阅读说明：本技术 一种低温磷酸铁锂锂离子动力电池及其低温放电方法 (Low-temperature lithium iron phosphate lithium ion power battery and low-temperature discharging method thereof ) 是由 不公告发明人 于 2021-08-18 设计创作，主要内容包括：本发明公开了一种低温磷酸铁锂锂离子动力电池,包括电池本体,电池本体安装在壳体组件内,绝缘壳体的两侧分别嵌装有导热体,该导热体由一体式铜质的横导热条和纵导热条组成,横导热条填充在该U形凹槽内；壳体组件包括不锈钢框体,中空盖体通过螺栓安装在不锈钢框体的顶部；不锈钢框体与中空底板设置为一体结构,不锈钢框体设置为内真空层和外真空层的双层中空结构；传输机构包括保温油箱,保温油箱的内部安装有电加热管；本发明通过双层真空的不锈钢框体以及传输机构的设置,能够实现对电池本体预热的作用；同时可以进行保温隔热,避免在低温环境中工作；还可以在工作中进行散热,避免电池本体在高温环境中工作。(The invention discloses a low-temperature lithium iron phosphate lithium ion power battery, which comprises a battery body, wherein the battery body is arranged in a shell assembly, heat conductors are respectively embedded at two sides of an insulating shell, each heat conductor consists of a transverse heat conducting strip and a longitudinal heat conducting strip which are made of integrated copper, and the transverse heat conducting strips are filled in U-shaped grooves; the shell assembly comprises a stainless steel frame body, and the hollow cover body is arranged at the top of the stainless steel frame body through a bolt; the stainless steel frame body and the hollow bottom plate are arranged into an integral structure, and the stainless steel frame body is arranged into a double-layer hollow structure of an inner vacuum layer and an outer vacuum layer; the transmission mechanism comprises a heat-insulating oil tank, and an electric heating pipe is arranged in the heat-insulating oil tank; according to the invention, the battery body can be preheated by arranging the double-layer vacuum stainless steel frame and the transmission mechanism; meanwhile, the heat preservation and insulation can be carried out, so that the work in a low-temperature environment is avoided; the heat dissipation can be carried out in the working process, so that the battery body is prevented from working in a high-temperature environment.)

1. The utility model provides a low temperature lithium iron phosphate lithium ion power battery, its characterized in that, includes battery body (1), super capacitor (3), casing subassembly (2), transmission device (4) and control box (5), install in casing subassembly (2) battery body (1).

2. The low-temperature lithium iron phosphate lithium ion power battery according to claim 1, wherein the battery body (1) comprises an insulating shell (101), a copper current collector (107) is fixedly mounted inside one end of the insulating shell (101), a graphite crystal layer (108) is arranged on one side of the copper current collector (107), an aluminum current collector (112) is mounted inside the other end of the insulating shell (101), a lithium iron phosphate electrode (111) is arranged on one side of the aluminum current collector (112), a diaphragm (109) is connected to the middle of the insulating shell (101), the diaphragm (109) separates the internal seal of the insulating shell (101) into two cavity regions, and the two cavity regions are provided with the electrolyte (110), a negative electrode (106) and a positive electrode (102) are respectively mounted at two ends of the upper part of the insulating shell (101), wherein the negative electrode (106) is electrically connected with the copper current collector (107), the positive electrode (102) is electrically connected with the aluminum current collector (112);

heat conductors are respectively embedded on two sides of the insulating shell (101), each heat conductor is composed of an integrated copper transverse heat conduction strip (105) and a longitudinal heat conduction strip (104), U-shaped grooves (113) which are horizontally concave inwards are formed in the outer walls of the two sides of the insulating shell (101), and the transverse heat conduction strips (105) are filled in the U-shaped grooves (113);

the shell assembly (2) comprises a stainless steel frame body (202), a hollow bottom plate (201) and a hollow cover body (6), the interiors of the hollow bottom plate (201) and the hollow cover body (6) are vacuum, and the hollow cover body (6) is installed on the top of the stainless steel frame body (202) through bolts; the stainless steel frame body (202) and the hollow bottom plate (201) are arranged into an integral structure, and the stainless steel frame body (202) is arranged into a double-layer hollow structure of an inner vacuum layer (2021) and an outer vacuum layer (2022);

the transmission mechanism (4) comprises a heat-preservation oil tank (401), an electric heating pipe (402) is installed inside the heat-preservation oil tank (401), and a first temperature sensor (403) used for detecting the oil temperature inside the heat-preservation oil tank (401) is installed on one side of the heat-preservation oil tank (401);

the bottom of the heat-insulation oil tank (401) is communicated with the inner vacuum layer (2021) through an oil filling pipe (410), an oil filling pump (411) is installed on the oil filling pipe (410), the bottom of the heat-insulation oil tank (401) is communicated with the outer vacuum layer (2022) through an oil pumping pipe (412), an oil well pump (413) is installed on the oil pumping pipe (412), the oil filling pipe (410) is communicated with the end, close to the stainless steel frame body (202), of the oil pumping pipe (412) through a lower communicating pipe (414), and a lower electromagnetic valve (415) is installed on the lower communicating pipe (414);

the upper part of the heat-preservation oil tank (401) is communicated with the inner vacuum layer (2021) through an inner oil return pipe (404), an inner electromagnetic valve (405) is installed on the inner oil return pipe (404), the upper part of the heat-preservation oil tank (401) is communicated with the outer vacuum layer (2022) through an outer oil return pipe (406), an outer electromagnetic valve (407) is installed on the outer oil return pipe (406), the end parts, close to the stainless steel frame body (202), of the inner oil return pipe (404) and the outer oil return pipe (406) are communicated through an upper communication pipe (408), and an upper electromagnetic valve (409) is installed on the upper communication pipe (408); a second temperature sensor (416) for detecting the internal temperature of the shell assembly (2) is arranged at the upper part of one end of the stainless steel frame body (202); a third temperature sensor (417) for detecting the internal temperature of the inner vacuum layer (2021) is arranged at the lower part of one end of the stainless steel frame body (202);

the control box (5) is fixedly arranged on the heat-preservation oil tank (401), and a fourth temperature sensor (501) is further arranged on the control box (5); a single chip microcomputer and a double-battery intelligent management module controlled by the single chip microcomputer are installed in the control box (5), the double-battery intelligent management module is used for managing a battery body (1) and a super capacitor (3), the super capacitor (3) is fixedly installed in a connecting shell (301), and the connecting shell (301) is fixedly connected between the shell assembly (2) and a heat-preservation oil tank (401);

the signal output ends of the first temperature sensor (403), the second temperature sensor (416), the third temperature sensor (417) and the fourth temperature sensor (501) are all connected with a single chip microcomputer, and the oil injection pump (411), the oil well pump (413), the inner electromagnetic valve (405), the outer electromagnetic valve (407), the upper electromagnetic valve (409) and the lower electromagnetic valve (415) are all controlled by the single chip microcomputer;

hollow bottom plate (201) are connected with heat preservation oil tank (401) through connecting plate (7) between, be provided with installing zone (702) on connecting plate (7), oiling pump (411), oil-well pump (413), interior solenoid valve (405), outer solenoid valve (407), go up solenoid valve (409), down solenoid valve (415) all set up in installing zone (702), install L shape cardboard (8) on installing zone (702).

3. The lithium iron phosphate lithium ion power battery with low temperature according to claim 2, wherein the connecting plate (7) and the connecting shell (301) are respectively provided with a clamping hole (701), two ends of the L-shaped clamping plate (8) are respectively provided with a clamping block (802), and the clamping blocks (802) are clamped in the clamping holes (701).

4. The lithium iron phosphate lithium ion power battery with low temperature according to claim 3, wherein a thermal insulation cotton ball is filled between the mounting region (702) and the L-shaped clamping plate (8), the thermal insulation cotton ball plays a thermal insulation role, and a notch (801) convenient to mount and dismount is arranged at the top of the L-shaped clamping plate (8).

5. The low-temperature lithium iron phosphate lithium ion power battery according to claim 2, wherein a through hole (601) is formed in the hollow cover body (6), a sealing and heat-insulating rubber gasket (602) is fixedly bonded to the bottom of the hollow cover body (6), a threaded hole aligned with the through hole (601) is formed in the top of the stainless steel frame body (202), one end of a bolt penetrates through the through hole to be mounted in the threaded hole and fix the hollow cover body (6), and a reserved hole (603) facilitating exposure of the positive electrode (102) and the negative electrode (106) is further formed in the hollow cover body (6).

6. The lithium iron phosphate low-temperature lithium ion power battery as claimed in claim 2, wherein the hollow bottom plate (201) and the hollow cover body (6) are provided with vacuum cavities (2011) inside.

7. The low-temperature lithium iron phosphate lithium ion power battery according to claim 2, wherein the heat-conducting oil which is not easy to volatilize is arranged inside the heat-insulating oil tank (401), the heat-conducting oil occupies 80% -90% of the capacity in the heat-insulating oil tank (401), and the heat-conducting oil is silicone or engine oil; wherein, the residual spaces of the inner vacuum layer (2021), the outer vacuum layer (2022) and the heat-insulating oil tank (401) are set to be vacuum.

8. The lithium iron phosphate lithium ion power battery with low temperature according to claim 2, wherein the two ends of the insulating shell (101) are provided with notches (103) for facilitating the removal of the battery body (1).

9. A method for low temperature discharge of a low temperature lithium iron phosphate lithium ion power cell as claimed in any one of claims 2 to 8, comprising the steps of:

s1, starting for the first time, controlling the super capacitor (3) to supply power through the double-battery intelligent management module, simultaneously starting the electric heating pipe (402) and the oil injection pump (411), and opening the inner electromagnetic valve (405) to realize inner circulation between the inner vacuum layer (2021) and the heat preservation oil tank (401);

s2, when the temperature in the shell assembly (2) rises to 5 ℃, the battery body (1) is controlled to supply power through the double-battery intelligent management module, and meanwhile, the electric heating tube (402) is closed, so that the operation of preheating before discharging in a low-temperature environment is realized, and the discharging in the low-temperature environment is avoided;

s3, when the temperature in the shell assembly (2) rises to 20 ℃, the inner electromagnetic valve (405) is closed, the upper electromagnetic valve (409) and the outer electromagnetic valve (407) are opened, the inner vacuum layer (2021), the outer vacuum layer (2022) and the heat-preservation oil tank (401) form internal circulation, heat is absorbed by heat conduction oil of the inner vacuum layer (2021) and transferred to the outer vacuum layer (2022), heat dissipation is carried out through the side wall, heat dissipation efficiency is improved, and the battery is prevented from working at high temperature;

s4, when the vehicle is flamed out and is not used for a while, the oil injection pump (411), the upper electromagnetic valve (409) and the outer electromagnetic valve (407) are closed, the lower electromagnetic valve (415) is opened, the oil well pump (413) is started, and heat conducting oil in the inner vacuum layer (2021) and the outer vacuum layer (2022) is pumped into the heat preservation oil tank (401) to form double-layer vacuum heat insulation;

s5, when the temperature in the shell assembly (2) is reduced to 0 ℃, the lower electromagnetic valve (415) is closed, the oil injection pump (411) and the inner electromagnetic valve (405) are opened, internal circulation is formed, temperature control is carried out in the shell assembly (2), the temperature reduction of the battery body (1) is avoided, and the next use is facilitated.

10. The method of claim 9, wherein a controller is installed on the vehicle for connecting to a single-chip microcomputer, and the battery operating state or parameters can be adjusted manually.

Technical Field

The invention relates to the technical field of power batteries, in particular to a low-temperature lithium iron phosphate lithium ion power battery and a low-temperature discharging method thereof.

Background

The lithium iron phosphate battery is a lithium ion battery using lithium iron phosphate as a positive electrode material. When the lithium ion battery is charged, part of lithium ions in the lithium iron phosphate are removed and are transferred to the negative electrode through the electrolyte, and meanwhile, electrons are released from the positive electrode and reach the negative electrode from an external circuit to maintain the balance of chemical reaction; during discharging, lithium ions are extracted from the negative electrode and reach the positive electrode through the electrolyte, and meanwhile, electrons are released from the negative electrode and reach the positive electrode from an external circuit to provide energy for the outside. The lithium iron phosphate battery has the characteristics of high output efficiency, no combustion, no explosion, good performance at high temperature, long cycle life, quick charge, low cost, no memory effect, small volume, light weight, no pollution to the environment and the like. Therefore, lithium iron phosphate batteries are widely used in large electric vehicles as well as light electric vehicles.

However, the lithium iron phosphate battery has a large attenuation rate of battery capacity at low temperature, and is not suitable for use in a low-temperature environment; therefore, a low-temperature lithium iron phosphate lithium ion power battery and a low-temperature discharging method thereof are provided.

Disclosure of Invention

The technical task of the invention is to provide a low-temperature lithium iron phosphate lithium ion power battery and a low-temperature discharging method thereof aiming at the defects, and the battery body can be preheated by arranging a double-layer vacuum stainless steel frame and a transmission mechanism; meanwhile, the heat preservation and insulation can be carried out, so that the work in a low-temperature environment is avoided; the heat dissipation can be carried out in the working process, and the problem that the battery body works in a high-temperature environment to solve is avoided.

The technical scheme of the invention is realized as follows:

a low-temperature lithium iron phosphate lithium ion power battery comprises a battery body, a super capacitor, a shell component, a transmission mechanism and a control box, wherein the battery body is arranged in the shell component,

the battery body comprises an insulating shell, a copper current collector is fixedly arranged in one end of the insulating shell, a graphite crystal layer is arranged on one side of the copper current collector, an aluminum current collector is arranged in the other end of the insulating shell, a lithium iron phosphate electrode is arranged on one side of the aluminum current collector, a diaphragm is connected to the middle of the insulating shell, the inside of the insulating shell is sealed and separated into two cavity areas by the diaphragm, electrolyte is arranged in each of the two cavity areas, a negative electrode and a positive electrode are respectively arranged at two ends of the upper part of the insulating shell, the negative electrode is electrically connected with the copper current collector, and the positive electrode is electrically connected with the aluminum current collector;

heat conductors are embedded on two sides of the insulating shell respectively and consist of integrated copper transverse heat conducting strips and integrated copper longitudinal heat conducting strips, U-shaped grooves which are horizontally concave inwards are formed in the outer walls of the two sides of the insulating shell, and the transverse heat conducting strips are filled in the U-shaped grooves;

the shell assembly comprises a stainless steel frame body, a hollow bottom plate and a hollow cover body, the interiors of the hollow bottom plate and the hollow cover body are vacuum, and the hollow cover body is installed at the top of the stainless steel frame body through a bolt; the stainless steel frame body and the hollow bottom plate are arranged into an integral structure, and the stainless steel frame body is arranged into a double-layer hollow structure of an inner vacuum layer and an outer vacuum layer;

the transmission mechanism comprises a heat-preservation oil tank, an electric heating pipe is installed inside the heat-preservation oil tank, and a first temperature sensor used for detecting the oil temperature inside the heat-preservation oil tank is installed on one side of the heat-preservation oil tank;

the bottom of the heat-insulating oil tank is communicated with the inner vacuum layer through an oil injection pipe, an oil injection pump is installed on the oil injection pipe, the bottom of the heat-insulating oil tank is communicated with the outer vacuum layer through an oil pumping pipe, an oil well pump is installed on the oil pumping pipe, the oil injection pipe is communicated with the end part, close to the stainless steel frame body, of the oil pumping pipe through a lower communicating pipe, and a lower electromagnetic valve is installed on the lower communicating pipe;

the upper part of the heat-preservation oil tank is communicated with the inner vacuum layer through an inner oil return pipe, an inner electromagnetic valve is installed on the inner oil return pipe, the upper part of the heat-preservation oil tank is communicated with the outer vacuum layer through an outer oil return pipe, an outer electromagnetic valve is installed on the outer oil return pipe, the end parts, close to the stainless steel frame body, of the inner oil return pipe and the outer oil return pipe are communicated through an upper communicating pipe, and an upper electromagnetic valve is installed on the upper communicating pipe; a second temperature sensor for detecting the internal temperature of the shell assembly is arranged at the upper part of one end of the stainless steel frame body; a third temperature sensor for detecting the internal temperature of the inner vacuum layer is arranged at the lower part of one end of the stainless steel frame;

the control box is fixedly arranged on the heat-preservation oil tank, and a fourth temperature sensor is also arranged on the control box; the control box is internally provided with a single chip microcomputer and a double-battery intelligent management module controlled by the single chip microcomputer, the double-battery intelligent management module is used for managing a battery body and a super capacitor, the super capacitor is fixedly arranged in a connecting shell, and the connecting shell is fixedly connected between the shell assembly and the heat-preservation oil tank;

the signal output ends of the first temperature sensor, the second temperature sensor, the third temperature sensor and the fourth temperature sensor are all connected with the single chip microcomputer, and the oil injection pump, the oil well pump, the inner electromagnetic valve, the outer electromagnetic valve, the upper electromagnetic valve and the lower electromagnetic valve are all controlled by the single chip microcomputer.

Preferably, the hollow bottom plates are connected with the heat-preservation oil tank through connecting plates, mounting areas are arranged on the connecting plates, the oil injection pump, the oil well pump, the inner electromagnetic valve, the outer electromagnetic valve, the upper electromagnetic valve and the lower electromagnetic valve are all arranged in the mounting areas, and the L-shaped clamping plates are mounted on the mounting areas.

Preferably, the connecting plate and the connecting shell are both provided with clamping holes, the two ends of the L-shaped clamping plate are both provided with clamping blocks, and the clamping blocks are clamped in the clamping holes.

Preferably, a heat insulation cotton ball is filled between the mounting area and the L-shaped clamping plate, a heat insulation effect is achieved through the heat insulation cotton ball, and a notch convenient to disassemble and assemble is formed in the top of the L-shaped clamping plate.

Preferably, the hollow cover body is provided with a through hole, the bottom of the hollow cover body is fixedly bonded with a sealing heat-insulating rubber pad, the top of the stainless steel frame body is provided with a threaded hole aligned with the through hole, one end of a bolt penetrates through the through hole to be installed in the threaded hole and fix the hollow cover body, and the hollow cover body is further provided with a reserved hole facilitating exposure of the anode and the cathode.

Preferably, the hollow bottom plate and the hollow cover are provided with vacuum chambers inside.

Preferably, the heat-conducting oil which is not easy to volatilize is arranged inside the heat-insulating oil tank, the heat-conducting oil occupies 80-90% of the capacity in the heat-insulating oil tank, and the heat-conducting oil is silicone or engine oil; wherein, the residual space of the inner vacuum layer, the outer vacuum layer and the heat-insulating oil tank is set to be vacuum.

Preferably, the two ends of the insulating shell are provided with notches which are convenient for taking out the battery body.

The invention also provides a low-temperature discharge method of the low-temperature lithium iron phosphate lithium ion power battery, which comprises the following steps of:

s1, starting for the first time, controlling the super capacitor to supply power through the double-battery intelligent management module, simultaneously starting the electric heating pipe and the oil injection pump, and opening the inner electromagnetic valve to realize inner circulation between the inner vacuum layer and the heat preservation oil tank;

s2, when the temperature in the shell assembly rises to 5 ℃, the battery body is controlled by the double-battery intelligent management module to supply power, and meanwhile, the electric heating pipe is closed, so that the operation of preheating before discharging in a low-temperature environment is realized, and the discharging in the low-temperature environment is avoided;

s3, when the temperature in the shell assembly rises to 20 ℃, the inner electromagnetic valve is closed, the upper electromagnetic valve and the outer electromagnetic valve are opened, the inner vacuum layer, the outer vacuum layer and the heat preservation oil tank form internal circulation at the moment, the heat conduction oil in the inner vacuum layer absorbs the heat and transfers the heat to the outer vacuum layer, the heat is dissipated through the side wall, the heat dissipation efficiency is improved, and the battery is prevented from working at high temperature;

s4, when the vehicle is flamed out and is not used for a while, the oil injection pump, the upper electromagnetic valve and the outer electromagnetic valve are closed at the moment, the lower electromagnetic valve is opened, the oil well pump is started, and heat conducting oil in the inner vacuum layer and the outer vacuum layer is pumped into the heat preservation oil tank to form double-layer vacuum heat insulation;

s5, when the temperature in the shell assembly is reduced to 0 ℃, the lower electromagnetic valve is closed, the oil injection pump and the inner electromagnetic valve are opened to form internal circulation, the temperature in the shell assembly is controlled, the temperature reduction of the battery body is avoided, and the next use is facilitated.

Preferably, a controller connected to the single chip microcomputer is mounted on the vehicle, and the battery operating state or parameters can be adjusted manually.

Compared with the prior art, the invention has the advantages and positive effects that:

1. according to the low-temperature lithium iron phosphate lithium ion power battery, the heat conductors are embedded on the two sides of the insulating shell, so that the heat conduction effect of the battery body is improved, and the battery body is convenient to heat or radiate;

2. according to the low-temperature lithium iron phosphate lithium ion power battery, the preheating effect on the battery body can be realized through the arrangement of the double-layer vacuum stainless steel frame and the transmission mechanism; meanwhile, the heat insulation can be carried out, and the attenuation during the work in a low-temperature environment is avoided; the heat dissipation can be carried out during the work, so that the battery body is prevented from working in a high-temperature environment;

3. according to the low-temperature lithium iron phosphate lithium ion power battery, the super capacitor can perform discharging work first, and when the temperature of the battery body is higher, the battery body is switched to perform discharging work, so that the condition that the battery body works at a low temperature is avoided;

4. according to the discharging method of the low-temperature lithium iron phosphate lithium ion power battery, the double-battery intelligent management module is matched with the single-chip microcomputer to control the transmission mechanism to work, so that the intelligentization is realized, the manual operation is not needed, and the discharging method is very convenient.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

Fig. 1 is a schematic diagram of an exploded structure of a low temperature lithium iron phosphate lithium ion power cell according to an embodiment of the invention;

fig. 2 is a schematic structural view of a battery body according to an embodiment of the present invention;

fig. 3 is an exploded structure view of the inside of a battery body according to an embodiment of the present invention;

FIG. 4 is a schematic cross-sectional view of an insulating housing according to an embodiment of the invention;

FIG. 5 is a schematic structural view of a U-shaped groove according to an embodiment of the present invention;

FIG. 6 is a schematic cross-sectional view of a stainless steel frame according to an embodiment of the present invention;

FIG. 7 is a schematic structural diagram of a transport mechanism according to an embodiment of the present invention;

FIG. 8 is a block diagram of an electrical connection according to an embodiment of the present invention;

fig. 9 is a flowchart illustrating a low-temperature discharge method of a low-temperature lithium iron phosphate lithium ion power battery according to an embodiment of the present invention.

In the figure:

1. a battery body; 101. an insulating housing; 102. a positive electrode; 103. a notch; 104. a longitudinal heat conducting strip; 105. a transverse heat conducting strip; 106. a negative electrode; 107. a copper current collector; 108. a graphite crystal layer; 109. a diaphragm; 110. an electrolyte; 111. a lithium iron phosphate electrode; 112. an aluminum current collector; 113. a U-shaped groove; 2. a housing assembly; 201. a hollow base plate; 2011. a vacuum chamber; 202. a stainless steel frame body; 2021. an inner vacuum layer; 2022. an outer vacuum layer;

3. a super capacitor; 301. a connecting shell; 4. a transport mechanism; 401. a heat preservation oil tank; 402. an electric heating tube; 403. a first temperature sensor; 404. an internal oil return pipe; 405. an inner solenoid valve; 406. an outer oil return pipe; 407. an external solenoid valve; 408. an upper communicating pipe; 409. an upper solenoid valve; 410. an oil filling pipe; 411. an oil injection pump; 412. an oil pumping pipe; 413. an oil well pump; 414. a lower communicating pipe; 415. a lower electromagnetic valve; 416. a second temperature sensor; 417. a third temperature sensor;

5. a control box; 501. a fourth temperature sensor; 6. a hollow cover body; 601. a through hole; 602. sealing the heat insulation rubber pad; 603. reserving a hole; 7. a connecting plate; 701. a clamping hole; 702. an installation area; 8. an L-shaped clamping plate; 801. a recess; 802. and (7) clamping blocks.

Detailed Description

In order that the above objects, features and advantages of the present invention can be more clearly understood, the present invention will be further described with reference to the accompanying drawings and examples. It should be noted that the embodiments and features of the embodiments of the present application may be combined with each other without conflict.

The invention is further described with reference to the following figures and specific examples.

Example 1

As shown in fig. 1-8, a low-temperature lithium iron phosphate lithium ion power battery according to an embodiment of the present invention includes a battery body 1, a super capacitor 3, a housing assembly 2, a transmission mechanism 4, and a control box 5, where the battery body 1 is installed in the housing assembly 2;

as shown in fig. 3 to 5, the battery body 1 includes an insulating case 101, a copper current collector 107 is fixedly mounted inside one end of the insulating case 101, a graphite crystal layer 108 is disposed on one side of the copper current collector 107, an aluminum current collector 112 is mounted inside the other end of the insulating case 101, a lithium iron phosphate electrode 111 is disposed on one side of the aluminum current collector 112, a diaphragm 109 is connected to the middle of the insulating case 101, the diaphragm 109 hermetically separates the inside of the insulating case 101 into two cavity regions, an electrolyte 110 is disposed in each cavity region, a negative electrode 106 and a positive electrode 102 are respectively mounted at two ends of the upper portion of the insulating case 101, wherein the negative electrode 106 is electrically connected to the copper current collector 107, and the positive electrode 102 is electrically connected to the aluminum current collector 112;

as shown in fig. 4 and 5, heat conductors are respectively embedded on two sides of the insulating housing 101, the heat conductors are composed of integrated copper transverse heat conducting strips 105 and longitudinal heat conducting strips 104, the outer walls of two sides of the insulating housing 101 are provided with horizontal concave U-shaped grooves 113, and the transverse heat conducting strips 105 are filled in the U-shaped grooves 113;

as shown in fig. 1 and 6, the housing assembly 2 includes a stainless steel frame 202, a hollow bottom plate 201 and a hollow cover 6, the hollow bottom plate 201 and the hollow cover 6 are in vacuum, and the hollow cover 6 is mounted on the top of the stainless steel frame 202 by bolts; the stainless steel frame 202 and the hollow bottom plate 201 are arranged into an integral structure, and the stainless steel frame 202 is arranged into a double-layer hollow structure of an inner vacuum layer 2021 and an outer vacuum layer 2022;

as shown in fig. 7, the transmission mechanism 4 includes a thermal insulation oil tank 401, an electric heating pipe 402 is installed inside the thermal insulation oil tank 401, and a first temperature sensor 403 for detecting the oil temperature inside the thermal insulation oil tank 401 is installed on one side of the thermal insulation oil tank 401; the bottom of the heat-insulating oil tank 401 is communicated with the inner vacuum layer 2021 through an oil filling pipe 410, the oil filling pipe 410 is provided with an oil filling pump 411, the bottom of the heat-insulating oil tank 401 is communicated with the outer vacuum layer 2022 through an oil pumping pipe 412, the oil pumping pipe 412 is provided with an oil well pump 413, the oil filling pipe 410 is communicated with the end part of the oil pumping pipe 412 close to the stainless steel frame body 202 through a lower communicating pipe 414, and the lower communicating pipe 414 is provided with a lower electromagnetic valve 415;

the upper part of the heat-preservation oil tank 401 is communicated with the inner vacuum layer 2021 through an inner oil return pipe 404, an inner electromagnetic valve 405 is installed on the inner oil return pipe 404, the upper part of the heat-preservation oil tank 401 is communicated with the outer vacuum layer 2022 through an outer oil return pipe 406, an outer electromagnetic valve 407 is installed on the outer oil return pipe 406, the end parts, close to the stainless steel frame body 202, of the inner oil return pipe 404 and the outer oil return pipe 406 are communicated through an upper communicating pipe 408, and an upper electromagnetic valve 409 is installed on the upper communicating pipe 408; a second temperature sensor 416 for detecting the internal temperature of the housing assembly 2 is mounted on the upper portion of one end of the stainless steel frame 202; a third temperature sensor 417 for detecting the internal temperature of the inner vacuum layer 2021 is installed at the lower part of one end of the stainless steel frame 202;

as shown in fig. 1, the control box 5 is fixedly installed on the thermal insulation oil tank 401, and the control box 5 is also provided with a fourth temperature sensor 501; a single chip microcomputer and a double-battery intelligent management module controlled by the single chip microcomputer are installed in the control box 5, the double-battery intelligent management module is used for managing the battery body 1 and the super capacitor 3, the super capacitor 3 is fixedly installed in the connecting shell 301, and the connecting shell 301 is fixedly connected between the shell assembly 2 and the heat preservation oil tank 401;

as shown in fig. 8, the signal output terminals of the first temperature sensor 403, the second temperature sensor 416, the third temperature sensor 417 and the fourth temperature sensor 501 are all connected to a single chip, and the oil injection pump 411, the oil well pump 413, the inner solenoid valve 405, the outer solenoid valve 407, the upper solenoid valve 409 and the lower solenoid valve 415 are all controlled by the single chip. The oil filling pump 411 and the oil well pump 413 are all micropumps, and the inner electromagnetic valve 405, the outer electromagnetic valve 407, the upper electromagnetic valve 409 and the lower electromagnetic valve 415 are all micro electromagnetic valves.

As shown in fig. 1 and 7, the hollow bottom plates 201 are connected with the thermal insulation oil tank 401 through the connecting plate 7, the connecting plate 7 is provided with a mounting area 702, the oil filling pump 411, the oil well pump 413, the inner electromagnetic valve 405, the outer electromagnetic valve 407, the upper electromagnetic valve 409 and the lower electromagnetic valve 415 are all arranged in the mounting area 702, and the mounting area 702 is provided with an L-shaped clamping plate 8. The L-shaped clamping plate 8 is used for protecting and insulating, and the equipment is prevented from working in a low-temperature environment.

As shown in fig. 1, the connecting plate 7 and the connecting shell 301 are both provided with a clamping hole 701, two ends of the L-shaped clamping plate 8 are both provided with a clamping block 802, and the clamping block 802 is clamped in the clamping hole 701. The L-shaped clamping plate 8 is convenient to disassemble and assemble.

Specifically, the heat preservation cotton balls are filled between the mounting area 702 and the L-shaped clamping plate 8, the heat preservation effect is achieved through the heat preservation cotton balls, and the notch 801 convenient to disassemble and assemble is arranged at the top of the L-shaped clamping plate 8. The heat preservation cotton ball is utilized for heat preservation, so that heat is prevented from being emitted outwards from the mounting area 702, and the heat preservation effect is achieved.

As shown in fig. 1, a through hole 601 is formed in the hollow lid 6, a sealing and heat insulating rubber pad 602 is fixedly bonded to the bottom of the hollow lid 6, a threaded hole aligned with the through hole 601 is formed in the top of the stainless steel frame 202, one end of a bolt passes through the through hole and is installed in the threaded hole to fix the hollow lid 6, and a reserved hole 603 for exposing the positive electrode 102 and the negative electrode 106 is further formed in the hollow lid 6. Vacuum chambers 2011 are provided in the hollow base plate 201 and the hollow lid 6.

In implementation, the heat-conducting oil which is not easy to volatilize is arranged inside the heat-insulating oil tank 401, the heat-conducting oil occupies 80% -90% of the capacity in the heat-insulating oil tank 401, and the heat-conducting oil is silicone or engine oil; the remaining spaces of the inner vacuum layer 2021, the outer vacuum layer 2022, and the thermal oil tank 401 are set to be vacuum. The insulating case 101 has notches 103 formed at both ends thereof for easy removal of the battery body 1.

As shown in fig. 9, the low-temperature lithium iron phosphate lithium ion power battery of the present invention includes the following steps:

s1, starting for the first time, controlling the super capacitor 3 to supply power through the double-battery intelligent management module, simultaneously starting the electric heating pipe 402 and the oil injection pump 411, and opening the inner electromagnetic valve 405 to realize the inner circulation between the inner vacuum layer 2021 and the heat preservation oil tank 401;

s2, when the temperature inside the housing assembly 2 rises to 5 ℃, the battery body 1 is controlled by the dual-battery intelligent management module to supply power (wherein the dual-battery intelligent management module is the prior art and includes a power switching circuit), and at the same time, the electric heating tube 402 is turned off, so as to realize the operation of preheating before discharging in a low-temperature environment and avoid discharging in a low-temperature environment;

s3, when the temperature inside the case assembly 2 rises to 20 ℃, the inner solenoid valve 405 is closed, the upper solenoid valve 409 and the outer solenoid valve 407 are opened, so that the inner vacuum layer 2021, the outer vacuum layer 2022 and the thermal oil tank 401 form an internal circulation, the heat-conducting oil in the inner vacuum layer 2021 absorbs the heat and transfers the heat to the outer vacuum layer 2022, and the heat is dissipated through the sidewall, thereby improving the heat dissipation efficiency and preventing the battery from working at high temperature;

s4, when the vehicle is flamed out and is not used for a while, the oil injection pump 411, the upper electromagnetic valve 409 and the outer electromagnetic valve 407 are closed at the moment, the lower electromagnetic valve 415 is opened, the oil well pump 413 is started, and heat conducting oil in the inner vacuum layer 2021 and the outer vacuum layer 2022 is pumped into the heat preservation oil tank 401 to form double-layer vacuum heat insulation;

s5, when the temperature in the shell assembly 2 is reduced to 0 ℃, the lower electromagnetic valve 415 is closed, the oil injection pump 411 and the inner electromagnetic valve 405 are opened, an inner circulation is formed, the temperature in the shell assembly 2 is controlled, the temperature reduction of the battery body 1 is avoided, and the next use is facilitated.

The vehicle is provided with a controller connected with the singlechip, and the working state or parameters of the battery can be adjusted manually.

In the actual application of the method, the device is used,

according to the low-temperature lithium iron phosphate lithium ion power battery, the heat conductors are embedded on the two sides of the insulating shell 101, so that the heat conduction effect of the battery body 1 is improved, and the battery body is convenient to heat or radiate; the battery body 1 can be preheated by the arrangement of the double-layer vacuum stainless steel frame body 202 and the transmission mechanism 4; meanwhile, the heat preservation and insulation can be carried out, so that the work in a low-temperature environment is avoided; the heat dissipation can be carried out during the work, so that the battery body 1 is prevented from working in a high-temperature environment; the super capacitor 3 can perform discharge operation first, and when the temperature of the battery body 1 is higher, the battery body 1 is switched to perform discharge operation, so that the condition that the battery body 1 works at a low temperature is avoided. According to the discharging method of the low-temperature lithium iron phosphate lithium ion power battery, the double-battery intelligent management module is matched with the single-chip microcomputer to control the transmission mechanism 4 to work, so that the intelligentization is realized, the manual operation is not needed, and the discharging method is very convenient.

The present invention can be easily implemented by those skilled in the art from the above detailed description. It should be understood, however, that the intention is not to limit the invention to the particular embodiments described. On the basis of the disclosed embodiments, a person skilled in the art can combine different technical features at will, thereby implementing different technical solutions.