Preparation method and application of flexible chloride positive electrode material

Abstract

The invention discloses a preparation method and application of a flexible chloride positive electrode material, and the preparation method comprises the following steps: (1) carrying out mechanical ball milling I on mixed powder containing a lithium source and a chlorine source under the condition of an inactive atmosphere I to obtain a chloride positive electrode precursor; and (2) mixing the chloride precursor obtained in the step (1) with a conductive additive under the condition of an inactive atmosphere II, and performing mechanical ball milling II to obtain the flexible chloride positive electrode material, wherein the preparation process is carried out under an anhydrous condition; in the mixed powder, the chemical formula stoichiometric ratio of the lithium source to the chlorine source is (0.1-2): 1. The chloride positive electrode material prepared by the method provided by the invention has flexibility and deformability, can realize close contact between the positive electrode material layer and the electrolyte layer, and improves the stability of the electrode structure; and meanwhile, the lithium ion battery has high ionic conductivity and can realize rapid lithium ion conduction, so that the addition of supporting electrolyte is avoided, and the energy density of a battery system is improved.

Description

Technical Field

[0001] The present application relates to a preparation method and application of a flexible chloride cathode material, belonging to the technical field of solid-state batteries. Background Art

[0002] Since rechargeable lithium-ion batteries were introduced into the consumer market in the early 1990s, with the revolution of portable electronic products, they have changed the global communication field and are a mature and efficient energy storage technology in terms of energy and power density, service life, and design flexibility. Although the development of lithium-ion batteries has been very rapid, the current level of lithium-ion batteries using liquid electrolytes cannot fully meet the commercial needs of the public. Consumers strongly hope to develop superior lithium-ion batteries, including excellent cycling performance, high-rate performance, a wide operating temperature range, and outstanding safety performance.

[0003] All-solid-state lithium batteries improve the energy density of the battery system by using non-flammable inorganic solid electrolytes, and solid-state lithium batteries can be used in combination with lithium metal anodes to improve the energy density of the battery system. Compared with lithium anodes (3860 mAh g -1 ) and silicon anodes (4200 mAh g -1 ) with high theoretical specific capacities, the cathode materials with relatively low theoretical specific capacities have always been the key limiting the development of the energy density of solid-state battery systems.

[0004] Traditional oxide cathode materials (LiCoO2, LiFePO4, NCM111) have low ionic conductivities, and the transmission speed of lithium ions is slow during the charge and discharge processes of the battery. Therefore, it is necessary to add a supporting electrolyte with high ionic conductivity to the positive electrode side of the all-solid-state lithium battery to artificially construct an ion transport channel. However, the addition of the supporting electrolyte will reduce the mass ratio of the positive electrode active material and lower the energy density of the battery system. In addition, the addition of the supporting electrolyte will introduce a space charge layer and grain boundaries with poor conductivity, reducing the ion transport ability at the interface.

[0005] Secondly, whether it is a "deintercalation" type cathode or a "conversion" type cathode, during the cycling process, it will maintain the "solid-solid contact" between the cathode material and the solid electrolyte layer. However, due to the volume change of the cathode particles during the charge and discharge process, the cathode material is likely to fall off from the electrolyte layer, resulting in the loss of active substances, capacity attenuation, and reduced cycling stability of the battery system.

[0006] In summary, it is particularly important to research and develop a solid-state lithium battery cathode material that is flexible and has high ionic conductivity itself, realizes rapid ion conduction by itself, avoids the addition of a supporting electrolyte, and reduces the stress generated during the particle volume expansion process to improve the cycling stability of the battery system. Summary of the Invention

[0007] In view of this, the purpose of this application is to develop a flexible chloride cathode material with high ionic conductivity. The chloride cathode material of this application is flexible, which can achieve close contact between the cathode material layer and the electrolyte layer, reduce the capacity loss caused by the volume change of the cathode material during charge and discharge, thereby improving the stability of the electrode structure, and the assembled all-solid-state battery exhibits good cycle stability; this cathode material also has high ionic conductivity, which can achieve rapid lithium-ion conduction by itself, avoiding the addition of a supporting electrolyte, thereby improving the energy density of the battery system.

[0008] In one aspect of this application, a preparation method of a flexible chloride cathode material is provided, and the preparation method includes:

[0009] (1) Under the condition of inert atmosphere I, mechanically ball-mill a mixed powder containing a lithium source and a chlorine source to obtain a chloride cathode precursor;

[0010] (2) Under the condition of inert atmosphere II, mix the chloride precursor obtained in step (1) with a flexible conductive additive and mechanically ball-mill II to obtain the flexible chloride cathode material;

[0011] Among them, the preparation process is carried out under anhydrous conditions;

[0012] In the mixed powder, the stoichiometric ratio of the lithium source to the chlorine source is 0.1-2:1.

[0013] Optionally, the stoichiometric ratio of the lithium source to the chlorine source is independently selected from any value of 0.1:1, 0.5:1, 1:1, 1.5:1, 2:1 or the range value between any two of the above.

[0014] Optionally, the lithium source is lithium hydroxide;

[0015] The chlorine source is a transition metal element chloride.

[0016] Optionally, the chlorine source is selected from at least one of iron chloride, manganese chloride, cobalt chloride, nickel chloride, and copper chloride.

[0017] In this application, the ball-milling beads for mechanical ball-milling synthesis include at least two diameter types, and the mechanical ball-milling synthesis program includes forward rotation, intermittent, reverse rotation, intermittent, and circulates in this synthesis order.

[0018] Before mechanical ball-milling, dry the ball-milling tank and ball-milling beads in an oven, and then add materials for sealing treatment.

[0019] Optionally, the rotation speed of the mechanical ball-milling I is 300-1000 rpm;

[0020] The time of the mechanical ball milling I is 1 to 48 hours;

[0021] The ball milling beads of the mechanical ball milling I include ball milling beads I with a diameter of 10 to 20 mm and ball milling beads II with a diameter of 3 to 5 mm;

[0022] The mass ratio of the ball milling beads I to the ball milling beads II is 2 to 5:1.

[0023] Optionally, the rotation speed of the mechanical ball milling I is independently selected from any value of 300 rpm, 500 rpm, 800 rpm, 1000 rpm or the range value between any two of the above.

[0024] Optionally, the time of the mechanical ball milling I is independently selected from any value of 1 hour, 8 hours, 16 hours, 24 hours, 32 hours, 40 hours, 48 hours or the range value between any two of the above.

[0025] Optionally, the mass ratio of the ball milling beads I to the ball milling beads II is independently selected from any value of 2:1, 3:1, 4:1, 5:1 or the range value between any two of the above.

[0026] Optionally, the rotation speed of the mechanical ball milling II is 300 to 1000 rpm;

[0027] The time of the mechanical ball milling II is 1 to 48 hours;

[0028] The ball milling beads of the mechanical ball milling II include ball milling beads III with a diameter of 10 to 15 mm and ball milling beads IV with a diameter of 2 to 5 mm;

[0029] The mass ratio of the ball milling beads III to the ball milling beads IV is 2 to 5:1.

[0030] Optionally, the rotation speed of the mechanical ball milling II is independently selected from any value of 300 rpm, 500 rpm, 800 rpm, 1000 rpm or the range value between any two of the above.

[0031] Optionally, the time of the mechanical ball milling II is independently selected from any value of 1 hour, 8 hours, 16 hours, 24 hours, 32 hours, 40 hours, 48 hours or the range value between any two of the above.

[0032] Optionally, the mass ratio of the ball milling beads I to the ball milling beads II is independently selected from any value of 2:1, 3:1, 4:1, 5:1 or the range value between any two of the above.

[0033] Optionally, the inert atmosphere I and the inert atmosphere II are independently selected from at least one of argon, nitrogen, and helium.

[0034] Optionally, the inert atmosphere is high-purity argon with a purity greater than 99.999%, and the contents of oxygen and water are less than 0.01 ppm.

[0035] Optionally, the flexible conductive additive is selected from at least one of carbon nanotubes, graphene, carbon nanofibers, BP2000, KB600, KB300, XC-72, SuperP, acetylene black, and activated carbon.

[0036] Optionally, the mass ratio of the chloride precursor to the conductive additive is 1 to 20.

[0037] Optionally, the mass ratio of the chloride precursor to the conductive additive independently selects any value among 1, 0.1, 0.05 or the range value between any two of the above.

[0038] As a specific embodiment, a method for preparing a flexible chloride cathode material with high ionic conductivity is provided, including: S1, grinding an anhydrous lithium source and an anhydrous chlorine source material in an inert atmosphere to obtain a mixed powder; S2, mechanically ball-milling the powder in the inert atmosphere to synthesize a chloride cathode material precursor; S3, mechanically ball-milling the precursor material and a conductive additive in the inert atmosphere to obtain a chloride cathode material.

[0039] The anhydrous lithium source is lithium hydroxide (LiOH); the anhydrous chlorine source is one of transition metal element chlorides such as iron chloride (FeCl3), manganese chloride (MnCl2), cobalt chloride (CoCl2), nickel chloride (NiCl2), and copper chloride (CuCl2).

[0040] In another aspect of the present application, a flexible chloride cathode material prepared by the above preparation method is provided, and the ionic conductivity of the flexible chloride cathode material is 0.1 to 3 mS / cm.

[0041] In yet another aspect of the present application, a all-solid-state lithium-ion battery is provided, and the all-solid-state lithium-ion battery includes a positive electrode, a negative electrode, and a solid electrolyte;

[0042] Among them, the material of the positive electrode is selected from the above flexible chloride cathode material.

[0043] Optionally, the negative electrode is a lithium foil;

[0044] The solid electrolyte is lithium phosphorus sulfur chlorine and lithium zirconium chloride.

[0045] The beneficial effects that the present application can produce include:

[0046] 1) The preparation process of the flexible chloride cathode material prepared in this application is simple, and the required product can be obtained by a simple ball milling method; the raw materials are inexpensive, and large-scale application is expected to be achieved;

[0047] 2) The flexible chloride cathode material prepared in this application has flexibility and deformability, can achieve close contact with the electrolyte layer, and the phenomenon that the cathode material falls off due to volume change will not occur during the charge and discharge process of the battery, thereby improving the cycle stability of the battery;

[0048] 3) The flexible chloride cathode material prepared in this application has high ionic conductivity itself, can achieve rapid lithium ion conduction by itself, and can carry out normal charge and discharge processes of the battery without adding a supporting electrolyte, thereby reducing the proportion of inactive substances on the cathode side, increasing the proportion of active cathode substances, and improving the energy density of the battery system.

[0049] 4) The flexible chloride cathode material prepared in this application has good deformability, and a pore-free electrode can be prepared under a small pressure. Combining with the soft-pack manufacturing process is expected to solve the problem of maintaining the working pressure of solid-state lithium batteries, and has good application prospects. Description of the Drawings

[0050] Figure 1 is a flowchart of the preparation method of the flexible and highly ion-conductive chloride cathode material of this application;

[0051] Figure 2 is the SEM image of the cathode materials prepared in Example 1, Example 2, Comparative Example 1, and Comparative Example 2 of this application. The scale bars of Example 1 and Example 2 are 2μm, the scale bar of Comparative Example 1 is 10μm, and the scale bar of Comparative Example 2 is 20μm;

[0052] Figure 3 is the pressed tablet SEM image of the cathode materials prepared in Example 1, Example 2, Comparative Example 1, and Comparative Example 2 of this application, and the scale bar is 50μm;

[0053] Figure 4 is the X-ray diffraction pattern of the cathode materials prepared in Example 1, Example 2, Comparative Example 1, and Comparative Example 2 of this application;

[0054] Figure 5 is the EIS spectrum of the cathode materials prepared in Example 1, Example 2, Comparative Example 1, and Comparative Example 2 of this application;

[0055] Figure 6 is the cycle performance graph of the cathode materials prepared in Example 1, Example 2, Comparative Example 1, and Comparative Example 2 of this application in solid-state lithium batteries. Detailed Embodiments

[0056] The present application will be described in detail below in conjunction with embodiments, but the present application is not limited to these embodiments.

[0057] Unless otherwise specified, the raw materials in the embodiments of the present application are all purchased through commercial channels.

[0058] The present application can regulate the physical state of chloride cathode materials with different lithium concentrations through simple mechanical ball milling synthesis. By regulating the lithium content based on mechanical ball milling synthesis, the chloride cathode material can have good flexibility, and the ionic conductivity of the target product can reach 3 mS cm at room temperature. -1 When the prepared chloride cathode material is used in a solid-state lithium battery, it can achieve close contact with the electrolyte layer to improve the cycle stability of the battery; at the same time, the material itself has high ionic conductivity, which can avoid the addition of a supporting electrolyte, increase the proportion of the positive electrode active material, and improve the overall energy density of the battery system.

[0059] In the examples of the present application, a preparation method for a flexible chloride cathode material with high ionic conductivity is provided. Please refer to Figure 1 , including: S1, grinding an anhydrous lithium source and an anhydrous chlorine source material in an inert atmosphere to obtain a mixed powder; S2, mechanically ball milling the powder in the inert atmosphere to obtain a precursor of the chloride cathode material; S3, mechanically ball milling the precursor material and a conductive additive in the inert atmosphere to obtain the chloride cathode material.

[0060] Among them, in S1, the raw materials are lithium hydroxide (LiOH, anhydrous grade, 99.9%) and iron chloride (FeCl3, anhydrous grade, 99.9%).

[0061] The optimal manual grinding time in S1 is 30 minutes.

[0062] The molar ratio of the raw materials LiOH:FeCl3 = 1:1, and the corresponding dosages are LiOH (0.1035 g) and FeCl3 (1.3965 g). In this dosing method, the room-temperature ionic conductivity of the obtained positive electrode material is the best.

[0063] The specific steps of mechanical ball milling synthesis include a pre-mixing process. All the mixed raw materials in S1 are put into a ball milling jar with a volume of 100 mL. Subsequently, ball milling beads with a certain mass ratio are added, and the ball milling jar is strictly sealed in a glove box to ensure an inert and dry atmosphere inside the jar. Subsequently, the sealed ball milling jar is placed in a ball mill and fixed. Then, the working program of the ball mill is set to rotate forward for 5 minutes, intermittent for 10 minutes; rotate backward for 5 minutes, intermittent for 10 minutes, and at the same time, the rotation speed is set to 1000 revolutions per minute. To ensure the uniformity of the reaction, the ball milling jar is opened in the glove box for mixing every 4 hours, and then repeated 4 times to prepare the precursor of the cathode material. Subsequently, in the glove box, the precursor of the cathode material and the conductive additive are added to the ball milling jar at a weight ratio of 95:5, and the ball milling jar is strictly sealed in the glove box. Immediately, the ball milling jar is placed in the ball mill and fixed, and the working program of the ball mill is set to rotate forward for 5 minutes, intermittent for 10 minutes; rotate backward for 5 minutes, intermittent for 10 minutes, and at the same time, the rotation speed is set at 500 revolutions per minute. After the ball milling program ends, a flexible chloride cathode material with high ionic conductivity can be prepared.

[0064] On the basis of the above embodiments, the stoichiometric ratio of lithium hydroxide and iron chloride in the mixture is 0.1 - 2:1.

[0065] On the basis of the above embodiments, the ball milling beads for mechanical ball milling synthesis include at least two diameter types, and the rotation speed of the mechanical ball milling synthesis is 300 - 1000 rpm, and the time is 1 - 48 hours.

[0066] On the basis of the above embodiments, the mechanical ball milling synthesis program includes forward rotation, intermittent, reverse rotation, and intermittent, and circulates in this order.

[0067] On the basis of the above embodiments, the ball milling beads include two diameter types of 10 mm and 5 mm, and the mass ratio of the ball milling beads is 2 - 5:1.

[0068] On the basis of the above embodiments, the stoichiometric ratio of the lithium source and the chlorine source in the mixture is 0.1 - 2:1.

[0069] On the basis of the above embodiments, the purity of high-purity argon gas is ≥99.999%, and the oxygen and water content is less than 0.01 ppm.

[0070] High-purity argon gas has the function of protecting the inert atmosphere in the glove box, and the oxygen and water content less than 0.01 ppm can reduce the influence of material moisture absorption on its electrochemical performance.

[0071] Based on the above embodiments, a conductive additive is added, which is one of carbon nanotubes, graphene, carbon nanofibers, BP2000, KB600, KB300, XC-72, SuperP, acetylene black, and activated carbon. Adding the conductive additive is to construct an electron transport network inside the cathode material and reduce the polarization problem caused by the low electronic conductivity of the cathode material.

[0072] Based on the above embodiments, before mechanical ball milling synthesis, it also includes drying the ball milling tank and ball milling beads in an oven and then adding materials for sealing.

[0073] Before mechanical ball milling synthesis, the ball milling tank and ball milling beads need to be dried in an oven at 60 °C for 12 hours to fully remove the small amount of moisture on the ball milling tank and ball milling beads, and then the feeding operation is carried out, followed by mechanical ball milling synthesis. The moisture on the ball milling tank and ball milling beads will cause the raw materials and the final product to absorb moisture, resulting in a hydrolysis reaction of the material and ultimately affecting its product state.

[0074] The flexible chloride cathode material with high ionic conductivity prepared by mechanical ball milling synthesis in this application has good deformability, improving the cycle stability of the battery system; and the material has high ionic conductivity, avoiding the addition of a supporting electrolyte and improving the energy density of the battery system. In addition, the cathode material prepared based on the mechanical ball milling method does not require high-temperature treatment, has a simple process, and reduces production energy consumption.

[0075] In the subsequent examples and comparative examples of this application, anhydrous lithium hydroxide (LiOH) is fixed as the lithium source, and anhydrous ferric chloride (FeCl3) is fixed as the chlorine source.

[0076] In the examples of this application, the instrument and equipment for preparing the chloride cathode material sheet include a common cylindrical mold (Φ10 mm), a manual tablet press, and the above process needs to be used in cooperation with a dry inert atmosphere glove box, in which the oxygen and water contents are both below 0.01 ppm;

[0077] The instrument and equipment for testing the ionic conductivity of the chloride cathode material and assembling the solid-state full battery include a common cylindrical mold (Φ10 mm), a solid-state battery test mold (Φ10 mm), a manual tablet press, a multi-channel electrochemical workstation, and a battery detection system. The solid-state full battery assembly process is carried out in a dry inert atmosphere glove box, in which the oxygen and water contents are both below 0.01 ppm.

[0078] Example 1

[0079] Weigh 5 mmol of lithium hydroxide (LiOH, anhydrous grade, 99.9%) and 10 mmol of ferric chloride (FeCl3, anhydrous grade, 99.9%) in a glove box, place them in an agate mortar and grind manually for 30 minutes, then put them into a ball mill jar with a volume of 100 mL. Subsequently, add 50 g of ball milling beads (40 g of 10 mm diameter ball milling beads and 10 g of 5 mm diameter ball milling beads) into the jar, and strictly seal the ball mill jar in the glove box to ensure an inert dry atmosphere inside the jar. The inert dry atmosphere is high-purity argon, and the purity of high-purity argon is ≥99.999%, where the oxygen and water content is less than 0.01 ppm. Subsequently, place the sealed ball mill jar in a ball mill, fix it, and set the working program of the ball mill to 5 minutes of forward rotation and 10 minutes of intermittent; 5 minutes of reverse rotation and 10 minutes of intermittent mode, and at the same time set the rotation speed to 1000 revolutions per minute. To ensure the uniformity of the reaction, open the ball mill jar in the glove box for mixing every 4 hours, and then repeat 4 times to prepare the precursor of the cathode material. Subsequently, add the precursor of the cathode material and Ketjenblack conductive additive into the ball mill jar in a weight ratio of 95:5 in the glove box, strictly seal the ball mill jar in the glove box, and set the working program of the ball mill to 5 minutes of forward rotation and 10 minutes of intermittent; 5 minutes of reverse rotation and 10 minutes of intermittent mode, and at the same time set the rotation speed at 500 revolutions per minute. After the ball milling program is completed, a flexible chloride cathode material with high ionic conductivity can be prepared.

[0080] Example 2

[0081] Compared with Example 1, the difference is that the molar ratio of the addition amount of LiOH:FeCl3 is 1:1.

[0082] Other processes and conditions are the same as those in Example 1.

[0083] Comparative Example 1

[0084] Compared with Example 1, the difference is that the molar ratio of the addition amount of LiOH:FeCl3 is 3:1.

[0085] Other processes and conditions are the same as those in Example 1.

[0086] Comparative Example 2

[0087] Compared with Example 1, the difference is that the molar ratio of the addition amount of LiOH:FeCl3 is 4:1.

[0088] Other processes and conditions are the same as those in Example 1.

[0089] Test Example 1

[0090] The chloride cathode materials prepared in Examples 1 and 2 and Comparative Examples 1 and 2 were subjected to SEM tests using a scanning electron microscope (Scanning electron microscopy, SEM, JEOL 6360LV@15kV and JSM 7800F@3kV). The test results are shown in Figure 2 . From Figure 2 the SEM images, it can be seen that there are no crystals inside the clay-like samples (Examples 1-2) prepared from lithium hydroxide and anhydrous ferric chloride in a fixed ratio, and its uneven surface structure is caused by the sample preparation process. In Comparative Examples 1-2, it can be clearly observed that there are grains inside the samples, which is completely different from the results of Examples 1-2.

[0091] Test Example 2

[0092] The chloride cathode materials prepared in Examples 1 and 2 and Comparative Examples 1 and 2 were added to a common cylindrical mold (Φ10mm), and a pressure of 50 MPa was applied using a manual tablet press. After cold pressing for 1 minute and then retracting the tablet, cathode material sheets with a diameter of 10 mm can be obtained respectively. The obtained cathode material sheets were respectively subjected to SEM tests using a scanning electron microscope (Scanning electron microscopy, SEM, JEOL6360LV@15kV and JSM 7800F@3kV). The test results are shown in Figure 3 . Figure 3 The results show that after applying a small pressure, the surfaces of Examples 1 and 2 are in a uniform state, and there are no pores on the surface, highlighting the flexibility of Examples 1 and 2. The uneven surface structure is caused by the uneven surface of the electrode. As powder samples, Comparative Examples 1 and 2 have more pore structures on the surface and poor deformability after being formed under a certain pressure.

[0093] The obtained cathode material sheets were respectively subjected to X-ray diffraction tests using a Rigaku X-ray diffractometer. The test results are shown in Figure 4 , the horizontal axis is the diffraction angle 2θ, and the vertical axis is the diffraction intensity. From Figure 4 it can be obtained that the flexible cathode materials of the examples do not show peaks in the diffraction range and are in an amorphous state; while the powder samples of the comparative examples show diffraction peaks mainly composed of lithium chloride, indicating that the visible grains in the SEM images are lithium chloride crystals.

[0094] Test Example 3

[0095] A certain amount of cathode precursor material was added to a common cylindrical mold (Φ10mm), and a pressure of 500 MPa was applied using a manual tablet press. After cold pressing for 1 minute. Subsequently, an ion conductivity test was carried out on it using a Biologic multi-channel electrochemical workstation. The test frequency in this test was 7 MHz to 1 Hz, and the applied bias voltage was 100 mV.

[0096] Figure 5 The electrochemical AC impedance spectrogram of the cathode precursor materials of Examples 1 and 2 and Comparative Examples 1 and 2. The abscissa is the real part impedance and the ordinate is the imaginary part impedance. It can be concluded that the cathode precursor materials obtained in the examples have a high conductivity of about 3 mS cm at room temperature. -1 or so.

[0097] Test Example 4

[0098] A certain amount of lithium zirconium chloride solid electrolyte was added to the battery core of a solid-state battery test mold (Φ10 mm), and a pressure of 50 MPa was applied and cold pressed for 1 min; then a certain amount of lithium phosphorus sulfur chloride solid electrolyte was added to the battery core, and a pressure of 100 MPa was applied and cold pressed for 1 min; subsequently, a certain amount of chloride cathode material was added to the side of the lithium zirconium chloride electrolyte, and a pressure of 500 MPa was applied and cold pressed for 1 min; a lithium sheet was added to the side of the lithium phosphorus sulfur chloride electrolyte sheet, and aluminum foil and copper foil were added to the positive and negative electrode sides. After assembling the battery, the battery mold was maintained at a pressure of 100 MPa and electrochemical tests were carried out using a Blue Power battery tester. In this test, the applied current density was 0.1 mA cm -2 .

[0099] Figure 6 The electrochemical performance curves of the solid-state full batteries based on the chloride cathode materials provided in Examples 1 and 2 and Comparative Examples 1 and 2. The abscissa is the number of cycles and the ordinate is the working voltage. Among them, the mass ratio of the chloride precursor is 95 wt.%. It can be concluded that the full battery assembled with the flexible and highly conductive example has better cycle stability compared to the powdery comparative example.

[0100] As described above, these are only several embodiments of the present application and do not impose any form of limitation on the present application. Although the present application is disclosed with preferred embodiments as above, it is not intended to limit the present application. Any person skilled in the art, without departing from the scope of the technical solution of the present application, making some changes or modifications using the disclosed technical content is equivalent to equivalent implementation cases and all belong to the scope of the technical solution.

Claims

1. A preparation method of a flexible chloride cathode material, characterized in that, The preparation method includes: (1) Under the condition of inert atmosphere I, mechanically ball-mill a mixed powder containing a lithium source and a chlorine source for the first time to obtain a chloride cathode precursor; (2) Under the condition of inert atmosphere II, mix the chloride precursor obtained in step (1) with a flexible conductive additive and mechanically ball-mill for the second time to obtain the flexible chloride cathode material; Wherein, the preparation process is carried out under anhydrous conditions; In the mixed powder, the stoichiometric ratio of the lithium source to the chlorine source is 0.1-2:

1.

2. The preparation method according to claim 1, characterized in that, The lithium source is lithium hydroxide; The chlorine source is a transition metal element chloride.

3. The preparation method according to claim 2, characterized in that, The chlorine source is selected from at least one of iron chloride, manganese chloride, cobalt chloride, nickel chloride, and copper chloride.

4. The preparation method according to claim 1, characterized in that, The rotation speed of the first mechanical ball-milling is 300-1000 rpm; The time of the first mechanical ball-milling is 1-48 hours; The ball-milling beads for the mechanical ball-milling include ball-milling beads I with a diameter of 10-20 mm and ball-milling beads II with a diameter of 3-5 mm; The mass ratio of the ball-milling beads I to the ball-milling beads II is 2-5:

1.

5. The preparation method according to claim 1, characterized in that, The rotation speed of the second mechanical ball-milling is 300-1000 rpm; The time of the second mechanical ball-milling is 1-48 hours; The ball-milling beads for the mechanical ball-milling include ball-milling beads III with a diameter of 10-15 mm and ball-milling beads IV with a diameter of 2-5 mm; The mass ratio of the ball-milling beads III to the ball-milling beads IV is 2-5:

1.

6. The preparation method according to claim 1, characterized in that, The inert atmosphere I and the inert atmosphere II are independently selected from at least one of argon, nitrogen, and helium; 7. The preparation method according to claim 1, characterized in that, The flexible conductive additive is selected from at least one of carbon nanotubes, graphene, carbon nanofibers, BP2000, KB600, KB300, XC-72, SuperP, acetylene black, and activated carbon; Preferably, the mass ratio of the chloride precursor to the conductive additive is 1-20.

8. A flexible chloride cathode material prepared by the preparation method according to any one of claims 1 to 7, characterized in that, The ionic conductivity of the flexible chloride cathode material is 0.1-3 mS / cm.

9. A all-solid-state lithium-ion battery, characterized in that, The all-solid-state lithium-ion battery includes a cathode, an anode, and a solid electrolyte; Wherein, the material of the cathode is selected from the flexible chloride cathode materials described in any one of claims 1-7.

10. The all-solid-state lithium-ion battery according to claim 9, characterized in that, The anode is a lithium sheet; The solid electrolyte is lithium phosphorus sulfur chlorine and lithium zirconium chloride.

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