阅读说明：本技术 电芯制备及优化方法、电芯 (Battery cell preparation and optimization method and battery cell ) 是由 屠晓强 张春芳 于 2021-07-16 设计创作，主要内容包括：本发明实施例提供了一种电芯制备及优化方法、电芯,涉及电池技术领域。电芯制备方法包括：基于电芯的高温存储数据,得到电芯的负极材料减少量；根据电芯的正极材料用量与电芯的负极材料减少量,得到所述电芯的负极目标材料用量；利用所述电芯的正极材料用量与负极目标材料用量进行电芯的制备。本发明中,在制备电芯时减少了负极材料用量,减少的负极材料的空间可用于填充更多的正极活性物质,提升了电芯的体积能量密度和重量能量密度,提升了正极首效,减小了电芯正极与负极之间的首效差距。(The embodiment of the invention provides a battery cell preparation and optimization method and a battery cell, and relates to the technical field of batteries. The preparation method of the battery cell comprises the following steps: obtaining the reduction amount of the negative electrode material of the battery cell based on the high-temperature storage data of the battery cell; obtaining the usage amount of a negative electrode target material of the battery cell according to the usage amount of the positive electrode material of the battery cell and the reduction amount of the negative electrode material of the battery cell; and preparing the battery cell by using the amount of the anode material and the amount of the cathode target material of the battery cell. According to the invention, the using amount of the negative electrode material is reduced when the battery cell is prepared, the reduced space of the negative electrode material can be used for filling more positive active substances, the volume energy density and the weight energy density of the battery cell are improved, the first effect of the positive electrode is improved, and the first effect difference between the positive electrode and the negative electrode of the battery cell is reduced.)

1. A method for preparing a battery cell is characterized by comprising the following steps:

obtaining the reduction amount of the negative electrode material of the battery cell based on the high-temperature storage data of the battery cell;

obtaining the usage amount of a negative electrode target material of the battery cell according to the usage amount of the positive electrode material of the battery cell and the reduction amount of the negative electrode material of the battery cell;

and preparing the battery cell by using the amount of the anode material and the amount of the cathode target material of the battery cell.

2. The method for preparing the battery cell of claim 1, wherein the obtaining of the amount of reduction of the negative electrode material of the battery cell based on the high-temperature storage data of the battery cell comprises:

based on the high-temperature storage data of the battery cell, obtaining the consumption data of lithium ions in the battery cell;

and obtaining the reduction amount of the negative electrode material of the battery cell according to the consumption data of the lithium ions.

3. The method for preparing the battery cell of claim 2, wherein the storing the data at the high temperature comprises: presetting storage temperature, preset storage time and battery cell charge state data of a battery cell;

the obtaining of the consumption data of lithium ions in the battery cell based on the high-temperature storage data of the battery cell includes:

and obtaining the charge state change data of the battery cell after the battery cell stores the preset storage time at the preset storage temperature based on the charge state data of the battery cell in the high-temperature storage data, wherein the consumption data of lithium ions in the battery cell comprises the charge state change data.

4. The battery cell preparation method of any one of claims 1 to 3, wherein the obtaining of the target negative electrode material usage amount of the battery cell according to the positive electrode material usage amount of the battery cell and the negative electrode material reduction amount of the battery cell comprises:

calculating the usage of a negative reference material of the battery cell according to the usage of the positive material of the battery cell;

and obtaining the target material consumption of the negative electrode of the battery cell according to the reference material consumption of the negative electrode and the reduction amount of the negative electrode material.

5. The method according to claim 4, wherein the consumption data of lithium ions is a rate of decrease in state of charge of the battery cell after the battery cell is stored at a preset storage temperature for a preset storage time period; the formula of the usage amount of the cathode target material of the battery cell is as follows:

N’＝N*(1-b％)；

wherein N' represents the usage amount of the negative electrode target material of the battery cell, N represents the usage amount of the negative electrode reference material of the battery cell, and b% represents the charge state reduction ratio of the battery cell after the battery cell is stored in a preset storage temperature for a preset storage time.

6. A method for optimizing a cell, comprising:

charging the battery cell to be optimized to a preset charge state; wherein the battery cell to be optimized is a battery cell prepared based on the battery cell preparation method of any one of claims 1 to 5, and the preset state of charge is an initial state of charge in high-temperature storage data adopted when the battery cell is prepared;

controlling the temperature of the environment where the electric core to be optimized is located to be a pre-stored temperature, wherein the pre-stored temperature is a storage temperature in high-temperature storage data adopted when the electric core is prepared;

and taking the to-be-optimized battery cell which is stored at the preset temperature for a preset storage time as an optimized battery cell, wherein the preset storage time is the storage time in high-temperature storage data adopted during the preparation of the battery cell.

7. The cell optimization method according to claim 6, further comprising, before charging the cell to be optimized to a preset state of charge:

and charging the electric core to be optimized to a preset voltage for activation.

8. The cell optimization method according to claim 6, wherein the preset state of charge is in the range of [ 50%, 80% ].

9. The cell optimization method according to claim 6, wherein the preset storage temperature is in a range of [45 ℃, 60 ℃ ].

10. A battery cell, characterized in that it is manufactured based on the cell manufacturing method of any of claims 1 to 5 and/or optimized based on the cell optimization method of any of claims 6 to 9.

Technical Field

The invention relates to the technical field of batteries, in particular to a battery cell preparation and optimization method and a battery cell.

Background

A lithium ion battery (hereinafter referred to as a lithium battery) is one of the currently used batteries, and mainly comprises a positive electrode, a negative electrode, a separation film and an electrolyte. Coulombic efficiency, also called discharge efficiency, refers to the ratio of the battery discharge capacity to the charge capacity in the same cycle process, i.e. the percentage of the discharge capacity to the charge capacity; the first coulombic efficiency (hereinafter referred to as first effect) of the anode of the conventional lithium battery is 86-91%, the first effect of the cathode is about 93%, and the problem of unmatched first effects exists between the anode and the cathode of the lithium battery.

At present, for the first effect mismatch problem that exists between the positive pole and the negative pole of lithium cell, common solution includes two kinds, one is to improve the first effect of positive pole, and the other is to reduce the first effect of negative pole.

However, when the first effect of the positive electrode is improved, the nickel content of the lithium battery is higher and higher, the phenomenon of mixed discharging of lithium and nickel is more and more serious, the technical difficulty is higher, and the first effect of the positive electrode is difficult to obviously improve in a short time; when the first effect of the negative electrode is reduced, the performance of the lithium battery is damaged by adding silicon or graphite with low first effect.

Disclosure of Invention

The invention aims to provide a cell preparation and optimization method and a cell, which reduce the using amount of a negative electrode material when the cell is prepared, and the reduced space of the negative electrode material can be used for filling more positive active substances, so that the volume energy density and the weight energy density of the cell are improved, the first effect of the positive electrode is improved, and the first effect difference between the positive electrode and the negative electrode of the cell is reduced; and a part of redundant lithium ions in the battery core can be consumed through the subsequent high-temperature aging operation of the battery, so that the requirement of the battery core on the N/P ratio can be met under the condition of reducing the using amount of the negative electrode material, and the performance of the battery core cannot be influenced.

In order to achieve the above object, the present invention provides a method for preparing a battery cell, comprising: obtaining the reduction amount of the negative electrode material of the battery cell based on the high-temperature storage data of the battery cell; obtaining the usage amount of a negative electrode target material of the battery cell according to the usage amount of the positive electrode material of the battery cell and the reduction amount of the negative electrode material of the battery cell; and preparing the battery cell by using the amount of the anode material and the amount of the cathode target material of the battery cell.

The invention also provides a battery cell optimization method, which is used for charging the battery cell to be optimized to a preset charge state; the battery cell to be optimized is the battery cell prepared by the battery cell preparation method, and the preset charge state is an initial charge state in high-temperature storage data adopted in the preparation of the battery cell; controlling the temperature of the environment where the electric core to be optimized is located to be a pre-stored temperature, wherein the pre-stored temperature is a storage temperature in high-temperature storage data adopted when the electric core is prepared; and taking the to-be-optimized battery cell which is stored at the preset temperature for a preset storage time as an optimized battery cell, wherein the preset storage time is the storage time in high-temperature storage data adopted during the preparation of the battery cell.

The invention also provides a battery cell, and the battery cell is prepared based on the battery cell preparation method and/or optimized based on the battery cell optimization method.

In the embodiment of the invention, when the battery cell is prepared, the reduction amount of the negative electrode material of the battery cell is obtained based on the high-temperature storage data of the battery cell, the target material usage amount of the negative electrode of the battery cell is obtained according to the usage amount of the positive electrode material of the battery cell and the reduction amount of the negative electrode material of the battery cell, and the battery cell is prepared by using the usage amount of the positive electrode material of the battery cell and the target material usage amount of the negative electrode; the using amount of the negative electrode material is reduced when the battery cell is prepared, the reduced space of the negative electrode material can be used for filling more positive active substances, the volume energy density and the weight energy density of the battery cell are improved, the first effect of the positive electrode is improved, and the first effect difference between the positive electrode and the negative electrode of the battery cell is reduced; and a part of redundant lithium ions in the battery core can be consumed through the subsequent high-temperature aging operation of the battery, so that the requirement of the battery core on the N/P ratio can be met under the condition of reducing the using amount of the negative electrode material, and the performance of the battery core cannot be influenced.

In one embodiment, the obtaining the negative electrode material reduction amount of the battery cell based on the high-temperature storage data of the battery cell includes:

based on the high-temperature storage data of the battery cell, obtaining the consumption data of lithium ions in the battery cell;

and obtaining the reduction amount of the negative electrode material of the battery cell according to the consumption data of the lithium ions.

In one embodiment, the high temperature storage data comprises: presetting storage temperature, preset storage time and battery cell charge state data of a battery cell;

the obtaining of the consumption data of lithium ions in the battery cell based on the high-temperature storage data of the battery cell includes:

and obtaining the charge state change data of the battery cell after the battery cell stores the preset storage time at the preset storage temperature based on the charge state data of the battery cell in the high-temperature storage data, wherein the consumption data of lithium ions in the battery cell comprises the charge state change data.

In one embodiment, the obtaining of the target negative electrode material usage amount of the battery cell according to the positive electrode material usage amount of the battery cell and the negative electrode material reduction amount of the battery cell includes:

calculating the usage of a negative reference material of the battery cell according to the usage of the positive material of the battery cell;

and obtaining the target material consumption of the negative electrode of the battery cell according to the reference material consumption of the negative electrode and the reduction amount of the negative electrode material.

In one embodiment, the consumption data of the lithium ions is a charge state reduction ratio of the battery cell after the battery cell stores a preset storage time at a preset storage temperature; the formula of the usage amount of the cathode target material of the battery cell is as follows:

N’＝N*(1-b％)；

wherein N' represents the usage amount of the negative electrode target material of the battery cell, N represents the usage amount of the negative electrode reference material of the battery cell, and b% represents the charge state reduction ratio of the battery cell after the battery cell is stored in a preset storage temperature for a preset storage time.

In one embodiment, before the charging the cell to be optimized to the preset state of charge, the method further includes:

and charging the electric core to be optimized to a preset voltage for activation.

In one embodiment, the predetermined state of charge is in the range of [ 50%, 80% ].

In one embodiment, the preset storage temperature is in the range of [45 ℃, 60 ℃ ].

Drawings

Fig. 1 is a detailed flowchart of a cell manufacturing method according to a first embodiment of the present invention;

fig. 2 is a detailed flowchart of step 101 of the cell preparation method in fig. 1;

fig. 3 is a detailed flowchart of step 102 of the cell preparation method in fig. 1;

fig. 4 is a specific flowchart of a cell optimization method according to a second embodiment of the present invention.

Detailed Description

The embodiments of the present invention will be described in detail below with reference to the accompanying drawings in order to more clearly understand the objects, features and advantages of the present invention. It should be understood that the embodiments shown in the drawings are not intended to limit the scope of the present invention, but are merely intended to illustrate the spirit of the technical solution of the present invention.

In the following description, for the purposes of illustrating various disclosed embodiments, certain specific details are set forth in order to provide a thorough understanding of the various disclosed embodiments. One skilled in the relevant art will recognize, however, that the embodiments may be practiced without one or more of the specific details. In other instances, well-known devices, structures and techniques associated with this application may not be shown or described in detail to avoid unnecessarily obscuring the description of the embodiments.

Throughout the specification and claims, the word "comprise" and variations thereof, such as "comprises" and "comprising," are to be understood as an open, inclusive meaning, i.e., as being interpreted to mean "including, but not limited to," unless the context requires otherwise.

Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

As used in this specification and the appended claims, the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise. It should be noted that the term "or" is generally employed in its sense including "or/and" unless the context clearly dictates otherwise.

In the following description, for the purposes of clearly illustrating the structure and operation of the present invention, directional terms will be used, but terms such as "front", "rear", "left", "right", "outer", "inner", "outer", "inward", "upper", "lower", etc. should be construed as words of convenience and should not be construed as limiting terms.

The first embodiment of the invention relates to a battery cell preparation method, which is characterized in that the battery cell is prepared by utilizing high-temperature storage data of the battery cell, the using amount of a negative electrode material can be reduced when the battery cell is prepared, the reduced space of the negative electrode material can be used for filling more positive active substances, and the volume energy density and the weight energy density of the battery cell are improved; follow-up through battery high temperature ageing operation, consume partly unnecessary lithium ion in the electric core, promoted positive pole first effect in other words, reduced the first effect difference between electric core positive pole and the Negative pole, can satisfy the requirement of electric core to N/P ratio (Negative/positive) simultaneously under the condition that reduces the Negative pole material quantity. In this embodiment and the following embodiments, the battery cell is taken as the lithium ion battery (abbreviated as lithium battery) for example.

A specific flow of the battery cell preparation method of the embodiment is shown in fig. 1.

And step 101, obtaining the reduction amount of the negative electrode material of the battery cell based on the high-temperature storage data of the battery cell.

Referring to fig. 2, step 101 includes the following sub-steps:

and a substep 1011, obtaining consumption data of lithium ions in the battery cell based on the high-temperature storage data of the battery cell. High temperature storage data is associated with lithium ion consumption of the cells during aging.

Specifically, the high-temperature storage data of the battery cell may be consumption rates of lithium ions of the battery cell at different aging temperatures and different initial SOCs (states of Charge), and the high-temperature storage data of the battery cell specifically includes: the battery pack comprises a preset storage temperature, a preset storage time and battery cell state of charge data of a battery cell, wherein the state of charge data of the battery cell at least comprises an initial SOC (recorded as SOC1) of the battery cell during high-temperature storage and a residual SOC (recorded as SOC2) of the battery after the preset storage time of the battery cell during high-temperature storage, and the SOC data of the battery cell also comprises an SOC (recorded as SOC3) consumed by the battery during the preset storage time of the battery cell. Wherein the initial SOC1 of the battery core during high-temperature storage is in the range of [ 50%, 80% ].

Based on the high-temperature storage data of the battery cell, obtaining the consumption data of lithium ions in the battery cell, including: and obtaining the charge state change data of the battery cell after the battery cell stores the preset storage time at the preset storage temperature based on the charge state data of the battery cell in the high-temperature storage data, wherein the consumption data of lithium ions in the battery cell comprises the charge state change data. Specifically, the consumption data of lithium ions in the battery cell may be represented by SOC variation data of the battery cell after the battery cell stores the preset storage time at the preset storage temperature, where the SOC variation data includes an SOC reduction amount of the battery cell after the battery cell stores the preset storage time at the preset storage temperature, and/or an SOC reduction ratio b% of the battery cell after the battery cell stores the preset storage time at the preset storage temperature. The SOC reduction amount is the SOC3, where SOC3 is SOC 1-2; the SOC reduction ratio b% ((SOC 1-SOC2)/SOC1 × 100% ("SOC 3)/SOC 1 × 100%), and the consumption data of lithium ions in the cell is represented by the SOC reduction ratio b%, which can be applied to cells of different capacities.

And a substep 1012, obtaining the reduction amount of the negative electrode material of the battery cell according to the consumption data of the lithium ions.

Specifically, the reduction of the negative electrode material of the cell is characterized by a reduction of a target negative electrode material usage of the cell relative to a negative electrode reference material usage of the cell, and the consumption data of lithium ions in the cell is characterized by a SOC reduction ratio of b%, so that the reduction of the negative electrode material of the cell is b%.

And step 102, obtaining the target material consumption of the negative electrode of the battery cell according to the positive electrode material consumption of the battery cell and the negative electrode material consumption of the battery cell.

Referring to fig. 3, step 102 includes the following sub-steps:

and a substep 1021, calculating the negative reference material consumption of the battery cell according to the positive material consumption of the battery cell.

Specifically, the amount of the positive electrode material in the battery cell can be obtained based on the designed capacity of the battery cell, when the battery cell is prepared, the ratio of the amount of the positive electrode material in the battery cell to the amount of the negative electrode material in the battery cell is constant, and a represents the ratio of the amount of the positive electrode material P to the amount of the negative electrode material N, that is, a is P/N; the negative electrode reference material usage N ═ P/a can thus be obtained.

And a substep 1022, obtaining the target material usage of the negative electrode of the battery cell according to the reference material usage of the negative electrode and the reduction amount of the negative electrode material.

Specifically, when the consumption data of lithium ions in the battery cell is represented by a state of charge reduction ratio b%, the amount of the negative electrode material of the battery cell is reduced by b%, and the target material usage amount of the negative electrode of the battery cell is represented by N', then:

the formula of the cathode target material dosage N' of the battery cell is as follows:

N’＝N*(1-b％)；

wherein, N' represents the usage of the negative electrode target material of the battery cell, N represents the usage of the negative electrode reference material of the battery cell, and b% represents the charge state reduction ratio of the battery cell after the battery cell is stored in the preset storage temperature for the preset storage time.

It should be noted that, in this embodiment, the consumption data of lithium ions in the battery cell may be represented by selecting a state of charge reduction ratio or a state of charge reduction amount according to the capacity of the currently prepared battery cell, for example, if the capacity of the currently prepared battery cell matches the capacity of the battery cell indicated in the high-temperature storage data (that is, the difference between the capacities is within a preset range), the consumption data of lithium ions in the battery cell may be represented by the state of charge reduction amount or the state of charge reduction ratio; if the capacity of the currently prepared battery cell is not matched with the capacity of the battery cell indicated in the high-temperature storage data (namely, the difference of the capacities exceeds a preset range), the consumption data of lithium ions in the battery cell is represented by the charge state reduction proportion.

And 103, preparing the battery cell by using the usage of the anode material and the usage of the cathode target material of the battery cell.

Specifically, according to the obtained usage of the positive electrode material and the negative electrode target material of the battery core, the positive electrode slurry and the negative electrode slurry are respectively coated on a base material according to the designed surface density, a positive plate and a negative plate are formed after rolling, and then the positive plate, the negative plate, the isolating membrane, the electrolyte, the battery shell and the like are assembled to obtain the battery core. The positive electrode material of the battery cell can be NCM811, and the negative electrode material can be graphite.

It should be noted that, in step 103, only the materials and the preparation processes used for preparing the battery cell are described simply, and the preparation processes and the materials of the battery cell are not limited at all, as long as the battery cell is prepared by using the battery cell preparation method of the present invention, the present invention is within the protection scope of the present invention.

The high-temperature storage data of the battery core in the embodiment is data obtained in a high-temperature aging process of the battery, that is, a certain number of battery cores are prepared according to a normal positive-negative electrode material ratio for high-temperature aging, and then the data of the battery cores in the high-temperature aging process are recorded, namely the high-temperature storage data; and then, preparing the battery cell according to the battery cell preparation method of the example by using the high-temperature storage data.

In this embodiment, when a battery cell is prepared, a reduced amount of a negative electrode material of the battery cell is obtained based on high-temperature storage data of the battery cell, a target amount of the negative electrode material of the battery cell is obtained according to an amount of the positive electrode material of the battery cell and the reduced amount of the negative electrode material of the battery cell, and the battery cell is prepared by using the amount of the positive electrode material of the battery cell and the target amount of the negative electrode material of the battery cell; the using amount of the negative electrode material is reduced when the battery cell is prepared, the reduced space of the negative electrode material can be used for filling more positive active substances, the volume energy density and the weight energy density of the battery cell are improved, the first effect of the positive electrode is improved, and the first effect difference between the positive electrode and the negative electrode of the battery cell is reduced; and a part of redundant lithium ions in the battery core can be consumed through the subsequent high-temperature aging operation of the battery, so that the requirement of the battery core on the N/P ratio can be met under the condition of reducing the using amount of the negative electrode material, and the performance of the battery core cannot be influenced.

A second embodiment of the present invention relates to a method for optimizing a battery cell, in which the battery cell prepared in the first embodiment is optimized through high-temperature aging, and a part of redundant lithium ions in the battery cell are consumed in the high-temperature aging process, so as to meet the requirement of the battery cell on the N/P ratio under the condition of reducing the usage amount of a negative electrode material, and avoid affecting the performance of the battery cell.

A specific flow of the cell optimization method according to this embodiment is shown in fig. 4.

Step 201, charging the battery cell to be optimized to a preset voltage for activation.

Specifically, the battery cell to be optimized is the battery cell prepared based on the battery cell preparation method in the first embodiment, and after the battery cell is prepared, the battery cell needs to be activated, and the purpose of activating the battery cell is to fully activate active substances and electrolyte in the battery cell so as to achieve stable electrochemical performance; the process of cell activation comprises: charging the battery cell by adopting small current, controlling the battery cell to be charged to a preset voltage, reducing an oxide layer of an active substance on the surface of an electrode of the battery cell, improving the activity of the electrode and gradually improving the capacity of the battery cell; after a plurality of small-current charge-discharge cycles, the active substances on the surface of the battery cell electrode are fully activated, so that the capacity and the performance of the battery cell reach better degrees. The preset voltage is in the range of [3.15V, 3.75V ], and different preset voltages can be selected for activation according to different battery cores. It should be noted that, in this embodiment, the cell optimization method includes the step 201 as an example for description, and the step 201 is not necessary to implement the present invention.

Step 202, charging the battery cell to be optimized to a preset charge state; the battery cell to be optimized is the battery cell prepared based on the battery cell preparation method in the first embodiment, and the preset charge state is an initial charge state in high-temperature storage data adopted in the battery cell preparation process.

Step 203, controlling the temperature of the environment where the electric core to be optimized is located to be a preset storage temperature, where the preset storage temperature is a storage temperature in high-temperature storage data adopted when the electric core is prepared.

And 204, taking the to-be-optimized battery cell stored at the preset temperature for the preset storage time as the optimized battery cell, wherein the preset storage time is the storage time in the high-temperature storage data adopted during the preparation of the battery cell.

Specifically, steps 202 to 204 are a process of performing high-temperature aging on the battery cell to be optimized, and since the battery cell to be optimized is a battery cell prepared based on the battery cell preparation method in the first embodiment, the high-temperature storage data used in preparing the battery cell includes a preset storage temperature, a preset storage duration, and battery cell state of charge data of the battery cell; the state of charge data of the battery cell at least comprises an initial SOC (recorded as SOC1) of the battery cell during storage and a remaining SOC (recorded as SOC2) of the battery after the battery cell is stored for a preset storage time.

Before the high-temperature aging of the battery cell to be optimized, the battery cell needs to be charged to a preset SOC by adopting normal voltage, the preset SOC adopts initial SOC1 in high-temperature storage data during the preparation of the battery cell, and the preset SOC can be 50% -80%.

After the battery cell is charged to the preset SOC, the temperature of the environment where the battery cell is located is adjusted to the preset storage temperature, the storage temperature in high-temperature storage data when the battery cell is prepared is adopted in the preset storage temperature, the preset storage temperature can be between 45 ℃ and 60 ℃, then the battery cell is kept static under the environment of the preset storage temperature for the preset storage time, the storage time in the high-temperature storage data when the battery cell is prepared is adopted in the preset storage time, the preset storage time can be between 2 days and 15 days, and after the preset storage time is kept static under the environment of the preset storage temperature, the optimized battery cell can be obtained.

In one example, after the high-temperature aging of the battery cell is completed, redundant gas in the battery cell can be extracted, and the electrolyte is supplemented in the battery cell, so that the energy density of the battery cell can be further improved.

For example, the first positive effect and the first negative effect of the battery cell prepared by the battery cell preparation method in the first embodiment are 89% and 94%, respectively, and the amount of the negative electrode material used in the preparation of the battery cell is reduced; and then, the electric core is aged at high temperature by adopting the electric core optimization method in the embodiment, redundant lithium ions in the electric core are consumed, and the first effect of the positive electrode of the electric core is improved to more than 89%.

In this embodiment, for an electric core prepared by using high-temperature storage data, high-temperature aging is performed on the electric core by using capacity, temperature and storage duration corresponding to the high-temperature storage data, that is, the electric core is subjected to high-temperature aging in a high-temperature environment at a preset storage temperature, when the electric core is kept still in a preset duration in the environment at the preset storage temperature, a part of redundant lithium ions released by the positive electrode of the electric core can be consumed, so that even if the graphite usage amount of the Negative electrode is reduced in the process of preparing the electric core, a preset N/P ratio (Negative/positive) of the electric core can be still satisfied, that is, a positive-Negative electrode ratio (Cell Balance, abbreviated as CB value) of the electric core satisfies a set condition, so that a difference between the first effect of the positive electrode of the electric core and the first effect of the Negative electrode of the electric core is reduced. Therefore, even if the usage amount of the negative electrode material (such as graphite) of the battery cell is reduced and more positive active materials are filled in the reduced negative electrode material part when the battery cell is prepared, the volume energy density of the battery cell is improved, but the performance of the battery cell is not affected.

A third embodiment of the present invention relates to a battery cell, which may be a lithium ion battery, and the lithium ion battery includes a positive plate, a negative plate, an isolation film, an electrolyte, and a battery case.

The cell in this embodiment may be prepared by the cell preparation method in the first embodiment, and/or optimized by the cell optimization method in the second embodiment.

For example, the battery cell in this embodiment may be prepared by the battery cell preparation method in the first embodiment, and optimized by the battery cell optimization method in the second embodiment; the using amount of the negative electrode material is reduced when the battery cell is prepared, the reduced space of the negative electrode material can be used for filling more positive active substances, the volume energy density and the weight energy density of the battery cell are improved, the first effect of the positive electrode is improved, and the first effect difference between the positive electrode and the negative electrode of the battery cell is reduced; and subsequently, through the high-temperature aging operation of the battery, a part of redundant lithium ions in the battery cell are consumed, so that the requirement of the battery cell on the N/P ratio can be met under the condition of reducing the using amount of the negative electrode material, and the performance of the battery cell cannot be influenced.

While the preferred embodiments of the present invention have been described in detail above, it should be understood that aspects of the embodiments can be modified, if necessary, to employ aspects, features and concepts of the various patents, applications and publications to provide yet further embodiments.

These and other changes can be made to the embodiments in light of the above detailed description. In general, in the claims, the terms used should not be construed to be limited to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments along with the full scope of equivalents to which such claims are entitled.