CN-121054983-B - Cell liquid injection method and system

CN121054983BCN 121054983 BCN121054983 BCN 121054983BCN-121054983-B

Abstract

The application discloses a battery cell liquid injection method and a system, wherein the battery cell liquid injection method comprises the steps of obtaining deviation between actual liquid injection quantity and reference liquid injection quantity of a liquid injected battery cell group, determining a plurality of candidate liquid injection adjustment quantities based on the deviation under the condition that the deviation is not in a liquid injection quantity qualified interval, evaluating the candidate liquid injection adjustment quantities according to at least one liquid injection quantity evaluation index for each candidate liquid injection adjustment quantity to obtain scores corresponding to the candidate liquid injection adjustment quantities, and controlling liquid injection equipment to inject liquid into a battery cell to be injected based on target liquid injection adjustment quantities corresponding to scores meeting preset conditions in the scores. The scheme provided by the application can improve the performance of the battery cell.

Inventors

REN GAOQIANG
HU DIANGANG
Qin Anxiang
ZHANG XUAN
ZHENG XIAOYU
LI WENSHEN

Assignees

宁德时代新能源科技股份有限公司

Dates

Publication Date: 20260512
Application Date: 20251103

Claims (11)

1. A method for injecting liquid into a cell, comprising: acquiring the deviation between the actual liquid injection amount of the injected battery cell group and the reference liquid injection amount; determining a plurality of candidate injection adjustment amounts based on the deviation if the deviation is not within the injection amount qualified interval; for each candidate injection adjustment amount, respectively evaluating the candidate injection adjustment amount according to at least one injection amount evaluation index to obtain a score corresponding to the candidate injection adjustment amount, wherein the injection amount evaluation index is an index for evaluating the influence degree of the injection amount on the performance of the battery cell; controlling the liquid injection equipment to inject liquid into the to-be-injected battery cell based on target liquid injection adjustment quantity corresponding to scores meeting preset conditions in the scores; The determining a plurality of candidate priming adjustment amounts based on the deviation includes: Determining a deviation allowance zone based on the deviation; obtaining a plurality of deviation adjustment coefficients corresponding to the deviation; And in the deviation allowable interval, respectively adjusting the deviation based on a plurality of deviation adjustment coefficients to obtain a plurality of candidate injection adjustment amounts.
2. The method according to claim 1, wherein for each of the candidate injection adjustment amounts, evaluating the candidate injection adjustment amounts according to at least one injection amount evaluation index, respectively, to obtain scores corresponding to the candidate injection adjustment amounts, includes: for each candidate liquid injection adjustment amount, respectively determining a candidate liquid injection amount based on the candidate liquid injection adjustment amount and a reference liquid injection amount; And evaluating the candidate liquid injection amounts according to at least one liquid injection amount evaluation index respectively to obtain scores corresponding to the candidate liquid injection adjustment amounts.
3. The method according to claim 2, wherein the number of the liquid injection amount evaluation indexes is plural, and the evaluating the candidate liquid injection amounts according to at least one liquid injection amount evaluation index, respectively, to obtain scores corresponding to the candidate liquid injection adjustment amounts, includes: for each candidate liquid injection amount, evaluating the candidate liquid injection amount according to each liquid injection amount evaluation index to obtain a sub-score of each liquid injection amount evaluation index; and adding the sub scores to obtain scores corresponding to the candidate liquid injection adjustment amounts.
4. The method of claim 3, wherein the injection amount evaluation index comprises an injection amount average value, an injection amount reject ratio, and an injection amount process capability index.
5. The method of claim 1, wherein the injected cell group comprises N cells, N being a positive integer, and wherein the obtaining a deviation of an actual injection amount of the injected cell group from a reference injection amount comprises: For each cell, calculating the cell liquid injection amount deviation of the actual liquid injection amount of the cell and the reference liquid injection amount respectively; And calculating the average value of the deviations of the liquid injection amounts of the N electric cores to obtain the deviation of the actual liquid injection amount and the reference liquid injection amount of the injected electric core group.
6. The method according to claim 1, wherein the controlling the liquid filling device to fill the liquid to-be-filled cell based on the target liquid filling adjustment amount corresponding to the score satisfying the preset condition among the scores includes: Obtaining a relation coefficient of the target marking liquid adjustment quantity and the filling liquid adjustment quantity set by the filling liquid equipment from a coefficient library; Correcting the target injection adjustment amount based on the relation coefficient to obtain a target set injection adjustment amount of the injection equipment; And controlling the liquid injection equipment to inject liquid into the cell to be injected based on the target setting liquid injection adjustment quantity.
7. The method of claim 6, wherein obtaining the relationship coefficient between the target marking fluid adjustment and the filling device setting filling fluid adjustment comprises: Acquiring the previous relation coefficients of the target injection adjustment amounts of Q previous injected cell groups injected before the injected cell groups and the injection adjustment amounts set by the injection equipment from a coefficient library, wherein the injection time of the Q previous injected cell groups is Q cell groups closest to the injection time of the injected cell groups; And determining the relation coefficient of the target marking liquid adjusting quantity and the filling liquid adjusting quantity set by the filling liquid equipment based on the Q previous relation coefficients.
8. The method according to claim 6 or 7, characterized in that the method further comprises: and storing the relation coefficient between the target marking liquid adjusting quantity and the target setting liquid injection adjusting quantity into a coefficient library.
9. The method according to any one of claims 1-7, further comprising: and controlling the liquid injection equipment to inject the liquid into the to-be-injected battery cell according to the reference liquid injection amount under the condition that the deviation is positioned in the liquid injection amount qualified section.
10. The battery cell liquid injection system is characterized by comprising a weighing device, an upper computer and liquid injection equipment; the weighing equipment is used for weighing each electric core in the injected electric core group to obtain the actual injection amount of the injected electric core group, and the actual injection amount of the injected electric core group is sent to the upper computer; the upper computer is connected with the weighing equipment and is used for executing the method of any one of claims 1-9; And the liquid injection equipment is connected with the upper computer and is used for injecting liquid into the liquid to-be-injected electric core according to a control signal which is sent by the upper computer and carries the target liquid injection adjustment quantity.
11. A method for injecting liquid into a cell, comprising: weighing the actual liquid injection amount of the injected battery cell group through a weighing device; Based on the actual liquid injection amount of the injected battery cell group, acquiring the deviation between the actual liquid injection amount of the injected battery cell group and the reference liquid injection amount through an upper computer; The method comprises the steps of determining a plurality of candidate injection adjustment amounts based on a deviation when the deviation is not in an injection amount qualified interval through an upper computer, evaluating the candidate injection adjustment amounts according to at least one injection amount evaluation index for each candidate injection adjustment amount to obtain scores corresponding to the candidate injection adjustment amounts, wherein the injection amount evaluation index is an index for evaluating the influence degree of the injection amount on the performance of a battery cell; according to a control signal which is sent by the upper computer and carries the target injection adjustment amount, injecting liquid into the electric core to be injected through the injection equipment; The determining a plurality of candidate priming adjustment amounts based on the deviation includes: Determining a deviation allowance zone based on the deviation; obtaining a plurality of deviation adjustment coefficients corresponding to the deviation; And in the deviation allowable interval, respectively adjusting the deviation based on a plurality of deviation adjustment coefficients to obtain a plurality of candidate injection adjustment amounts.

Description

Cell liquid injection method and system Technical Field The application relates to the field of batteries, in particular to a battery cell liquid injection method and a system. Background The electrolyte is an important component of the battery cell, the liquid injection amount of the battery cell is a key control parameter in the battery processing and production process, and the service life and the safety performance of the battery can be directly influenced by excessive or insufficient liquid injection amount. Therefore, how to control the injection of an appropriate amount of electrolyte into the battery cell to improve the performance of the battery cell is a problem to be solved in the industry. Disclosure of Invention In view of the above problems, the present application provides a method and a system for injecting a battery cell to improve the performance of the battery cell. The application provides a cell injection method, which comprises the steps of obtaining deviation of actual injection quantity and reference injection quantity of an injected cell group, determining a plurality of candidate injection adjustment quantities based on the deviation when the deviation is not in an injection quantity qualified interval, evaluating the candidate injection adjustment quantities according to at least one injection quantity evaluation index for each candidate injection adjustment quantity to obtain scores corresponding to the candidate injection adjustment quantities, and controlling injection equipment to inject the cell to be injected based on target injection adjustment quantities corresponding to scores meeting preset conditions in the scores. As can be seen from the above, in the embodiment of the present application, when determining the target injection adjustment amount of the cell to be injected, the deviation between the actual injection amount of the injected cell group and the reference injection amount is first obtained, and when the deviation is not within the injection amount qualification interval (may be a CP (CONTROL POINT) interval), a plurality of candidate injection adjustment amounts may be determined based on the deviation, and then the candidate injection adjustment amounts are evaluated by using the injection amount evaluation index to obtain scores corresponding to the candidate injection adjustment amounts, and the candidate injection adjustment amounts corresponding to the scores satisfying the preset condition in the plurality of scores are determined as the target injection adjustment amounts. In this way, in the embodiment of the present application, when the deviation of the liquid injection amount is not within the qualified interval of the liquid injection amount, the liquid injection adjustment amount is determined, instead of being adjusted solely by the deviation, a plurality of optional candidate liquid injection adjustment amounts are determined according to the deviation, and then the scores of the plurality of candidate liquid injection adjustment amounts are obtained according to the liquid injection amount evaluation index, and the candidate liquid injection adjustment amounts whose scores meet the preset condition are selected as the target liquid injection adjustment amounts. Therefore, in the embodiment of the application, when the target injection adjustment amount is determined, the score obtained based on the injection amount evaluation index is referred to in addition to the deviation, so that the limitation that the injection amount is adjusted only when the deviation is in a CPP (CONTROL PROCESS POINT, process control point) interval is broken through, and the battery cell with better battery cell performance index can be obtained when the injection is finally performed based on the target injection adjustment amount. In some embodiments, the determining a plurality of candidate priming adjustment amounts based on the deviation includes determining a deviation allowance zone based on the deviation, and determining a plurality of candidate priming adjustment amounts in the deviation allowance zone. And determining a plurality of candidate injection adjustment amounts in the deviation allowable interval, wherein a reasonable boundary range can be set for the injection adjustment amounts, so that all the candidate adjustment amounts are ensured to be in the range of safe injection of the battery cell, and negative influence on the performance of the battery cell can be reduced as much as possible. In some embodiments, determining the plurality of candidate priming adjustment amounts in the deviation allowable interval includes obtaining a plurality of deviation adjustment coefficients corresponding to the deviation, and adjusting the deviation based on the plurality of deviation adjustment coefficients in the deviation allowable interval to obtain the plurality of candidate priming adjustment amounts. By setting the deviation coefficient in the deviatio