CN116759537B - Lithium battery negative electrode and preparation method and application thereof - Google Patents

Abstract

The application provides a lithium battery cathode, a preparation method and application thereof. The lithium battery cathode of the application consists of an elongated lithium or lithium alloy strip and a current collecting and collecting part combined on at least one side edge of the elongated lithium or lithium alloy strip, wherein the at least one side edge of the lithium or lithium alloy strip is provided with a pretreatment area, the current collecting and collecting part comprises an area with a stress buffer layer, and the pretreatment area and the area with the stress buffer layer are mutually covered.

Description

Lithium battery negative electrode and preparation method and application thereof

Technical field

The present invention relates to the technical field of electrochemical energy storage, and in particular to lithium negative electrodes for metal lithium batteries and their preparation methods and applications.

Background technique

As society has higher and higher requirements for the energy density of lithium-ion batteries. First, a negative electrode material with a higher specific capacity must be used. Metal lithium is considered to be the optimal negative electrode material due to its capacity of 3860 mAh/g and low potential of -3.04V. At present, many battery manufacturers use pure metal lithium strips as negative electrodes for direct use. The thickness of metal lithium is 50-80um. Metal lithium itself is very soft. When the thickness is less than 100um, it is very difficult to mechanize the roll production. The metal lithium strip is rolled into a roll to lead out the tabs. More difficult. The CN209641727 patent discloses that metal lithium is first die-cut into negative electrode pieces one by one, and then the copper tabs are attached to the single piece of pole pieces using a force of 0.3 to 0.5MPa to draw out the tabs. This process is time-consuming to draw out the tabs. It is laborious and cannot be applied in large-scale production. In addition, many scientific research institutes use lithium-copper laminated tape as the negative electrode. Since the density of copper is 8.96g/cm ³ , which is 16 times the density of metallic lithium, 6um copper foil is equivalent to 100um thick lithium, and the entire surface is laminated with copper foil. The specific energy of metallic lithium products is limited, so existing negative electrodes still cannot meet the requirements of high specific energy batteries.

Contents of the invention

The present invention proposes a new type of metallic lithium negative electrode. In this lithium negative electrode, the bonding area between the tab and the lithium belt is very narrow, and the proportion is very small, which greatly improves the specific energy of the battery, and the way of extracting the tab is relatively small. It is convenient and can be used in large-scale batch production in rolls.

At present, most lithium-copper lamination processes use the pressure lamination process. The inventor of this application found that when copper foil is laminated only on the edge of the lithium strip as the tab, because the copper and lithium cladding area is very narrow (3-10mm), the force only acts on the very narrow cladding area. When the pressure is small during lamination, the adhesion between lithium and copper is not good, and the lithium is easily peeled off from the copper, and the current collection effect is poor; when the pressure is high during lamination, the lithium material in the lamination area will expand accordingly, but the lithium material in other unlaminated areas will expand accordingly. Lithium materials will not stretch without stress. During the roll production process of metallic lithium anode products, the lithium in the coated area and the lithium in the uncoated area are inconsistent in length (this inconsistency becomes more obvious as the length increases), resulting in The lithium in the uncoated area exhibits tensile deformation.

In response to the above problems, the inventor designed a stress buffer layer. The stress buffer layer is arranged in the area where the tab is to be combined with the lithium belt. It is composed of raised discontinuous metal particles. These raised particles are located between the tab and the lithium belt. When bonded, it can be stretched and deformed under the action of external force (the height of the convex particles becomes smaller), so that the stress generated during lamination can be buffered and released, reducing or avoiding the extension of the lithium material in the lamination area under the action of stress. In addition, the area where the lithium belt is to be combined with the tab can also be pre-treated to form a thinned pre-treatment area with a new metallic lithium surface (the original lithium surface has a passivation layer, which is not conducive to lithium laminated together with copper), which is conducive to better lamination of the stress buffer layer and the lithium tape. At the same time, the convex particles in the stress buffer layer can also fill the thinning area after deformation to obtain a self-contained tape with a smooth surface. The metal lithium negative electrode of the pole.

The technical solution of the present invention is as follows.

One aspect of the present invention provides a lithium battery negative electrode. The lithium battery negative electrode is composed of a long lithium belt or a lithium alloy belt and a lithium battery bonded to at least one edge of the long lithium belt or lithium alloy belt. The current collection part is composed of a pretreatment area on at least one edge of the lithium belt or the lithium alloy belt, the current collection part includes a region with a stress buffer layer, the pretreatment area and the stress buffer layer Areas of layers overlap each other.

According to one embodiment, the current collecting part further includes a portion that is not covered with the pretreatment area and extends beyond the width of the lithium strip or lithium alloy strip, and this portion is die-cut into tabs.

According to one embodiment, the thickness of the metallic lithium strip or the lithium alloy strip is 0.01-0.15mm, and the width is 10-1500mm. Preferably, the thickness of the metallic lithium belt or lithium alloy belt is 0.01-0.10mm, more preferably 0.010-0.05mm; the width of the metallic lithium belt or lithium alloy belt is 20-1500mm, more preferably 50-1500mm, such as 150-1500mm, 200 -1500mm, 250-1500mm, 300-1500mm, 350-1500mm, 400-1500mm, 450-1500mm, or 500-1500mm.

According to one embodiment, the width of the pretreatment area is 2-10mm, and the thickness of the pretreatment area is 0.1-5um thinner than the thickness elsewhere, preferably 1-5um; the pretreatment method includes erasing, rolling, and gluing.

According to one embodiment, the lithium alloy includes binary alloys and/or multi-component alloys, preferably binary alloys and/or ternary alloys.

According to one embodiment, the lithium alloy is composed of metallic lithium and any one of Ag, Au, Sn, Si, Zn, Al, Mg, In, Ga, B, Mn, Sb, Cr, V, Cu, Fe or Ti or At least two elements are combined and the mass proportion of metallic lithium in the lithium alloy can be more than 50%, preferably more than 70%, more preferably more than 80%, or even more than 90%.

According to one embodiment, the current collecting part is made of metal foil, and the metal foil is selected from copper foil, nickel foil, stainless steel foil or composite metal current collector; the thickness of the foil is 3-10um, preferably 3-8um.

According to one embodiment, the width of the current collection part is 12-30 mm; the width of the stress buffer layer is 2-10 mm.

According to one embodiment, the stress buffer layer contains discontinuous protruding metal particles, the metal particles are formed by vapor deposition, and the particle size of the metal particles is 1-7um, preferably 1-5um. The protrusion height of metal particles is 1-5um; the area ratio of metal particles in the stress buffer layer is 1:3 to 9:10.

According to one embodiment, the metal particles include at least one of tin particles, zinc particles, magnesium particles, aluminum particles, silver particles, and lithium particles.

According to one embodiment, the metal particles are of the same type as the alloying elements contained in the lithium alloy strip.

According to one embodiment, the type of metal particles is different from the alloying elements contained in the lithium alloy strip.

According to one embodiment, the pretreatment area and the area with the stress buffer layer of the current collection part are laminated together by means of at least one of diffusion welding, ultrasonic welding, resistance welding, and pressure welding processes; the width of the laminated area ranges from 2-10mm.

According to one embodiment, the area where the stress buffer layer of the current collection part and the lithium strip or lithium alloy strip are coated can be continuous or discontinuous; because atoms are constantly diffusing, the discontinuous area will also diffuse subsequently. to a uniform state. For example, the stress buffer layer of the current collection part can be divided into several discontinuous parts, and each part is separated by a certain distance, for example, 0.1-1 mm. The stress buffer layer may also have a grid shape.

According to one embodiment, the thickness of the stress buffer layer of the current collecting part and the lithium strip or lithium alloy strip covering area is equal to or slightly greater than the thickness of the pure lithium strip or lithium alloy strip. For example: the thickness of the lithium strip is 50um, the thickness of the stress buffer layer at the current collecting part and the lithium strip covering area is 55um; the thickness of the lithium strip is 60um, the thickness of the stress buffer layer at the current collecting part and the lithium strip covering area is 60um; the thickness of the lithium-magnesium (10% magnesium content) alloy strip is 60um, and the thickness of the stress buffer layer and the lithium strip covering area of the current collector is 63um; the thickness of the lithium-silver (1% silver content) alloy strip is 40um, and the thickness of the lithium-magnesium (10% magnesium content) alloy strip is 63um. The thickness of the stress buffer layer and the lithium strip covering area at the flow collection part is 40um.

Another aspect of the present invention provides a method for preparing the above-mentioned lithium battery negative electrode, including:

Step 1: Deposit discontinuous convex metal particles on the metal foil through a vapor deposition process to obtain a current collection part covered with a stress buffer layer in some areas;

Step 2: Pre-process at least one side edge area of the lithium belt or lithium alloy belt by at least one of erasing, rolling, and gluing to form a pre-processed area with a width of 2-10 mm;

Step 3: Use at least one of diffusion welding, ultrasonic welding, resistance welding, and pressure welding to weld the area with the stress buffer layer of the current collecting part obtained in step 1 and the pretreated area of the lithium strip or lithium alloy strip obtained in step 2. Welding together, the metal particles of the stress buffer layer and the lithium in the lithium belt or lithium alloy belt are fused together to form a fusion zone of lithium and metal particles; and

Optional step 4: Die-cut the portion of the current collecting portion that is not covered with the pretreatment area and extends beyond the width of the lithium belt or lithium alloy belt to form a tab.

According to one embodiment, in step one, the conductive foil of the current collection part is first subjected to low-temperature plasma degreasing treatment; the deoiled conductive foil is dried, and after drying, the conductive foil is deposited through vapor deposition process, depositing discontinuous raised metal lithium particles to obtain a stress buffer layer, the width of the stress buffer layer is 2-10mm.

Another aspect of the present invention provides the application of the above-mentioned high specific energy lithium battery negative electrode in lithium ion batteries. The above-mentioned high specific energy metal lithium negative electrode can be used as the negative electrode of metal lithium batteries.

According to one embodiment, the present invention provides a lithium battery, which includes the above-mentioned lithium battery negative electrode, and the positive electrode material is selected from the group consisting of ternary nickel cobalt manganese materials, ternary nickel cobalt aluminum materials, lithium-rich manganese-based positive electrode materials, and lithium cobalt oxide, Lithium iron phosphate, sulfur cathode material.

According to one embodiment, the electrolyte of the lithium battery can be liquid electrolyte or solid electrolyte; the liquid electrolyte can be ester or ether; the solid electrolyte can be oxide solid electrolyte, sulfide solid electrolyte or polymer electrolyte, for example PEO (mixed oxide or sulfide powder) type electrolyte.

For liquid batteries, the separator is made of PP, PE or three-layer laminated separator of PP and PE. The separator can be coated with ceramic coating.

Batteries can be formed into square, soft-pack, or cylindrical batteries.

The invention has at least one of the following advantages:

(1) The high specific energy metal lithium negative electrode of the present invention can be produced in rolls and in batches, which solves the problem of difficulty in extracting tabs from pure lithium belt negative electrode engineering.

(2) The high specific energy lithium metal negative electrode of the present invention comes with its own tabs, which can be directly die-cut out for use without the need for additional tabs.

(3) The high specific energy metal lithium negative electrode of the present invention can be directly used as a negative electrode. Since the current collector has a small area and a small proportion, the negative electrode can be used with a high-capacity positive electrode material to prepare an energy density exceeding 500wh/kg. Battery.

(4) It solves the problem that the lithium and the current collection part are not tightly bonded. The stress buffer layer can be in close contact with the lithium belt or lithium alloy belt, and the current collection effect is good.

Description of the drawings

Figure 1 is a schematic diagram of the planar structure of the lithium battery negative electrode of the present invention;

Figure 2 is a cross-sectional view of the lithium battery negative electrode of the present invention. In the figure, the thickness of the lithium and the current collecting part is greater than the thickness of the lithium strip or lithium alloy strip;

Figure 3 is another cross-sectional view of the lithium battery negative electrode of the present invention. In the figure, the thickness of the lithium and the current collecting part is equal to the thickness of the lithium strip or lithium alloy strip;

Figure 4 is a physical diagram of lithium metal particles in the stress buffer layer in Example 2;

Figure 5 is a physical diagram of the magnesium metal particles in the stress buffer layer in Example 5.

Detailed ways

In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

In addition, the various product structure parameters, various reaction participants and process conditions used in the following examples are relatively typical examples. However, after extensive testing and verification by the inventor of the present case, other than those listed above Different structural parameters, other types of reaction participants and other process conditions are also applicable, and can all achieve the technical effects claimed by the present invention.

Figure 1 is a schematic diagram (top view) of the planar structure of the lithium battery negative electrode of the present invention. The lithium battery negative electrode includes a lithium belt or lithium alloy belt 1 and a current collecting part combined on one edge of the lithium belt or lithium alloy belt. 2. Figures 2 and 3 show cross-sectional views of the lithium battery negative electrode of the present invention, in which the pre-processed area of the lithium belt or lithium alloy belt 1 and the area with the stress buffer layer of the current collecting part 2 are laminated together to form a joint part 3 (fusion zone of lithium and metal particles). In Figure 2, the thickness of the cladding area is greater than the thickness of the lithium strip or lithium alloy strip. In Figure 3, the thickness of the cladding area is equal to the thickness of the lithium strip or lithium alloy strip.

Example 1

The thickness of the roll of copper foil (current collection part) is 5um and the width is 20mm; under the conditions of vacuum degree of 10 ^-3 Pa and temperature of 500°C, the particle size deposited on the surface of one edge area of the copper foil (3mm width area) 2um lithium particles, the area ratio of lithium particles is half, and the stress buffer layer is obtained;

Erase the edge area (3mm wide) on one side of the rolled lithium tape (50um thick, 100mm wide), and the erased thickness is 1um; pass the stress buffer layer area on the copper foil and the lithium tape erased area through pressure Welding together (pressure: 50MPa, temperature: 40°C), a lithium negative electrode with a thickness of 55um in the lithium-copper cladding area was obtained. In the lithium-copper composite tape obtained in this example, the surface of the lithium tape is smooth.

Example 2

The thickness of the rolled copper foil (current collection part) is 3.5um and the width is 15mm; under the conditions of vacuum degree of 10 ^-3 Pa and temperature of 500℃, particles are deposited on the surface of one edge area of the copper foil (5mm width area) Lithium particles with a diameter of 1 μm, and the area ratio of the lithium particles is three-fifths, to obtain a stress buffer layer; Figure 4 shows a physical picture of the lithium metal particles in the stress buffer layer in this embodiment.

Roll the edge area (5mm wide) on one side of the rolled lithium strip (60um thick, 200mm wide), and the thickness of the roller is 4um; pass the stress buffer layer area on the copper foil and the roller removed area of the lithium strip through Weld together using pressure welding (pressure 80MPa, temperature 30°C) to obtain a lithium negative electrode with a thickness of 60um in the lithium-copper cladding area.

Example 3

The roll of copper foil (current collection part) has a thickness of 4um and a width of 20mm; under the conditions of a vacuum of 10 ^-3 Pa and a temperature of 500°C, lithium particles with a particle size of 1um are deposited on the surface of the copper foil (3mm width area). The area ratio of lithium particles is one-half to obtain a stress buffer layer;

Erase the edge area (3mm wide) on one side of the rolled lithium tape (50um thick, 500mm wide), and the erased thickness is 3um; pass the stress buffer layer area on the copper foil and the erased area of the lithium tape through Weld together using pressure welding (pressure 40MPa, temperature 30°C) to obtain a lithium negative electrode with a thickness of 50um in the lithium-copper cladding area.

Example 4

The thickness of the roll of stainless steel foil (current collection part) is 10um and the width is 20mm; under the conditions of vacuum degree of 10 ^-5 Pa and temperature of 1000°C, tin particles with a particle size of 1um are deposited on the surface of the stainless steel foil (5mm width area). The area ratio of tin particles is one-half to obtain a stress buffer layer;

Roll the edge area (5mm wide) on one side of the rolled lithium-tin alloy strip (60um thick, 300mm wide, tin content 5%), and the thickness removed by the roller is 3um; remove the stress buffer layer area on the stainless steel foil and The roller removal areas of the lithium-tin alloy strip are welded together by pressure welding (pressure 80MPa, temperature 40°C) to obtain a high specific energy metallic lithium anode product.

Example 5

The rolled copper foil (current collection part) has a thickness of 5um and a width of 20mm; under the conditions of a vacuum of 10 ^-5 Pa and a temperature of 700°C, magnesium particles with a particle size of 2um are deposited on the surface of the copper foil (3mm width area). The area ratio of the magnesium particles is one-third to obtain a stress buffer layer; Figure 5 shows a physical picture of the magnesium metal particles in the stress buffer layer in this embodiment.

Erase the edge area (5mm wide) on one side of the rolled lithium-magnesium alloy strip (50um thick, 100mm wide, 10% magnesium content), and the erased thickness is 3um; remove the stress buffer layer area on the copper foil and The erased areas of the lithium-magnesium alloy strips are welded together by pressure welding (pressure 60MPa, temperature 30°C) to obtain a high specific energy metal lithium anode product.

Example 6

The rolled copper foil (current collection part) has a thickness of 5um and a width of 20mm; under the conditions of a vacuum of 10 ^-5 Pa and a temperature of 700°C, magnesium particles with a particle size of 2um are deposited on the surface of the copper foil (3mm width area). The area ratio of magnesium particles is one-third to obtain a stress buffer layer;

Erase the edge area (5mm wide) on one side of the rolled lithium tape (50um thick, 300mm wide), and the erased thickness is 3um; pass the stress buffer layer area on the copper foil and the erased area of the lithium tape through Weld together using pressure welding (pressure 50MPa, temperature 40°C) to obtain a high specific energy metal lithium anode product.

Example 7

The negative electrode uses the high specific energy metal lithium negative electrode of Example 1; the positive electrode uses NCM ternary positive electrode, which is dried at 130°C for 12 hours before being made into a battery; the separator uses Celgard2500, the electrolyte uses 1M LiPF ₆ , EC: EMC=3:7 ( vol/vol). The high specific energy metal lithium negative electrode, NCM ternary positive electrode and separator of Example 1 were assembled into a soft-pack battery with the help of a lamination machine. The capacity of the battery core was 2 Ah.

The test voltage range is 3-4.25V, and the charge and discharge current is 0.5C.

Example 8

The high specific energy metal lithium anode of Example 5 was selected as the negative electrode, and the NCM ternary cathode was used as the positive electrode. It was dried at 130°C for 12 hours before being made into a battery; the separator was made of Celgard2500, and the electrolyte was 1M LiPF _6. EC: EMC=3:7 ( vol/vol). The high specific energy metal lithium negative electrode, NCM ternary positive electrode and separator of Example 5 were assembled into a soft-pack battery with the help of a lamination machine. The capacity of the battery core was 2 Ah. The test voltage range is 3-4.25V, and the charge and discharge current is 0.5C.

Comparative example 1

The thickness of the copper foil in the roll is 5um, the width is 20mm; the lithium strip in the roll (60um thick), the width is 100mm; the edge area on one side of the copper foil (3mm wide) and the edge area on one side of the lithium strip (3mm wide) are rolled and laminated Put them together and set the pressure to 70MPa. During the production process, it was found that the length of the lithium belt in the roll-laminated area and the pure lithium belt area without lamination were inconsistent. The lamination area was easy to pull the lithium in the pure lithium belt area without lamination. Deformation. When the length of the produced product reaches about 20 meters, the lithium belt is severely stretched and deformed. There are many pits on the surface of the lithium belt. It cannot be used as a negative electrode and the winding stops.

Comparative example 2

The thickness of the rolled copper foil (collection area) is 5um and the width is 120mm; the thickness of the lithium strip is 25um and the width of the lithium strip is 100mm. The lithium strip is laminated on both sides to the rolled copper foil to obtain double-sided copper foil clad metal. Lithium products (use the entire copper foil as a current collection area).

Use this negative electrode, use NCM ternary cathode as the positive electrode, and dry it at 130°C for 12 hours before making the battery; use Celgard2500 as the separator, use 1M LiPF ₆ as the electrolyte, EC: EMC=3:7 (vol/vol). The negative electrode, NCM ternary positive electrode and separator are assembled into a soft-pack battery with the help of a lamination machine. The capacity of the battery core is 2Ah. The test voltage range is 3-4.25V, and the charge and discharge current is 0.5C.

Table 1: Comparison of specific energy of batteries assembled with different negative electrodes

experimental group Actual battery capacity Cell specific energy (Wh/kg) Example 7 2.02Ah 512.3 Example 8 1.98Ah 510.8 Comparative example 2 2.01Ah 413.5

As can be seen from Table 1, Examples 7 and 8 use very narrow copper foil as the current collector, and the specific energy can exceed 500wh/kg. Comparative Example 2 uses a whole copper foil as the current collector, because the density of the copper foil is very high. , the copper foil uses a large area, so the specific energy is only 413.5Wh/kg.

It should be understood that the above descriptions are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention shall be included in the present invention. within the scope of protection of the invention.

Claims (10)

1. A lithium battery cathode is characterized in that, the lithium battery cathode consists of an elongated lithium belt or a lithium alloy belt and a current collecting and gathering part combined on at least one side edge of the elongated lithium belt or the lithium alloy belt, wherein

At least one side edge of the lithium strip or the lithium alloy strip is provided with a pretreatment area, the current collecting and collecting part comprises an area with a stress buffer layer, the pretreatment area and the area with the stress buffer layer are mutually covered together,

wherein, the pretreatment is as follows: the method comprises the steps of preprocessing a region to be combined with a tab of a lithium belt to form a preprocessed region with thinned thickness, wherein the preprocessed region is provided with a new metal lithium surface;

the stress buffer layer is as follows: the stress buffer layer is formed by raised discontinuous metal particles in the region of the tab to be bonded to the lithium strip, the raised particles being ductile under the action of an external force when the tab is bonded to the lithium strip.

2. The lithium battery negative electrode of claim 1, wherein the current collecting and collecting portion further comprises a portion extending beyond the width of the lithium or lithium alloy strip that is not covered by the pretreatment region, the portion being die cut into tabs.

3. The lithium battery anode according to claim 1, wherein the lithium strip or lithium alloy strip has a thickness of 0.01 to 0.15mm and a width of 10 to 1500mm; the width of the pretreatment area is 2-10mm, the thickness of the pretreatment area is 0.1-5um thinner than the thickness of other parts, and the pretreatment mode comprises erasing, roller removal and gluing.

4. The lithium battery negative electrode according to claim 1, wherein the lithium alloy is formed by combining metallic lithium with any one or at least two elements of Ag, au, sn, si, zn, al, mg, in, ga, B, mn, sb, cr, V, cu, fe or Ti.

5. The lithium battery anode according to claim 1, wherein the current collecting and collecting part is made of a metal foil selected from copper foil, nickel foil, stainless steel foil or composite metal current collector;

the thickness of the current collecting and converging part is 3-10um; the width is 12-30mm; the stress buffer layer has a width of 2-10mm.

6. The lithium battery anode according to claim 1, wherein the discontinuous raised metal particles in the stress buffer layer are formed by vapor deposition, the metal particles having a particle size of 1-7um; the height of the bulges of the metal particles is 1-5um; the area ratio of the metal particles in the stress buffer layer is 1:3 to 9:10.

7. the lithium battery negative electrode of claim 6, wherein the metal particles comprise at least one of tin particles, zinc particles, magnesium particles, aluminum particles, silver particles, and lithium particles.

8. The lithium battery anode according to claim 1, wherein the pre-treated region and the region of the current collecting and collecting portion having the stress buffering layer are bonded together by at least one of diffusion welding, ultrasonic welding, resistance welding, pressure welding process; the width of the overlap region ranges from 2 to 10mm.

9. A method of preparing the lithium battery anode of any one of claims 1 to 8, comprising:

step one: depositing discontinuous raised metal particles on the metal foil through a vapor deposition process to obtain a current collecting and converging part with partial areas covered with a stress buffer layer;

step two: pre-treating at least one side edge area of the lithium belt or the lithium alloy belt by at least one of erasing, roller removing and gluing to form a pre-treated area with the width of 2-10 mm;

step three: welding the area with the stress buffer layer of the current collecting and collecting part obtained in the first step and the pretreatment area of the lithium belt or the lithium alloy belt obtained in the second step together by means of at least one of diffusion welding, ultrasonic welding, resistance welding and pressure welding, so that the metal particles of the stress buffer layer and the lithium in the lithium belt or the lithium alloy belt are fused together to form a fusion area of the lithium and the metal particles; and

optional step four: and die-cutting the part, which is not covered with the pretreatment area, of the current collecting and converging part and extends beyond the width of the lithium strip or the lithium alloy strip to form the tab.

10. A lithium battery, characterized in that the lithium battery comprises a lithium battery anode according to any one of claims 1-8, the positive electrode material being selected from the group consisting of ternary nickel cobalt manganese materials, ternary nickel cobalt aluminum materials, lithium-rich manganese-based positive electrode materials, lithium iron phosphate, lithium cobalt oxide and sulfur positive electrode materials.