CN108682919B - A system and method for thermal management of lithium-ion battery packs based on phase-change microcapsule suspensions - Google Patents

Abstract

The present invention discloses a system and method for thermal management of lithium ion battery packs based on phase-change microcapsule suspension. The system includes a box body and a lithium ion battery pack composed of square lithium-ion battery cells arranged side by side in the box body. One side of the lithium ion battery pack is provided with a liquid inlet pipe, and the other side is provided with a liquid outlet pipe. A micro-channel metal plate is also arranged in the box. The micro-channel metal plate and the lithium-ion battery cells are arranged vertically at intervals. A temperature sensor is arranged in the lithium-ion battery pack, and a controller, a water pump, a heater and a radiator are arranged outside the box. and refrigerator. The invention utilizes the characteristics of phase change microcapsule suspension with large latent heat of liquid phase change, constant temperature in the phase change process of microcapsule, and convective heat transfer of the suspension under the action of a water pump, and uses the phase change microcapsule suspension for battery thermal management. The combination of active and passive thermal management, with both heating and cooling functions, enables precise control of the temperature inside the lithium-ion battery pack.

Description

A system for thermal management of lithium-ion battery packs based on phase-change microcapsule suspension and method

Technical field:

The present invention relates to the technical field of lithium ion batteries, in particular to a system and method for thermal management of lithium ion battery packs based on phase-change microcapsule suspension.

Background technique:

As an important part of electric vehicles, lithium-ion batteries have high requirements on the working environment. The results show that temperature has an important influence on the charge-discharge performance and service life of lithium-ion batteries. When the ambient temperature is lower than 0 °C, the internal resistance of the lithium-ion battery is too large when the electrochemical reaction occurs, the discharge power is low, and it cannot be charged normally; The heat is relatively balanced. When charging and discharging at a high rate, the heat production increases rapidly, and the difference between different regions is obvious. The heat production rate is higher in the area near the battery tabs; limited by the battery material, the thermal conductivity of the square battery is very low, and near the tabs The temperature in the middle of the battery is relatively high. If the battery cannot be cooled in a timely and effective manner, it will seriously affect the battery life and even cause safety problems such as thermal runaway. Therefore, in order to ensure the normal operation of the lithium-ion battery pack and prolong the battery cycle life, it is necessary to use the battery pack thermal management system to control the temperature within 25-40°C, and the temperature difference between modules is less than 5°C.

At present, the thermal management of lithium-ion battery packs for electric vehicles mainly adopts air cooling and liquid cooling. Among them, the air cooling method refers to a heat dissipation method that uses low-temperature air as a medium to reduce the temperature of the battery. It uses natural wind or a fan to cool the battery with the radiator that comes with the car. It is the most widely used in the battery thermal management system of electric vehicles. The air cooling system has a simple structure and is easy to maintain, but the cooling effect is poor under the conditions of high ambient temperature and continuous heavy load. Liquid cooling refers to the use of liquid coolant to exchange heat with the battery pack by means of convection heat transfer, to take away the heat generated by the battery to reduce the battery temperature. Since the specific heat capacity and thermal conductivity of the liquid medium are greater than that of air, the convective heat transfer effect is significantly increased and the cooling speed is fast. But this method needs to increase the circulating water pump, which increases the complexity of the system.

Invention content:

The purpose of the present invention is to provide a system and method for thermal management of lithium ion battery packs based on phase change microcapsule suspension, which utilizes the large latent heat of phase change microcapsule suspension liquid phase change, constant temperature during microcapsule phase change, and phase change. The microcapsule suspension has the characteristics of convective heat transfer under the action of the water pump. The phase change microcapsule suspension is applied to the battery thermal management. The active and passive thermal management is combined, and it has both heating and cooling functions. It is suitable for different ambient temperatures and Using the working conditions, the temperature of the battery can be controlled within the optimal range to the maximum extent through the flexible thermal management method, and the maximum temperature difference of the single battery can be reduced, which can effectively improve the safety of the battery, prolong the service life of the battery, and reduce the energy consumption. consumption.

The present invention is achieved through the following technical solutions:

One object of the present invention is to provide a system for thermal management of lithium-ion battery packs based on phase-change microcapsule suspension, including a box body and a plurality of square lithium-ion battery cells arranged in the box and placed side by side vertically. Lithium-ion battery pack, the lithium-ion battery pack is provided with a liquid inlet pipe on one side and a liquid outlet pipe on the other side, and a micro-channel metal plate is also arranged in the box, and the micro-channel metal plate and The lithium-ion battery cells are arranged vertically at intervals, and the phase-change microcapsule suspension enters the microchannel metal plate through the liquid inlet pipe to cool or heat the lithium-ion battery cells, and then flows out through the liquid outlet pipe. The lithium-ion battery pack A temperature sensor is arranged inside, and a controller, a water pump, a heater, a radiator and a refrigerator are arranged outside the box body, and the controller, the heater, the water pump and the box body form a closed battery low-temperature heating loop, The controller, the radiator, the water pump and the box form a closed battery normal temperature cooling loop, the controller, the cooler, the water pump and the box form a closed battery high temperature cooling loop, and the controller also Connect the temperature sensor to receive the signal from the temperature sensor.

Phase change microcapsule suspension is a special functional fluid, which is uniformly mixed by phase change microcapsules and carrier fluid. The phase change material is sealed in the phase change microcapsule, which absorbs and releases a large amount of heat through the latent heat of the phase change, while ensuring a constant temperature. The phase change microcapsule suspension has good flow characteristics and can flow like water when driven by a water pump. The battery thermal management system based on the phase change microcapsule suspension combines the phase change latent heat of the phase change microcapsules and the flow characteristics of the carrier fluid together. The heat exchange temperature difference with the lithium-ion battery is beneficial to improve the convective heat exchange effect. At the same time, the phase-change microcapsule suspension absorbs a large amount of heat through natural convection in a static state. Combined with the heater, radiator, and refrigerator that comes with electric vehicles, it provides the possibility for a flexible and changeable thermal management mode, which is conducive to reducing The energy consumption of the thermal management system.

Preferably, the micro-channel metal plate is provided with a micro-channel for the flow of the phase-change microcapsule suspension, the micro-channel includes several uniformly distributed vertical channels, upper horizontal channels and lower horizontal channels, wherein the inlet of the micro-channel It is located at one end of the upper horizontal channel and at the upper left of the microchannel metal plate, and the outlet of the microchannel is located at one end of the lower horizontal channel and at the lower right of the microchannel metal plate; the total microchannel area of the microchannel metal plate accounts for 70% of the area of the microchannel metal plate. %; the wall thickness of the micro-channel metal plate is 0.5 mm, the cross-section of the micro-channel is rectangular, and the thickness is 3.5 mm.

Preferably, the materials of the microchannel metal plate, the liquid inlet pipe and the liquid outlet pipe are all aluminum. The material of the micro-channel metal plate is aluminum, which enhances the thermal conductivity during the thermal management process and reduces the local temperature difference of the battery.

Preferably, the pipe section of the liquid inlet pipe is flat, and the pipe section of the liquid outlet pipe is flat.

Preferably, the phase-change microcapsule suspension is composed of water with a mass fraction of 80% and phase-change microcapsules with a mass fraction of 20%, and the average particle size of the phase-change microcapsules is 0.1-1000 μm. The temperature of the phase change microcapsules is about 35℃.

Preferably, the wall material of the phase-change microcapsules is melamine resin or urea-formaldehyde resin, and the phase-change material in the phase-change microcapsules is paraffin or paraffin hydrocarbon.

Preferably, the lithium ion battery cell is provided with a positive electrode tab and a negative electrode tab, the liquid inlet pipe is arranged outside the positive electrode tab of the lithium ion battery cell, and the liquid outlet pipe is arranged on the lithium ion battery cell. Below the outer side of the negative electrode tab of the battery cell, the temperature sensor is arranged near the positive electrode tab or the negative electrode tab. Since the temperature at the positive electrode or the negative electrode is the highest, the temperature sensor should be set close to the positive electrode or the negative electrode, so as to detect the temperature of the lithium-ion battery in time and ensure that the lithium-ion battery works within the normal temperature range.

Another object of the present invention is to provide a method for thermal management of a lithium-ion battery pack based on a phase change microcapsule suspension, using the above system, comprising the following steps:

(1) Under cold conditions, the temperature sensor detects that the temperature in the lithium-ion battery pack is lower than 10 °C, the controller starts the water pump and the heater, and opens the battery low-temperature heating loop. After the phase change microcapsule suspension is heated up by the heater, the water pump is heated It enters the box under the drive of the ionizer, flows through the liquid inlet pipe, the microchannel metal plate and the liquid outlet pipe, and heats the lithium-ion battery pack by means of convection heat exchange. The temperature of the ion battery pack is maintained within the optimal range of 25°C to 40°C;

(2) Under normal temperature conditions, when the lithium-ion battery pack is charged and discharged at a small rate, the heat generation of each part of the lithium-ion battery cell is uniform and the heat generation is small, the phase change microcapsule suspension is in a static state, and the lithium ion battery in the lithium-ion battery pack is in a static state. In the microchannel metal plate between the battery cells, the phase change microcapsule suspension absorbs the heat generated by the battery through thermal conduction, and the phase change microcapsule in the phase change microcapsule suspension reduces the maximum temperature of the lithium-ion battery pack by its latent heat of phase change. , Reduce the temperature difference of each part of the lithium-ion battery pack;

(3) Under normal temperature conditions, when the lithium-ion battery pack is charged and discharged at a high rate, the calorific value of each part of the lithium-ion battery cell varies greatly, and the calorific value near the positive electrode tab or the negative electrode tab of the lithium-ion battery cell is large. The highest, when the temperature sensor near the positive electrode or negative electrode detects that the temperature is higher than 40 °C, the controller starts the water pump and radiator, opens the battery cooling loop at room temperature, and the phase change microcapsule suspension is driven by the water pump. The lithium-ion battery pack flows through the liquid inlet pipe, the microchannel metal plate and the liquid outlet pipe, and cools the lithium-ion battery pack by means of convection heat exchange, while reducing the temperature difference between the lithium-ion battery cell and the lithium-ion battery pack, Maintain the temperature of the lithium-ion battery pack within the optimal range of 25°C to 40°C;

(4) In the case of high temperature, when the temperature sensor in the lithium-ion battery pack detects that the temperature of the lithium-ion battery pack is higher than 40°C, the controller starts the water pump and the refrigerator, opens the high-temperature cooling loop of the battery, and the phase-change microcapsule suspension After being cooled by the refrigerator, it enters the lithium-ion battery pack under the drive of the water pump, flows through the liquid inlet pipe, the micro-channel metal plate and the liquid outlet pipe, and cools the lithium-ion battery pack by convection heat exchange, while reducing the lithium ion The temperature difference between the battery cell and the lithium-ion battery pack maintains the temperature of the lithium-ion battery pack within the optimal range of 25°C to 40°C.

The beneficial effects of the present invention are as follows: the present invention utilizes the characteristics of large latent heat of phase change microcapsule suspension liquid phase change, constant temperature during the phase change process of microcapsules, and convective heat transfer of the suspension under the action of a water pump, and suspends the phase change microcapsules. The liquid is used for battery thermal management. The combination of active and passive thermal management has both heating and cooling functions. It is suitable for different ambient temperatures and working conditions, and realizes precise control of the temperature in the square lithium-ion battery pack; The use of water pumps and heaters can effectively heat the battery, so that the lithium-ion battery pack can work at a suitable temperature to ensure the normal operation of the lithium-ion battery pack; under normal temperature and low load conditions, only relying on heat conduction and phase change latent heat of phase change microcapsules can affect the battery. Cooling; under normal temperature and high load conditions, the use of water pumps and radiators can enhance the heat dissipation of the battery through convection heat transfer. Under high temperature conditions, with the use of water pumps and refrigerators, forced convection is used to cool the battery, while absorbing charge and discharge. The heat generated in the process can reduce the temperature of the battery to the maximum extent; on the basis of the application of the phase change microcapsule suspension, the invention can control the temperature of the battery within the optimal range to the greatest extent through a flexible thermal management method, and reduce the temperature of the battery. The maximum temperature difference of the single battery can effectively improve the safety of the battery, prolong the service life of the battery, and reduce the energy consumption at the same time.

Description of drawings:

Fig. 1 is the structural representation of the present invention;

FIG. 2 is a schematic structural diagram of the lithium-ion battery pack in FIG. 1;

Fig. 3 is the longitudinal section of the microchannel metal plate in Fig. 2;

Fig. 4 is the control principle schematic diagram of the present invention;

Description of reference numerals: 1, controller, 2, temperature sensor, 3, water pump, 4, heater, 5, radiator, 6, refrigerator, 7, box, 8, lithium ion battery cell, 9, lithium Ion battery pack, 10, microchannel metal plate, 11, liquid inlet tube, 12, liquid outlet tube, 13, microchannel inlet, 14, microchannel outlet, 15, vertical microchannel, 16, upper (lower) horizontal microchannel Channel, 17. Phase change microcapsule suspension.

Detailed ways:

The following is a further description of the present invention, rather than a limitation of the present invention.

Unless otherwise specified, the equipment and materials mentioned in the present invention are commercially available.

Example:

As shown in Figures 1-4, a thermal management system for a lithium-ion battery pack based on a phase-change microcapsule suspension, the system includes a box 7, a plurality of square lithium ions arranged in the box 7 and placed side by side vertically Lithium-ion battery pack 9 composed of battery cells 8 , phase-change microcapsule suspension 17 , liquid inlet pipe 11 , liquid outlet pipe 12 , microchannel metal plate 10 and temperature sensor 2 , controller 1 arranged outside box 7 , a water pump 3, a heater 4, a radiator 5 and a refrigerator 6, the lithium ion battery cell 8 is provided with a positive electrode tab and a negative electrode tab, one side of the lithium ion battery pack 9 is close to the positive electrode tab of the lithium ion battery cell A flat liquid inlet pipe 11 is provided, a flat liquid outlet pipe 12 is provided below the other side of the lithium ion battery pack 9, and the microchannel metal plate 10 and the square lithium ion battery cells 8 are vertically arranged at intervals. The lithium-ion battery pack 9 is provided with a temperature sensor 3, the heater 4, the radiator 5 and the refrigerator 6 are connected in parallel, and the heater 4 is connected in series with the water pump 3, the liquid inlet pipe 11, the tank 7, the liquid outlet pipe 12 and the controller 1 A closed battery low temperature heating loop is formed. The radiator 5 and the water pump 3, the liquid inlet pipe 11, the box 7, the liquid outlet pipe 12 and the controller 1 are connected in series to form a closed battery normal temperature cooling loop. The refrigerator 6 and the water pump 3. The liquid inlet pipe 11, the box 7, the liquid outlet pipe 12 and the controller 1 are connected in series to form a closed battery high temperature cooling loop. The controller 1 is connected to the temperature sensor 2 and receives the signal from the temperature sensor 2 to decide to run the battery. Low temperature heating loop, battery normal temperature cooling loop or battery high temperature cooling loop, so as to control the operation of the lithium-ion battery thermal management system and ensure the normal operation of the lithium-ion battery.

The liquid inlet pipe 11 is connected to the microchannel inlet 13 of the microchannel metal plate 10, and the liquid outlet pipe 12 is connected to the microchannel outlet 14 of the microchannel metal plate 10. The phase-change microcapsule suspension enters from the liquid inlet pipe 11, and flows into uniform dispersion. The microchannel metal plate 10 between the adjacent lithium ion battery cells 8, and then the microchannels are evenly distributed in the microchannel metal plate 10 to cool or heat the lithium ion battery 8, and the phase change microcapsule suspension 17 is finally cooled or heated by the microchannel. The channel outlet 14 is collected in the liquid outlet pipe 12 and flows out of the battery thermal management system.

The microchannel metal plate 10 is provided with a microchannel for the liquid flow of the phase change microcapsule suspension 17. The microchannel includes several evenly distributed vertical channels 15 and upper (lower) horizontal channels 16, wherein the microchannel inlet 13 is located in the upper horizontal channel. One end of 16, the upper left of the microchannel metal plate 10, the microchannel outlet 14 is located at one end of the lower horizontal channel 16, and the lower right of the microchannel metal plate 10; the total microchannel area of the microchannel metal plate 10 accounts for 70% of the area of the microchannel metal plate 10 ; The wall thickness of the micro-channel metal plate 10 is 0.5 mm, the cross-section of the micro-channel is rectangular, and the thickness is 3.5 mm.

The phase-change microcapsule suspension 17 is composed of water with a mass fraction of 80% and phase-change microcapsules with a mass fraction of 20%. The average particle size of the phase-change microcapsules is 0.1-1000 μm. ℃ or so. The wall material of the phase-change microcapsules is melamine resin or urea-formaldehyde resin, and the phase-change material in the phase-change microcapsules is paraffin or paraffin hydrocarbon.

Using the above device, a method for thermal management of a lithium-ion battery pack based on a phase-change microcapsule suspension, comprising the following steps:

Under cold conditions, the temperature sensor 2 detects that the temperature in the lithium-ion battery pack 9 is lower than 10°C, the controller 1 starts the water pump 3 and the heater 4, opens the battery low temperature heating loop, and the phase change microcapsule suspension 17 passes through the heater. 4. After the temperature rises, it enters the lithium-ion battery pack 9 under the drive of the water pump 3, flows through the liquid inlet pipe 11, the micro-channel metal plate 10, and the liquid outlet pipe 12, and heats the lithium-ion battery pack 9 by means of convection heat exchange. The temperature of the lithium-ion battery pack 9 is controlled to be above 25°C.

Under normal temperature conditions, when the lithium-ion battery pack 9 is charged and discharged at a small rate, the heat generation of each part of the lithium-ion battery cell 8 is relatively uniform and the heat generation is small. The phase change suspension in the battery thermal management system is in a static state, and the lithium-ion battery In the micro-channel metal plate 10 between the lithium-ion battery cells 8 in the group 9, the phase-change suspension absorbs the heat generated by the battery through thermal conduction, and the phase-change microcapsules in the phase-change microcapsule suspension 17 are reduced by their latent heat of phase change. The maximum temperature of the lithium-ion battery pack 9 reduces the temperature difference of each part of the lithium-ion battery pack 9 .

Under normal temperature conditions, when the lithium-ion battery pack 9 is charged and discharged at a high rate, the calorific value of each part of the square lithium-ion battery cell 8 varies greatly. 2 When the temperature is higher than 40°C, the controller 1 starts the water pump 3 and the radiator 5, opens the battery cooling loop at room temperature, and the phase change microcapsule suspension 17 is driven by the water pump 3 to enter the lithium-ion battery pack 9, and flows through the battery pack 9. The liquid inlet pipe 11, the micro-channel metal plate 10, and the liquid outlet pipe 12 cool the lithium-ion battery pack 9 by means of convection heat exchange, and at the same time reduce the temperature difference between the lithium-ion battery cell 8 and the lithium-ion battery pack 9. The temperature of the lithium-ion battery pack is maintained within the optimal range of 25°C to 40°C.

In the case of high temperature, when the temperature sensor 2 in the lithium-ion battery pack 9 monitors that the temperature of the lithium-ion battery pack 9 is higher than 40°C, the controller 1 starts the water pump 3 and the refrigerator 6, opens the high-temperature cooling loop, and the phase-change microcapsules After being cooled by the refrigerator 6, the suspension 17 enters the lithium-ion battery pack 9 under the drive of the water pump 1, flows through the liquid inlet pipe 11, the microchannel metal plate 10, and the liquid outlet pipe 12, and transfers heat to the lithium-ion battery by means of convection heat. The temperature of the group 9 is lowered, and the temperature difference between the lithium ion battery cell 8 and the lithium ion battery group 9 is reduced at the same time, and the temperature of the lithium ion battery group is maintained within the optimal range of 25°C to 40°C.

A system and method for thermal management of lithium ion batteries based on phase change microcapsule suspension provided by the present invention have been described in detail above. The descriptions of the above embodiments are only used to help understand the technical solutions and core ideas of the present invention. It should be pointed out that for those skilled in the art, without departing from the principle of the present invention, several improvements and modifications can also be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims (7)

1. A system for thermal management of a lithium-ion battery pack based on a phase-change microcapsule suspension, characterized in that it comprises a box body and a lithium ion battery composed of a number of side-by-side vertically placed square lithium-ion battery cells arranged in the box body. Ion battery pack, the lithium ion battery pack is provided with a liquid inlet pipe on one side and a liquid outlet pipe on the other side, and a microchannel metal plate is also arranged in the box, and the microchannel metal plate and lithium The ion battery cells are arranged vertically at intervals, and the phase change microcapsule suspension enters the microchannel metal plate through the liquid inlet pipe to cool or heat the lithium ion battery cells, and then flows out through the liquid outlet pipe. A temperature sensor is provided, and a controller, a water pump, a heater, a radiator and a refrigerator are arranged outside the box body, and the controller, the heater, the water pump and the box body form a closed battery low-temperature heating loop, so The controller, radiator, water pump and box form a closed battery cooling loop at room temperature, the controller, cooler, water pump and box form a closed battery high temperature cooling loop, and the controller is also connected to Temperature sensor, receiving the signal from the temperature sensor; The micro-channel metal plate is provided with a micro-channel for the flow of the phase-change microcapsule suspension, the micro-channel includes several evenly distributed vertical channels, an upper horizontal channel and a lower horizontal channel, wherein the inlet of the micro-channel is located in the upper horizontal channel. One end of the channel, the upper left of the microchannel metal plate, the outlet of the microchannel is located at one end of the lower horizontal channel, and the lower right of the microchannel metal plate; the phase change microcapsule suspension is composed of 80% water and 20% water. The phase change microcapsules are composed of the phase change microcapsules, and the average particle size of the phase change microcapsules is 0.1-1000 μm. 2 . The system for thermal management of lithium-ion battery packs based on phase-change microcapsule suspension according to claim 1 , wherein the total microchannel area of the microchannel metal plate accounts for 70% of the area of the microchannel metal plate. 3 . %; the wall thickness of the micro-channel metal plate is 0.5 mm, the cross-section of the micro-channel is rectangular, and the thickness is 3.5 mm. 3. The system for thermal management of lithium-ion battery packs based on phase-change microcapsule suspension according to claim 1, wherein the materials of the microchannel metal plate, the liquid inlet pipe and the liquid outlet pipe are all aluminum . 4 . The system for thermal management of lithium ion battery packs based on phase-change microcapsule suspension according to claim 1 , wherein the pipe section of the liquid inlet pipe is flat, and the liquid outlet pipe has a flat cross-section. 5 . The pipe section is flat. 5. The system for thermal management of lithium-ion battery packs based on phase-change microcapsule suspension according to claim 1, wherein the wall material of the phase-change microcapsules is melamine resin or urea-formaldehyde resin, so The phase-change material in the phase-change microcapsules is paraffin or paraffin hydrocarbon. 6 . The system for thermal management of lithium ion battery packs based on phase change microcapsule suspension according to claim 1 , wherein the lithium ion battery cell is provided with a positive electrode tab and a negative electrode tab, and the The liquid inlet pipe is arranged on the outside of the positive electrode tab of the lithium ion battery cell, the liquid outlet pipe is arranged below the outside of the negative electrode tab of the lithium ion battery cell, and the temperature sensor is close to the positive electrode tab or the negative electrode tab. setting. 7. A method for thermal management of a lithium-ion battery pack based on a phase-change microcapsule suspension, characterized in that the phase-change microcapsule suspension-based lithium-ion battery according to any one of claims 1 to 6 is used. A system for group thermal management, including the following steps: (1) Under cold conditions, the temperature sensor detects that the temperature in the lithium-ion battery pack is lower than 10 °C, the controller starts the water pump and the heater, and opens the battery low-temperature heating loop. After the phase change microcapsule suspension is heated up by the heater, the water pump is heated It enters the box under the drive of the liquid, flows through the liquid inlet pipe, the micro-channel metal plate and the liquid outlet pipe, and heats the lithium-ion battery pack by means of convection heat exchange, and controls the temperature of the lithium-ion battery pack above 25 ℃; (2) Under normal temperature conditions, when the lithium-ion battery pack is charged and discharged at a small rate, the heat generation of each part of the lithium-ion battery cell is uniform and the heat generation is small, the phase change microcapsule suspension is in a static state, and the lithium ion battery in the lithium-ion battery pack is in a static state. In the microchannel metal plate between the battery cells, the phase change microcapsule suspension absorbs the heat generated by the battery through thermal conduction, and the phase change microcapsule in the phase change microcapsule suspension reduces the maximum temperature of the lithium-ion battery pack by its latent heat of phase change. , Reduce the temperature difference of each part of the lithium-ion battery pack; (3) Under normal temperature conditions, when the lithium-ion battery pack is charged and discharged at a high rate, the calorific value of each part of the lithium-ion battery cell varies greatly, and the calorific value near the positive electrode tab or the negative electrode tab of the lithium-ion battery cell is large. The highest, when the temperature sensor near the positive electrode or negative electrode detects that the temperature is higher than 40 °C, the controller starts the water pump and radiator, opens the battery cooling loop at room temperature, and the phase change microcapsule suspension is driven by the water pump. The lithium-ion battery pack flows through the liquid inlet pipe, the micro-channel metal plate and the liquid outlet pipe, and cools the lithium-ion battery pack by means of convection heat exchange, while reducing the temperature difference between the lithium-ion battery cell and the lithium-ion battery pack; (4) In the case of high temperature, when the temperature sensor in the lithium-ion battery pack detects that the temperature of the lithium-ion battery pack is higher than 40°C, the controller starts the water pump and the refrigerator, opens the high-temperature cooling loop of the battery, and the phase-change microcapsule suspension After being cooled by the refrigerator, it enters the lithium-ion battery pack under the drive of the water pump, flows through the liquid inlet pipe, the micro-channel metal plate and the liquid outlet pipe, and cools the lithium-ion battery pack by convection heat exchange, while reducing the lithium ion Temperature difference between battery cells and lithium-ion battery packs.

Images