Metal lithium powder and lithium alloy powder material preparation device and method

Abstract

The application relates to a metal lithium powder and lithium alloy powder material preparation device and method, which comprises a smelting cavity, a filtering cavity and a cooling cavity, the upper port of the filtering cavity is communicated with the smelting cavity, the lower port is communicated with the cooling cavity through a guide hole, the outer end face of the smelting cavity is provided with a heating cover, the upper port of the filtering cavity is provided with a first filter screen, the lower end opening is provided with a second filter screen, and a ventilation pipe is communicated on the side wall of the filtering cavity; a circulating pump, inert cold quenching liquid and a partition plate are arranged in the cooling cavity, the circulating pump and the inert cold quenching liquid are arranged below the partition plate, and a plurality of sieve plates are arranged on the side face of the partition plate. The molten alloy liquid is extruded into the filter core of the filter screen through the pressure difference between the upper and lower parts, the high-speed gas atomizes the molten liquid through the filter core, and the molten liquid is further impacted, dispersed and cooled along the airflow in the zigzag wall, falls into the inert cold extraction liquid, and is further cooled through the cooling circulating pipe and the gradient sieve plate to obtain powder particles with more uniform particle size.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of new material preparation, and in particular to a metal lithium powder and a lithium alloy powder material preparation device and method. BACKGROUND

[0002] After more than 30 years of development, lithium ion batteries have approached the upper limit of their theoretical energy density. In response to the increasing diversification of energy needs, people are working hard to develop "next-generation" secondary batteries based on lithium ion batteries to meet the requirements of human society for secondary batteries in terms of energy density, rate performance, cycle life, safety and cost. Lithium secondary batteries with metal lithium as the negative electrode have returned to the field of view due to their outstanding energy density.

[0003] However, the direct use of metal lithium as the negative electrode of a lithium ion battery will cause many problems, such as poor cycle stability, easy formation of lithium dendrites, volume expansion, and interface side reactions. Therefore, the commonly used commercial negative electrode material on the market is still mainly carbon-silicon material. For conventional negative electrode materials, an SEI film will be generated at the negative electrode during the first charge and discharge process, causing the loss of active lithium in the positive electrode material, reducing the battery capacity, and causing the reduction of the initial efficiency, so pre-lithiation of the negative electrode is needed to alleviate the series of disadvantages caused by the reduction of the initial efficiency.

[0004] Patent No. CN215279880U, application date May 27, 2021, discloses a metal lithium powder production device. The metal lithium powder production device comprises: a pressure-resistant container, the pressure-resistant container comprises a container wall and an internal space defined by the container wall, the container wall is provided with a feeding port and a discharging port, the discharging port is provided with a discharging valve and a pressurizing port; and a baffle located outside the pressure-resistant container and arranged opposite to the discharging port.

[0005] The above-mentioned patent can efficiently prepare metal lithium powder with small particle size and high purity through the metal lithium powder production device. However, the controllability of the operation is not high, and the product quality is unstable.

[0006] Patent No. CN105826545B, application date May 23, 2016, discloses a preparation method of lithium powder or lithium alloy powder, comprising the following steps: 1) adding lithium or lithium alloy into a container containing inert organic solvent; the inert organic solvent is an organic solvent that does not react with lithium or lithium alloy; 2) ultrasonic treatment, to obtain lithium powder or lithium alloy powder stored in the organic solvent.

[0007] The above-mentioned patent can prepare the product at a temperature lower than the melting point of lithium through the preparation method, the operation is simple, the requirement for equipment is low, and micron-level lithium powder or lithium alloy powder can be obtained. However, the product morphology obtained is not uniform, and it is difficult to form a uniform film in actual use. SUMMARY

[0008] The technical problem to be solved by the present application is to provide a device for preparing ultra-thin alkali metal strip, which promotes the extrusion of molten alloy liquid into the filter core of the filter screen through the pressure difference between the upper and lower pressures, atomizes the molten liquid through the filter core by high-speed gas, and further collides, disperses and cools in the cooled zigzag wall along with the airflow, and falls into the inert cold extraction liquid, and further obtains powder particles with more uniform particle size through the cooling circulation pipe and the gradient sieve.

[0009] The technical solution adopted by the present application to solve the technical problem is:

[0010] A metal lithium powder and lithium alloy powder material preparation device, comprising a melting cavity, a filtering cavity and a cooling cavity, the upper port of the filtering cavity is communicated with the melting cavity, the lower port is communicated with the cooling cavity through a guide hole, the outer end face of the melting cavity is provided with a heating cover, the upper port of the filtering cavity is provided with a first filter screen, and the lower end opening is provided with a second filter screen, the side wall of the filtering cavity is communicated with an air pipe, the second filter screen is arranged between the guide hole and the air pipe, and the guide hole is in a curved shape.

[0011] The cooling cavity is provided with a circulating pump, inert cold quenching liquid and a partition plate, the circulating pump and the inert cold quenching liquid are arranged below the partition plate, a plurality of sieve plates are arranged on the side surface of the partition plate, and the side wall of the cooling cavity is provided with a cooling circulation pipe and a gas discharge pipe.

[0012] The side wall of the melting cavity is connected with an air inlet pipe, and the air inlet pipe is provided with a gas pressure reducing valve.

[0013] The melting cavity and the cooling cavity are connected with a guide pipe, and the guide pipe is provided with a differential pressure gauge.

[0014] The first filter screen and the second filter screen are made of 316L stainless steel sintering.

[0015] A preparation method of a metal lithium powder and lithium alloy powder material preparation device, characterized in that the method comprises the following steps:

[0016] S1, placing the weighed metal lithium and other doped elements in the melting cavity, placing the inert cold extraction liquid in the cooling cavity as needed, and connecting the air inlet pipe, the air pipe and the gas discharge pipe;

[0017] S2, purging the device in the drying room;

[0018] S3, heating the heating cover to heat the melting cavity to 300-600 DEG C, and keeping warm for 30 min;

[0019] S4, after the temperature of the melting cavity reaches 300-600 DEG C, heating the gas in the air pipe, and inputting the cooling liquid in the cooling circulation pipe 34 to reduce the temperature in the cooling cavity to 10 DEG C;

[0020] S5, when the gas in the ventilation pipe is heated to 300 DEG C, slowly open the ventilation pipe to input gas into the guide hole;

[0021] S6, slowly open the gas pressure reducing valve, input gas into the smelting cavity, increase the pressure difference between the smelting cavity and the cooling cavity to a specified pressure (the greater the pressure, the faster the flow rate, and the larger the particle size);

[0022] S7, the molten metal lithium is formed at a temperature of 300-600 DEG C, under the pressure of the smelting cavity, the molten liquid passes through the first filter screen and the second filter screen in turn, and the molten liquid is atomized under the action of the gas flow in the ventilation pipe, and then impacts on the guide hole wall, since the guide hole is curved, the atomized molten liquid is dispersed by impact and enters the cooling cavity for cooling;

[0023] S8, the circulation pump drives the inert cold quenching liquid to flow on the sieve plate, at the same time, the atomized molten liquid fills into the cooling cavity, and the flowing inert cold quenching liquid carries particles of different particle sizes to pass through the sieve plate, so that the particles of different particle sizes in the range are screened out;

[0024] S9, the inside of the cooling cavity is observed, and after the powder particles continuously fall into the inert cold quenching liquid, the pressure difference between the smelting cavity and the cooling cavity is stopped from increasing until the dispersion and pouring process is completed;

[0025] S10, sequentially close the smelting cavity heating, gas pressure reducing valve, cooling circulation pipe, cooling circulation pipe and ventilation pipe, and the preparation is completed.

[0026] The inert cold quenching liquid is an inert organic solvent, the inert organic solvent is a hydrocarbon solvent, an ester solvent, an amide solvent or an ether solvent, the hydrocarbon solvent is cyclohexane, n-hexane or paraffin, the ester solvent is dimethyl carbonate or ethyl acetate, the amide solvent is N-methyl pyrrolidone, and the ether solvent is 1-dioxolane or 3-dioxolane.

[0027] The gas in the ventilation pipe is argon or a mixed gas of argon and carbon dioxide, the flow rate of the gas ranges from 0.5 MPa to 1.5 MPa, and the pressure difference between the smelting cavity and the cooling cavity ranges from 0 to 2 KPa.

[0028] The present application has the following beneficial effects:

[0029] 1. The lithium powder or lithium alloy powder can be directly obtained by cooling and dispersion, or the surface of the lithium powder or lithium alloy powder can be directly passivated by adding carbon dioxide to the protective gas, so that the safety is high, the inert cold quenching liquid in the cooling cavity is circulated, the sieve plate is used to obtain products with different particle sizes, the particle size is controlled, and the film is uniformly formed.

[0030] 2. The inert gas (argon or a mixture of argon and carbon dioxide) is injected into the cooling cavity by using Bernoulli principle, and the pressure difference between the smelting cavity and the cooling cavity is controlled in a certain range by controlling the gas pressure reducing valve, so that the molten alloy liquid is extruded into the filter core of the filter screen, the high-speed gas passes through the filter core to atomize the molten liquid, and the molten liquid is further impacted, dispersed and cooled in the cooling zigzag wall along with the airflow, and then falls into the inert cold extraction liquid, and then the powder particles with more uniform particle size are obtained through the cooling circulation pipe and the gradient screen. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 It is a structural schematic diagram of the present application.

[0032] Figure 2 It is a volume density curve diagram.

[0033] Figure 3 It is a volume cumulative curve diagram.

[0034] Figure 4 It is a screen volume density curve diagram.

[0035] Figure 5 It is a screen volume cumulative curve diagram.

[0036] Figure 6 It is an alloy volume density curve diagram.

[0037] Figure 7 It is an alloy volume cumulative curve diagram.

[0038] As shown in the figure: 1-smelting cavity; 2-filtering cavity; 3-cooling cavity; 4-guide hole; 10-heating cover; 11-gas inlet pipe; 12-gas pressure reducing valve; 13-conduit; 14-differential pressure gauge; 20-first filter screen; 21-second filter screen; 22-ventilation pipe; 30-circulation pump; 31-inert cold quenching liquid; 32-separation plate; 33-screening plate; 34-cooling circulation pipe; 35-bleeding pipe. DETAILED DESCRIPTION

[0039] The present application will be further described below in combination with the drawings and examples.

[0040] Example 1

[0041] As Figures 1 to 7As shown, a kind of metal lithium powder and lithium alloy powder material preparation device, including smelting cavity 1, filter cavity 2 and cooling cavity 3, the upper port of the filter cavity 2 is communicated with smelting cavity 1, the lower port is communicated with cooling cavity 3 by guide hole 4, the outer end face of the smelting cavity 1 is provided with heating cover 10, the upper port of the filter cavity 2 is provided with first filter screen 20, and the lower end opening is provided with second filter screen 21, the side wall of the filter cavity 2 is communicated with air pipe 22, the second filter screen 21 is arranged between guide hole 4 and air pipe 22, and the guide hole 4 is curved;

[0042] The cooling cavity 3 is provided with circulating pump 30, inert cold quenching liquid 31 and partition plate 32, the circulating pump 30 and inert cold quenching liquid 31 are arranged below the partition plate 32, a plurality of sieve plates 33 are arranged on the side surface of the partition plate 32, and cooling circulating pipe 34 and air release pipe 35 are arranged on the side wall of the cooling cavity 3.

[0043] The side wall of the smelting cavity 1 is connected with air inlet pipe 11, and the air inlet pipe 11 is provided with gas pressure reducing valve 12.

[0044] The smelting cavity 1 and the cooling cavity 3 are connected with conduit 13, and the conduit 13 is provided with differential pressure gauge 14.

[0045] The first filter screen 20 and the second filter screen 21 are made of 316L stainless steel sintering.

[0046] A kind of metal lithium powder and lithium alloy powder material preparation device preparation method, characterized in that, including the following steps:

[0047] S1, after weighing, metal lithium and other doped elements are placed in smelting cavity 1, inert cold extraction liquid 31 is placed in cooling cavity 3 as required, and air inlet pipe 11, air pipe 22 and air release pipe 35 are connected;

[0048] S2, gas washing is carried out on the device in the drying room;

[0049] S3, heating cover 10 is heated, so that smelting cavity 1 is heated to 300-600 DEG C, and kept for 30 min;

[0050] S4, after the temperature of smelting cavity 1 reaches 300-600 DEG C, the gas in air pipe 22 is heated, and cooling liquid is input in cooling circulating pipe 34, so that the temperature in cooling cavity 3 is reduced to 10 DEG C;

[0051] S5, when the gas in air pipe 22 is heated to 300 DEG C, slowly open air pipe 22 to input gas into guide hole 4;

[0052] S6, slowly open the gas pressure reducing valve 12, input gas into the smelting cavity 1, increase the pressure difference between the smelting cavity 1 and the cooling cavity 3 to a specified pressure (the greater the pressure, the faster the flow rate, and the larger the particle size);

[0053] S7, the molten metal lithium at a temperature of 300-600 DEG C, under the pressure of the smelting cavity 1, the molten liquid passes through the first filter screen 20 and the second filter screen 21 in turn, and under the action of the airflow in the vent pipe 22, the molten liquid is atomized and impacts on the wall of the guide hole 4, since the guide hole 4 is curved, the atomized molten liquid is dispersed by the impact and enters the cooling cavity 3 for cooling;

[0054] S8, the circulating pump 30 drives the inert cold quenching liquid 31 to flow on the sieve plate 33, and at the same time, the atomized molten liquid fills into the cooling cavity 3, and the flowing inert cold quenching liquid 31 carries particles of different particle sizes through the sieve plate 33, so that the particles of the range are screened out;

[0055] S9, observe the internal condition of the cooling cavity, and after the powder particles continuously fall into the inert cold quenching liquid 31, stop increasing the pressure difference between the smelting cavity 1 and the cooling cavity 3 until the dispersion and pouring process is completed;

[0056] S10, sequentially close the heating of the smelting cavity 1, the gas pressure reducing valve 12, the cooling circulating pipe 34, the cooling circulating pipe 34 and the vent pipe 22, and complete the preparation.

[0057] The inert cold quenching liquid is an inert organic solvent, the inert organic solvent is a hydrocarbon solvent, an ester solvent, an amide solvent or an ether solvent, the hydrocarbon solvent is cyclohexane, n-hexane or paraffin, the ester solvent is dimethyl carbonate or ethyl acetate, the amide solvent is N-methyl pyrrolidone, and the ether solvent is 1-dioxolane or 3-dioxolane.

[0058] The gas in the vent pipe 22 is argon or a mixed gas of argon and carbon dioxide, the flow range of the gas is 0.5MPa-1.5MPa, and the pressure difference between the smelting cavity 1 and the cooling cavity 3 is 0-2KPa.

[0059] The lithium powder or lithium alloy powder can be directly obtained by cooling and dispersion, or the composition of the protective gas is adjusted, carbon dioxide is appropriately added to directly passivate the surface, the safety is high, the inert cold quenching liquid in the cooling cavity is circulated, and products with different particle sizes are obtained by cooperating with the sieve plate, the particle size is controlled, and the film is uniformly formed.

[0060] The inert gas (argon or a trace amount of argon and carbon dioxide mixed gas) is injected into the cooling cavity 3 by using the Bernoulli principle, and the pressure difference between the smelting cavity 1 and the cooling cavity 3 is controlled within a certain range by controlling the gas pressure reducing valve 12. The pressure difference promotes the molten alloy liquid to extrude into the filter core of the filter screen. The high-speed gas passes through the filter core to atomize the molten liquid, and the atomized liquid is further impacted, dispersed and cooled in the cooling zigzag wall, and then falls into the inert cooling liquid. The liquid is further cooled and circulated through the gradient screen to obtain powder particles with more uniform particle size.

[0061] The product particle size can be improved by using the curved guide hole 4, properly applying pressure and increasing the gas flow rate.

[0062] The overall particle size can be made more uniform by increasing the curved guide hole 4.

[0063] Increasing the pressure of the upper and lower cavities can reduce the product particle size and increase the product output speed.

[0064] Increasing the gas flow rate can increase the crushing effect in the curved guide hole 4, making the particle size more refined and uniform.

[0065] The smaller the surface tension of the lithium alloy relative to the surface of the metal lithium, the easier it is to pass through the two filter screens, and the smaller the pressure of the upper and lower cavities.

[0066] Generally, the larger the amount of alloy doping, the smaller the surface tension, and the easier it is to pass through the filter screen by its own gravity.

[0067] Using metal lithium as raw material, smelting temperature 400℃, using no zigzag wall, gas pressure 0.5MPa, cooling circulation using commercial hydrocarbon cooling oil, cooling cavity is lowered to 10℃, no pressure is applied to the smelting cavity, pressure difference control is 0KPa, product particle size is measured by using Mastersizer 3000 laser particle size analyzer.

[0068] Example 2

[0069] Using metal lithium as raw material, smelting temperature 400℃, using zigzag wall, gas pressure 0.5MPa, cooling circulation using commercial hydrocarbon cooling oil, cooling cavity is lowered to 10℃, no pressure is applied to the smelting cavity, pressure difference control is 0KPa, product particle size is measured by using Mastersizer 3000 laser particle size analyzer.

[0070] Example 3

[0071] Using metal lithium as raw material, smelting temperature 400℃, using no zigzag wall, gas pressure 0.5MPa, cooling circulation using commercial hydrocarbon cooling oil, cooling cavity is lowered to 10℃, pressure is applied to the smelting cavity, pressure difference control is 2KPa, product particle size is measured by using Mastersizer 3000 laser particle size analyzer.

[0072] Example 4

[0073] Using metal lithium as raw material, smelting temperature 400℃, using zigzag wall, gas pressure 0.5MPa, cooling cycle using commercial hydrocarbon cooling oil, cooling cavity is lowered to 10℃, pressure is applied to the smelting cavity, pressure difference control is 2KPa, product particle size is measured by Mastersizer 3000.

[0074] Example 5

[0075] Using metal lithium as raw material, smelting temperature 400℃, using zigzag wall, gas pressure 1MPa, cooling cycle using commercial hydrocarbon cooling oil, cooling cavity is lowered to 10℃, pressure is applied to the smelting cavity, pressure difference control is 2KPa. Product particle size is measured by Mastersizer 3000.

[0076] Example 6

[0077] Using metal lithium as raw material, smelting temperature 400℃, using zigzag wall, gas pressure 1MPa, cooling cycle using commercial hydrocarbon cooling oil, cooling cavity is lowered to 10℃, pressure is applied to the smelting cavity, pressure difference control is 2KPa, using sieve design mesh number is 200, 300, 500, 800, 1000 respectively, product particle size is measured by Mastersizer 3000.

[0078] Example 7

[0079] Using metal lithium-0.5wt% aluminum alloy as raw material, smelting temperature 400℃, using zigzag wall, gas pressure 1MPa, cooling cycle using commercial hydrocarbon cooling oil, cooling cavity is lowered to 10℃, pressure is applied to the smelting cavity, pressure difference control is 1KPa, product particle size is measured by Mastersizer 3000.

[0080] Example 8

[0081] Using metal lithium-2wt% zinc as raw material, smelting temperature 400℃, using zigzag wall, gas pressure 1MPa, cooling cycle using commercial hydrocarbon cooling oil, cooling cavity is lowered to 10℃, pressure is applied to the smelting cavity, pressure difference control is 500Pa, product particle size is measured by Mastersizer 3000.

[0082] Particle size (pm) D90 D50 D10 Geometric mean Control 313.13 227.70 155.25 232.58 Example 2 230.91 148.03 82.97 115.49 Example 3 160.01 111.09 69.94 159.94 Example 4 89.85 52.21 30.89 63.25 Example 5 46.07 25.35 10.07 39.03 Example 6 - 200 mesh 61.83 52.72 48.28 52.59 Example 6 - 300 mesh 45.55 36.98 29.42 37.93 Example 6 - 500 mesh 27.90 21.11 15.10 21.99 Example 6 - 800 mesh 13.99 11.40 8.87 11.82 Example 6 - 1000 mesh 8.93 7.10 5.11 7.65 Example 7 22.90 13.62 6.77 14.69 Example 8 17.11 10.57 5.47 11.42

[0083] The metal lithium is battery-grade metal lithium; the lithium alloy is a lithium-based phase or a lithium solid solution phase as a main phase, and the second phase element or solid solution element includes but is not limited to one or more of boron, carbon, sodium, magnesium, aluminum, silicon, sulfur, copper, zinc, gallium, germanium, silver, indium, tin, lead; the multi-element system molten liquid corresponding to the melting point should not be higher than the highest temperature of the filter screen that can withstand corrosion.

[0084] The screen mesh number of the screen plate 33 is 100-10000, and several grades are selected, so that the visible powder particles can be further accurately screened.

[0085] The gas is heated to 300 DEG C, which can effectively prevent the second-order filter from being blocked due to cooling; the gas flow range is 0.5-1.5 MPa, generally 0.5 MPa for pure lithium due to large surface tension, 1.0 MPa for total content of doping elements ≤1 wt.%, and 1.5 MPa for total content of doping elements >1 wt.%;

[0086] The pressure difference control range is 0-2 KPa, the pressure difference is 2 KPa when the battery-grade metal lithium is used; 1 KPa is used when the total content of doping elements ≤1 wt.%, and 500 Pa is used when the total content of doping elements >1 wt.%.

[0087] The above is only the preferred embodiment of the present application and is not used to limit the present application, and the present application can have various changes and variations for those skilled in the art, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection of the present application.

Claims

1. A device for preparing metal lithium powder and lithium alloy powder material, comprising a smelting cavity (1), a filtering cavity (2) and a cooling cavity (3), characterized in that: The upper port of the filtering cavity (2) is communicated with the smelting cavity (1), and the lower port is communicated with the cooling cavity (3) through the guide hole (4), the outer end face of the smelting cavity (1) is provided with a heating cover (10), the upper port of the filtering cavity (2) is provided with a first filter screen (20), and the lower end opening is provided with a second filter screen (21), the sidewall of the filtering cavity (2) is communicated with a breather pipe (22), the second filter screen (21) is arranged between the guide hole (4) and the breather pipe (22), and the guide hole (4) is in a curved shape; The cooling cavity (3) is provided with a circulating pump (30), inert cold quenching liquid (31) and a partition plate (32), the circulating pump (30) and the inert cold quenching liquid (31) are arranged below the partition plate (32), a plurality of sieve plates (33) are arranged on the side face of the partition plate (32), and the sidewall of the cooling cavity (3) is provided with a cooling circulating pipe (34) and a gas discharge pipe (35); The sidewall of the smelting cavity (1) is connected with an air inlet pipe (11), the air inlet pipe (11) is provided with a gas pressure reducing valve (12), and the gas pressure reducing valve (12) is used for controlling the pressure difference between the smelting cavity (1) and the cooling cavity (3); The metal lithium forms a molten liquid at a temperature of 300-600 DEG C, under the action of the downward pressure of the smelting cavity (1), the molten liquid passes through the first filter screen (20) and the second filter screen (21) in sequence, the molten liquid is atomized under the action of the airflow in the breather pipe (22), and then collides on the wall of the guide hole (4). Since the guide hole (4) is in a curved shape, the atomized molten liquid is dispersed by impact and enters the cooling cavity (3) to be cooled.

2. The apparatus for producing metal lithium powder and lithium alloy powder material according to claim 1, wherein The smelting cavity (1) and the cooling cavity (3) are connected with a conduit (13), and the conduit (13) is provided with a differential pressure gauge (14).

3. The apparatus for producing metal lithium powder and lithium alloy powder material according to claim 1, wherein The first filter screen (20) and the second filter screen (21) are made of 316L stainless steel sintering.

4. A method of producing a metal lithium powder and a lithium alloy powder material production apparatus according to any one of claims 1 to 3, characterized in that, The method comprises the following steps: S1, the metal lithium and the doping element are placed in the smelting cavity (1), the inert cold extraction liquid (31) is placed in the cooling cavity (3), and the air inlet pipe (11), the breather pipe (22) and the gas discharge pipe (35) are communicated; S2, the device is washed in a drying room; S3, the heating cover (10) is heated, the smelting cavity (1) is heated to 300-600 DEG C, and the temperature is kept for 30 min; S4, after the temperature of the smelting cavity (1) reaches 300-600 DEG C, the gas in the breather pipe (22) is heated, the cooling liquid is input into the cooling circulating pipe (34), and the temperature in the cooling cavity (3) is reduced to 10 DEG C; S5, when the gas in the breather pipe (22) is heated to 300 DEG C, the breather pipe (22) is opened to input gas into the guide hole (4); S6, the gas pressure reducing valve (12) is opened, the gas is input into the smelting cavity (1), and the pressure difference between the smelting cavity (1) and the cooling cavity (3) is increased. S7, the molten liquid of the metal lithium at 300-600℃ forms, under the pressure of the downward of the smelting cavity (1), the molten liquid passes through the first filter screen (20) and the second filter screen (21) in turn, under the action of the airflow in the air pipe (22), the molten liquid is atomized, and then impacts on the wall of the guide hole (4), since the guide hole (4) is curved, the atomized molten liquid is dispersed by the impact and enters the cooling cavity (3) for cooling; S8, the circulating pump (30) drives the inert cold quenching liquid (31) to flow on the sieve plate (33), at the same time, the atomized molten liquid fills into the cooling cavity (3), and the flowing inert cold quenching liquid (31) carries the particles of different particle sizes to pass through the sieve plate (33), so that the particles of the range are sieved out; S9, the inside of the cooling cavity is observed, after the powder particles continuously fall into the inert cold quenching liquid (31), the pressure difference between the smelting cavity (1) and the cooling cavity (3) is stopped to be increased, until the dispersion and pouring process is completed; S10, the heating of the smelting cavity (1), the gas pressure reducing valve (12), the cooling circulating pipe (34), the cooling circulating pipe (34) and the air pipe (22) are sequentially closed, and the preparation is completed.

5. The preparation method of the lithium metal powder and lithium alloy powder preparation apparatus as described in claim 4, characterized in that; The inert cold quenching liquid is an inert organic solvent, the inert organic solvent is a hydrocarbon solvent, an ester solvent, an amide solvent or an ether solvent, the hydrocarbon solvent is cyclohexane, n-hexane or paraffin, the ester solvent is dimethyl carbonate or ethyl acetate, the amide solvent is N-methyl pyrrolidone, and the ether solvent is 1-dioxolane or 3-dioxolane.

6. The preparation method of the lithium metal powder and lithium alloy powder preparation apparatus as described in claim 4, characterized in that; The gas in the air pipe (22) is argon or a mixed gas of argon and carbon dioxide, the flow range of the gas is 0.5MPa-1.5MPa, and the pressure difference between the smelting cavity (1) and the cooling cavity (3) is 0-2KPa.

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