Negative electrode active material powder supplemented with metal m, and method of manufacturing, manufacturing apparatus, and use thereof

Abstract

The application belongs to the field of battery materials, and particularly relates to a negative electrode active material powder supplemented with metal M, a preparation method, a preparation device and application thereof. The preparation device of the negative electrode active material powder supplemented with metal M comprises a container, a diaphragm, an M end current collector, a slurry stirring current collector, a slurry storage tank, a circulating pump and a metal M donor material. The diaphragm is arranged in the container and divides the container into a metal reaction cavity and a slurry reaction cavity. The M end current collector and the metal M donor material are arranged in the metal reaction cavity. The slurry stirring current collector is arranged in the slurry reaction cavity. The application can realize uniform supplement of metal M in the negative electrode active material, improve process stability, and improve the performance and quality stability of the subsequently prepared negative electrode.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of battery materials, and particularly relates to the technical field of metal M (M = Li, Na and / or K) supplementing negative electrode materials. BACKGROUND

[0002] Metal M (lithium, sodium, potassium) ion batteries play an important role in many fields such as mobile electronic products, new energy vehicles and energy storage power stations. With the rapid development of these fields, the demand for battery energy density is increasing. However, during the first charging process of the battery, the formation of the negative electrode SEI film and other factors will cause irreversible loss of metal M, thereby affecting its electrochemical performance, especially the first coulombic efficiency.

[0003] Taking lithium batteries as an example, pre-lithiation of the battery negative electrode is an effective means to solve the problem of lithium irreversible loss in the first cycle. This pre-lithiation process not only improves the initial efficiency of the negative electrode and forms a high-quality SEI interface film, but also is expected to pre-deposit a certain amount of lithium metal in the lithium metal negative electrode material, thereby more fully exploiting the potential of the negative electrode material. Therefore, it is particularly important to develop a technology for pre-supplementing metal M in the battery negative electrode.

[0004] Electrochemical pre-supplementing metal M can accurately control the amount of metal M insertion and deposition, and can adjust the SEI. However, the commonly used method of electrochemical supplementing metal M is to mix active materials, conductive agents, binders, etc., then coat them on the current collector to prepare a negative electrode sheet, and then perform non-in situ electrochemical supplementing metal M on the negative electrode sheet through charging and discharging. For example, Japanese patent document No. JP2020536348A discloses a negative electrode lithium supplementing method, which pre-prepares a negative electrode sheet, and then performs lithium insertion treatment on the sheet. Again, patent document No. CN117832375A also discloses a similar device and method of pre-forming a negative electrode sheet and then performing lithium insertion on the sheet.

[0005] In summary, the process of pre-forming a sheet and then supplementing metal M has certain application prospects and can supplement metal M in the negative electrode to some extent, but still has certain limitations, such as: the adhesion failure and destruction of the conductive network of the electrode sheet caused by the expansion of the active material during charging and discharging, which will make it difficult to control the uniformity of metal M insertion and metal M deposition in the negative electrode sheet, and will also lead to uneven quality of the SEI film on the surface of the material. In addition, the negative electrode sheet needs to be prepared and then supplemented with metal M, and the thickness of the sheet also needs to be controlled due to polarization, so the efficiency of supplementing metal M is greatly reduced. The damage to the negative electrode sheet during the supplementing of metal M will also lead to the inability to effectively exert the performance of the assembled battery. Most importantly, the process of electrochemically supplementing metal M in the negative electrode sheet requires additional processes of sheet assembly and disassembly, which increases the complexity and uncontrollability of the production process.

[0006] Therefore, there is a need in the industry for a technology that can homogenously supplement lithium, sodium or potassium to negative active material powder itself. SUMMARY

[0007] In view of the lack of metal M supplementing technology for negative active material powder, the first object of the present application is to provide a device for preparing negative active material powder supplemented with metal M, so as to homogenously supplement metal M to negative active material powder based on the device.

[0008] The second object of the present application is to provide a method for preparing negative active material powder supplemented with metal M by using the device.

[0009] The third object of the present application is to provide the application of the negative active material powder supplemented with metal M.

[0010] The mainstream method for supplementing metal M to negative electrode in the industry is to coat negative active material in advance to form a pole piece, and then supplement metal M to the pole piece. This process has many defects such as damage to the pole piece in the metal M supplementing stage, expansion and peeling of the negative electrode material, etc. In view of the current situation in the industry, the present application has previously attempted to propose a method for supplementing metal M to negative powder, but is hindered by the lack of such research and the lack of equipment, etc., making it difficult to solve the problem of uniformity of powder supplementing metal M. In view of the problems existing in the supplementing of metal M to particles, the present application provides the following improved scheme after in-depth research:

[0011] The device for preparing negative active material powder supplemented with metal M comprises a container, a separator, an M-end current collector (also referred to as a first current collector), a slurry stirring current collector (also referred to as a second current collector), a slurry storage tank, a circulating pump and a metal M donor material; wherein the metal M is at least one of Li, Na and K;

[0012] The separator is arranged in the container and divides the container into a metal reaction cavity and a slurry reaction cavity;

[0013] The M-end current collector and the metal M donor material are arranged in the metal reaction cavity; the slurry stirring current collector is a current collector with stirring function, which is arranged in the slurry reaction cavity;

[0014] The slurry reaction cavity is further provided with a slurry inlet and a slurry outlet on the cavity wall, wherein the slurry inlet and the circulating outlet of the slurry storage tank are connected by pipeline A, and the slurry outlet and the circulating inlet of the slurry storage tank are connected by pipeline B, wherein the pipeline A and / or the pipeline B is provided with a circulating pump.

[0015] In view of the problem of non-ideal uniformity of the metal M supplementing the negative electrode powder, the application provides a reaction device, which is combined by the double-cavity structure of the metal reaction cavity and the slurry reaction cavity, and further cooperates with the combined and synergistic control of the slurry stirring collector with stirring function, so as to realize the uniform supplement of the metal M to the negative electrode active material, improve the process stability, and improve the performance and quality stability of the subsequent prepared negative electrode.

[0016] In the application, the M-terminal current collector is a conductive metal, a conductive alloy or a material with a conductive coating. The conductive metal is, for example, a pure metal such as copper, aluminum, nickel or platinum. The alloy is, for example, a conductive copper alloy. The conductive coating is, for example, a known organic-metal composite material with conductive ability.

[0017] The metal M donor material is a material capable of providing the metal M, which can be the metal M or an alloy of the metal M.

[0018] The metal M donor material is combined on the M-terminal current collector, for example, by a conventional physical, chemical or electrochemical method.

[0019] In the application, the separator can be any separator material known in the industry, for example, at least one of a polyolefin separator, a ceramic-coated separator, a non-woven fabric separator and a solid-state electrolyte.

[0020] The slurry stirring collector is a mechanism with conductive ability and stirring function, which can include a stirring shaft and a stirring paddle (stirring mechanism) arranged on the stirring shaft. In the application, the slurry stirring collector with synchronous conductive and stirring ability is combined with the double-cavity electrolysis structure of the application, so as to effectively improve the performance of the metal M supplementing the particles and the process stability.

[0021] In the application, the structure of the stirring mechanism is not particularly limited, and the stirring mechanism can be conductive and capable of stirring, for example, a paddle, a turbine, a frame or an anchor paddle; or a propeller, a screw or a spiral paddle.

[0022] The stirring paddle can be multiple groups (for example, 1-5 groups) of stirring paddles arranged along the height direction of the stirring shaft.

[0023] In the application, the slurry stirring collector is a 3D current collector, which is a multi-stage stirring mechanism with stirring function, and the material can be a pure metal such as copper, aluminum, nickel or platinum, an alloy or an organic-metal composite material. The slurry stirring collector of the application can strengthen the synergy of the process and improve the stability of the powder supplementing the metal M.

[0024] In the present application, the slurry storage tank further comprises a feeding bin and a discharging bin.

[0025] The present application also provides a preparation method of metal M-supplemented negative electrode active material powder, which is prepared by using the preparation device of the present application, and in the preparation process, electrolyte is first injected into the metal reaction chamber, and slurry containing the negative electrode active material powder to be treated and electrolyte is injected into the slurry reaction chamber, the circulating pump is started, the slurry stirring collector is used for stirring, and the M terminal collector and the slurry stirring collector are electrically connected with the external power supply for metal M supplement treatment, and then the negative electrode active material powder and the liquid are separated to obtain the metal M-supplemented negative electrode active material powder.

[0026] In the present application, the electrolyte is a mixed solution of conductive salt containing metal M and solvent, wherein the solvent includes at least one of chain acid ester, cyclic acid ester, chain ether and cyclic ether, the concentration of metal M is 0.1-10M, further can be 0.5-2M, and more further can be 1-1.5M.

[0027] The negative electrode active material is at least one of carbon negative electrode active material, alloy negative electrode active material, metal / carbon composite active material and oxide negative electrode active material.

[0028] Further, the carbon negative electrode active material can include graphite, soft carbon, hard carbon and the like; the alloy negative electrode active material can include nano-silicon powder, silicon-carbon composite material, SiOx material, tin-based alloy material, antimony-based alloy material and the like; the metal-carbon composite active material can include lithium-carbon composite material, sodium-carbon composite material, potassium-carbon composite material and the like; and the oxide negative electrode active material can include lithium titanate, titanium dioxide, iron oxide and the like.

[0029] The slurry can further contain at least one of conductive agent, dispersant and additive.

[0030] Further, the dispersant can be a conventional surfactant, such as TX-100, but not limited to, the content of which in the slurry is less than 5wt.%, further can be 0.5-4wt.%, and more further can be 1-3wt.%. In the present application, the addition of the dispersant is helpful to the structure and the powder lithium supplement idea of the present application, and is helpful to further improve the uniformity and effect of powder lithium supplement.

[0031] Further, the conductive agent includes but is not limited to acetylene black, super-P, carbon nanotube and the like, the content of which in the slurry is less than 5wt.%, further can be 0.5-4wt.%, and more further can be 1-3wt.%. The conductive agent is helpful to maintain good electronic path between the active material and the current collector, and is helpful to improve the stability of metal M supplement.

[0032] Furthermore, the additives include, but are not limited to, boron-based additives (lithium bis(oxalatoborate), nitrogen-based additives (lithium nitrate), fluorine-based additives (fluoroethylene carbonate), silicon-based additives (diphenyldimethoxysilane), and phosphorus-based additives (triethyl phosphite). The amount of these additives can be adjusted as needed, for example, to comprise less than 10 wt.% of the electrolyte in the slurry, further ranging from 1 to 10 wt.%, and further ranging from 3 to 6 wt.%. Research in this invention demonstrates that the combination of these additives, the structure described in this invention, and the powder lithium replenishment strategy can further improve the uniformity and effectiveness of powder lithium replenishment, and contribute to improving the surface structure and electrochemical properties of the replenished material.

[0033] Furthermore, the metal M replenishing process includes a single metal M replenishing process or multiple metal M replenishing processes;

[0034] The multiple metal M replenishment process is a single metal M replenishment process repeated N times, wherein N is an integer from 2 to 20, preferably from 5 to 15. In the present invention, the combination of the aforementioned devices and the multiple metal M replenishment process can further enhance the lithium replenishment effect and stability of the process.

[0035] In the present invention, the process of single metal M replenishment is: the M-end current collector is conductively connected to the positive electrode of the external power supply, the slurry stirring current collector is conductively connected to the negative electrode of the external power supply, and power is applied at a fixed current density until the cut-off voltage is 0V. Then, the conductive connection mode of the external power supply (that is, the M-end current collector is conductively connected to the negative electrode of the external power supply, and the slurry stirring current collector is conductively connected to the positive electrode of the external power supply) is reversed, and power is applied at a fixed current density until the cut-off voltage is 3V. This is repeated a fixed number of times or until the coulombic efficiency is stable.

[0036] In the present invention, there is no special requirement for the current density during the lithium replenishment stage, and it can be, for example, 0.005 to 0.05 mA / cm 2 ; further can be 0.01~0.03 mA / cm 2 .

[0037] In the present invention, the voltage range during the lithium replenishment process can be 0-4V, and further can be 0-3V.

[0038] The present invention also provides a negative electrode active material powder for supplementing the metal M.

[0039] The present invention also provides an application of the metal M-supplemented negative electrode active material powder, which is used as a negative electrode active material, compounded with a conductive agent and a binder, coated on a current collector, and dried to obtain a negative electrode sheet.

[0040] Furthermore, the negative electrode plate and the positive electrode plate are assembled to form a battery.

[0041] Advantages

[0042] The application innovatively provides a particle metal M supplement reaction device, which can realize uniform metal M supplement of negative active material, improve process stability, and improve performance and quality stability of the prepared negative electrode by the combination of the metal reaction cavity and the slurry reaction cavity, and the combined cooperation of the slurry stirring collector. BRIEF DESCRIPTION OF DRAWINGS

[0043] Figure 1 It is a structural schematic diagram of the electrochemical metal M supplement device.

[0044] Figure 2 It is a cycle diagram of the lithium-supplemented material of Example 1. DETAILED DESCRIPTION

[0045] The exemplary embodiments of the application are described below in conjunction with the accompanying drawings.

[0046] Reference Figure 1 The application provides an electrochemical metal M supplement device (such as lithium supplement, sodium supplement or potassium supplement), which comprises: (1) a container, (2) an M end collector, (3) a metal reaction cavity, (4) a diaphragm, (5) a slurry stirring collector, (6) a slurry reaction cavity, (7) a slurry storage tank, (8) a circulating pump, and (9) a metal M donor material.

[0047] The diaphragm (4) is arranged in the container (1) and divides the container (1) into the metal reaction cavity (3) and the slurry reaction cavity (6).

[0048] The M end collector (2) and the metal M donor material (9) are arranged in the metal reaction cavity (3) (the metal M donor material (9) can be compounded on the M end collector (2)), and the slurry stirring collector (5) is arranged in the slurry reaction cavity (6).

[0049] The slurry reaction cavity (6) is further provided with a slurry inlet and a slurry outlet on a cavity wall, the slurry inlet and a circulating outlet of the slurry storage tank (7) are connected through a pipeline A, the slurry outlet and a circulating inlet of the slurry storage tank (7) are connected through a pipeline B, and the circulating pump (8) is arranged on the pipeline A and / or the pipeline B.

[0050] The slurry stirring collector (5) comprises a stirring shaft and a stirring paddle arranged on the stirring shaft.

[0051] In the application, the structure of the stirring paddle is not particularly required, for example, as an optional scheme, the following case can adopt a paddle stirring paddle as shown in Figure 1

[0052] ​The stirring shaft is vertically arranged in the slurry reaction cavity. The stirring paddle is arranged in 1-4 groups along the height direction of the stirring shaft. The material of the slurry stirring collector is a material with electric conductivity, such as a single conductive metal, a conductive alloy, or a material coated with a conductive coating.

[0053] In the present application, the method for supplementing metal M by using the device is, for example:

[0054] S1, slurry the negative electrode active material to be treated, an electrolyte to form a slurry; at least one of the dispersant, the conductive agent and the additive is selectively added in the slurry;

[0055] S2, the M end collector containing metal M is placed in the metal reaction cavity;

[0056] S3, the electrolyte is injected into the metal reaction cavity, the slurry is injected into the slurry storage tank and the slurry positive electrode reaction cavity, the circulating pump is opened and the stirring function of the slurry stirring collector is started;

[0057] S4, the power supply is connected, first the M end collector and the slurry stirring collector are respectively connected with the positive electrode and the negative electrode of the external power supply to fix the current density and power on, until the cut-off voltage 0V is reached, then the power supply is reversed (reversed, that is, the M end collector and the slurry stirring collector are respectively connected with the negative electrode and the positive electrode of the external power supply), to fix the current density and power on, until the cut-off voltage 3V is reached, to supplement metal M to the active material, after the metal M is supplemented, the active slurry is obtained, the active slurry is washed with an organic solvent and separated and dried to obtain a pre-metal M active material;

[0058] Considering the demand for lithium supplement, the charging and discharging steps of S4 can be repeated to realize continuous metal M supplement.

[0059] The negative electrode is prepared by using the pre-metal M active material prepared by the device and the method, and is assembled to form a battery corresponding to the metal M. For example, the lithium-supplemented negative electrode active material is prepared to obtain a negative electrode, and a lithium secondary battery is assembled. The sodium-supplemented negative electrode active material is prepared to obtain a negative electrode, and a sodium secondary battery is assembled. The potassium-supplemented negative electrode active material is prepared to obtain a negative electrode, and a potassium secondary battery is assembled.

[0060] In the present application, the step of preparing the negative electrode from the pre-metal M active material is, for example: the pre-metal M active material, the conductive agent and the binder are slurred and coated on the negative electrode collector, and then dried to obtain the negative electrode.

[0061] In the following cases, the negative electrode active material to be treated is taken as an example of a conventional commercial hard carbon.

[0062] The following case, the base electrolyte can be electrolyte A, which is an organic solution dissolved with LiPF6, wherein the solvent includes EC / DEC / DMC in a volume ratio of 1:1:1; wherein, EC is ethylene carbonate, DEC is diethyl carbonate, and DMC is dimethyl carbonate.

[0063] In addition, the electrolyte B of the present application can be an electrolyte in which fluoroethylene carbonate FEC is added to the electrolyte A, wherein the concentration of FEC in the electrolyte B is 5wt.%.

[0064] Example 1

[0065] This example uses Figure 1 The electrochemical metal M device, taking the hard carbon negative material for lithium ion battery as an example, specifically adopts the following electrochemical lithium supplement method:

[0066] S1, uniformly mix the active material (hard carbon), electrolyte A, dispersant (TX-100), and conductive agent (carbon nanotube) in a mass ratio of 10:86:2:2 to form a slurry;

[0067] S2, insert the lithium plate / copper current collector (M end current collector-M donor material composite material, which means that there is a lithium foil composite on the copper current collector) into the metal reaction cavity;

[0068] S3, inject electrolyte A into the metal reaction cavity, inject slurry into the slurry storage tank and the slurry reaction cavity, and turn on the stirring mechanism (slurry stirring current collector with four groups of copper four-blade stirring mechanism arranged in the height direction), the rotating speed is 300 rpm, and the circulating pump is turned on, the flow rate is 0.5 L / h;

[0069] S4, connect the power supply to supplement lithium to the active material. The specific process is to perform 1 charge-discharge on the slurry, first, the M end current collector and the slurry stirring current collector are respectively conductively connected with the positive electrode and the negative electrode of the external power supply, and the power supply is connected with a current density of 0.01 mA / cm 2 , to the cut-off voltage 0V, then the power supply is reversed, and the power supply is connected with a current density of 0.01 mA / cm 2 , to the cut-off voltage 3V, the lithium supplement is completed, and the active slurry is obtained; the active slurry is washed with EC solvent and dried to obtain pre-lithiated active material;

[0070] A slurry was prepared using pre-lithiated active material, conductive agent (acetylene black), binder (PVDF) in a mass ratio of 9:0.5:0.5 in NMP solvent, and was coated on a copper current collector to prepare a hard carbon negative electrode sheet, and was assembled into a full battery with a LiCoO2 positive electrode sheet (the positive electrode material included LiCoO2, PVDF, and acetylene black in a mass ratio of 9:0.5:0.5), and an electrolyte B, and in the test process, the pre-activation current density was 0.1 C for 3 cycles, and then the cycle was 350 cycles at 1 C and 30°C, and the voltage range was 1.5-4.2 V. The cycle results are shown in Table 1. Figure 2 .

[0071] Example 2

[0072] Compared with Example 1, the only difference is that the slurry further contains an additive, which is fluoroethylene carbonate FEC, and the content of FEC is 5wt.% of the weight of electrolyte A. The other operations and parameters are the same as those in Example 1.

[0073] Example 3

[0074] Compared with Example 1, the only difference is that the charging and discharging process of step S4 is repeated 10 times, that is, the slurry is subjected to continuous charging and discharging for 10 times.

[0075] Example 4

[0076] This example uses Figure 1 The electrochemical metal M device uses a hard carbon negative electrode material for a sodium ion battery, and specifically uses the following electrochemical lithium supplement method:

[0077] S1, uniformly mix active material (hard carbon), electrolyte C (1 M NaPF6 organic solution, wherein the solvent is EC / DEC in a volume ratio of 1:1), dispersant (TX-100), and conductive agent (carbon nanotube) in a mass ratio of 10:86:2:2 to form a slurry;

[0078] S2, insert a sodium plate / aluminum current collector into the metal reaction cavity;

[0079] S3, inject electrolyte C into the metal reaction cavity, inject the slurry into the slurry storage tank and the slurry reaction cavity, and open the slurry uniform device with a flow rate of 0.5 L / min;

[0080] S4, connect the power supply to supplement lithium to the active material. The specific process is to charge and discharge the slurry for 10 times, and the cutoff voltage range is 0-3 V, and the current density is 0.01 mA / cm 2 After the lithium supplement is completed, the active slurry is obtained. The active slurry is washed with an EC solvent and dried to obtain a pre-lithiated active material;

[0081] A slurry was prepared using pre-sodiated active material, conductive agent (acetylene black), and binder (PVDF) in a mass ratio of 9:0.5:0.5 in NMP solvent, was coated on a copper current collector by doctor blade, to prepare a hard carbon negative electrode sheet, and was assembled into a full cell with a sodium vanadium phosphate positive electrode sheet, and the electrolyte was a 1 M NaPF6 solution, wherein the solvent was DME, the current density was 20 mA / g, and the voltage range was 1.0-3.8 V.

[0082] Example 5

[0083] Compared with Example 1, the only difference was that no dispersant was added to the slurry, and other operations and parameters were the same as those of Example 1.

[0084] Example 6

[0085] Compared with Example 1, the only difference was that no conductive agent was added to the slurry, and other operations and parameters were the same as those of Example 1.

[0086] Comparative Example 1

[0087] Compared with Example 1, the only difference was that a hard carbon that had not been subjected to a pre-lithiation process was used as the active material to prepare the negative electrode sheet, and the same full cell was assembled.

[0088] It was found that the first-cycle coulombic efficiency was 57.02%, and the first-cycle discharge capacity was 95.52 mAh / g.

[0089] Comparative Example 2

[0090] Compared with Example 1, the only difference was that the slurry stirring current collector was replaced by a non-conductive stirring device with stirring function and a copper foil current collector, and during the electrolysis process, the stirring device was turned on, and the current collectors in the metal reaction chamber and the slurry reaction chamber were conductively connected, and other operations and parameters were the same as those of Example 1.

[0091] Other operations and parameters were the same as those of Example 1.

[0092] Comparative Example 3

[0093] Compared with Comparative Example 2, the only difference was that no stirring device was added to the slurry reaction chamber, and other operations and parameters were the same as those of Comparative Example 2.

[0094] Comparative Example 4

[0095] The conventional scheme of first forming a pole piece and then supplementing lithium to the pole piece is adopted, and the steps are as follows: using hard carbon (same as in Example 1), conductive agent (acetylene black), and binder (PVDF) in a mass ratio of 9:0.5:0.5 to prepare a slurry in an NMP solvent, and then coating the slurry on a copper current collector to prepare a hard carbon negative pole piece. The hard carbon negative pole piece is assembled with a lithium foil to form a half battery, and the specific process is as follows: the pole piece is subjected to 1 cycle of charge and discharge, the cutoff voltage range is 0-3V, the current density is 1 mA / cm 2 , and the lithium supplementing is completed to obtain a lithium-supplemented pole piece. The lithium-supplemented pole piece is assembled with a LiCoO2 positive pole piece to form a full battery, and the electrolyte is electrolyte B.

[0096] The results of the repeated experiments of each example are shown in Table 1.

[0097]

[0098] In Table 1, compared with Example 1, Example 2 further adds an additive to the slurry, which can further synergize and strengthen the lithium supplementing effect and the stability of the lithium supplementing process in cooperation with the lithium supplementing device. In addition, as can be seen from Example 3 and Example 1, the lithium supplementing device and the multi-stage lithium supplementing process can further improve the lithium supplementing effect and the stability of the lithium supplementing process.

[0099] As can be seen from Example 4, the sodium supplementing process can also be realized by using the process of the application.

[0100] As can be seen from Example 1, Example 5, and Example 6, further adding a dispersing agent and / or a conductive agent to the slurry in cooperation with the lithium supplementing device and process of the application can further strengthen the lithium supplementing performance and process stability of the negative pole powder.

[0101] The results of the repeated experiments of each comparative example are shown in Table 2.

[0102]

[0103] In Table 2, compared with Example 1, Comparative Example 2, and Comparative Example 3, the current collector with the conductive-stirring function is used in the lithium supplementing process, which can unexpectedly further strengthen the lithium supplementing effect and the stability of the lithium supplementing process.

[0104] In addition, compared with Example 1 and Comparative Example 4 (conventional pole piece lithium supplementing), the lithium supplementing device and process of the application can further strengthen the lithium supplementing performance and process stability.

[0105] In summary, the lithium supplementing device and method of the application can realize the particle lithium supplementing effect and improve the lithium supplementing performance and the stability of the lithium supplementing process.

Claims

1. An apparatus for producing a negative electrode active material powder for supplementing a metal M, characterized by, a container, a diaphragm, an M tab current collector, a slurry stirring current collector, a slurry tank, a circulating pump, a metal M donor material; wherein the metal M is at least one of Li, Na, and K; the diaphragm is arranged in the container and divides the container into a metal reaction cavity for injecting electrolyte and a slurry reaction cavity for injecting slurry containing negative electrode active material to be treated and electrolyte; the M tab current collector and the metal M donor material are arranged in the metal reaction cavity; the slurry stirring current collector is a current collector with stirring function, which is arranged in the slurry reaction cavity; the M tab current collector and the slurry stirring current collector are electrically connected with an external power source in the process of supplementing metal M; the slurry reaction cavity is further provided with a slurry inlet and a slurry outlet on the cavity wall, wherein the slurry inlet and a circulating outlet of the slurry tank are connected by pipeline A, and the slurry outlet and a circulating inlet of the slurry tank are connected by pipeline B, wherein the pipeline A and / or the pipeline B are provided with a circulating pump.

2. The apparatus for producing a negative electrode active material powder supplementing metal M according to claim 1, characterized by, the M tab current collector is a conductive metal or a material with a conductive coating; the metal M donor material is a material capable of providing metal M; the metal M donor material is compounded on the M tab current collector.

3. The apparatus for producing a negative-electrode active material powder supplementing metal M according to claim 1, characterized in that, the diaphragm includes at least one of a polyolefin diaphragm, a ceramic coated diaphragm, a non-woven fabric diaphragm, and a solid-state electrolyte; the slurry stirring current collector is a mechanism with electric conductivity and stirring function, which includes a stirring shaft and a stirring paddle arranged on the stirring shaft; the stirring paddle is a paddle blade of paddle type, turbine type, frame type, or anchor type; or a helical surface paddle of propeller type, screw type, or ribbon type.

4. A method for producing a negative electrode active material powder supplementing a metal M, characterized by, The preparation device of any one of claims 1-3 is used for preparation, and in the preparation process, electrolyte is pre-injected into the metal reaction cavity, slurry containing negative electrode active material powder to be treated and electrolyte is injected into the slurry reaction cavity, the circulating pump is started, the slurry stirring current collector is used for stirring, the M tab current collector and the slurry stirring current collector are electrically connected with an external power source, charging and discharging is performed, metal M is supplemented, then the negative electrode active material powder and the electrolyte are separated, and negative electrode active material powder after supplementing metal M is obtained.

5. The method for producing a negative electrode active material powder of a metal M supplementing material according to claim 4, characterized by, the electrolyte is a mixed solution of conductive salt containing metal M and solvent, wherein the solvent includes at least one of chain acid ester, cyclic acid ester, chain ether, and cyclic ether, and the concentration of metal M is 0.1-10 M; the negative electrode active material is at least one of carbon negative electrode active material, alloy negative electrode active material, metal / carbon negative electrode composite active material, and oxide negative electrode active material.

6. The method for producing a negative electrode active material powder of a metal M supplementing material according to claim 5, characterized by, the slurry contains conductive agent and dispersant; the content of the dispersant in the slurry is below 5wt.%; and the content of the conductive agent in the slurry is below 5wt.%; the slurry selectively contains additives, and the additives include at least one of boron-based additive, nitrogen-based additive, fluorine-based additive, silicon-based additive, and phosphorus-based additive; the amount of the additives is below 10wt.% of the electrolyte part in the slurry.

7. The method for producing a negative electrode active material powder of a metal M supplementing metal according to any one of claims 4 to 6, characterized by, the process of supplementing metal M includes single-time supplementing of metal M or multiple-time supplementing of metal M. The multiple metal M supplementing process is a single metal M supplementing process repeated N times, wherein N is an integer from 2 to 20.

8. The metal M supplemented negative electrode active material powder prepared by the method of any one of claims 4 to 7.

9. Use of the negative electrode active material powder of claim 8, wherein the metal M is supplemented by, The negative electrode active material is compounded with a conductive agent and a binder to prepare a negative electrode sheet.

10. The use of the negative-electrode active material powder of metal M supplementing metal M according to claim 9, characterized by, The negative electrode sheet is assembled with a positive electrode sheet to form a battery.

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