass ratio of the molecular crowding agent, water and the electrolyte salt is 3-19:1:0.5-3, kg:kg:mol.

2. An all-polymer aqueous battery as claimed in claim 1, It is characterized in that The number average molecular weight of the molecular crowding agent is 200-1000.

3. An all-polymer aqueous battery as claimed in claim 2, It is characterized in that The molecular crowding agent is one of polyethylene glycol dimethyl ether, polyethylene glycol, polypropylene glycol, polypropylene glycol dimethyl ether, glucose, urea, polyvinyl alcohol, polyacrylic acid or polyacrylamide.

4. The all-polymer aqueous battery according to claim 1, It is characterized in that The electrolyte salt is NaTFSI, NaOTF, NaFSI, NaClO 4 , LiTFSI, LiFSI, LiOTF, LiClO 4 , LiBF 4 、KFSI、KTFSI、KClO 4 ,KOTF,Mg(TFSI) 2 Mg(FSI) 2 Mg(OTF) 2 、Ca(TFSI) 2 、Ca(FSI) 2 、Ca(OTF) 2 or Al(OTF) 3 One of them.

5. The all-polymer aqueous battery according to claim 1, It is characterized in that The separator is a non-woven fabric or a glass fiber separator.

6. An all-polymer aqueous battery according to any one of claims 1 to 5, It is characterized in that The electrolyte is prepared as follows: after the molecular crowding reagent and water are evenly mixed, an electrolyte salt is added and dissolved.

7. A method for preparing an all-polymer aqueous battery according to any one of claims 1 to 6, It is characterized in that The preparation method is as follows: S1. Preparation of electrolyte After the molecular crowding agent and water are evenly mixed, an electrolyte salt is added and dissolved, wherein the mass molar mass ratio of the molecular crowding agent, water and electrolyte salt is 3-19:1:0.5-3, kg:kg:mol; S2. Preparation of all-polymer aqueous batteries Polyaniline is used as the positive electrode and the negative electrode respectively, and the positive electrode, the negative electrode and the separator are assembled with the electrolyte prepared in step S1.

8. Application of an all-polymer aqueous battery as described in any one of claims 1 to 6 in a flexible battery.

9. The use according to claim 8, It is characterized in that The flexible battery is a flexible thin film planar battery.

10. The use according to claim 9, It is characterized in that The flexible thin film planar battery is prepared as follows: S1. Preparation of electrolyte After the molecular crowding agent and water are evenly mixed, an electrolyte salt is added and dissolved, wherein the molecular crowding agent, water and electrolyte salt have a molar mass ratio of 3-19:1:0.5-3, kg:kg:mol; S2. Preparation of flexible thin film planar batteries Polyaniline is used as the positive electrode and the negative electrode respectively, and the separator is placed between the positive electrode and the negative electrode, and then the whole is placed in a hydrogenated styrene-butadiene block copolymer bag, and then the electrolyte prepared in step S1 is injected and sealed under vacuum, and finally further packaged with polyparaxylene.

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