Test system of self-heating battery

Abstract

The utility model provides a test system of a self-heating battery. An environment control box is used for controlling temperature and humidity in the box; the self-heating battery cell is placed in the environment control box, and the self-heating battery cell is a naked battery cell obtained by laminating a positive electrode, a negative electrode, a nickel electrode and a diaphragm; the multipath thermodetector is connected with the self-heating battery cell through a circuit and is used for monitoring the electrical index of the self-heating battery cell; the heating control device is used for controlling the heating function of the self-heating battery cell; the device is controlled in a traditional manual mode, is used for single-time or short-term testing, and is high in operation precision and good in convenience; intelligent relay control is adopted for long-term or cyclic testing, and the testing efficiency is improved; according to the utility model, when the heating function of the self-heating cell is verified, short-term and long-term tests can be carried out, a BMS system is directly replaced, and the problems of high use and maintenance cost, inconvenience and the like are effectively solved.

Description

Technical Field

[0001] The utility model relates to the field of lithium-ion batteries, in particular to a testing system for self-heating batteries. Background Art

[0002] While their high energy density and durability have made lithium-ion batteries a staple power source for applications ranging from consumer electronics to electric vehicles, unresolved challenges remain. Lithium-ion batteries experience significant power losses at subzero temperatures due to sluggish charge transfer kinetics, slow solid-state diffusion of lithium in electrode materials, reduced electrolyte diffusivity and conductivity, and high solid electrolyte interface (SEI) resistance, a particularly challenging issue for the expanding electric vehicle industry. These limitations significantly reduce driving range and prohibit regeneration and fast charging in winter, weaknesses that exacerbate drivers' range anxiety. To address this "range anxiety" issue in low-temperature conditions, self-heating batteries have emerged that heat lithium-ion batteries from within the battery.

[0003] While BMS systems are relatively intelligent for testing modules and battery packs, testing single-cell products directly requires complex hardware and software design. These systems often suffer from inconvenient control and complex operation, and professional support is required in the event of equipment failure or technical issues. These systems also impose certain limitations on test scenarios, making it impossible to fully simulate the operating conditions of various usage scenarios. Single-cell testing is expensive, requiring operators to familiarize themselves with the equipment. Furthermore, it's difficult to use a single test system for different cell specifications, resulting in inefficient product development for each specification.

[0004] CN109916454A discloses a battery system thermal runaway simulation device, which heats the battery externally to complete comprehensive data collection after the battery cell thermal runaway. It cannot realize and verify the service life detection of self-heating single battery cell.

[0005] To this end, we propose a self-heating battery testing system to solve the above problems. Utility Model Content

[0006] The purpose of this utility model is to solve the shortcomings of the prior art. In order to achieve the above purpose, this utility model adopts the following technical solutions:

[0007] A self-heating battery testing system comprises a multi-channel thermometer, an environmental control box, a self-heating battery cell and a heating control device; the environmental control box is used to control the temperature and humidity inside the box; the self-heating battery cell is placed in the environmental control box, and the self-heating battery cell is a bare battery cell obtained by laminating a positive electrode, a negative electrode, a nickel electrode and a diaphragm; the multi-channel thermometer is connected to the self-heating battery cell via a circuit and is used to monitor the electrical indicators of the self-heating battery cell; the heating control device is used to control the heating function of the self-heating battery cell.

[0008] Further preferably, the heating control device is a manual switch, and the manual switch is connected in series with the positive electrode of the self-heating battery cell, the shunt, the fuse and the nickel electrode of the self-heating battery cell.

[0009] Further preferably, the heating control device is a relay, and the relay is connected in series with the positive electrode of the self-heating battery cell, the shunt, the fuse and the nickel electrode of the self-heating battery cell.

[0010] Further preferably, the shunt is connected to a multi-channel temperature measuring instrument via a current detection line.

[0011] Further preferably, the relay is connected to the multi-channel temperature measuring instrument through a circuit breaker.

[0012] Further preferably, the multi-channel thermometer is connected to the positive electrode and the negative electrode of the self-heating battery cell respectively through voltage detection lines.

[0013] Further preferably, the multi-channel thermometer monitors the temperature of the self-heating battery core through a temperature monitoring line.

[0014] Compared with the prior art, the beneficial effects of the present invention are:

[0015] This utility model uses a multi-channel thermometer to detect the electrical performance data of the battery cell (circuit current, voltage, temperature, etc.) to test the heating function of the self-heating battery cell. It can meet the requirements of high quality, high efficiency and low cost while simulating real usage conditions. At the same time, it ensures data accuracy and lays a reliable foundation for the consistency of modules / battery packs.

[0016] The utility model adopts traditional manual control for single or short-term testing, and has high operating accuracy and good convenience; it adopts intelligent relay control for long-term or cyclic testing to improve test efficiency; the utility model can perform short-term and long-term tests on self-heating batteries when verifying the heating function, and it directly replaces the BMS system, effectively solving the problems of high use and maintenance costs and inconvenience. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is the circuit diagram of the manual control of the utility model;

[0018] Figure 2 This is the circuit diagram of the intelligent control of this utility model.

[0019] In the figure: manual switch 1, fuse 2, shunt 3, multi-channel temperature meter 4, environmental control box 5, self-heating battery 6, current detection line 7, temperature monitoring line 8, voltage detection line 9, circuit breaker 10, relay N. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0021] Reference Figure 1-Figure 2 A self-heating battery testing system includes a multi-channel thermometer 4, an environmental control box 5, a self-heating battery cell 6 and a heating control device; the environmental control box 5 is used to control the temperature and humidity in the box; the self-heating battery cell 6 is placed in the environmental control box 5, and the self-heating battery cell 6 is a bare battery cell obtained by laminating a positive electrode, a negative electrode, a nickel electrode and a diaphragm; the multi-channel thermometer 4 is connected to the self-heating battery cell 6 through a line to monitor the electrical indicators of the self-heating battery cell 6; the heating control device is used to control the heating function of the self-heating battery cell 6.

[0022] The heating control device is a manual switch 1, which is connected in series with the positive electrode of the self-heating battery core 6, the shunt 3, the fuse 2 and the nickel electrode of the self-heating battery core 6.

[0023] In one implementation: Figure 1 As shown, the current, voltage, temperature and other performance of the battery cell are monitored by a multi-channel thermometer. When heating is required, the manual switch 1 is used to connect the positive electrode and the nickel electrode (ACT). At this time, the positive and negative electrodes of the battery cell are conductive, and the current passes through the nickel foil in series. Under the action of the Joule effect (heat generated by the current passing through the carrier), the battery cell reaches the required equilibrium temperature of 0 or 25°C. When the battery cell temperature reaches the specified value (0 or 55°C), the manual switch 1 is closed to disconnect the positive electrode and the nickel electrode (ACT). The multi-channel thermometer is a separate component with high-precision data acquisition and temperature cut-off functions. Under the control of the multi-channel thermometer, in conjunction with the environmental control box 5 (controlling the constant temperature of the environment) and the manual switch 1, a manual, simple and reliable testing system can be realized.

[0024] In one embodiment, a charge and discharge control device is installed in the environmental control box 5, which can charge the self-heating battery cell 6 to ensure that the battery cell has sufficient power for the next heating after self-heating multiple times (when SOC < 20%).

[0025] The heating control device is a relay N, which is connected in series with the positive electrode of the self-heating battery core 6, the shunt 3, the fuse 2 and the nickel electrode of the self-heating battery core 6.

[0026] In one implementation: Figure 2 As shown, the intelligent closing device features multi-channel control, with the addition of relay N and circuit breaker 10. A multi-channel thermometer 4 sets cutoff conditions (voltage > 2.5V, current = cell voltage / short-circuit internal resistance, temperature = 0 or 25°C). This controls relay N to close, maintaining the cell at a reasonable operating temperature. Excessive operating temperatures (above 65°C) can cause cell failure. During this process, if current or other abnormalities occur (temperature > 65°C, circuit current greater than 20% of the set value), fuse 2 opens, and circuit breaker 10 acts as an emergency switch. If the circuit breaker becomes uncontrolled, the emergency switch closes, relay N opens, and heating stops, ensuring test safety.

[0027] The shunt 3 is connected to the multi-channel thermometer 4 through the current detection line 7; the relay N is connected to the multi-channel thermometer 4 through the circuit breaker 10; the multi-channel thermometer 4 is respectively connected to the positive and negative poles of the self-heating battery core 6 through the voltage detection line 9; the multi-channel thermometer 4 monitors the temperature of the self-heating battery core 6 through the temperature monitoring line 8. Example

[0028] 1. Select cells with good electrical performance consistency from the finished cells and connect them to this test system for performance testing as required:

[0029] 1. Measure the internal resistance between the negative electrode and the nickel electrode (ACT) of the battery cell and check that it is the designed value (e.g. 30±1mΩ);

[0030] 2. Adjust the internal resistance of the connection between the positive electrode and the nickel electrode (ACT) to ≤ 4.5mΩ (the line inside the module is short). The overcurrent value of the incoming wire must be greater than 300A, and the heat resistance performance can be -50~100℃;

[0031] 3. Connect the heating circuit in series from the positive electrode of the battery cell → shunt → fuse → relay + circuit breaker (only manual switch is required in manual mode) → nickel electrode (ACT);

[0032] 4. Connect one end of the temperature sensing wire to the wiring hole on the back of the multi-channel thermometer (temperature, current, voltage, signal control interface is connected to the wire in automatic mode, and the circuit breaker is connected in series), and the other end is attached to the surface of the battery cell to measure the temperature, the positive and negative poles of the battery cell to measure the voltage, and the positive and negative poles of the shunt to detect the circuit current;

[0033] 5. Place the connected battery cells in the incubator, place the multi-channel thermometer outside the incubator, and install the incubator charging device at the positive and negative poles of the battery to facilitate charging when the battery cells are out of power later.

[0034] 6. Set the multi-channel thermometer parameters (protection conditions: voltage <2.3V, current >100A (depending on the battery system), temperature >65℃) (cut-off conditions: temperature = 0℃, voltage <2.5V) (control closing and opening signal conditions: temperature = -30℃ or open, temperature = 0℃ closed) (SOC <40% stops heating, adjust the temperature of the incubator to 25℃, and fully charge the cell).

[0035] 2. To ensure the stability of long-term circulation, use Figure 1 The test system raises the battery cell temperature to 0°C (the specific temperature range can vary according to demand) in a -30°C environment and conducts a test once. The collected temperature rise and electrical performance data must be within the design value range before long-term testing can be carried out.

[0036] 3. Confirm that there is no abnormality in the heating performance of the battery cell. Figure 2 The test system is used for testing. At an ambient temperature of -30°C (the specific temperature range can vary with demand), the battery cell is cyclically heated from -30°C to 0°C. The battery cell is fully charged and heated for 7 cycles. The capacity is calibrated every 50 cycles until the battery cell capacity retention rate reaches 80% or the DCR increases by 30%. The battery cell design is then evaluated to see whether its heating cycle life is within the required range (1000 heating cycles).

[0037] This utility model uses a multi-channel thermometer to detect the electrical performance data of the battery cell (circuit current, voltage, temperature, etc.) to test the heating function of the self-heating battery cell. It can meet the requirements of high quality, high efficiency and low cost while simulating real usage conditions. At the same time, it ensures data accuracy and lays a reliable foundation for the consistency of modules / battery packs.

[0038] The utility model adopts traditional manual control for single or short-term testing, with high operation accuracy and good convenience; it adopts intelligent relay control for long-term or cyclic testing to improve test efficiency; the utility model can perform short-term and long-term tests on self-heating batteries when verifying the heating function, and it directly replaces the BMS system, effectively solving the problems of high use and maintenance costs and inconvenience.

Claims

1. A self-heating battery testing system, characterized in that: Including multi-channel temperature measuring instrument, environmental control box, self-heating battery cell and heating control device; The environmental control box is used to control the temperature and humidity inside the box; The self-heating battery cell is placed in the environmental control box, and the self-heating battery cell is a bare battery cell obtained by laminating a positive electrode, a negative electrode, a nickel electrode and a diaphragm; The multi-channel temperature measuring instrument is connected to the self-heating battery cell through a circuit to monitor the electrical index of the self-heating battery cell; The heating control device is used to control the heating function of the self-heating battery core.

2. The self-heating battery testing system according to claim 1, characterized in that: The heating control device is a manual switch, which is connected in series with the positive electrode of the self-heating battery core, the shunt, the fuse and the nickel electrode of the self-heating battery core.

3. The self-heating battery testing system according to claim 1, characterized in that: The heating control device is a relay, which is connected in series with the positive electrode of the self-heating battery core, the shunt, the fuse and the nickel electrode of the self-heating battery core.

4. The self-heating battery testing system according to claim 2 or 3, characterized in that: The shunt is connected to the multi-channel temperature measuring instrument through a current detection line.

5. The self-heating battery testing system according to claim 3, characterized in that: The relay is connected to the multi-channel temperature measuring instrument through a circuit breaker.

6. The self-heating battery testing system according to claim 1, characterized in that: The multi-channel temperature measuring instrument is respectively connected to the positive electrode and the negative electrode of the self-heating battery cell through voltage detection lines.

7. The self-heating battery testing system according to claim 1, characterized in that: The multi-channel temperature measuring instrument monitors the temperature of the self-heating battery core through a temperature monitoring line.

Images