Cooling and heating different-side heat management structure and method for power battery

Abstract

The invention relates to the technical field of power batteries, and discloses a power battery cooling and heating different-side heat management structure and method.The power battery cooling and heating different-side heat management structure comprises a single battery cell, and a heating assembly is arranged at the top of the single battery cell; a cooling assembly is arranged at the bottom of the single battery cell; an upper-layer NTC is arranged at one end of the single battery cell, is arranged close to the heating assembly side and is used for collecting the highest temperature of the system; and a lower NTC is arranged at the other end of the single battery cell, is arranged close to the cooling assembly side and is used for collecting the lowest temperature of the system. The double-layer NTC layered arrangement is adopted, the real heat requirement and the local temperature fluctuation are distinguished, the cooling triggering or heating requirement caused by heating or cooling is reduced, the energy consumption of the whole vehicle is reduced, and the service life of parts is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium-ion power batteries, and in particular to a power battery cooling and heating opposite-side thermal management structure and method. Background Art

[0002] In lithium-ion battery thermal management systems, the accuracy and stability of temperature control directly impacts battery performance, lifespan, and safety. Currently, conventional thermal management methods rely on NTCs (negative temperature coefficient thermistors) placed at key locations within the battery module to monitor temperature and adjust the cooling or heating system based on this temperature data.

[0003] However, in actual operation, due to the uneven temperature distribution within the battery, the NTC near the cooling side may measure a lower temperature due to faster local heat dissipation. This can cause the system to misjudge demand under high-temperature conditions and trigger the heating function unnecessarily. Conversely, under low-temperature heating conditions, the NTC near the heating side may reach the set threshold prematurely due to faster local heating, thereby erroneously triggering the cooling system. This frequent misoperation not only increases the vehicle's energy consumption but also causes key components such as the compressor and heating relay to start and stop repeatedly, accelerating their aging and reducing system reliability. Furthermore, continuous temperature fluctuations can exacerbate internal battery inconsistencies, further affecting the battery's overall lifespan. Summary of the Invention

[0004] The present invention aims to provide a thermal management structure and method for cooling and heating the opposite sides of a power battery, so as to solve the problems of the existing wake-up method, such as high energy consumption and response delay, low balancing efficiency, and inability to optimize and adjust for various working conditions.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: Solution 1: A power battery cooling and heating different-side thermal management structure, including a single cell, a heating component is provided on the top of the single cell; a cooling component is provided at the bottom of the single cell; an upper NTC is provided at one end of the single cell, the upper NTC is arranged close to the heating component side, and is used to collect the highest temperature of the system; a lower NTC is provided at the other end of the single cell, the lower NTC is arranged close to the cooling component side, and is used to collect the lowest temperature of the system.

[0006] Solution 2: A power battery cooling and heating opposite-side thermal management method, applied to the above power battery cooling and heating opposite-side thermal management structure, includes the following management modes: Normal mode: The upper NTC collects the highest temperature of the system; the lower NTC collects the lowest temperature of the system; the actual demand of the system is determined according to the set demand conditions, and enters cooling mode or heating mode when it is met; Cooling mode: Under high temperature conditions, when the upper NTC triggers cooling demand, the lower and upper NTCs will simultaneously reduce the cooling temperature during the cooling process, and the lower NTC temperature reduction is greater than the upper NTC temperature reduction. When the lower NTC temperature drops to the heating demand threshold, cooling is suspended according to the cooling shutdown condition. Heating mode: Under low-temperature conditions, when the lower NTC triggers heating demand, the lower and upper NTCs heat up synchronously during the heating process, and the upper NTC temperature rises faster than the lower NTC temperature rise; when the upper NTC temperature rises to the cooling demand threshold, heating is suspended according to the heating shutdown condition.

[0007] The principles and advantages of this solution are: The limitations of temperature measurement deviations and control strategies in existing lithium-ion battery thermal management systems stem from their traditional design's reliance on a single-layer NTC layout, which prevents the system from accurately sensing the true temperature distribution within the battery. In-depth analysis revealed that due to the significant temperature gradients within the battery module during charge and discharge, single-point or single-layer NTC monitoring methods only reflect local temperatures and fail to capture the overall thermal state. For example, under high-temperature heat dissipation conditions, the NTC on the cooling side, due to its proximity to the cooling source, may be at a lower temperature. The system may misjudge that the battery is still cold, thereby erroneously initiating heating. Conversely, during low-temperature heating, the NTC closer to the heating source heats up faster and reaches the threshold first, triggering unnecessary cooling. This misjudgment not only increases energy consumption but also shortens the lifespan of components such as compressors and relays due to their frequent operation.

[0008] However, existing technologies generally use a single-layer NTC layout. This is driven, in part, by a focus on cost control and system simplification, believing that multi-point temperature measurement increases hardware complexity and the data processing burden on the BMS. Furthermore, the industry has long relied on empirical thermal model compensation, believing that single-point monitoring combined with algorithmic predictions is sufficient. This technical bias has compromised temperature monitoring accuracy and overlooked the potential value of multi-point coordinated temperature measurement in preventing false triggering and optimizing energy consumption.

[0009] This solution breaks with conventional thinking by creatively proposing a dual-layer NTC layout. By placing sensors in layers within the thermally critical areas of the battery module, the system can more comprehensively capture temperature gradients, distinguishing whether the system's highest and lowest temperatures are caused by heating or cooling or actual demand. This allows for a precise assessment of the battery's true thermal state and demand, avoiding misleading local temperature fluctuations. This design not only addresses the vulnerability of single-layer NTCs to local temperature fluctuations, but also fuses data from multiple layers through intelligent algorithms, significantly reducing the probability of misjudgment and unnecessary heating or cooling, ultimately achieving the dual benefits of optimizing energy consumption and extending component life. The ingenuity of this solution lies in its approach, which goes beyond simply increasing the number of sensors. Instead, through a rational spatial layout and data fusion strategy, it elevates temperature monitoring from "single-point inference" to "global awareness," ensuring system reliability while overcoming the inherent shortcomings of existing technologies. This innovative approach transcends the industry's reliance on single-layer NTCs, demonstrating a non-obvious technological breakthrough and providing a superior solution for battery thermal management. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 This is a schematic diagram of the power battery structure of Example 1 of the present invention.

[0011] Figure 2 Schematic diagram of the internal structure of the power battery according to the first embodiment of the present invention.

[0012] Figure 3 This is a schematic diagram of the internal structure of a power battery according to the second embodiment of the present invention.

[0013] Figure 4 for Figure 3 Enlarged view of part A in the middle.

[0014] Figure 5 Schematic diagram of the cooling mode in the thermal management of the power battery according to the third embodiment of the present invention.

[0015] Figure 6 Schematic diagram of the heating mode in the thermal management of the power battery according to the third embodiment of the present invention.

[0016] The symbols in the drawings of the specification include: single cell 1, heating component 2, cooling component 3, upper NTC 4, lower NTC 5, filling material 6, first notch 7, second notch 8, third notch 9, thermal conductive structural glue 10. DETAILED DESCRIPTION

[0017] The following is further described in detail through specific implementation methods: Example 1 This embodiment demonstrates a power battery cooling and heating opposite-side thermal management structure and method, utilizing a dual-layer NTC arrangement to dynamically capture battery temperature gradients, accurately determining the battery's true demand and reducing the potential for misjudgment in single-point predictions. Based on the precise data from the dual-layer NTC, the system can distinguish between true thermal demand and local temperature fluctuations, achieving effective opposite-side thermal management for cooling and heating. This resolves the issue of conflicting cooling and heating triggering and reduces the risk of local overheating or overcooling caused by misjudgment.

[0018] In this embodiment, a power battery cooling and heating side thermal management structure is provided, as shown in the attached Figure 1 As shown, the battery comprises a single cell 1, a heating assembly 2 disposed on the top of the single cell 1, and a cooling assembly 3 disposed on the bottom of the single cell 1. In this embodiment, the heating assembly 2 can be a heating film attached to the top surface of the battery cell 1, which is heated by power supply to achieve heating; the cooling assembly 3 can be a cooling plate or a cooling pipe circulated on the bottom of the battery cell to achieve cooling.

[0019] An upper NTC 4 is installed inside one end of a cell 1, near the heating assembly 2, for collecting the system's highest temperature. It's located 9-11 mm from the top of the cell 1. A lower NTC 5 is installed at the other end of the cell 1, near the cooling assembly, for collecting the system's lowest temperature. It's located 13-16 mm from the bottom of the cell 1. In this embodiment, the upper and lower NTCs 4 and 5 are positioned diagonally to ensure more accurate maximum and minimum temperature measurements and avoid mutual interference that could affect the determination results.

[0020] In this embodiment, the installation structure of the upper NTC4 and the lower NTC5 is as shown in the attached figure. Figure 2 As shown, filling material 6 is placed between the battery cells, forming a material layer. In this embodiment, the filling material is foam or structural material. A first notch 7, which is a rectangular parallelepiped structure, is defined at one end of the filling material 6. The upper NTC 4 is inserted into this notch 7 from the top, positioning the upper NTC 4 entirely above one end of the battery cells. In this embodiment, the insertion depth of the upper NTC 4 can be set to 10 mm.

[0021] A second rectangular notch 8 is defined at the other end of the filler material 6, extending from top to bottom. This notch 8 is longer than the first notch 7, ensuring that the first notch 7 is located at the upper layer of the cell and the second notch 8 is located at the lower layer. The lower NTC 5 is inserted from the top to the bottom of the second notch 8, positioning the lower NTC 5 entirely below the other end of the cell and arranged diagonally with the upper NTC 4. In this embodiment, the lower NTC 5 is inserted to a depth of 15 mm from the bottom of the cell.

[0022] In this embodiment, by introducing a double-layer NTC architecture, a three-dimensional temperature-sensing measurement method is established for the first time in battery thermal management. This structure does not require complex hardware modifications and cleverly circumvents the limitations of algorithm compensation, making the originally fuzzy temperature field clearly discernible. Through the carefully designed double-layer NTC spatial layout, a three-dimensional temperature measurement network is formed in key thermal areas. Combined with an innovative dynamic data analysis and judgment method, the system can intelligently distinguish between local temperature anomalies and overall thermal demand. Not only does this solve the stubborn problem of conflicting cooling and heating triggering in traditional solutions, but it also achieves low energy consumption with almost zero hardware modification and significantly improves component life.

[0023] Example 2 Different from the first embodiment, in this embodiment, as shown in the attached Figure 3 As shown, the upper NTC 4 is arranged on the top of the single cell 1, and the lower NTC 5 is installed on the lower side of the filling material 6. Figure 4 As shown, the upper NTC 4 is bonded to the top of the cell using thermally conductive structural adhesive 10. Filler material 6 is placed between the cells. A third rectangular notch 9 is cut transversely below one end of the filler material 6. The lower NTC 5 is inserted transversely into this notch 9, positioning it below the other end of the cell and diagonally across from the upper NTC 4. In this embodiment, the lower NTC 5 is inserted to a depth of 15 mm from the bottom.

[0024] Through this structural design, the processing flow of filling materials can be further simplified, the improvement of hardware structure can be further reduced, and processing efficiency can be improved. At the same time, double-layer NTC temperature monitoring can be realized, reducing the risk of misjudgment, thereby reducing the energy consumption and cost of the entire vehicle and improving battery life.

[0025] Example 3 In this embodiment, a power battery cooling and heating opposite-side thermal management method is provided, which is applied to the above-mentioned power battery cooling and heating opposite-side thermal management structure. The cooling and heating opposite-side thermal management method is adopted, and the upper NTC and the lower NTC are considered to trigger cooling or heating during normal use, so as to effectively distinguish whether the highest temperature and the lowest temperature of the system are caused by heating or cooling or by real demand, so as to reduce misjudgment. In this embodiment, the bottom cooling and top heating are used as an example to illustrate the thermal management of heating and cooling opposite sides, including the following management modes: 1) Normal mode.

[0026] That is, when there is no heating or cooling, the upper NTC4 detects the system's highest temperature, while the lower NTC5 detects the system's lowest temperature. The system's actual demand is determined based on the set demand conditions, and the system enters cooling mode or heating mode when the demand conditions are met.

[0027] 2) Cooling mode.

[0028] Under high temperature conditions, when the upper NTC4 triggers the cooling demand, the lower NTC5 and the upper NTC4 synchronously reduce the cooling temperature during the cooling process, and the cooling amplitude of the lower NTC5 is greater than that of the upper NTC4; when the temperature of the lower NTC5 drops to the heating demand threshold, cooling is suspended according to the cooling shutdown condition.

[0029] Combined with attachment Figure 5 As shown in the cooling mode management flow chart, in the cooling mode, first the battery PACK is powered on, and the NTC value obtained by the system is read through the BMS. In this embodiment, the temperature value obtained by the upper NTC4 is recorded as T 上1 、T 上2 、T 上3 ...T 上n , the temperature value obtained by the lower NTC5 is recorded as T 下1 、T 下2 、T 下3 ...T 下n Then obtain the highest temperature of the upper NTC And the lowest temperature of the lower NTC .

[0030] In this embodiment, the upper NTC has the highest temperature ; Lower NTC lowest temperature ; And calculate the temperature difference between the highest temperature of the upper NTC layer and the lowest temperature of the lower NTC layer in real time In this embodiment, .

[0031] By monitoring the temperature difference between the upper and lower NTCs, the system determines whether a pre-heating or cooling condition is in effect. When the temperature difference remains within the normal range, it indicates no active heating or cooling. When the temperature difference exceeds the set threshold, it indicates that the system is actively heating or cooling. Using the temperature difference as a basis for judgment, the system accurately distinguishes between heating and cooling conditions and effectively determines whether the condition is due to actual demand or pre-heating thermal management, improving judgment accuracy and reducing the risk of misjudgment and false triggering.

[0032] The cooling requirement is to obtain the highest temperature of the upper NTC and set the highest temperature Cooling demand threshold 1 Compare and calculate the system temperature difference calibration value during heating .

[0033] when ,and , then the cooling start condition is met and a cooling request can be sent to start cooling. In this embodiment, Can be set to 40℃; Can be set to 15℃.

[0034] Or determine the highest temperature of the upper NTC With cooling demand open threshold 2 The size of , then the cooling start condition is met and a cooling request can be sent to start cooling. In this embodiment, Can be set to 50℃.

[0035] The cooling start temperature sets two thresholds to take into account the fact that the temperature difference cannot accurately determine whether cooling is needed under special working conditions. Unable to start cooling, set up a second cooling program based on system safety risks , forced cooling.

[0036] When the cooling start condition is met, the BMS sends a cooling request instruction and sends the target water temperature value T0 to start cooling. At the same time, in this embodiment, the target water temperature value T0 can be set to 25°C.

[0037] During the cooling process, the system determines the highest temperature of the upper NTC, the lowest temperature of the lower NTC, and the temperature difference in real time. When the cooling shutdown conditions are met, the cooling will be shut down.

[0038] In this embodiment, the cooling shutdown condition is the highest temperature of the upper NTC4 ,and ;or .

[0039] Where, The threshold 1 for cooling demand shutdown can be set to 35°C; It is the system temperature difference calibration value during the heating process, which can be set to 15℃; Cooling demand shutdown threshold 2 can be set to 33°C. When the shutdown condition is detected, a shutdown request is sent to terminate the cooling operation, thereby avoiding frequent cooling on and off errors, reducing energy consumption and improving battery life. At the same time, this solution can effectively prevent overcooling of the battery cells by accurately collecting the temperature of the battery cells at the distance from the cooling source, especially in the refrigerant direct cooling solution, thereby controlling the battery cells to operate within a reasonable operating temperature range and reducing the risk of overcooling.

[0040] 3) Heating mode.

[0041] Under low-temperature conditions, when the lower NTC5 triggers the heating demand, the lower NTC5 and the upper NTC4 are heated and heated synchronously during the heating process, and the temperature rise of the upper NTC4 is greater than that of the lower NTC5; when the temperature of the upper NTC4 rises to the cooling demand threshold, the heating is suspended according to the heating shutdown condition.

[0042] As attached Figure 6 As shown, in the heating mode, first the battery pack is powered on and the NTC value is obtained to obtain the highest temperature of the upper NTC. And the lowest temperature of the lower NTC , and the temperature difference between the highest temperature of the upper NTC and the lowest temperature of the lower NTC The calculation process is the same as that in the cooling mode and will not be repeated here.

[0043] The heating requirement condition is to set the minimum temperature Heating demand start threshold 1 Compare and calculate the temperature difference The system temperature difference calibration value during the cooling process For comparison, the lowest temperature of the lower NTC ,and When the heating requirement is met, the upper minimum temperature and the heating requirement threshold 2 are met. For comparison, when , then the heating start requirement is met. In this embodiment, Can be set to -15℃; Can be set to 15℃; It can be set to 0°C to avoid interference or mutual influence, ensure accurate acquisition of actual battery demand, and reduce the risk of misjudgment.

[0044] The heating start temperature sets two thresholds to take into account the fact that the temperature difference cannot accurately determine whether heating is needed under special working conditions. Unable to start heating, set the second heating program based on the risk of system use , forced heating.

[0045] When the heating on condition is met, the BMS closes the heating relay and turns on the heating. During the heating process, the system determines the upper NTC maximum temperature, the lower NTC minimum temperature, and the temperature difference in real time. When the heating off condition is met, the heating is turned off.

[0046] In this embodiment, the heating shut-off condition is the lowest temperature of the lower NTC. ,and ;or .

[0047] Where, The threshold 1 for heating demand shutdown can be set to 10°C; It is the system temperature difference calibration value during the cooling process, which can be set to 10℃; The forced heating shutdown threshold 1 can be set to 20°C. When the shutdown condition is detected, the BMS disconnects the heating relay to end heating, avoiding misjudgments and effectively reducing the risk of local overheating or overcooling, improving safety and stability. This prevents the inability to accurately capture the minimum cell temperature in low-temperature conditions, ensuring accurate acquisition of the minimum and maximum cell temperatures under all operating conditions, resulting in more accurate cell charging and discharging, and a more precise SOC.

[0048] In this embodiment, an innovative battery thermal management method based on a double-layer NTC architecture is proposed to distinguish between the temperature difference of the non-heating system and the temperature difference of the system caused by heating, determine whether cooling is really needed, avoid frequent cooling and the reduction of compressor life, and optimize energy consumption. By breaking through the limitations of traditional single-point temperature measurement, accurate perception and intelligent control of the battery temperature field are achieved. However, the existing technology has been limited to the single-layer NTC layout for a long time. Although this design simplifies the system structure, it cannot capture the true temperature gradient inside the battery, resulting in frequent misjudgments and energy loss. The reason for this is that the industry generally has a fixed mindset that "adding sensors will inevitably increase complexity", as well as a technical bias that over-relies on algorithm compensation and ignores the accuracy of physical monitoring.

[0049] The above is only an embodiment of the present invention, and the common knowledge such as the specific technical solutions and / or characteristics in the solution are not described in detail here. It should be pointed out that for those skilled in the art, without departing from the technical solution of the present invention, several variations and improvements can be made, which should also be regarded as the scope of protection of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the description can be used to interpret the content of the claims.

Claims

1. A power battery cooling and heating opposite-side thermal management structure, characterized by: It includes a single cell, a heating component is provided on the top of the single cell; a cooling component is provided at the bottom of the single cell; an upper NTC is provided at one end of the single cell, the upper NTC is arranged close to the heating component and is used to collect the highest temperature of the system; a lower NTC is provided at the other end of the single cell, the lower NTC is arranged close to the cooling component and is used to collect the lowest temperature of the system.

2. The power battery cooling and heating opposite-side thermal management structure according to claim 1, characterized in that: A filling material is provided between the battery cells, a first notch is provided from top to bottom at one end of the filling material, and the upper NTC is provided in the top of the first notch; a second notch is provided from top to bottom at the other end of the filling material, and the lower NTC is provided at the bottom of the second notch.

3. The power battery cooling and heating opposite-side thermal management structure according to claim 1, characterized in that: The upper NTC is arranged on the top of the single cell; a filling material is arranged between the cells, and the lower NTC is arranged on the lower side of the filling material.

4. The power battery cooling and heating opposite-side thermal management structure according to claim 2, characterized in that: The upper NTC is 9-11 mm away from the top of the single cell; the lower NTC is 13-16 mm away from the bottom of the single cell.

5. The power battery cooling and heating opposite-side thermal management structure according to claim 3, characterized in that: The upper layer NTC is bonded to the top of the battery core by heat-conducting structural glue; a third notch is transversely provided on the lower side of one end of the filling material, and the lower layer NTC is transversely provided in the third notch.

6. A power battery cooling and heating opposite side thermal management method, characterized in that: The power battery cooling and heating opposite-side thermal management structure applied to any one of claims 1-5 includes the following management modes: Normal mode: The upper NTC collects the highest temperature of the system; the lower NTC collects the lowest temperature of the system; the actual demand of the system is determined according to the set demand conditions, and enters cooling mode or heating mode when it is met; Cooling mode: Under high temperature conditions, when the upper NTC triggers cooling demand, the lower and upper NTCs will simultaneously reduce the cooling temperature during the cooling process, and the lower NTC temperature reduction is greater than the upper NTC temperature reduction. When the lower NTC temperature drops to the heating demand threshold, cooling is suspended according to the cooling shutdown condition. Heating mode: Under low-temperature conditions, when the lower NTC triggers heating demand, the lower and upper NTCs heat up synchronously during the heating process, and the upper NTC temperature rises faster than the lower NTC temperature rise; when the upper NTC temperature rises to the cooling demand threshold, heating is suspended according to the heating shutdown condition.

7. The power battery cooling and heating opposite-side thermal management method according to claim 6, characterized in that: In cooling mode, the cooling requirement condition is the highest temperature of the upper NTC ,and ;in, ;or Where, Enable threshold 1 for cooling demand; It is the calibration value of the system temperature difference during the heating process; Turn on threshold 2 for cooling demand.

8. The power battery cooling and heating opposite-side thermal management method according to claim 6, characterized in that: In heating mode, the heating requirement condition is the lowest temperature of the lower NTC ,and ;or Where, Turn on threshold 1 for heating demand; It is the calibration value of the system temperature difference during the cooling process; Turn on threshold 2 for heating demand.

9. The power battery cooling and heating opposite-side thermal management method according to claim 6, characterized in that: In cooling mode, the cooling shut-off condition is the highest temperature of the upper NTC ,and ;or Where, Turn off threshold 1 for cooling demand; It is the calibration value of the system temperature difference during the heating process; Turn off threshold 2 for cooling demand.

10. The power battery cooling and heating opposite-side thermal management method according to claim 6, characterized in that: In heating mode, the heating shut-off condition is the lowest temperature of the lower NTC. ,and ;or Where, Turn off threshold 1 for heating demand; It is the calibration value of the system temperature difference during the cooling process; Turn off threshold 1 for forced heating.

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