CN-122026033-A - Gradient infiltration liquid injection method and system based on dynamic temperature regulation and control, and lithium ion battery

CN122026033ACN 122026033 ACN122026033 ACN 122026033ACN-122026033-A

Abstract

The application provides a gradient infiltration liquid injection method and system based on dynamic temperature regulation and control and a lithium ion battery, and relates to the field of lithium ion battery preparation. The method comprises a preheating and low-viscosity filling stage, a gradient guiding and viscosity rising infiltration stage, a balancing and stabilizing stage and a soaking stage, wherein electrolyte with a first temperature and a viscosity eta 1 is injected, the first temperature is higher than the ambient temperature, the gradient guiding and viscosity rising infiltration stage is used for enabling different areas in the battery to be at different temperatures after the electrolyte is injected, so that the temperature gradient is formed, the temperature gradient guiding the electrolyte to flow, the temperature of the electrolyte is reduced from the first temperature in the flowing process, the viscosity of the electrolyte is increased from eta 1 to eta 2, and the balancing and stabilizing stage is used for uniformly adjusting the whole temperature of the battery to a target temperature to finish infiltration. The method ensures uniform and stable infiltration of the electrolyte in the battery, thereby improving the interface performance and consistency of the battery.

Inventors

WANG MING
QIU LUYANG
YIN YUTING

Assignees

河南省鹏辉电源有限公司

Dates

Publication Date: 20260512
Application Date: 20260327

Claims (10)

1. The gradient infiltration liquid injection method based on dynamic temperature regulation is characterized by comprising the following steps of: A pre-heating and low-viscosity filling stage of injecting an electrolyte having a first temperature and a viscosity η1, said first temperature being greater than ambient temperature; The gradient guiding and viscosity rising permeation stage comprises the steps of establishing and maintaining a space temperature field in the battery after electrolyte is injected, and enabling different areas in the battery to be at different temperatures so as to form a temperature gradient, wherein the temperature gradient guides the electrolyte to flow; And in the balancing and stabilizing stage, the whole temperature of the battery is uniformly regulated to the target temperature, and the infiltration is completed.
2. The gradient infiltration liquid filling method based on dynamic temperature control according to claim 1, wherein the dynamic viscosity of the electrolyte at 25 ℃ is greater than 5 mPa s.
3. The gradient infiltration liquid injection method based on dynamic temperature regulation according to claim 1, wherein the temperature gradient is a vertical gradient decreasing from the liquid injection port to the bottom along the thickness direction of the battery; Or alternatively, the first and second heat exchangers may be, Radial gradients decreasing from the center to the edge of the cell.
4. The dynamic temperature regulation-based gradient infiltration liquid injection method of claim 1, wherein the spatial temperature field is established and maintained by controlling the temperatures of different areas of a clamp holding the battery.
5. The dynamic temperature regulation-based gradient infiltration liquid injection method according to claim 1, wherein at least one of the following conditions is satisfied: a. The first temperature is 40-70 ℃; b. the target temperature is 60-80 ℃.
6. The dynamic temperature regulation-based gradient infiltration liquid injection method according to any one of claims 1 to 5, wherein at least one of the following conditions is satisfied: c. η1 is 4-6mPa.s; d. η2 is 1-3mPa.s.
7. A dynamic temperature regulated injection system for implementing the method of any one of claims 1-6, comprising: The precise temperature control liquid injection unit comprises a liquid injection needle, a heating element integrated on the liquid injection needle and a first temperature sensor, and is used for heating the flowing electrolyte in real time and controlling the temperature at the first temperature; An intelligent temperature field management unit comprising a clamp for clamping a battery, wherein the clamp is integrated with a partition temperature control module and a second temperature sensor and is used for establishing and maintaining the space temperature field on the battery; and the central controller is electrically connected with the first temperature sensor, the second temperature sensor, the heating element and the partition temperature control module, and is used for receiving the temperature signals and controlling the working states of the heating element and the partition temperature control module according to a preset program so as to execute the liquid injection method.
8. The dynamic temperature control infusion system of claim 7, wherein the zoned temperature control module is a semiconductor refrigeration sheet or a microfluidic circulation line integrated within the clamp.
9. The dynamic temperature control infusion system of claim 7, wherein the heating element of the infusion needle is a thin film heater wrapped around the outer wall of the needle or embedded in the wall of the needle.
10. A lithium ion battery prepared by the gradient impregnation liquid injection method based on dynamic temperature regulation as claimed in any one of claims 1 to 6.

Description

Gradient infiltration liquid injection method and system based on dynamic temperature regulation and control, and lithium ion battery Technical Field The application relates to the field of lithium ion battery preparation, in particular to a gradient infiltration liquid injection method based on dynamic temperature regulation, a liquid injection system and a lithium ion battery. Background The electrolyte injection is used as a core link in the production of lithium ion batteries, and the infiltration quality of the electrolyte injection is directly related to the interface stability, performance consistency and service life of the batteries. With the development of battery technology to the high energy density direction and the improvement of special performance requirements such as high safety, wide temperature adaptability and the like, the formula of the electrolyte is increasingly complicated, and components such as high-concentration lithium salt, high-molecular polymer additives, high-viscosity functional solvents and the like are generally introduced, so that the overall dynamic viscosity of the electrolyte is obviously increased. In conventional production environments, particularly when the ambient temperature is low, electrolyte fluidity further deteriorates, exacerbating the difficulty of the infiltration process. The vacuum liquid injection technology widely adopted in the current industry is essentially a passive infiltration mechanism, and mainly depends on capillary force and external pressure difference to drive electrolyte infiltration, so that the process can maintain basic efficiency for a low-viscosity system, but has serious limitation in facing modern high-viscosity electrolyte exposure, namely, the infiltration rate is greatly reduced, the production beat is prolonged, and the productivity is obviously restricted. While some of the solutions attempt to reduce the initial viscosity of the electrolyte by means of preheating, such methods generally only implement global, transient heating, the effect of which is limited to the initial stage of the injection. The simple heating strategy can not effectively meet the deep penetration requirement of the electrolyte in the micro-pore structure of the electrode, and in the rapid cooling process of the electrolyte after liquid injection, the viscosity is often increased along with the phenomenon of volume shrinkage, so that the novel problems of interface desorption or air gap formation and the like are easily caused, and the long-term reliability of the battery is damaged. Therefore, there is a need to develop an innovative method capable of actively controlling the temperature distribution and dynamically optimizing the infiltration kinetics path to solve the infiltration bottleneck of high-viscosity electrolyte in complex microstructure. In view of the above, there is a need in the art for improvements. Disclosure of Invention The application aims to provide a gradient infiltration liquid injection method and system based on dynamic temperature regulation and control and a lithium ion battery so as to solve the problems. In order to achieve the above purpose, the application adopts the following technical scheme: the application provides a gradient infiltration liquid injection method based on dynamic temperature regulation, which comprises the following steps: A pre-heating and low-viscosity filling stage of injecting an electrolyte having a first temperature and a viscosity η1, said first temperature being greater than ambient temperature; The gradient guiding and viscosity rising permeation stage comprises the steps of establishing and maintaining a space temperature field in the battery after electrolyte is injected, and enabling different areas in the battery to be at different temperatures so as to form a temperature gradient, wherein the temperature gradient guides the electrolyte to flow; And in the balancing and stabilizing stage, the whole temperature of the battery is uniformly regulated to the target temperature, and the infiltration is completed. Optionally, the electrolyte has a dynamic viscosity greater than 5 mPa s at 25 ℃. Optionally, the temperature gradient is a vertical gradient gradually decreasing from the liquid injection port to the bottom along the thickness direction of the battery; Or alternatively, the first and second heat exchangers may be, Radial gradients decreasing from the center to the edge of the cell. Optionally, the spatial temperature field is established and maintained by controlling the temperature of different areas of a clamp holding the battery. Optionally, the first temperature is 40-70 ℃. Optionally, the target temperature is 60-80 ℃. Alternatively, η1 is 4-6mpa.s. Alternatively, η2 is 1-3mpa.s. The application also provides a dynamic temperature regulation liquid injection system for realizing the gradient infiltration liquid injection method based on dynamic temperature regulation, which compr