阅读说明：本技术 防爆抑爆锂离子动力电池系统及其控制方法 (Explosion-proof explosion-suppression lithium ion power battery system and control method thereof ) 是由 谢松 黎桂树 平现科 陈现涛 贺元骅 于 2021-09-06 设计创作，主要内容包括：本发明涉及一种防爆抑爆锂离子动力电池系统及其控制方法,包括单体电池组成的锂离子动力电池组,锂离子动力电池组安装在电池模组外壳内,每个单体电池的顶部设有外向安全阀,底部设有内向安全阀,内向安全阀连接有管道,每个管道均汇集到管道集成装置,然后通过压力泵连接到废弃电解液储液罐,废弃电解液储液罐设有排液阀门,压力泵设有排气管道阀门；锂离子动力电池组的电池正负极、压力泵还分别与电池管理系统控制单元电信号连接。本发明能在锂离子电动力电池内部发生失控反应导致安全阀爆开后有效控制可燃气体的浓度,降低电池发生自燃与爆炸的危险；可以实现漏液收集与降温的效果,结构简单。(The invention relates to an explosion-proof explosion-suppression lithium ion power battery system and a control method thereof, and the system comprises a lithium ion power battery pack consisting of single batteries, wherein the lithium ion power battery pack is arranged in a battery module shell; the positive and negative electrodes of the battery of the lithium ion power battery pack and the pressure pump are respectively connected with the control unit of the battery management system through electric signals. The invention can effectively control the concentration of combustible gas after the safety valve is exploded due to the out-of-control reaction inside the lithium ion power battery, thereby reducing the danger of spontaneous combustion and explosion of the battery; the effect of weeping collection and cooling can be realized, simple structure.)

1. The explosion-proof explosion-suppression lithium ion power battery system comprises a lithium ion power battery pack (2) consisting of single batteries, wherein the lithium ion power battery pack (2) is installed in a battery module shell (1), and is characterized in that an outward safety valve (11) is arranged at the top of each single battery, an inward safety valve (13) is arranged at the bottom of each single battery, the inward safety valves (13) are connected with pipelines, each pipeline is converged to a pipeline integration device (8), and then is connected to a waste electrolyte liquid storage tank (3) through a pressure pump (5), the waste electrolyte liquid storage tank (3) is provided with a liquid discharge valve (4), and the pressure pump (5) is provided with an exhaust pipeline valve (6);

the positive and negative electrodes (12) of the lithium ion power battery pack (2) and the pressure pump (5) are respectively connected with the battery management system control unit (7) through electric signals.

2. An explosion-proof and explosion-proof lithium ion power battery system according to claim 1, characterized in that the side wall of the waste electrolyte storage tank (3) is provided with a phase change material (9), and the inner surface of the phase change material (9) is provided with an adsorption material (10).

3. An explosion-proof and explosion-suppression lithium ion power battery system according to claim 1, characterized in that the pressure pump (5) is a gas-liquid pressure pump.

4. The control method of an explosion-proof and explosion-proof lithium ion power battery system according to any one of claims 1 to 3, characterized by comprising the steps of:

when the lithium ion power battery pack (2) works, gas production and heat generation are started after an out-of-control reaction occurs in a single battery in the battery pack, the battery shell rapidly expands, and the internal pressure of the battery is increased to enable the outward safety valve (11) to be exploded outwards; meanwhile, the battery management system control unit (7) responds quickly after receiving the electric signal of the battery, controls the pressure pump (5) to start to extract the smoke, opens the exhaust pipeline valve (6) through the pressure pump (5), and discharges the combustible smoke generated by the battery into the atmosphere through the exhaust pipeline to dilute the combustible smoke;

the pressure pump (5) continuously pumps the electrolyte in the battery after discharging the flue gas, when the pressure in the battery is too low, the pressure pump (5) inwards pops open the internal safety valve (13), and the residual electrolyte is discharged into the waste electrolyte storage tank (3) together by the pressure pump (5) for cooling so as to inhibit the self reaction;

meanwhile, under the action of the pressure pump (5), convection heat exchange is formed between the interior of the battery and the outside, and the temperature in the battery is reduced to prevent excessive heat generation.

Technical Field

The invention belongs to the technical field of lithium batteries, and particularly relates to an explosion-proof and explosion-suppression lithium ion power battery system and a control method thereof.

Background

With the wide application of lithium ion batteries in the fields of portable equipment, electric automobiles, aerospace and the like, the safety problem of the lithium ion batteries is more and more prominent. The lithium ion power battery can be aged and attenuated to a certain degree in the normal use process, when the lithium ion power battery is subjected to abuse conditions such as overdischarge, overcharge, external short circuit, extrusion, falling and the like, the electrolyte is easy to decompose and generate toxic and flammable smoke due to internal reaction of the lithium ion power battery, and serious safety accidents can occur when the smoke concentration is too high.

In order to avoid explosion of the sealed metal shell when the lithium ion power battery fails, the lithium ion power battery is provided with a safety valve at the top. The safety valve is an important explosion-proof barrier for each lithium ion power battery, and when the internal pressure of the battery is overlarge, the top safety valve can open to exhaust and reduce the pressure, so that explosion is avoided. However, after the safety valve is opened, chemical substances leaked from the inside of the battery may chemically react with oxygen in the air under high temperature conditions, and thus fire may be generated.

Patent application No.: 202020124787.3, discloses a leakage flow guide structure for lithium battery electrolyte. The utility model discloses a pipe among the lithium cell weeping water conservancy diversion structure that the patent provided is used for guiding lithium cell relief valve combustion gas, liquid entering collection liquid storehouse. The liquid collecting bin plays a role in buffering gas and liquid sprayed by the lithium battery safety valve, and then the leakage liquid in the liquid collecting bin is discharged by the liquid discharge pipe, so that the lithium battery is prevented from being corroded by the leakage liquid adhered to the lithium battery, and meanwhile, the battery is prevented from being short-circuited by the leakage liquid. However, the structure as a whole requires a very large layout space and is not suitable for practical engineering applications. Meanwhile, the influence on the leakage pressure of the electrolyte is not considered, the liquid discharging effect is not obvious, the effect of isolating leakage, air leakage and battery cannot be achieved, the safety of the battery cannot be ensured, and the possibility of explosion reaction still exists after the electrolyte and the smoke are discharged.

Patent application No.: 202020150546.6, discloses a safety device of pressure relief valve of lithium ion power battery. The pressure relief valve device is arranged on an upper cover of the lithium ion power battery, a shell vent hole is arranged at an opening in the central position of the upper cover of the lithium ion power battery, at least one aluminum plate is arranged in the pressure relief valve device, and the peripheral edge of the aluminum plate is nicked or indented. When the internal pressure of the battery is too high, the device exhausts and reduces pressure in time through the arranged aluminum plate structure, so that safety accidents are avoided, and the safety performance of the lithium ion power battery is improved. However, the opening pressure of the aluminum plate additionally arranged on the device cannot be accurately controlled, the sealing performance of the power battery may be affected, and the device is easily opened in the use process of the lithium ion power battery, so that the safety problem of the lithium ion power battery is caused.

In summary, the safety valve of the conventional lithium ion power battery can only release pressure and exhaust gas after the battery generates gas and internal short circuit, but cannot inhibit the reaction inside the battery, the discharged combustible gas has a risk of combustion and explosion after reaching a certain concentration, and the electrolyte directly contacts with air after the safety valve is exploded, so that the risk of combustion promotion is also existed, and therefore, there is a strong need to develop an explosion-proof and explosion-suppression lithium ion power battery system, which can effectively inhibit the safety problems of spontaneous combustion, explosion and the like of the lithium ion power battery.

Disclosure of Invention

The invention adopts a battery system which utilizes a gas-liquid pressure pump to suck out flue gas and electrolyte in the pressure relief process of a lithium ion power battery safety valve. The system quickly sucks out the flue gas after short circuit gas generation in the battery, opens an electrolyte valve after expansion flue gas in the battery is exhausted, strongly sucks out electrolyte into a collection tank, relieves the reaction of the anode and the cathode of the battery, reduces the short circuit current in the battery, reduces the internal electrochemical reaction heat, and reduces the temperature of the electrolyte to be below the ignition point due to the fact that heat absorbing materials such as phase change materials are arranged on the inner wall of the tank body. After the internal pressure of the battery is reduced to a certain degree, the one-way safety valve is opened, residual electrolyte is discharged through air strong replacement, and meanwhile the effect of reducing the internal temperature of the battery is achieved, and the safety of the battery is ensured.

The specific technical scheme is as follows:

the explosion-proof explosion-suppression lithium ion power battery system comprises a lithium ion power battery pack consisting of single batteries, wherein the lithium ion power battery pack is arranged in a battery module shell, the top of each single battery is provided with an outward safety valve, the bottom of each single battery is provided with an inward safety valve, the outward safety valves are connected with pipelines, each pipeline is converged into a pipeline integration device and then is connected to a waste electrolyte storage tank through a pressure pump, the waste electrolyte storage tank is provided with a liquid discharge valve, and the pressure pump is provided with an exhaust pipeline valve;

the positive and negative electrodes of the battery of the lithium ion power battery pack and the pressure pump are respectively connected with the control unit of the battery management system through electric signals.

The side wall of the waste electrolyte storage tank is provided with a phase-change material, and the inner surface of the phase-change material is provided with an adsorption material.

The pressure pump is a gas-liquid pressure pump.

The battery is provided with the special inward safety valve, when the pressure pump pumps the electrolyte, the inward safety valve is bounced inward under the action of pressure, so that the pressure pump can be used for pumping the residual electrolyte in the battery, and meanwhile, the convection heat exchange cooling can be realized.

The invention effectively reduces the concentration of combustible flue gas by guiding the combustible flue gas into the atmosphere through the gas guide pipe, and reduces the danger of explosion accidents caused by overhigh concentration of the combustible flue gas near the battery pack.

The invention utilizes the signal of the battery management system to control the working state of the pressure pump without additionally resetting a control device.

The invention actively collects the electrolyte in the waste electrolyte storage tank, and the adsorption material in the tank body and the phase-change material on the inner wall cool the electrolyte and inhibit the reaction of the electrolyte.

The invention can realize the safe explosion prevention and control of the power battery only by adding the pressure pump, the waste electrolyte storage tank and related pipeline connection on the original battery system, conforms to the light weight design in practical application and has low additional installation cost.

The control method of the explosion-proof explosion-suppression lithium ion power battery system comprises the following steps:

when the lithium-ion power battery pack works, gas production and heat generation are started after an out-of-control reaction occurs in a single battery in the lithium-ion power battery pack, the battery shell rapidly expands, and the internal pressure of the battery is increased to enable the outward safety valve to be exploded outwards; meanwhile, the control unit of the battery management system rapidly responds after receiving the electric signal of the battery, controls the pressure pump to start to pump the smoke, opens the valve of the exhaust pipeline, and discharges the combustible smoke generated by the battery into the atmosphere through the exhaust pipeline to dilute the combustible smoke;

the pressure pump continuously pumps the electrolyte in the battery after discharging the flue gas, when the pressure in the battery is too low, the electrolyte bounces inwards towards the internal safety valve, and the pressure pump discharges the residual electrolyte into the waste electrolyte storage tank for cooling so as to inhibit the self reaction of the electrolyte;

meanwhile, under the action of the pressure pump, convection heat exchange is formed between the interior of the battery and the outside, and the temperature in the battery is reduced to prevent excessive heat generation.

The technical scheme of the invention has the following beneficial effects:

1. the invention can effectively control the concentration of combustible gas after the safety valve is exploded due to the out-of-control reaction inside the lithium ion power battery, and reduce the risk of spontaneous combustion and explosion of the battery.

2. The invention can realize the effects of leakage liquid collection and temperature reduction, and can quickly collect the electrolyte of the lithium ion power battery after leakage, thereby avoiding the further violent chemical reaction caused by the contact of the electrolyte and air and quickly reducing the temperature of the electrolyte under the action of the phase-change material.

3. The system disclosed by the invention is simple in design structure and meets the light weight requirement of the power battery on the actual design of the new energy electric automobile.

4. The invention immediately intervenes to work after single or a plurality of batteries in the lithium ion battery pack are out of control due to heat, and the system can still continue to work normally after the system reaches a safe state and the waste electrolyte in the liquid storage tank and the pipeline is cleaned to replace the failed battery.

5. The invention can also realize early warning of the whole battery pack in the working process, and the battery management system sends out a control instruction after receiving a signal that the first safety valve of the lithium ion battery bursts.

6. The application scene of the invention is not limited in the new energy electric automobile, the control function of the battery management system can be realized based on the embedded development of a single chip microcomputer or a raspberry group, and the application of the lithium ion battery in other use scenes is realized.

Drawings

FIG. 1 is a schematic view of the overall structure of the present invention;

FIG. 2 is a structural layout diagram of the present invention;

FIG. 3 is a cross-sectional view of a spent electrolyte reservoir;

fig. 4 is a schematic view of a unit cell.

In all the drawings, 1-a battery module shell, 2-a lithium ion power battery pack, 3-a waste electrolyte storage tank, 4-a liquid discharge valve, 5-a pressure pump, 6-an exhaust pipeline valve, 7-a battery management system control unit, 8-a pipeline integration device, 9-a phase change material, 10-an adsorption material, 11-an outward safety valve, 12-a battery anode and a battery cathode and 13-an inward safety valve.

Detailed Description

The specific technical scheme of the invention is described by combining the embodiment.

The explosion-proof explosion-suppression lithium ion power battery system comprises a lithium ion power battery pack 2 consisting of single batteries, wherein the lithium ion power battery pack 2 is arranged in a battery module shell 1, the top of each single battery is provided with an outward safety valve 11, the bottom of each single battery is provided with an inward safety valve 13, each inward safety valve 13 is connected with a pipeline, each pipeline is converged to a pipeline integration device 8 and then is connected to a waste electrolyte storage tank 3 through a pressure pump 5, the waste electrolyte storage tank 3 is provided with a liquid discharge valve 4, and the pressure pump 5 is provided with an exhaust pipeline valve 6;

the positive and negative electrodes 12 of the lithium ion power battery pack 2 and the pressure pump 5 are also respectively connected with the battery management system control unit 7 through electric signals.

The side wall of the waste electrolyte storage tank 3 is provided with a phase-change material 9, and the surface of the phase-change material 9 is provided with an adsorption material 10.

The pressure pump 5 is a gas-liquid pressure pump.

Battery module shell 1 for the work of the battery of fixed mounting group battery of being convenient for, group battery shell all is the higher non-metallic material of rigidity usually, also plays the effect of protection to the group battery.

The lithium ion power battery pack 2 is characterized in that a plurality of lithium ion power batteries are usually connected in parallel into a group in practical application, and the battery packs are connected in series to form the whole lithium ion power battery module.

Waste electrolyte liquid storage pot 3, the electrolyte storage that takes out force pump 5 through the pipeline is in the jar, and jar internal wall has phase change material 9, adsorbing material 10, and it cools down rapidly to discharge waste electrolyte liquid storage pot 3 with it when force pump 5 takes out electrolyte, avoids electrolyte to expose in the external environment acceleration reaction to restrain electrolyte self and take place the reaction.

And in the working process of the system, the liquid discharge valve 4 discharges the waste electrolyte to the waste electrolyte storage tank 3, and after the waste electrolyte is cooled and stops reacting, the waste electrolyte in the storage tank needs to be treated, so that the work of the storage tank is prevented from being influenced.

The pressure pump 5 is a gas-liquid pressure pump, the function of extracting smoke gas and liquid is realized by receiving a control signal of the battery management system control unit 7, the pressure pump 5 starts to work after the outward safety valve 11 is exploded, the pump body is internally integrated with a gas-liquid shunting function, and discharged gas can be discharged into the atmosphere by a pipeline to be diluted, so that the explosion caused by overhigh concentration of combustible gas is prevented.

And the exhaust pipeline valve 6 is opened to exhaust the flue gas extracted by the pressure pump 5, so that explosion caused by overhigh concentration of the flue gas around the lithium ion power battery pack 2 is avoided.

The battery management system control unit 7 is mainly used for receiving the electric signal of the lithium ion power battery pack 2, judging the safety state of the battery and sending an instruction to control the working state of the pressure pump 5. The battery management system control unit 7 can not only rely on the existing battery management system to realize the control function, but also develop an independent control unit based on a single chip microcomputer or a raspberry group.

And the pipeline integration device 8 is connected with the pressure pump 5 and a safety valve of a single battery in the lithium ion power battery pack 2.

The phase-change material 9 is mainly arranged on the outer layer of the waste electrolyte storage tank 3, so that the electrolyte discharged into the tank can be rapidly cooled, and the electrolyte is prevented from being directly exposed in the air, and further the continuous reaction of active substances in the electrolyte is inhibited.

The phase-change material 9 can be selected from paraffin, inorganic hydrated salt, sodium acetate trihydrate, zeolite-liquid water and other materials according to actual situations.

And the adsorption material 10 is used for adsorbing a part of the extracted electrolyte and preventing the reaction of the electrolyte to ensure safety.

The adsorbing material can be selected from activated carbon, activated carbon fiber, zeolite, humic acid adsorbent, etc. according to the components of the battery electrolyte.

The outward safety valve 11 is a one-way outward safety valve, when the inside of the battery is short-circuited, the electrolyte reacts to generate gas to expand the battery shell, and the outward safety valve 11 generates valve pressure which is greater than the pressure pumped by the pressure pump 5, so that the safety valve is exploded outwards to release the gas pressure;

the positive and negative electrodes 12 of the battery are connected in series to form a battery pack through the battery electrodes to realize the charging and discharging working condition, and the battery management system control unit 7 receives the electric signals of the battery through the electrodes.

The inward safety valve 13 is a one-way inward safety valve, after the pressure pump 5 pumps the smoke and the electrolyte in the battery, the internal pressure of the battery is reduced, and the valve is sprung inwards; the inward spring-open pressure of the valve is smaller than the pumping pressure of the pressure pump 5, so that the valve can be smoothly sprung open after the pressure pump 5 works to pump the internal electrolyte.

The control method of the explosion-proof explosion-suppression lithium ion power battery system comprises the following steps:

when the lithium ion power battery pack 2 works, gas production and heat generation are started after out-of-control reactions such as short circuit, diaphragm melting and the like occur in a certain single battery, the battery shell rapidly expands, and the internal pressure of the battery is increased to enable the outward safety valve 11 to be exploded outwards. Meanwhile, the battery management system control unit 7 responds quickly after receiving the electric signal of the battery, controls the pressure pump 5 to start to pump smoke, opens the exhaust pipeline valve 6 through the pressure pump 5, and discharges combustible smoke generated by the battery into the atmosphere through the exhaust pipeline to dilute the combustible smoke. The electrolyte in the battery is continuously pumped after the pressure pump 5 discharges the flue gas, when the pressure in the battery is too low, the internal safety valve 13 is bounced inwards, the pressure pump 5 can discharge the residual electrolyte into the waste electrolyte storage tank 3 for cooling, and the self reaction of the electrolyte is inhibited. Meanwhile, under the action of the pressure pump 5, convection heat exchange is formed between the interior of the battery and the outside, and the temperature in the battery is reduced to prevent the generated excessive heat from influencing other batteries. After the whole battery pack system is restored to a safe state, the waste electrolyte in the liquid storage tank and the pipeline is cleaned to replace the failed battery, and the system can still continue to work normally.