Electric vehicle battery temperature monitoring device

Abstract

The invention relates to the technical field of electric vehicle temperature monitoring devices, in particular to an electric vehicle battery temperature monitoring device which comprises a bag bottom and a bag surface, the edges of the bag bottom and the bag surface are connected to form an inner closed space, and a plurality of thermal reactant pockets are arranged on the bag bottom. The market blank of electric vehicle battery physical warning is filled; the electric vehicle battery does not need to be modified while an existing production line is not required to be changed, the production and installation cost is extremely low, and too high burden cannot be brought to consumers and production enterprises; the shape state of the product is observed regularly, and the stability of the battery operation temperature can be monitored in combination with a BMS system.

Description

Technical Field

[0001] The present invention relates to the technical field of electric vehicle temperature monitoring devices, and particularly to an electric vehicle battery temperature monitoring device. Background Art

[0002] The rise of electric vehicles has provided new solutions for environmental protection and energy conservation. A key component is the energy battery. As the power source of an electric vehicle, the operating temperature range of the battery is crucial for the driving safety of the vehicle. The normal operating temperature range of an electric vehicle battery is between 0 degrees Celsius and 40 degrees Celsius. Within this range, the battery can maintain good performance. If the battery system of an electric vehicle experiences a short circuit or overheating, it is extremely likely to cause spontaneous combustion. Battery thermal runaway, overcharging or discharging, and physical damage to the battery can all lead to abnormal battery systems, thereby triggering fires.

[0003] The working temperature ranges of different types of batteries vary. The following are the working temperature ranges of common batteries: alkaline batteries 0 to 55 degrees Celsius, nickel-cadmium batteries -20 to 50 degrees Celsius, lead-acid batteries -20 to 50 degrees Celsius, and lithium-ion batteries -20 to 60 degrees Celsius.

[0004] The BMS system (Battery Management System) is a battery management system. Its main function is to monitor and manage the state of the battery to ensure the safe and efficient operation of the battery. The BMS system prevents overcharging and over-discharging of the battery by real-time monitoring of key parameters such as the voltage, current, and temperature of the battery, thereby extending the service life of the battery. It can also maintain the consistency of each battery in the battery pack through balancing technology to avoid overcharging or over-discharging of individual batteries. However, frequent electric vehicle spontaneous combustion accidents are all caused by the failure of the BMS system to accurately monitor the battery temperature. The current situation is as follows: Firstly, the monitoring of the electric vehicle battery temperature relies too much on the BMS system and cannot give an alarm in time after the system fails. Therefore, a physical warning system to assist the BMS system is needed. Secondly, the number of currently sold electric vehicles is already relatively large. The method of returning to the factory to replace the warning system and improving the existing electric vehicle battery production line will greatly increase the cost, which is a solution unacceptable to both consumers and manufacturers. Summary of the Invention

[0005] The object of the present invention is to provide an electric vehicle battery temperature monitoring device that does not require changing the existing BMS system. It can provide a device for warning of excessive battery temperature in a physical manner on the basis of the existing BMS system. The purpose of this device is also to meet the characteristics of simple structure and low cost.

[0006] In view of the above ideas, the present invention provides an electric vehicle battery temperature monitoring device, which is characterized in that: the monitoring device is a planar bag structure, which is divided into a bag bottom and a bag surface. The edges of the bag bottom and the bag surface are connected to form an inner closed space. A plurality of heat-reactive pockets are arranged on the bag bottom. The heat-reactive substance releases gas through heating. There is a heat-reactive substance in the heat-reactive pocket, and air holes are arranged on it. The aperture of the air hole is smaller than the minimum diameter of the heat-reactive particles. The bag surface is a folded structure in the shape of a "J", and a through hole is arranged at the center of the bag surface. A sounding piece is fixed in the through hole, and a heat-softening film is pasted on the outer circumference of the through hole.

[0007] Preferably, the heat-softening film is PLA plastic.

[0008] Preferably, the heat-reactive substance is sodium bicarbonate.

[0009] Preferably, an adhesive layer is arranged on the back surface of the bag bottom.

[0010] Preferably, the heat-reactive substance is a mixture of sodium bicarbonate and a catalyst, and the catalyst is a reagent for adjusting the temperature released by heating sodium bicarbonate.

[0011] Preferably, the heat-reactive substance is a mixture of sodium bicarbonate and a color developer, and the color developer is a reagent for coloring the gas released by heating sodium bicarbonate.

[0012] Compared with the prior art, the present invention has the following remarkable advantages: First, the present invention fills the market gap of physical warning for electric vehicle batteries; Second, the present invention does not need to modify the existing production line while modifying the electric vehicle battery, and the production and installation costs are extremely low, which will not bring too much burden to consumers and production enterprises; Third, by regularly observing the shape and state of this product, the stability of the battery operating temperature can be monitored in combination with the BMS system.

[0013] The present invention will be further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the accompanying drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0015] Figure 1 It is a schematic structural diagram of the through hole in the present invention patent;

[0016] In the figure, heat-softening film 1, bag surface 2, through hole 3, sounding piece 4. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0017] To make the objectives, technical solutions and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below.

[0018] Example 1

[0019] For the selection of the thermal reactant, comparative data experiments were carried out between potassium chlorate + manganese dioxide catalyst and sodium bicarbonate.

[0020] Comparative Experiment 1

[0021] Potassium chlorate and manganese dioxide were mixed in a mass ratio of 3:1 and then heated.

[0022] 2MnO2 + KClO3 → 2KCl + Mn2O3 + 3O2↑

[0023] The volume of oxygen obtained from 1 g of potassium chlorate was 0.274 liters under standard conditions, and the oxygen obtained from each 1 g of the mixture was 0.2055 liters.

[0024] Sodium bicarbonate was heated.

[0025] 2NaHCO3 = Na2CO3 + CO2↑ + H2O

[0026] The volume of carbon dioxide obtained from 1 g of sodium bicarbonate was 0.133 liters under standard conditions.

[0027] Example 2

[0028] Observation of the working process of the thermal reactant

[0029] For the mixture of potassium chlorate and manganese dioxide, oxygen began to be released when heated to 100 °C, and began to be released in large quantities when heated to 350 °C.

[0030] Sodium bicarbonate is stable at room temperature and is easily decomposed by heat. It begins to decompose at about 50 °C and completely loses carbon dioxide at 270 °C.

[0031] Example 3

[0032] The expansion shape of the thermal reactant and the operating temperature stability of the electric vehicle battery

[0033] The self-ignition temperature of the electric vehicle battery is 600 °C, and the temperature of the daily working environment is 0 - 40 °C.

[0034] Each gram of the mixture of manganese dioxide and potassium chlorate generates 0.2 liters of oxygen. The reaction start temperature is 100 °C, and its complete release temperature is 350 °C. Each gram of sodium bicarbonate generates 0.13 liters of oxygen. The reaction start temperature is 50 °C, and 270 °C is the complete release of carbon dioxide.

[0035] When the two groups of hot reactants are under the heating stage, they both release gas. The volume inside the sealed bottom and the surface of the bag expands. The zigzag folding structure on the bag surface is stretched and expanded under the influence of air pressure. The PLA plastic on the bag surface softens when heated. When the air pressure reaches its extreme value, the expanding gas breaks through the PLA plastic, and the gas drives the sounding piece to emit a whistle for warning.

[0036] The advantage of the mixture of manganese dioxide and potassium chlorate is that it produces a large volume of gas. Its characteristic is that the starting reaction temperature is high, and the ending reaction temperature is similar to that of sodium bicarbonate. The disadvantage is that the oxygen generated is a combustion-supporting gas, and it is prone to deflagration at too high a temperature.

[0037] The advantage of using sodium bicarbonate as the heating substance is that the starting reaction temperature is close to but higher than the daily working temperature of the electric vehicle battery. When the temperature exceeds 50 degrees Celsius during daily work, the hot reactants can start to react and expand, which is beneficial for periodic vehicle condition inspection. At the same time, the gas generated is carbon dioxide, which is a flame-retardant gas and has higher safety.

[0038] Relatively speaking, it is more ideal to choose sodium bicarbonate as the hot reactant in terms of safety.

[0039] Example 4

[0040] The working temperature ranges of different types of batteries are different. The following are the working temperature ranges of common batteries:

[0041] Alkaline batteries: 0 to 55 degrees Celsius, nickel-cadmium batteries: -20 to 50 degrees Celsius, lead-acid batteries: -20 to 50 degrees Celsius, lithium-ion batteries: -20 to 60 degrees Celsius.

[0042] There are differences in the charging and discharging temperatures of different models of batteries. Therefore, the requirements for the release temperature of the hot reactants need to be changed according to needs. N,N'-dinitrosopentamethylenetetramine, also known as blowing agent H, is an organic compound with the chemical formula C5H10N6O2. It is mainly used as a blowing agent for rubbers, plastics such as polyvinyl chloride, etc. Blowing agent H can adjust the decomposition temperature of sodium bicarbonate to 130 degrees Celsius. After mixing stearic acid with sodium bicarbonate (accounting for 1% to 10%), the heating release temperature of sodium bicarbonate can be reduced. The specific dosage is adjusted according to the thermal reaction temperature requirements of the hot reactants.

[0043] The above blowing agent and stearic acid are used as catalysts for the heating reaction of sodium bicarbonate and are reagents for adjusting the heating release temperature of sodium bicarbonate. The specific adjustment degree is proportioned according to the different temperature requirements of different batteries. At the same time, the blowing agent and stearic acid are only the feasibility of one implementation plan, rather than representing all catalytic reaction reagents.

[0044] Example 5

[0045] Spray bromothymol blue, a light rose-colored crystalline powder, on the inner surface of the bag surface. After the heat reactant undergoes a thermal reaction, carbon dioxide and water are produced. Under high-temperature conditions, bromothymol blue comes into contact with water vapor and is slightly soluble, and a color change reaction can occur after contact with carbon dioxide.

[0046] Example 6

[0047] The specific size of this invention patent can be changed according to usage requirements. By arranging and pasting monitoring devices with a side length of 1 - 2 cm in an array, the working stability of the electric vehicle battery can be determined by observing the high-temperature color change of the local monitoring devices. Similarly, multiple single monitoring devices with a side length of 5 - 10 cm equipped with sound-emitting chips can be pasted to serve as a high-temperature warning device for the electric vehicle battery during driving.

[0048] Example 7

[0049] One of the core objectives of this invention is to provide a device for physically monitoring the temperature of an electric vehicle battery at a low cost. In terms of production cost, the current price of sodium bicarbonate varies from 1000 to 1900 yuan per ton. The cost of each control device with 40 grams of sodium bicarbonate is approximately 0.06 yuan. Taking LDPE as an example, the price of the bag surface and bag bottom materials of the monitoring device is about 8000 yuan per ton, and the cost of the bag surface and bag bottom of each monitoring device is 0.05 to 0.1 yuan. The current price of bromothymol blue (BTB), ACS, with a dye content of 95% is 5100 yuan per ton, and the cost of bromothymol blue required in each monitoring device is less than 0.01 yuan. The raw material cost of each monitoring device is approximately 0.15 to 0.2 yuan.

[0050] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. An electric vehicle battery temperature monitoring device, characterized in that: The monitoring device is a planar bag structure, which is divided into a bag bottom and a bag surface. The edges of the bag bottom and the bag surface are connected to form an inner closed space. A number of pockets for heat reactants are provided on the bag bottom. The heat reactants release gas through heating. There are heat reactants in the pockets for heat reactants, and ventilation holes are provided on them. The aperture of the ventilation holes is smaller than the minimum diameter of the heat reactant particles. The bag surface is a folded structure in the shape of a capital "J", and a through hole is provided at the center of the bag surface. A heat softening film is pasted on the outer circumference of the through hole.

2. The electric vehicle battery temperature monitoring device according to claim 1, wherein: A sounding piece is fixed inside the through hole.

3. The electric vehicle battery temperature monitoring device according to claim 1, characterized in that: The heat softening film is made of PLA plastic.

4. The electric vehicle battery temperature monitoring device according to claim 1, wherein: The heat reactant is sodium bicarbonate.

5. The electric vehicle battery temperature monitoring device according to claim 1, characterized in that: The planar shape of the monitoring device is rectangular. The ultimate expansion volume of the monitoring device is proportional to the mass of the heat reactant. Corresponding to the ultimate expansion volume of 0.8 liters of the monitoring device is 20 to 40 grams of sodium bicarbonate.

6. The electric vehicle battery temperature monitoring device according to claim 1, wherein: An adhesive layer is provided on the back surface of the bag bottom.

7. The electric vehicle battery temperature monitoring device according to claim 3, wherein: The heat reactant is a mixture of sodium bicarbonate and a catalyst, and the catalyst is a reagent for adjusting the temperature at which sodium bicarbonate releases heat.

8. The electric vehicle battery temperature monitoring device according to claim 3, characterized in that: The heat reactant is a mixture of sodium bicarbonate and a color developer, and the color developer is a reagent for coloring the gas released by heating sodium bicarbonate.

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