Lithium battery heating structure

Abstract

The utility model discloses a lithium battery heating structure, which relates to the field of lithium battery heating and comprises a plurality of lithium cells. The heating piece is attached to the outer side faces of the multiple lithium battery cells, the positive electrode of the heating film is connected with the positive electrode of the lithium battery, the negative electrode of the heating film is connected with the negative electrode of the lithium battery, and when the temperature is lower than 0 DEG C, the heating piece starts heating work; one of the two temperature sensors is mounted on the surface of the lithium cell and is used for monitoring the temperature of the lithium cell; one of the two temperature sensors is mounted on the surface of the heating plate and used for monitoring the temperature of the heating plate, the heating plate and the two temperature sensors are arranged, the heating plate is in contact with the lithium battery core of the lithium battery, and the two temperature sensors are in contact with the lithium battery core and the heating plate respectively and used for monitoring the temperature of the lithium battery core and the temperature of the heating plate; and when the temperature is lower than 0 DEG C, the heating plate is used for heating, so that the lithium separation risk of the lithium ion battery can be reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to lithium battery heating field, concretely is a lithium battery heating structure. BACKGROUND

[0002] Lithium ion battery is used for automobile starting has many advantages. For example: self-discharge is low, and storage time is long, instantaneous starting current is high etc. But also have shortcomings, such as 0 degree below cannot charge, and lithium ion battery zero degree below charging will increase the risk of lithium deposition in the cell. Lithium deposition is the phenomenon that lithium ion is abnormally deposited on the surface of negative electrode in the charging process of lithium battery. At low temperature, the risk of lithium deposition increases obviously, and lithium dendrite is more likely to form on the surface of negative electrode. The formation of lithium dendrite is mainly due to the fact that lithium ion is migrated to the negative electrode and deposited on the surface of negative electrode and forms dendritic metallic lithium during the charging process.

[0003] The influence of lithium dendrite mainly embodies in the following aspects:

[0004] 1. Internal short circuit: if lithium dendrite penetrates the separator inside the battery, it will cause the direct contact of positive and negative electrodes, thereby causing internal short circuit. This not only reduces the performance of the battery, but also may cause the self-ignition or explosion of the battery and other serious consequences.

[0005] 2. Shortened battery life: the formation of lithium dendrite consumes the active lithium in the battery, which leads to the gradual reduction of the capacity of the battery, thereby affecting the cycle life of the battery.

[0006] 3. Safety problem: lithium dendrite may cause the self-ignition or explosion of the battery, which threatens the safety of the user.

[0007] Once the vehicle is started, the vehicle-mounted generator will immediately start working to generate power for the vehicle and charge the battery. When the environmental temperature is lower than 0 degree, the vehicle will charge the battery at low temperature once it is started, which causes the lithium deposition risk of lithium ion battery. Therefore, the present application provides a lithium battery heating structure. UTILITY MODEL CONTENTS

[0008] The utility model aims at providing a lithium battery heating structure to solve the technical problems raised in the above background technology.

[0009] To achieve the above object, the utility model provides the following technical scheme: a lithium battery heating structure, comprising:

[0010] A plurality of lithium cells;

[0011] Heating sheet, adhere to the outside of the plurality of lithium cells, the positive electrode of heating film connects the positive electrode of lithium battery, the negative electrode of heating film connects the negative electrode of lithium battery, and the heating sheet starts heating work when the temperature is lower than 0 degree;

[0012] Two temperature sensors, one of which is installed on the surface of the lithium battery cell for monitoring the temperature of the lithium battery cell; the other is installed on the surface of the heating sheet for monitoring the temperature of the heating sheet.

[0013] As a preferred technical scheme of the utility model, the temperature sensor is an NTC temperature sensor.

[0014] As a preferred technical scheme of the utility model, the heating sheet is also attached to the bottom of the lithium battery cell.

[0015] As a preferred technical scheme of the utility model, the outer side of the plurality of lithium battery cells is provided with a support, and the positive and negative poles of the plurality of lithium battery cells are welded together to form a total positive pole and a total negative pole of the lithium battery cell.

[0016] As a preferred technical scheme of the utility model, the support comprises a base and a side plate fixedly connected with the base, the plurality of lithium battery cells are placed on the base, and the upper end of the side plate is further fixedly provided with a partition plate and an upper cover.

[0017] As a preferred technical scheme of the utility model, the upper cover is fixedly provided with a positive pole column and a negative pole column, and the positive pole column is connected with the total positive pole of the lithium battery cell.

[0018] As a preferred technical scheme of the utility model, the outer side of the support is further sleeved with an outer shell body, the heating sheet is located between the lithium battery cell and the outer shell body, and the heating sheet can heat the inner cavity of the outer shell body and the lithium battery cell when heating.

[0019] As a preferred technical scheme of the utility model, the partition plate is further provided with a bms lithium battery protection plate, the total negative pole of the lithium battery cell is connected with a negative pole end of the bms lithium battery protection plate, and a total negative pole end of the bms lithium battery protection plate is connected with the negative pole column of the upper cover.

[0020] As a preferred technical scheme of the utility model, the partition plate is further fixedly provided with a heating control plate, the positive pole of the heating control plate is connected with the positive pole column of the upper cover, the negative pole of the heating control plate is connected with the negative pole column of the upper cover, and the heating control plate is used for controlling the heating work of the heating sheet.

[0021] The heating control plate is provided with a relay one and a relay two, the normally closed end of the relay one of the heating control plate is connected with a charging mos control end pad on the bms protection plate, and the normally open end of the relay two is connected with a power supply line of the heating sheet.

[0022] Compared with the prior art, the utility model has the beneficial effects that:

[0023] The utility model discloses a heating piece and two temperature sensors are set up, and the heating piece contacts the lithium cell of lithium battery, and the two temperature sensors contact the lithium cell and the heating piece respectively, are used for monitoring the temperature of lithium cell and heating piece, can better realize the heating of lithium battery, when being below 0 centigrade, heating piece heating can reduce the risk of lithium ion battery's analysis lithium. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is the whole structure schematic diagram of the utility model;

[0025] Figure 2 It is the placement structure diagram of heating piece and lithium cell of the utility model;

[0026] Figure 3 It is the structure diagram of heating piece, lithium cell, support and baffle of the utility model;

[0027] Figure 4 It is the structure diagram of lithium cell bottom of the utility model;

[0028] Figure 5 It is the structure diagram of lithium cell and support of the utility model;

[0029] Figure 6 It is the structure diagram of baffle and support of the utility model;

[0030] Figure 7 It is the structure diagram of heating control board of the utility model;

[0031] Figure 8 It is the structure diagram of bms protection board of the utility model.

[0032] In the drawing: 1, lithium cell;2, support;21, base;22, side plate;23, baffle;3, heating piece;4, shell;5, upper cover. DETAILED DESCRIPTION

[0033] The technical scheme in the embodiments of the utility model will be described clearly and completely below in conjunction with the drawings in the embodiments of the utility model, and apparently, the described embodiments are only part of the embodiments of the utility model, not all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by the person skilled in the art without creative labor fall within the protection scope of the utility model.

[0034] Please refer to Figures 1-8 The utility model discloses a lithium battery heating structure, including multiple lithium cell 1 and support 2, and support 2 is located at the outside of multiple lithium cell 1, and the lithium cell is encapsulated in the inside of support 2. The positive pole of multiple lithium cell 1 is welded together and extends total positive pole upward, and the negative pole is also welded together and extends total negative pole upward.

[0035] The bracket 2 comprises a base 21, both sides of the base 21 are fixedly installed with side plates 22 through bolts, a plurality of lithium cells 1 are placed on the base 21, the two side plates 22 clamp the plurality of lithium cells 1 in the middle, the upper side of the two side plates 22 is further fixedly installed with a partition plate 23 through bolts, the total positive electrode and the total negative electrode are extended to the upper side of the partition plate 23. An upper cover 5 is fixedly installed on the upper side of the partition plate 23 through bolts.

[0036] The upper cover 5 is fixedly installed with a positive electrode column and a negative electrode column, the partition plate 23 is fixedly installed with a bms battery protection plate through bolts, the total positive electrode of the lithium cell is connected with the positive electrode column, the total negative electrode of the lithium cell is connected with the negative electrode end of the bms battery protection plate, and the total negative electrode end of the bms battery protection plate is connected with the negative electrode column of the upper cover 5. The bms battery protection plate is a prior art, which will not be described here.

[0037] The outer side and the bottom of the plurality of lithium cells 1 are fixedly installed with heating pieces 3, the heating pieces 3 can be connected with the side wall of the lithium cell 1 in a gluing manner, the heating pieces 3 wrap the lithium cell, and the heating effect on the lithium cell can be improved.

[0038] The NTC temperature sensor one and the NTC temperature sensor two are installed on the surface of the heating piece 3 and the surface of the lithium battery, the NTC temperature sensor one is used for monitoring the temperature of the heating piece 3, so as to avoid the situation that the temperature of the heating piece is too high, and the NTC temperature sensor two is used for monitoring the temperature of the lithium cell. The heating piece 3 is provided with a plurality of heating pieces on the surface of the lithium cell, and the specific number is set according to actual use requirements.

[0039] The heating control board is further fixedly installed on the partition plate 23, the main control of the heating control board adopts an STM32F103C8T6 single-chip microcomputer, which is a prior art and will not be described here, the positive electrode of the heating control board is connected with the positive electrode column of the upper cover 5, the negative electrode of the heating control board is connected with the negative electrode column of the upper cover 5, and the heating control board is used for controlling the heating work of the heating piece 3. The working temperature of the heating piece 3 is set to 0 degrees, and when the temperature is lower than 0 degrees Celsius, the heating piece 3 is powered on to heat the lithium battery. Two relays are further provided on the heating control board, which are respectively relay one and relay two, the normally closed end of the relay one of the heating control board is connected with the charging mos control end pad on the bms protection plate, and the normally open end of the relay two is connected with the power supply line of the heating piece.

[0040] Relay one and relay two are normally off by default, when the NTC temperature sensor two is detected to be lower than or equal to the set temperature value (default 0 degrees Celsius) and higher than the set voltage value (default 14V), the switch of relay one and relay two is turned on, when the NTC temperature sensor two is detected to be higher than the set temperature value (1 degree Celsius), a set delay value is entered, when the delay time arrives, the switch of relay one and relay two is turned off. Here, the delay setting is to prevent fluctuations in temperature at the edge of the critical value set by the system from causing frequent action of the relay. When designing the circuit, the delay is set to prevent frequent action of the relay caused by detection fluctuations, and the delay time can be set according to actual use requirements.

[0041] When the temperature is lower than 0 degrees, and the voltage is higher than 14V, the combination logic is confirmed that the ambient temperature is lower than 0 degrees and the car generator starts to work with current output, and the battery is in charging mode. After meeting the conditions, the heating control board will open two relay switches, relay one is a normally closed end control protection board charging mos tube, when relay one is turned on, the normally closed end is disconnected, the battery protection board charging mos tube is turned off, and the battery stops charging. Relay two is a normally open end control heating sheet power supply, when relay two is turned on, the normally open end is closed, the heating plate power supply is turned on, and the heating starts.

[0042] This logic control can prevent the vehicle from opening the heating sheet in the off state to cause the battery to run out of power and fail to start the vehicle. Only in the high voltage state after the generator runs will the heating sheet be turned on, and the generator output will be used to drive the heating sheet to work. And at the same time, the battery charging mos tube is turned off to prevent lithium battery damage caused by charging at low temperature.

[0043] When the temperature is higher than the set temperature, after a delay, relay one and relay two are turned off at the same time, cutting off the battery heating sheet power supply, and turning on the charging mos tube, so that the battery can be normally charged by the generator, avoiding the risk of low temperature charging.

[0044] NTC temperature sensor one is responsible for detecting the temperature of the heating sheet, when it is greater than or equal to the set temperature value (default 80 degrees Celsius), the switch of relay two is turned off, when the temperature is lower than the set temperature value, and condition one is in the state of whether to turn on the switch, if condition one still reaches the state of turning on the switch, the switch is turned on, if condition one does not reach the state of turning on the switch, the switch is turned off.

[0045] In the embodiment, in order to prevent the heating sheet from thermal runaway, the NTC temperature sensor specially monitors the temperature of the heating sheet, and when the temperature exceeds the set safety temperature, the power supply of the heating sheet is turned off.

[0046] The outer side of the support 2 is also sleeved with an outer shell 4, and the upper cover 5 can be fixedly connected with the top of the outer shell 4, the outer shell 4 wraps the support 2 and the plurality of lithium cells inside, the heating sheet 3 is located between the lithium cell and the outer shell 4, and the heating sheet 3 can heat the inner cavity of the outer shell 4 and the lithium cell when heating, and the heating effect on the lithium cell is better.

[0047] Meanwhile, the outer shell 4 also has a protective effect on the lithium cell and the heating sheet, avoiding damage to the lithium battery due to collision.

[0048] Although the embodiments of the present application have been shown and described, it can be understood by those skilled in the art that various changes, modifications, replacements and modifications can be made to these embodiments without departing from the principles and spirits of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A lithium battery heating structure, characterized by, The utility model relates to a lithium battery heating device, comprising: a plurality of lithium cells (1); a heating sheet (3) attached to the outer side of the plurality of lithium cells (1), the positive electrode of the heating film connected to the positive electrode of the lithium battery, the negative electrode of the heating film connected to the negative electrode of the lithium battery, the heating sheet (3) starts heating work when the temperature is below 0 degrees; two temperature sensors, one of which is installed on the surface of the lithium cell to monitor the temperature of the lithium cell, and the other is installed on the surface of the heating sheet (3) to monitor the temperature of the heating sheet (3).

2. The lithium battery heating structure of claim 1, wherein: The temperature sensor is an NTC temperature sensor.

3. A lithium battery heating structure according to claim 2, characterized in that: The heating sheet (3) is also attached to the bottom of the lithium cell.

4. The lithium battery heating structure of claim 1, wherein: The outer side of the plurality of lithium cells (1) is provided with a support (2), and the positive and negative electrodes of the plurality of lithium cells are welded together to form the total positive and negative electrodes of the lithium cell.

5. The lithium battery heating structure of claim 4, wherein: The support (2) comprises a base (21) and a side plate (22) fixedly connected with the base (21), and the plurality of lithium cells are placed on the base (21), and the upper end of the side plate (22) is further fixedly provided with a partition plate (23) and an upper cover (5).

6. The lithium battery heating structure of claim 5, wherein: The upper cover (5) is fixedly provided with a positive electrode column and a negative electrode column, and the positive electrode column is connected with the total positive electrode of the lithium cell.

7. The lithium battery heating structure of claim 4, wherein: The outer side of the support (2) is further provided with an outer shell (4), and the heating sheet (3) is located between the lithium cell and the outer shell (4), so that the heating sheet (3) can heat the inner cavity of the outer shell (4) and the lithium cell.

8. The lithium battery heating structure of claim 5, wherein: The partition plate (23) is further provided with a bms lithium battery protection plate, the total negative electrode of the lithium cell is connected with the cell negative electrode end of the bms battery protection plate, and the total negative electrode end of the bms battery protection plate is connected with the negative electrode column of the upper cover (5).

9. The lithium battery heating structure of claim 1, wherein: The over-temperature protection switch is installed on the heating sheet (3).

10. The lithium battery heating structure of claim 8, wherein: The partition plate (23) is further fixedly provided with a heating control board, the positive electrode of the heating control board is connected with the positive electrode column of the upper cover (5), the negative electrode of the heating control board is connected with the negative electrode column of the upper cover (5), and the heating control board is used for controlling the heating work of the heating sheet (3). The heating control board is provided with a relay one and a relay two, the normally closed end of the relay one of the heating control board is connected with the charging mos control end pad on the bms protection plate, and the normally open end of the relay two is connected with the power supply line of the heating sheet.

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