CN104810557A - Preparation method of lithium ion battery - Google Patents

Abstract

The invention belongs to the technical field of lithium-ion batteries, and in particular relates to a preparation method of lithium-ion batteries: the method mainly includes the preparation of lithium-rich bare cells, the formation of initial SEI films, the decomposition of initial SEI films, the regeneration of SEI films and finished products Cell preparation and other steps. Using this method to prepare lithium-ion batteries can fully decompose the initial SEI film with a large gap in structure and performance due to lithium supplementation, and form an SEI film with controllable structure and performance and excellent consistency through secondary formation. The core has better capacity and cycle performance.

Description

A kind of preparation method of lithium ion battery

technical field

The invention belongs to the technical field of lithium ion batteries, in particular to a preparation method of lithium ion batteries.

Background technique

Lithium-ion batteries have the advantages of high energy density, high voltage, low self-discharge and light weight, so they are widely used in various portable mobile electronic devices such as notebook computers, digital cameras, mobile phones, and MP3 players. With the miniaturization and multi-function development of portable mobile electronic devices, people have higher and higher requirements on the energy density of lithium-ion secondary batteries. Since the lithium-ion battery needs to form a solid electrolyte (SEI) film during the formation process, the Li ⁺ provided by the cathode is consumed, resulting in a loss of battery capacity and affecting the improvement of energy density. For the graphite system, the first conversion will bring about 10% energy loss; for some high-capacity alloy anode materials, such as silicon-based, tin-based and Sn~Co~Al composite materials, the first-time efficiency is even only 60%~ 80%, has seriously affected the practical application and popularization of alloy materials.

In order to greatly increase the energy density of the cell, it is necessary to increase the first Coulombic efficiency of the cell. Therefore, experts at home and abroad have carried out extensive research and achieved some results: the patent of the Chinese patent application publication number CN1177417A uses metal lithium sheets to cover the surface of the anode sheet (using the entire sheet of foil as a current collector), and then winding A lithium-rich lithium-ion battery is prepared by forming a battery and then perfusing the electrolyte. When using this method to replenish lithium, since the existing process cannot produce thinner lithium metal sheets, the amount of lithium that the anode sheet can absorb is far less than the amount of lithium provided by the metal lithium sheet, resulting in excessive lithium replenishment and battery failure. Lithium analysis, poor cycle performance and other problems. The Chinese patent with the publication number CN103199217A proposes that the perforated metal lithium sheet is used to cover the surface of the anode sheet, then wound to form a battery, and then filled with an electrolyte to prepare a lithium-rich lithium-ion battery, which effectively solves the problem of being unable to produce The problem of thin enough lithium metal sheets.

However, the above-mentioned methods of improving the first-time efficiency of the battery through lithium-rich means, and then increasing the battery capacity, in the battery preparation process, after the liquid injection, with the infiltration of the electrolyte, ion channels and electrons are formed between the lithium-rich material and the lithium-rich electrode. When channeling, a solid electrolyte film (SEI film) will be spontaneously formed on the surface of the lithium-rich material particles. The film formation process of the SEI film is an uncontrollable process, and the formed SEI film has poor composition and structure consistency. Cycle performance is poor.

In view of this, it is necessary to develop a new lithium-ion battery and its preparation method, which can not only enrich the entire battery system with lithium, but also form an SEI film with good consistency in structure and performance, and finally prepare a battery with excellent performance. .

Contents of the invention

The purpose of the present invention is to provide a method for preparing a lithium-ion battery in view of the deficiencies in the prior art: the method mainly includes the preparation of a lithium-rich bare cell, the generation of an initial SEI film, the decomposition of an initial SEI film, and the formation of an SEI film. Regeneration and preparation of finished batteries. Using this method to prepare lithium-ion batteries can fully decompose the initial SEI film with a large gap in structure and performance due to lithium supplementation, and form an SEI film with controllable structure and performance and excellent consistency through secondary formation. The core has better capacity and cycle performance.

In order to achieve the above object, the present invention adopts the following technical solutions:

A preparation method for a lithium ion battery, comprising the steps of:

Step 1, preparation of lithium-rich bare cells: compound lithium-rich material on the anode sheet to obtain lithium-rich anode sheet, the composite pressure used is 0.1MPa ~ 50MPa, and then separate the lithium-rich anode sheet from the dried cathode sheet, The membrane is assembled into a bare cell, and the electrolyte is injected into the shell/bag, and then sealed to obtain the injected cell;

Step 2, the formation of the initial solid electrolyte membrane (SEI membrane): the cell obtained in step 1 was left to stand at 10°C to 100°C for 1min to 100h, during the standing process, with the infiltration of the electrolyte, the rich The voltage difference between the lithium material and the anode active material will automatically promote the generation of SEI on the surface of the anode active material particles;

Step 3, Decomposition of the initial SEI film: Apply a surface pressure of 0 to 5 MPa to the cell obtained in step 2, and use 0.001C to 5C at 10°C to 100°C (C is the battery capacity value, for example, if the battery The capacity is 1500mAh, then 1C is the discharge current of 1500mA), and the discharge current is 2.5V~0V, so that the initially formed SEI film is fully decomposed;

Step 4, regeneration of the SEI film: charge and form the positive and negative cells of the cell obtained in step 3 to form an SEI film with uniform structure and performance;

Step 5, preparation of the finished battery cell: shaping and degassing the battery cell prepared in step 4 to make the finished battery cell.

As an improvement of the preparation method of the lithium ion battery of the present invention, the anode active material used in the anode sheet described in step 1 includes at least one of graphite, silicon, oxide and lithium titanate; the current collector is Continuous current collector or porous current collector.

As an improvement to the preparation method of the lithium-ion battery of the present invention, the lithium-rich substance described in step 1 is a substance that can provide a lithium source for anode lithium supplementation, including lithium powder, lithium powder slurry, lithium tape, and perforated lithium tape and at least one of lithium-rich organic compounds (such as 1,4-butyldilithium, 1,6-hexyldilithium, etc.).

As an improvement of the preparation method of the lithium-ion battery of the present invention, the composite pressure used in step 1 is 0.5MPa～10MPa; Stainless steel film bag.

As an improvement to the preparation method of the lithium-ion battery of the present invention, the additive content in the electrolyte in step 1 is 1.0 to 2.0 times, preferably 1.1 to 1.8 times, the additive content in the electrolyte injected by the non-lithium-rich battery cell, The electrolyte additives include FB, VC, PS, FEC, AND, etc.; the total content of additives in the electrolyte injected by the non-lithium-rich batteries is 0.1% to 30%, and the total content of additives in the electrolyte in step 1 is 0.2% % to 60%, preferably 0.11% to 54%.

As an improvement of the preparation method of the lithium-ion battery of the present invention, the method of injecting the electrolyte in step 1 is normal pressure injection or accelerated infiltration injection, and the accelerated infiltration injection method is negative pressure injection, clamping during injection. Hold the cell so that the liquid level does not exceed the bare cell, squeeze the cell after liquid injection or soak the bare cell in the electrolyte.

As an improvement of the preparation method of the lithium ion battery of the present invention, the standing temperature in step 2 is 20° C. to 85° C., and the standing time is 10 minutes to 50 hours.

As an improvement of the preparation method of the lithium-ion battery of the present invention, the surface pressure applied to the cell in step 3 is 0.1MPa-2MPa, the temperature is 20°C-85°C, the discharge current is 0.01C-2C, and the discharge is 2.0 ~0V.

As an improvement of the preparation method of the lithium-ion battery of the present invention, the surface pressure applied to the cell in step 3 is 0.2MPa-1.5MPa, the temperature is 30°C-80°C, the discharge current is 0.01C-1C, and the discharge current is 0.01C-1C. 1.5V～0V.

As an improvement of the preparation method of the lithium-ion battery of the present invention, the method of formation in step 4 is ordinary formation or fixture formation; , using a current of 0.01C to 0.5C to charge to 3% to 80% SOC; the fixture formation process is to apply a surface pressure of 0.1MPa to 5MPa on the cell, and use 0.1C to 10C at 20°C to 100°C The current is charged to 3% to 95% SOC (that is, the state of charge, 10% SOC is the state when the battery is charged to 10% of its capacity).

The advantage of the present invention is that: through the process of decomposing and re-forming the SEI film of the lithium-rich battery, the SEI film with poor structure and performance consistency formed during the lithium-rich battery is decomposed, and then the structure and performance are re-formed through the secondary formation process. Good SEI film, so the battery has better capacity and cycle performance.

Detailed ways

The present invention and its beneficial effects will be described in detail below in conjunction with specific embodiments, but the embodiments of the present invention are not limited thereto.

Comparative example 1, preparation of lithium-rich bare cells: select silicon-carbon composites as the anode active material, stir with conductive agent, adhesive and deionized water to obtain a slurry, and then coat it on the copper current collector, cold press , slitting, welding, pasting and drying for later use; choose lithium cobaltate as the cathode active material and stir evenly with conductive agent, adhesive and nitrogen methyl pyrrolidone to obtain a slurry, and then apply it on the aluminum fluid, Drying after cold pressing, stripping, welding, and pasting glue for use; use metal lithium strips as the lithium-rich source, select the lithium strips according to the capacity relationship of the first full battery efficiency of 95%, and then use 2MPa surface pressure to compound the lithium strips The surface of the anode after drying; the above-mentioned cathode sheet and lithium-rich anode sheet are wound to obtain a bare cell.

Formation of SEI film: Encapsulate the above-mentioned bare cell in an aluminum-plastic film to obtain a top-sealed cell; according to EC:DEC:PC:VC:FEC=35:35:30:1:5 (VC and FEC are additives ), choose LiPF6 as the lithium salt to configure the electrolyte for backup; inject the above electrolyte into the above-mentioned top-sealed battery cell for vacuum packaging; place it in an environment of 35°C for 24 hours to fully infiltrate the electrolyte; Due to the voltage difference between the lithium-rich material attached to the anode surface and the anode active material, it will automatically promote the generation of SEI on the surface of the anode active material particles;

Preparation of finished battery cells: Reshaping and degassing the above prepared battery cells to make finished battery cells.

Embodiment 1, different from Comparative Example 1, this embodiment comprises the following steps:

Preparation of lithium-rich bare cell: same as Comparative Example 1.

Formation of the initial SEI film: Encapsulate the above-mentioned bare cell in an aluminum-plastic film to obtain a top-sealed cell; according to EC:DEC:PC:VC:FEC=35:35:30:1.4:7 (VC, FEC are Additives), choose LiPF6 as the lithium salt to configure the electrolyte for standby; inject the above electrolyte into the above-mentioned top-sealed battery cell for vacuum packaging; place it in a 35°C environment for 24 hours to fully infiltrate the electrolyte; The infiltration of the liquid, due to the voltage difference between the lithium-rich material attached to the anode surface and the anode active material, will automatically promote the generation of SEI on the surface of the anode active material particles;

Decomposition of the initial SEI film: Apply a surface pressure of 1.0 MPa to the prepared cell with the initial SEI film, place it at a temperature of 70°C, and discharge it with a current of 0.5C to 1.5V, so that the initially formed SEI film is fully decomposed. the

Regeneration of SEI film: At 45°C, without applying pressure to the surface of the cell, use 0.02C current to charge the cell with 10% SOC, and then charge 30% SOC at 0.5C, so that the cell re-forms the SEI film.

Preparation of finished cell: same as Comparative Example 1.

The rest are the same as those of Comparative Example 1 and will not be repeated here.

Embodiment 2, different from Embodiment 1, this embodiment includes the following steps:

Decomposition of the initial SEI film: Apply a surface pressure of 0 MPa to the prepared cell with the initial SEI film, place it at a temperature of 20°C, and discharge it to 2.5V with a current of 0.01C, so that the initially formed SEI film is fully decomposed. the

Regeneration of SEI film: At 20°C, apply 0.1MPa pressure to the surface of the cell, use 0.01C current to charge the cell with 3% SOC, and then charge 30% SOC at 1C, so that the cell re-forms the SEI film.

The rest are the same as in Embodiment 1, and will not be repeated. the

Embodiment 3, different from Embodiment 1, this embodiment includes the following steps:

Decomposition of the initial SEI film: Apply a surface pressure of 0.1MPa to the prepared cell with the initial SEI film, place it at a temperature of 30°C, and discharge it with a current of 0.1C to 2V, so that the initially formed SEI film is fully decomposed. the

Regeneration of SEI film: At 60°C, apply a pressure of 0 MPa to the surface of the cell, and use a current of 0.5C to charge the cell with 80% SOC of electricity, so that the cell re-forms the SEI film.

The rest are the same as in Embodiment 1, and will not be repeated. the

Embodiment 4, different from Embodiment 1, this embodiment includes the following steps:

Decomposition of the initial SEI film: Apply a surface pressure of 0.2 MPa to the prepared cell with the initial SEI film, place it at a temperature of 10°C, and discharge it to 1.0V with a current of 0.05C, so that the initially formed SEI film is fully decomposed. the

Regeneration of SEI film: At 100°C, apply a pressure of 0.4MPa to the surface of the cell, and charge the cell with 20% SOC of electricity with a current of 10C, so that the cell re-forms the SEI film.

The rest are the same as in Embodiment 1, and will not be repeated. the

Embodiment 5, different from Embodiment 1, this embodiment includes the following steps:

Decomposition of the initial SEI film: Apply a surface pressure of 1.5MPa to the prepared cells forming the initial SEI film, place them at a temperature of 100°C, discharge to 0V with a current of 5C, and then discharge to 0V with 1C, so that the initially formed SEI film is fully break down. the

Regeneration of SEI film: At 50°C, apply a pressure of 5 MPa to the surface of the cell, and charge the cell with 95% SOC of electricity with a current of 0.5C, so that the cell re-forms the SEI film.

The rest are the same as in Embodiment 1, and will not be repeated. the

Embodiment 6, different from Embodiment 1, this embodiment includes the following steps:

Decomposition of the initial SEI film: Apply a surface pressure of 2 MPa to the prepared cell forming the initial SEI film, place it at a temperature of 85°C, discharge it to 0V with a current of 2C, and then discharge it to 0V with a current of 0.5C, so that the initially formed SEI film is fully break down. the

Regeneration of SEI film: At 80°C, apply a pressure of 1.5MPa to the surface of the cell, and use 4C current to charge the cell with 60% SOC of electricity, so that the cell re-forms the SEI film.

The rest are the same as in Embodiment 1, and will not be repeated. the

Embodiment 7, different from Embodiment 1, this embodiment includes the following steps:

Decomposition of the initial SEI film: apply a surface pressure of 0.8MPa to the prepared cell forming the initial SEI film, place it at a temperature of 80°C, discharge it to 0.5V with a current of 1C, and then discharge it to 0V with a current of 0.1C, so that the initially formed SEI Membrane fully disintegrated. the

Regeneration of SEI film: At 75°C, apply a pressure of 0.9MPa to the surface of the cell, and use 2C current to charge the cell with 66% SOC, so that the cell re-forms the SEI film.

The rest are the same as in Embodiment 1, and will not be repeated. the

Embodiment 8, different from Embodiment 1, this embodiment includes the following steps:

Preparation of lithium-rich bare cells: select silicon-carbon composites as the anode active material, stir evenly with conductive agent, adhesive and deionized water to obtain a slurry, and then coat it on the copper current collector, cold press, slitting, After welding and pasting, dry it for use; choose lithium cobaltate as the cathode active material, stir it with conductive agent, adhesive and nitrogen methyl pyrrolidone to obtain a slurry, and then apply it on the aluminum fluid, cold press, separate strips, welded, and glued and then dried for use; the metal lithium strip is used as the lithium-rich source, and the lithium strip is selected according to the capacity relationship of the first full battery efficiency of 95%, and then the lithium strip is combined with a surface pressure of 0.1MPa after drying The surface of the anode; the above-mentioned cathode sheet and lithium-rich anode sheet are wound to obtain a bare cell.

Formation of SEI film: Encapsulate the above-mentioned bare cell in an aluminum-plastic film to obtain a top-sealed cell; according to EC:DEC:PC:VC:FEC=35:35:30:1:5 (VC and FEC are additives ), select LiPF6 as the lithium salt to configure the electrolyte for backup; inject the above electrolyte into the above-mentioned top-sealed cell for vacuum packaging; place it in an environment of 10°C for 100 hours to fully infiltrate the electrolyte; Due to the voltage difference between the lithium-rich material attached to the anode surface and the anode active material, it will automatically promote the generation of SEI on the surface of the anode active material particles;

The rest are the same as in Embodiment 1, and will not be repeated. the

Embodiment 9, different from Embodiment 1, this embodiment includes the following steps:

Preparation of lithium-rich bare cells: select graphite anode active material, stir with conductive agent, adhesive and deionized water to obtain slurry, and then apply it on copper current collector, cold press, slitting, welding, and pasting After drying, it is ready to use; choose lithium iron phosphate as the cathode active material, stir it with conductive agent, adhesive and nitrogen methyl pyrrolidone to obtain a slurry, and then apply it on the aluminum fluid, cold pressing, slitting, welding, After pasting the glue, dry it for use; use metal lithium powder as the lithium-rich source, select the lithium strip according to the capacity relationship of the first full battery efficiency of 94%, and then use 0.5MPa surface pressure to compound the lithium strip on the surface of the dried anode; The above-mentioned cathode sheet and lithium-rich anode sheet are wound to obtain a bare cell.

Formation of SEI film: Encapsulate the above-mentioned bare cell in an aluminum-plastic film to obtain a top-sealed cell; according to EC:DEC:PC:VC:FEC=35:35:30:1.1:5.5 (VC and FEC are additives ), select LiPF6 as the lithium salt to configure the electrolyte for backup; inject the above electrolyte into the above-mentioned top-sealed battery core for vacuum packaging (the liquid injection method is: negative pressure liquid injection, and hold the battery core when injecting liquid to keep High enough electrolyte liquid level, and after the liquid injection is completed, squeeze the cell to speed up the electrolyte infiltration); place it in an environment of 100°C for 1min to fully infiltrate the electrolyte; during the process, with the infiltration of the electrolyte, due to the anode There is a voltage difference between the lithium-rich material attached to the surface and the anode active material, which will automatically promote the generation of SEI on the surface of the anode active material particles;

The rest are the same as in Embodiment 1, and will not be repeated. the

Embodiment 10, different from Embodiment 1, this embodiment includes the following steps:

Preparation of lithium-rich bare cells: Lithium titanate-silicon composite is selected as the anode active material, stirred evenly with conductive agent, adhesive and deionized water to obtain a slurry, which is then coated on the copper current collector, cold-pressed, Slitting, welding, and gluing after drying for use; choose lithium cobaltate as the cathode active material and stir evenly with conductive agent, adhesive, and nitrogen-methylpyrrolidone to obtain a slurry, which is then coated on the aluminum fluid and cooled After pressing, stripping, welding, and pasting glue, dry it for use; use the metal lithium strip as the lithium-rich source, select the lithium strip according to the capacity relationship of the first full battery efficiency of 95%, and then use 10MPa surface pressure to compound the lithium strip in the oven. The surface of the anode after drying; the above-mentioned cathode sheet and lithium-rich anode sheet are wound to obtain a bare cell.

Formation of the SEI film: according to the quality relationship of EC:DEC:PC:VC:FEC=35:35:30:1.8:9 (VC, FEC are additives), LiPF6 is selected as the lithium salt configuration electrolyte for standby; The cell is soaked in the above electrolyte, while controlling the temperature of the electrolyte to 85°C, and the soaking time is 10 minutes to fully infiltrate the electrolyte, and then package the bare cell in the aluminum-plastic film; during the process, with the infiltration of the electrolyte, due to the anode There is a voltage difference between the lithium-rich material attached to the surface and the anode active material, which will automatically promote the generation of SEI on the surface of the anode active material particles;

The rest are the same as in Embodiment 1, and will not be repeated. the

Embodiment 11, different from Embodiment 1, this embodiment includes the following steps:

Preparation of lithium-rich bare cells: Lithium titanate-silicon composite is selected as the anode active material, stirred evenly with conductive agent, adhesive and deionized water to obtain a slurry, which is then coated on the copper current collector, cold-pressed, Slitting, welding, and gluing after drying for use; choose lithium cobaltate as the cathode active material and stir evenly with conductive agent, adhesive and nitrogen-methylpyrrolidone to obtain a slurry, which is then coated on the aluminum fluid and cooled After pressing, stripping, welding, and pasting glue, dry it for use; use the metal lithium strip as the lithium-rich source, and select the lithium strip according to the capacity relationship of the first full battery efficiency of 95%, and then use the surface pressure of 50MPa to compound the lithium strip in the oven. The surface of the anode after drying; the above-mentioned cathode sheet and lithium-rich anode sheet are wound to obtain a bare cell.

Formation of SEI film: according to the quality relationship of EC:DEC:PC:VC:FEC=35:35:30:2:10 (VC, FEC are additives), select LiPF6 as the lithium salt configuration electrolyte for standby; The cell is soaked in the above electrolyte, while controlling the temperature of the electrolyte to 20°C, and the soaking time is 50 hours so that the electrolyte is fully infiltrated, and then the bare cell is packaged in the aluminum-plastic film; during the process, with the infiltration of the electrolyte, due to the anode surface There is a voltage difference between the attached lithium-rich material and the anode active material, which will automatically promote the generation of SEI on the surface of the anode active material particles;

The rest are the same as in Embodiment 1, and will not be repeated. the

Characterization and testing:

Capacity test: Take 100 batteries in Comparative Example 1 and Example 1~Example 11, and conduct a capacity test on the batteries in an environment of 35°C according to the following procedure: let stand for 3 minutes; charge at a constant current of 0.5C to 4.2V, constant voltage charging to 0.05C; standing for 3min; 0.5C constant current discharging to 3.0V to get the first discharge capacity D0; after standing for 3min, complete the capacity test, and then calculate the average value of the capacity of 100 batteries in each group , and calculate the Sigma of the capacity; the results are shown in Table 1.

Cycle test: For the cells in Comparative Example 1 and Example 1 to Example 11, take 5 cells each, and conduct a cycle test in an environment of 35°C. The process is: stand for 3 minutes; charge at 0.5C constant current to 4.2V, Charge at constant voltage to 0.05C; stand still for 3min; discharge at constant current at 0.5C to 3.0V to obtain the first discharge capacity, then calculate the average capacity of each group of 5 cells as D ₀ ; after standing for 3min, repeat the above process for 500 cycles The cell capacity was measured, and then the average capacity of 5 cells in each group was calculated as D ₄₉₉ , then the cell capacity retention rate η=D ₄₉₉ /D ₀ *100%, the results are shown in Table 1.

Table 1, the electrical performance table of the lithium-ion battery prepared by the method of comparative example and embodiment

As can be seen from Table 1, when adopting the method of the present invention to prepare lithium-ion batteries, the battery cell obtained has a higher capacity, and the capacity distribution is more concentrated; in addition, the cycle performance of the battery cell prepared by the present invention is better.

According to the disclosure and teaching of the above specification, those skilled in the art to which the present invention pertains can also change and modify the above embodiment. Therefore, the present invention is not limited to the above-mentioned specific implementation manners, and any obvious improvement, substitution or modification made by those skilled in the art on the basis of the present invention shall fall within the protection scope of the present invention. In addition, although some specific terms are used in this specification, these terms are only for convenience of description and do not constitute any limitation to the present invention.

Claims (10)

1. a preparation method for lithium ion battery, is characterized in that, comprises the steps:

Step 1, the preparation of the naked battery core of rich lithium: rich lithium material is compounded on anode strip and obtains rich lithium anode sheet, the composite pressure used is 0.1MPa ~ 50MPa, afterwards rich lithium anode sheet and the cathode sheets after drying, barrier film are assembled into naked battery core, inject electrolyte after entering shell/bag, sealing afterwards obtains the battery core after fluid injection;

Step 2, the generation of initial SEI film: battery core step 1 obtained leaves standstill 1min ~ 100h at 10 DEG C ~ 100 DEG C, along with the infiltration of electrolyte in the process of leaving standstill, the voltage difference existed between the rich lithium material of anode surface attachment and anode active material will facilitate the generation of anode active material particle surface SEI automatically;

Step 3, the decomposition of initial SEI film: the battery core obtained step 2, applies the face pressure of 0 ~ 5MPa, and at 10 DEG C ~ 100 DEG C, adopts the discharging current of 0.001C ~ 5C, be discharged to 2.5V ~ 0V, and the initial SEI film formed fully is decomposed;

Step 4, the regeneration of SEI film: carry out charging to the Zhenyang interpolar of the battery core that step 3 obtains and change into, forms structure and the homogeneous SEI film of performance;

Step 5, the preparation of finished product battery core: the battery core that step 4 is obtained carries out shaping, degasification obtains finished product battery core.

2. a preparation method for lithium ion battery according to claim 1, is characterized in that, the anode active material used in the anode strip described in step 1 comprises at least one in graphite, silicon, oxide and lithium titanate; Described collector is continuum fluid or porous current collector.

3. the preparation method of a lithium ion battery according to claim 1, it is characterized in that, rich lithium material described in step 1, for mending for anode the material that lithium provides lithium source, comprises at least one in lithium powder, lithium powder slurry, lithium band, punching lithium band and rich lithium organic substance.

4. a preparation method for lithium ion battery according to claim 1, is characterized in that, the composite pressure that step 1 uses is 0.5MPa ~ 10MPa; Described enter shell for entering aluminum hull or entering box hat, enter bag for entering aluminum plastic film bag or rustless steel membrane bag.

5. a preparation method for lithium ion battery according to claim 1, is characterized in that, 1.0 times ~ 2.0 times of additive level note to by non-lipid lithium cell additive level in electrolyte in electrolyte described in step 1.

6. the preparation method of a lithium ion battery according to claim 1, it is characterized in that, the mode injecting electrolyte in step 1 is normal pressure fluid injection or accelerates to infiltrate fluid injection, extrudes or naked battery core is soaked in electrolyte after clamping battery core makes liquid level not have naked battery core, fluid injection when described acceleration infiltration fluid injection mode is negative pressure liquid injection, fluid injection to battery core.

7. a preparation method for lithium ion battery according to claim 1, is characterized in that, the temperature left standstill described in step 2 is 20 DEG C ~ 85 DEG C, and the duration left standstill is 10min ~ 50h.

8. a preparation method for lithium ion battery according to claim 1, is characterized in that, the face pressure applied battery core described in step 3 is 0.1MPa ~ 2MPa, and temperature is 20 DEG C ~ 85 DEG C, and discharging current is 0.01C ~ 2C, is discharged to 2.0 ~ 0V.

9. a preparation method for lithium ion battery according to claim 8, is characterized in that, the face pressure applied battery core described in step 3 is 0.2MPa ~ 1.5MPa, and temperature is 30 DEG C ~ 80 DEG C, and discharging current is 0.01C ~ 1C, is discharged to 1.5V ~ 0V.

10. a preparation method for lithium ion battery according to claim 1, is characterized in that, the mode changed in step 4 is common to change into or fixture changes into; Described common chemical synthesis technology, for be placed in burn-in board by battery core, at 20 DEG C ~ 60 DEG C, uses current charges to the 3% ~ 80%SOC of 0.01C ~ 0.5C; Described fixture chemical synthesis technology is face pressure battery core being applied to 0.1MPa ~ 5MPa, at 20 DEG C ~ 100 DEG C, uses current charges to the 3% ~ 95%SOC of 0.1C ~ 10C.