CN104008244B - Suppress the method for designing of power battery module thermal runaway extension - Google Patents

Abstract

The present invention provides a kind of design for suppressing the extension of power battery module thermal runaway, including：The heating thermal runaway in adiabatic environment is carried out for one first electrokinetic cell monomer to test；One first Mathematical Modeling is set up for the heating thermal runaway experimental result；Thermal runaway triggering experiment is carried out for one second electrokinetic cell monomer；Experimental result for thermal runaway triggering experiment sets up one second Mathematical Modeling；According to first Mathematical Modeling and the second Mathematical Modeling, the 3rd Mathematical Modeling of thermal runaway extension is set up；Thermal runaway way of extensive experimentation is carried out, the Mathematical Modeling of experiment show the 3rd extended using thermal runaway；Thermal insulation layer is set between the battery cell of the 3rd Mathematical Modeling, and simulation calculation is carried out using the 3rd Mathematical Modeling, obtain the parameter of the thermal insulation layer；Experimental verification is carried out for the parameter of the thermal insulation layer, the design for suppressing the power battery module thermal runaway extension is obtained.

Description

Suppress the method for designing of power battery module thermal runaway extension

Technical field

The invention belongs to field of batteries, it is related to a kind of design for suppressing the extension of power battery module thermal runaway.

Background technology

Under energy crisis and the dual-pressure of environmental pollution, automobile dynamic system motorized becomes the weight of development of automobile One of indicate.Currently, using the electrokinetic cell with higher energy density, such as lithium ion more than new energy car electrokinetic cell system Electrokinetic cell.However, accidental security incident causes that lithium-ion power battery system is under suspicion.

Electrokinetic cell system accident is usually that thermal runaway occurs by electrokinetic cell to cause.Electrokinetic cell thermal runaway refer to by In electrokinetic cell internal material at a certain temperature, it is the process of heat energy by chemical energy Transient transformation.Electrokinetic cell system is usual Single power battery comprising more piece connection in series-parallel connection, percentage of batteries monomer occurs after thermal runaway, the heat energy for acutely discharging The battery of surrounding will being involved, causing battery around to continue because there is thermal runaway by high-temperature heating.This surrounding battery is received Then there is the process of thermal runaway, the referred to as expansion process of thermal runaway to the influence of existing thermal runaway.The extension of thermal runaway is very Dangerous, it means that after electrokinetic cell system locally occurs thermal runaway, whole system will all be sent out because of the extension of thermal runaway Heat is out of control.The generation for preventing the thermal runaway in electrokinetic cell system from extending, part is limited in by thermal runaway, is possible to carry significantly The security performance of electrokinetic cell system high, it is ensured that the security of the lives and property of the people.

However, the current design for suppressing the extension of power battery module thermal runaway, simply by the method for trial and error, enters To determine design parameter, the method takes time and effort the substantial amounts of experiment of row, and accuracy is not high.If can be designed that a kind of effect Rate and the precision scheme for suppressing the extension of power battery module thermal runaway higher, will be of great significance.

The content of the invention

In view of this, the suppression power battery module thermal runaway extension it is necessory to provide a kind of efficiency and precision is higher Design.

The present invention provides a kind of design for suppressing the extension of power battery module thermal runaway, and it is comprised the following steps：

S1：Heating thermal runaway experiment is carried out to one first electrokinetic cell monomer under adiabatic environment, and records described first Electrokinetic cell monomer is in temperature T (t) not in the same time；

S2：Set up one first Mathematical Modeling T of the first electrokinetic cell monomer in thermal runaway experimentation is heated (t)_I, first Mathematical Modeling T (t) is demarcated using T (t)_I, first Mathematical Modeling T (t)_IIt is the first electrokinetic cell list The temperature of body at a time t under the conditions of thermal runaway is heated；

S3：One second electrokinetic cell monomer is provided, the second electrokinetic cell monomer and the first electrokinetic cell single phase Together, thermal runaway triggering experiment is carried out to the second electrokinetic cell monomer, and records the second electrokinetic cell monomer when different Temperature T ' (t) at quarter；

S4：Set up one second Mathematical Modeling T of the second electrokinetic cell monomer in thermal runaway triggering experimentation (t)_II, and demarcate second Mathematical Modeling T (t) using T ' (t)_II, second Mathematical Modeling T (t)_IIFor described second dynamic The temperature of power battery cell at a time t in thermal runaway triggering experimentation；

S5：One first power battery module is carried out to heat thermal runaway way of extensive experimentation, first power battery module includes At least two batteries monomers, the battery cell is same with the first electrokinetic cell monomer and the second electrokinetic cell single phase, and Thermal runaway triggering form in first power battery module triggers form phase with the thermal runaway of the second electrokinetic cell monomer Together, first power battery module temperature T " (t) not in the same time is recorded；

S6：By first Mathematical Modeling T (t)_IAnd second Mathematical Modeling T (t)_IIObtain first power One threeth Mathematical Modeling T (t) of the battery module during thermal runaway way of extensive experimentation is heated_III, using T, " (t) demarcates the 3rd Mathematical Modeling T (t)_III, the 3rd Mathematical Modeling T (t)_IIIFor first power battery module is real in heating thermal runaway extension The at a time temperature of t during testing；

S7：In the 3rd Mathematical Modeling T (t)_IIIBattery cell between a thermal insulation layer is set, using the described 3rd number Learn model T (t)_IIISimulation calculation is carried out, acquisition can suppress the thermal insulation layer of the first power battery module thermal runaway extension Parameter；And

S8：One second power battery module is chosen, second power battery module is in the first electrokinetic cell film block Adjacent cell monomer between the thermal insulation layer be set obtain, thermal runaway extension is carried out to second power battery module real Test, the thermal runaway triggering form in second power battery module triggers form with the thermal runaway of first power battery module It is identical, using the experimental result of the second power battery module thermal runaway way of extensive experimentation to step S7 in the thermal insulation layer Parameter carries out experimental verification, is determined to suppress the design parameter of the thermal insulation layer that thermal runaway extends, and obtains and suppresses electrokinetic cell mould The design of block thermal runaway extension.

The design for suppressing the extension of power battery module thermal runaway that the present invention is provided, sets by between battery cell Thermal insulation layer is put, and by setting up the Mathematical Modeling of power battery module thermal runaway expansion process, is imitated using the Mathematical Modeling It is true to calculate the parameter for obtaining the thermal insulation layer that suppress the extension of power battery module thermal runaway, and determined by experimental verification should be every The parameter of thermosphere, the design can greatly shorten experimental period, improve efficiency, and effectively save R＆D costs.In addition, The design is higher by experimental verification accuracy.

Brief description of the drawings

Fig. 1 is the result of calculation and experimental result comparison diagram of the first Mathematical Modeling in the embodiment of the present invention.

Fig. 2 is the result of calculation and experimental result comparison diagram of the second Mathematical Modeling in the embodiment of the present invention.

Fig. 3 is the structural representation of the first power battery module of offer in the embodiment of the present invention.

Fig. 4 is the result of calculation and experimental result of battery cell obtained by the 3rd Mathematical Modeling in the embodiment of the present invention Comparison diagram.

Fig. 5 is the result of calculation and experimental result of battery electrode column obtained by the 3rd Mathematical Modeling in the embodiment of the present invention Comparison diagram.

Fig. 6 is the simulation result pair of the thermal runaway extended model of increase different-thickness thermal insulation layer in the embodiment of the present invention Than figure.

Fig. 7 is the structural representation of the second power battery module of offer in the embodiment of the present invention.

The experimental result of the thermal runaway way of extensive experimentation that Fig. 8 is carried out by the second power battery module in the embodiment of the present invention.

Main element symbol description

Ternary lithium ion power 100

Battery

Battery cell 10

Positive terminal 11

Negative terminal 12

Metal connecting sheet 20

Metal fixture 30

First thermal insulation layer 40

Second thermal insulation layer 41

Pricker 50

Following specific embodiment will further illustrate the present invention with reference to above-mentioned accompanying drawing.

Specific embodiment

Below with reference to accompanying drawing, the present invention is further detailed explanation.

The method that the embodiment of the present invention provides heat output in a kind of quantitative analysis power battery module thermal runaway expansion process, It is comprised the following steps：

S1：Heating thermal runaway experiment is carried out to one first electrokinetic cell monomer under adiabatic environment, and records described first Electrokinetic cell monomer is in temperature T (t) not in the same time；

S2：Set up one first Mathematical Modeling T of the first electrokinetic cell monomer in thermal runaway experimentation is heated (t)_I, first Mathematical Modeling T (t) is demarcated using T (t)_I, first Mathematical Modeling T (t)_IIt is the first electrokinetic cell list The temperature of body at a time t under the conditions of thermal runaway is heated；

S3：One second electrokinetic cell monomer is provided, the second electrokinetic cell monomer and the first electrokinetic cell single phase Together, thermal runaway triggering experiment is carried out to the second electrokinetic cell monomer, and records the second electrokinetic cell monomer when different Temperature T ' (t) at quarter；

S4：Set up one second Mathematical Modeling T of the second electrokinetic cell monomer in thermal runaway triggering experimentation (t)_II, and demarcate second Mathematical Modeling T (t) using T ' (t)_II, second Mathematical Modeling T (t)_IIFor described second dynamic The temperature of power battery cell at a time t in thermal runaway triggering experimentation；

S5：One first power battery module is carried out to heat thermal runaway way of extensive experimentation, first power battery module includes At least two batteries monomers, the battery cell is same with the first electrokinetic cell monomer and the second electrokinetic cell single phase, and Thermal runaway triggering form in first power battery module triggers form phase with the thermal runaway of the second electrokinetic cell monomer Together, first power battery module temperature T " (t) not in the same time is recorded；

S6：By first Mathematical Modeling T (t)_IAnd second Mathematical Modeling T (t)_IIObtain first power One threeth Mathematical Modeling T (t) of the battery module during thermal runaway way of extensive experimentation is heated_III, using T, " (t) demarcates the 3rd Mathematical Modeling T (t)_III, the 3rd Mathematical Modeling T (t)_IIIFor first power battery module is real in heating thermal runaway extension The at a time temperature of t during testing；

S7：In the 3rd Mathematical Modeling T (t)_IIIBattery cell between a thermal insulation layer is set, using the described 3rd number Learn model T (t)_IIISimulation calculation is carried out, acquisition can suppress the thermal insulation layer of the first power battery module thermal runaway extension Parameter；And

S8：One second power battery module is chosen, second power battery module is in the first electrokinetic cell film block Adjacent cell monomer between the thermal insulation layer be set obtain, thermal runaway extension is carried out to second power battery module real Test, the thermal runaway triggering form in second power battery module triggers form with the thermal runaway of first power battery module It is identical, using the experimental result of the second power battery module thermal runaway way of extensive experimentation to step S7 in the thermal insulation layer Parameter carries out experimental verification, is determined to suppress the design parameter of the thermal insulation layer that thermal runaway extends, and obtains and suppresses electrokinetic cell mould The design of block thermal runaway extension.

In step S1, the first electrokinetic cell monomer can be a lithium-ion-power cell monomer.Under adiabatic environment Thermal runaway test is carried out to the first electrokinetic cell monomer, is conducive to accurately obtaining the first electrokinetic cell monomer in thermal runaway mistake The heat for being discharged in journey and being absorbed.Heat is carried out to the first electrokinetic cell monomer using adiabatic accelerating calorimeter in the present embodiment Test out of control, the first electrokinetic cell monomer is a ternary lithium-ion-power cell.

First Mathematical Modeling T (t) of the first electrokinetic cell monomer in thermal runaway experimentation is heated_ICan utilize Chemical reaction kinetics equation and Ohm's law are obtained.

For the first electrokinetic cell monomer, first Mathematical Modeling T (t)_IFoundation can with step include it is following Step：

S21：Obtain the summation Q of the heat power that the first electrokinetic cell monomer internal chemical reaction is produced_IThe meter of (t) Formula；

S22：According to Q_IT () sets up the first electrokinetic cell monomerCalculating formula；

S23：According toSet up the T (t) of the first electrokinetic cell monomer_ICalculating formula.

In step S21, the Q_IT the expression formula of () is：

Q_I(t)=Q_r(t)+Q_e(t) (1)。

Wherein, Q_rT () represents the first electrokinetic cell monomer internal material chemical reaction heat power, Q_eT () represents The electrical power of one electrokinetic cell monomer internal short-circuit release.

The Q_rT the expression formula of () is：

Q_r(t)=Q_SEI+Q_anode+Q_separator+Q_cathode+Q_electrolyte+Q_PVDF (2)。

Wherein, Q_SEIRepresent the heat production power of SEI film decomposition reactions；Q_anodeRepresent the heat production work(of negative pole and electrolyte reaction Rate；Q_separatorRepresent the Endothermic power of barrier film decomposition；Q_cathodeThe heat production power of positive polar decomghtion；Q_electrolyteElectrolyte decomposition Heat production power；Q_PVDFRepresent the heat production power of bonding agent decomposition reaction.The Q_SEI、Q_anode、Q_separator、Q_cathode、 Q_electrolyteAnd Q_PVDFCan be described with the form of Arrhenius formula.Such as Q_SEIComputing formula be：

Wherein, H_SEIThe releasable gross energy of SEI films decomposition reaction institute is represented, unit is J, can be selected according to existing document Take；c_SEIT () represents the normalized concentration of SEI films, i.e., c when reaction starts_SEI(0)=1, during reaction terminating, c_SEI(∞)=0, c_SEIT () is the variable for changing over time in simulation process and changing；A_SEIThe frequency factor of SEI film reactions is represented, Unit is s^-1；E_{A, SEI}It is the activation energy of chemical reaction, unit is J/mol, can be chosen according to existing document；R is perfect gas Constant, R=8.314J/ (molK)；T_iT () is that battery cell is the temperature of t in the time.It is appreciated that Q_anode, Q_separator, Q_cathode, Q_electrolyteAnd Q_PVDFExpression formula by by the Q_SEIThe subscript of expression formula carries out corresponding modification and obtains.

According to chemical reaction kinetics equation and law of conservation of energy, the first electrokinetic cell monomer Q_eThe meter of (t) Formula is：

For the first electrokinetic cell monomer, in t internal temperature of battery T_iT () is less than or equal to the first electrokinetic cell list The fusion temperature T of body internal diaphragm_onsetWhen, only there is micro-short circuit, corresponding reaction heat production work(inside the first electrokinetic cell monomer Rate is Q_short(t).In Q_shortIn the expression formula of (t), A_shortIt is the rate factor of weak shorts, b is the exponential term of short circuit.In t Internal temperature of battery T_iThe fusion temperature T of (t) more than the first electrokinetic cell monomer internal diaphragm_onsetWhen, the first electrokinetic cell list Internal portion can occur extensive internal short-circuit, and corresponding heat production power is Wherein Δ H represents the gross energy of short circuit release, and Δ t represents average reaction time, which determines the speed of reaction,The energy of the weak shorts that representative has occurred and that.

By the Q_r(t) and Q_eT the calculating formula of () brings Q into_I(t)=Q_r(t)+Q_eT () is that can obtain Q_IThe calculating formula of (t).

In step S22, according to law of conservation of energy, the first electrokinetic cell monomer meets public affairs during thermal runaway Formula：

Wherein, M is the quality of the first electrokinetic cell monomer, and unit is kg；C_pIt is the specific heat capacity of the first electrokinetic cell monomer, Unit is J/ (kgK).By Q_IT the calculating formula of () is brought formula (5) into and be can obtainCalculating formula.

In step S23, the temperature of the first electrokinetic cell monomer at a time t under the conditions of thermal runaway is heated, i.e., First Mathematical Modeling T (t)_IMeet formula：

T(0)_IIt is a known quantity.According toCalculating formula and formula (6) be available first Mathematical Modeling T (t)_I Calculating formula.

Utilization T (t) demarcates first Mathematical Modeling T (t)_IThe step of include：For Q_r(t), according to existing document Select one group of A_SEIAnd E_{A, SEI}, A_anodeAnd E_{A, anode}, A_separatorAnd E_{A, separator}, A_cathodeAnd E_{A, cathode}, A_electrolyteWith E_{A, electrolyte}, and A_{A, PVDF}And E_{A, PVDF}Value；For Q_eT (), one group of A is selected according to practical experience_short, b, Δ t and Δ H Value.Using first Mathematical Modeling T (t)_ICarry out simulation calculation and obtain the first electrokinetic cell monomer not in the same time Temperature, if differing larger with experimental result T (t) in step S1 by the temperature that the simulation calculation is obtained, one Determine adjustment A in scope_SEIAnd E_{A, SEI}, A_anodeAnd E_{A, anode}, A_separatorAnd E_{A, separator}, A_cathodeAnd E_{A, cathode}, A_electrolyteAnd E_{A, electrolyte}, A_{A, PVDF}And E_{A, PVDF}And A_short, the value of b, Δ t and Δ H often adjusted once using described the One Mathematical Modeling T (t)_IA simulation calculation is carried out, untill simulation result is close with experimental result.

In the present embodiment, calibrated A_SEIAnd E_{A, SEI}, A_anodeAnd E_{A, anode}, A_separatorAnd E_{A, sepatator}, A_cathodeWith E_{A, cathode}, A_electrolyteAnd E_{A, electrolyte}, A_{A, PVDF}And E_{A, PVDF}And A_short, the value of b, Δ t and Δ H refers to table 1.By Ternary lithium-ion-power cell, ternary material is used just to have two different chemical reactions in the present embodiment, so A in the corresponding preferred value of table 1_Cathode,, E_{A, cathode}, and H_cathodeValue have two groups, respectively A_{Cathode, 1}, E_{A, cathode, 1}, H_{Cathode, 1}, A_{Cathode, 2}, E_{A, cathode, 2}, H_{Cathode, 2}。

Table 1

Symbol	Preferred value	Symbol	Preferred value
						b	39.279
		Δt	4(s)
						ΔH	385000(J)

It is appreciated that for the first electrokinetic cell monomer, may further include to the first Mathematical Modeling T (t)_ICarry out Rational Simplification.Carrying out the first Mathematical Modeling T (t)_IIn simplified process, the first Mathematical Modeling T (t) is should ensure that_IIt is imitative True result of calculation is close with experimental result, that is, ensure the first Mathematical Modeling T (t)_IThe precision of simulation calculation.Due to described first In electrokinetic cell monomer, in t internal temperature of battery T_iThe fusing of (t) less than or equal to the first electrokinetic cell monomer internal diaphragm Temperature T_onsetWhen, only there is micro-short circuit inside the first electrokinetic cell monomer, the energy that the micro-short circuit is produced is smaller, can ignore Disregard.So in the first Mathematical Modeling T (t) of heating thermal runaway_IIn, step S21 can be further included Q_eT () is reduced to：

Fig. 1 is referred to, in the present embodiment, using the first Mathematical Modeling T (t)_I, the first electrokinetic cell monomer is carried out The result of simulation calculation is contrasted with experimental result T (t), with preferable precision.

In step S3, thermal runaway triggering experiment is carried out for the second electrokinetic cell monomer, the form of the triggering is not Limit, as long as can ensure that thermal runaway triggering can make the second electrokinetic cell monomer discharge enough heats, so that So that adjacent cell monomer has enough temperature liter high concurrent heats out of control.Preferably, the thermal runaway triggering form is Acupuncture is triggered, overcharges triggering or triggered.When thermal runaway triggering form uses acupuncture, the needle diameter is preferably 5~8mm, punctures speed and is preferably 10~30mm/s.In the present embodiment, the second electrokinetic cell monomer is carried out by acupuncture Thermal runaway triggering experiment, a diameter of 8mm of pricker 50, puncture speed is 10mm/s.

In step S4, second Mathematical Modeling T (t)_IISet up further comprising the steps：

S41：Set up the second electrokinetic cell monomer heat production power Q in thermal runaway trigger process_IIThe calculating formula of (t)；

S42：According to Q_IIT () drawsCalculating formula；

S43：According toDraw T (t)_IICalculating formula.

In step S41, the Q_IIT the computing formula of () is：

Q_II(t)=Q_r(t)+Q_{e_in}(t)-Q_h(t) (8)。

Wherein, Q_rThe reaction thermal power of the second electrokinetic cell monomer thermal chemical reaction release when () is heat triggering experiment t； Q_{e_in}T () is thermal power of the internal short-circuit by abrupt release out；Q_hT () is the power of the second electrokinetic cell single body radiating. Because the second electrokinetic cell monomer is identical with the first electrokinetic cell monomer, so, Q in formula (8)_r(t) Calculating formula and the Q with the first electrokinetic cell monomer_rT () calculating formula is identical, i.e. Q in formula (8)_rT () can be according to step Formula (2) and (3) are calculated in S21.In the present embodiment, for the second electrokinetic cell monomer, calibrated A_SEIWith E_{A, SEI}, A_anodeAnd E_{A, anode}, A_separatorAnd E_{A, separator,}A_cathodeAnd E_{A, cathode}, A_electrolyteAnd E_{A, electrolyt}E, A_{A, PVDF}And E_{A, PVDF}And A_short, the value of b, Δ t and Δ H is identical with the first electrokinetic cell monomer, refers to table 1.

Variant form according to chemical reaction kinetics equation draws, the Q_{e_in}T the computing formula of () is：

Wherein, during Δ H represents the short-circuit process that the second electrokinetic cell monomer occurs thermal runaway triggering, discharged due to short circuit Electric energy summation, for a certain particular battery monomer, Δ H is a known quantity；∫Q_{e_in}T () dt is represented and discharged when the time is as t Electric energy；V represents reaction rate exponentially form.

The Q_hT the computing formula of () is：

Q_h(t)=h_II·A_II·(T(t)_II-T_amb(t)) (10)。

Wherein, h_IIThe coefficient of heat transfer of the second electrokinetic cell monomer to environment is represented, unit is W/ (m²·K)；A_IIRepresent The surface radiating area of two electrokinetic cell monomers, unit is m²；T(t)_IIRepresent the simulation model temperature of the second electrokinetic cell monomer Degree, unit is K；T_ambT () represents the temperature of surrounding environment, unit is K.

In step S42, according to law of conservation of energy, the second electrokinetic cell monomer meets in thermal runaway trigger process Formula：

Wherein, M is the quality of the second electrokinetic cell monomer, and unit is kg；C_pIt is the second electrokinetic cell monomer Specific heat capacity, unit is J/ (kg.K).By Q_IIT the calculating formula of () is brought formula (11) into and be can obtainCalculating formula.

In step S43, the second electrokinetic cell monomer at a time temperature of t under thermal runaway trigger condition, i.e., Second Mathematical Modeling T (t)_IIMeet formula：

T(0)_IIIt is the temperature before the second electrokinetic cell monomer thermal runaway triggering, is a known quantity.According to step In S42Calculating formula and formula (12) be available second Mathematical Modeling T (t)_IICalculating formula.

Utilization T ' (t) demarcates second Mathematical Modeling T (t)_IIThe step of include：One group of Δ is selected based on experience value H、v、h_II, using the second Mathematical Modeling T (t)_IICarry out simulation calculation and obtain the second electrokinetic cell monomer in temperature not in the same time Degree, if by second Mathematical Modeling T (t)_IIExperimental result T ' (t) phase in the temperature that simulation calculation is obtained and step S3 Difference is larger, then adjust Δ H, v and h within the specific limits_IIValue, often adjust Δ H, v and a h_IIValue using second number Learn model T (t)_IIA simulation calculation is carried out, untill the result of simulation calculation is close with experimental result T ' (t).This implementation In example, calibrated Δ H=385000J, v=0.001, h_II=2W/ (m²·K)。

Fig. 2 is referred to, as can be seen from Figure, the second electrokinetic cell monomer passes through the second Mathematical Modeling T (t)_IICalculate Result compared with experimental result T ' (t), with preferable precision.

It is appreciated that may further include to second Mathematical Modeling T (t)_IICarry out Rational Simplification.Due to described Second Mathematical Modeling T (t)_IIIn, including some thermal runaway extended model calculating in influence less secondary cause.For these Influenceing less secondary cause carries out approximate or is ignored, such that it is able to improve the simulation calculation speed of thermal runaway extended model Degree.Carrying out the second Mathematical Modeling T (t)_IIIn simplified process, the second Mathematical Modeling T (t) is should ensure that_IISimulation result with Experimental result is close, that is, ensure the second Mathematical Modeling T (t)_IIThe precision of simulation calculation.Due to the Q_{e_in}In the calculating formula of (t) There is exponential form, calculating speed is slower, so, in the case where simulation calculation precision is ensured, can be by equation：It is simplified to linear equation：

In step S6, at least two batteries monomers in first power battery module can in series or simultaneously The mode of connection is connected.Fig. 3 is referred to, in the present embodiment, first power battery module is the ternary lithium of the 25Ah of side's shell Ion battery 100, the ternary lithium-ion-power cell 100 include six batteries monomers 10, multiple metal connecting sheet 20, Multiple metal fixtures 30 and multiple first thermal insulation layers 40.Each battery cell 10 includes a positive terminal 11 and a negative pole Post 12.The metal connecting sheet 20 is used to be cascaded six batteries monomers 10；The metal fixture 30 is used to clamp institute State battery cell 10；The first thermal insulation layer 40 is used to isolate the battery cell 10 and metal fixture 30.

Using lumped-parameter method, by each batteries monomer, the pole of each batteries monomer is accordingly to be regarded as with single quality, single The node of one thermal capacitance and single temperature.Each node has the mass M of its own_i, thermal capacitance C_piAnd temperature T_i。

Triggering electricity is saved headed by the battery cell definition that thermal runaway triggering experiment will be carried out in first power battery module Other battery cells outside first section triggering battery in first power battery module are defined as partial node extension battery by pond. The 3rd Mathematical Modeling T_i(t)_IIIAcquisition may further include following steps：

S61：First section triggering battery, partial node extension battery, battery electrode column and fixture is set up respectively to expand in heating thermal runaway Energy gradient Q under the conditions of exhibition_iCalculating formula；

S62：According to Q_iFirst section triggering battery, partial node extension battery, battery electrode column and fixture are set up respectively in heating heat Under expansion condition out of controlCalculating formula；

S63：According toThe first section triggering battery of foundation, partial node extension battery, battery electrode column and fixture are adding respectively T under hot thermal runaway expansion condition_i(t)_IIICalculating formula.

In step S61, according to law of conservation of energy, in the case where thermal runaway expansion condition is heated, head section triggerings battery, partial node expand The energy gradient Q of exhibition battery, battery electrode column and fixture_iCalculating formula be illustrated as：

Q_i(t)=Q_sheng(t)-Q_san(t) (14)。

Wherein, Q_sanT () represents heat radiation power；Q_shengT () represents heat power.For head section triggering batteries Q_sheng(t) =Q_I(t)=Q_r(t)+Q_{e_in}(t) ,-Q_san(t)=- ∑ Q_ij(t)-Q_ih(t)；Battery, Q are extended for partial node_sheng(t)=Q_II (t)=Q_r(t)+Q_e(t) ,-Q_san(t)=- ∑ Q_ij(t)-Q_ih(t)；Because pole and fixture are simple metal material, Bu Huifa Biochemical reaction, so for pole and fixture, Q_sheng(t)=0 ,-Q_san(t)=- ∑ Q_ij(t)-Q_ih(t).Wherein, Q_ijRepresent The heat radiation power that node i is conducted heat to node j；Q_ihT () represents the heat radiation power that node i is radiated to surrounding environment.

For first power battery module, Q_iCalculating formula be specially：

The heat transfer model set up between each node using heat resistance method, according to Fourier Heat Conduction formula, node i is entered to node j The heat radiation power Q of row heat transfer_ijCalculating formula be：

Q_ij(t)=A_ij·(T_i(t)_III-T_j(t)_III)/R_ij (16)。

Wherein, A_ijT () represents the effective heat transfer area between node i and node j, unit is m²；R_ijT () represents node i The thermal resistance conducted heat between node j, unit is (m²·K)/W；T_i(t)_IIIRepresent the temperature of t node i, T_j(t)_IIIRepresent t The temperature of moment node j.

According to Fourier Heat Conduction formula, the heat radiation power Q that node i is radiated to surrounding environment_ihT the calculating formula of () is：

Q_ih(t)=A_ih·(T_i(t)_III-T_h(t))/R_ih (17)

Wherein, the A_ihT () represents equivalent area of the node i to function of environment heat emission, unit is m²；R_ihT () is to function of environment heat emission Equivalent thermal resistance, unit is (m²·K)/W；T_i(t)_IIIThe temperature of t node i, T_hT () represents t environment temperature.

In formula (15), the partial node extends the short circuit energy Q of battery_eT the expression formula of () is：

Wherein, T_i ^*T () is the temperature drawn by interpolation calculation, the T_i ^*T () meets formula：

T_i ^*(t)=α T_i-1(t)+(1-α)T_i(t) (20)。

Wherein, α is the weight factor in calculating process, 0 ＜ α ＜ 0.5.Preferably, α=0.23；T_i-1T () is the i-th -1 section The model of battery cell calculates temperature, T_iT () is that the model of the i-th batteries monomer calculates temperature, i=2,3,4,5 or 6.

In step S62, according to law of conservation of energy：

The first section triggering battery, partial node extension battery and battery electrode column can be respectively obtained and fixture loses in heating heat Under control expansion conditionCalculating formula.

In step S63, in the case where thermal runaway expansion condition is heated, the first section triggering battery, partial node extension battery and electricity The T of pond pole and fixture_i(t)_IIIMeet formula：

Wherein, T (0)_IIIIt is a known quantity.WillRespectively obtained by bringing formula (21) into first section triggering battery, Partial node extends the 3rd Mathematical Modeling T (t) of battery and battery electrode column and fixture in the case where thermal runaway expansion condition is heated_III。

" (t) is to the 3rd Mathematical Modeling T (t) for the utilization T_IIICarrying out demarcation can include：Selected according to existing document Fixed one group of R_ijWith A_ijValue, using the 3rd Mathematical Modeling T (t)_IIICarry out simulation calculation and obtain power battery module respectively to save Put in temperature not in the same time, if " (t) differs larger, and R is adjusted within the specific limits with the experimental result T in step S5_ij With A_ijValue, often adjust once use the 3rd Mathematical Modeling T (t)_IIIA simulation calculation is carried out, until simulation calculation knot Untill fruit is close with experimental result.

First section triggering battery in first power battery module is defined as first segment battery cell, with the first economize on electricity Monomer adjacent battery cell in pond is second section battery cell, and the battery cell adjacent with second section battery cell is the 3rd economize on electricity Pond monomer, by that analogy.In the present embodiment, calibrated R_ijWith A_ijOne group of preferred result of value refer to table 2.

Table 2

Fig. 4-5 are referred to, as can be seen from Figure, the first section triggering that the present embodiment is calculated using the 3rd Mathematical Modeling Battery and its positive and negative electrode post and partial node extension battery and its positive and negative electrode post are in thermal runaway expansion process when different The temperature at quarter error compared with experimental result is smaller, illustrates the 3rd Mathematical Modeling T (t)_IIIWith preferable precision.

In step S7, thermal insulation layer is increased between the battery cell in the 3rd Mathematical Modeling, that is, increase adjacent cell Thermal resistance between monomer.Assuming that increased internal resistance is R because of increase thermal insulation layer_a, then the i-th batteries monomer and i+1 section Thermal resistance R ' between battery cell_{I, i+1}Calculating formula be：

R′_{I, i+1}=R_{I, i+1}+R_a (22)。

Wherein, R_{I, i+1}Representative does not add the heat before thermal insulation layer between the i-th batteries monomer and i+1 batteries monomer Resistance；R_a=δ/λ, δ represent the thickness of thermal insulation layer, and λ represents the thermal conductivity factor of thermal insulation layer.

The material of the thermal insulation layer is not limited, as long as having effect of heat insulation.In the present embodiment, the material of the thermal insulation layer It is asbestos, the thermal conductivity factor of the asbestos is λ=0.03Wm^-1·K^-1。

Fig. 6 is referred to, is between the first segment battery cell in three-power electric pool model and second section battery cell Add the simulation result of the insulating layer of asbestos of different-thickness.It can be seen that when thermal insulation layer is not added with, thermal runaway from First segment battery cell expands to second section battery cell.When the thickness δ of thermal insulation layer is between 0.06mm to 1mm, second section Battery cell will not occur thermal runaway.It can also be seen that the insulation thickness δ is in 0.06mm or 0.2mm from Fig. 6, the The temperature curve of two batteries monomers is non-with temperature curve before second section battery cell occurs thermal runaway when being not added with thermal insulation layer Very close to.When insulation thickness δ is in 0.5mm or 1mm, when the temperature curve distance of second section battery cell is not added with thermal insulation layer Temperature curve is farther out.Due to being had differences between different dynamic battery module under actual conditions, and work as the insulation thickness δ and exist When between 0.06mm to 0.2mm, the temperature curve of second section battery cell occurs with second section battery cell when being not added with thermal insulation layer Temperature curve before thermal runaway closely, so second section battery cell still may occur thermal runaway.It is therefore preferable that , the insulation thickness δ chooses more than 0.5mm, is now more beneficial for suppressing the inside thermal runaway of the first power battery module Extension.

Fig. 7 is referred to, in step S8, one second power battery module, second power battery module and described the is chosen One power battery module is essentially identical, and it is different only in that in second power battery module increases between adjacent cell monomer One second thermal insulation layer 41.The material of the second thermal insulation layer 41 is identical with the material of thermal insulation layer in step S7, the second thermal insulation layer 41 Parameter in the step s 7 by simulation calculation obtain thermal insulation layer parameter area in.In the present embodiment, the second thermal insulation layer 41 is asbestos, and thermal conductivity factor is λ=0.03W.m^-1·K^-1, thickness is more than 0.5mm.Second power battery module is carried out Thermal runaway way of extensive experimentation, the thermal runaway in second power battery module triggers the heat of form and first power battery module Triggering form out of control is identical.Specifically, each batteries monomer in second power battery module is fully charged, choose a diameter of The pricker 50 of 8mm.Pricker 50 is pierced into first segment battery cell with the speed of 10mm/s, and stops wherein.

Refer to Fig. 8, be the second thermal insulation layer thickness be 1mm when, the second power battery module carries out thermal runaway extension The experimental result of experiment.It can be seen that after first segment battery cell is subject to the concurrent heat of acupuncture out of control, second section Battery cell temperature is first raised, and slow afterwards to decline, second section battery cell does not occur thermal runaway, illustrates second power The extension of the thermal runaway of battery module has obtained effectively suppressing.

The scheme of suppression power battery module thermal runaway that the present embodiment is obtained extension is, the electricity in power battery module Increase thermal insulation layer between the monomer of pond, the material of the thermal insulation layer is thermal conductivity factor λ=0.03W.m^-1·K^-1Asbestos, asbestos thickness More than or equal to 0.5mm.It is appreciated that the thickness of the thermal insulation layer is relevant with the thermal conductivity factor that it uses material.For this implementation Power battery module in example, to suppress the thermal runaway extension inside power battery module, should be inside power battery module Increase between battery cell and be not less than 0.0167Wm^-2.K^-1Thermal resistance.

The design for suppressing the extension of power battery module thermal runaway that the present invention is provided, sets by between battery cell Thermal insulation layer is put, and by setting up the Mathematical Modeling of power battery module thermal runaway expansion process, is imitated using the Mathematical Modeling It is true to calculate the parameter for obtaining the thermal insulation layer that suppress the extension of power battery module thermal runaway, when greatly can shorten experiment Between, improve efficiency, and effectively save R＆D costs.In addition, the design is higher by experimental verification accuracy.

In addition, those skilled in the art can also do other changes in spirit of the invention, these are according to present invention spirit The change done, should all be included in scope of the present invention.

Claims (10)

1. a kind of to suppress the method for designing that power battery module thermal runaway extends, it is comprised the following steps：

S1：Heating thermal runaway experiment is carried out to one first electrokinetic cell monomer under adiabatic environment, and records first power Battery cell is in temperature T (t) not in the same time；

S2：Set up one first Mathematical Modeling T (t) of the first electrokinetic cell monomer in thermal runaway experimentation is heated_I, profit First Mathematical Modeling T (t) is demarcated with T (t)_I, first Mathematical Modeling T (t)_IFor the first electrokinetic cell monomer is adding The at a time temperature of t under the conditions of hot thermal runaway；

S3：One second electrokinetic cell monomer is provided, the second electrokinetic cell monomer is same with the first electrokinetic cell single phase, right The second electrokinetic cell monomer carries out thermal runaway triggering experiment, and records the second electrokinetic cell monomer in temperature not in the same time Degree T ' (t)；

S4：Set up one second Mathematical Modeling T (t) of the second electrokinetic cell monomer in thermal runaway triggering experimentation_II, and Second Mathematical Modeling T (t) is demarcated using T ' (t)_II, second Mathematical Modeling T (t)_IIIt is the second electrokinetic cell list The temperature of body at a time t in thermal runaway triggering experimentation；

S5：One first power battery module is carried out to heat thermal runaway way of extensive experimentation, first power battery module is included at least Two batteries monomers, the battery cell and the first electrokinetic cell monomer and the second electrokinetic cell single phase are same, and this Thermal runaway triggering form in one power battery module is identical with the thermal runaway triggering form of the second electrokinetic cell monomer, note Record first power battery module temperature T " (t) not in the same time；

S6：By first Mathematical Modeling T (t)_IAnd second Mathematical Modeling T (t)_IIObtain first electrokinetic cell One threeth Mathematical Modeling T (t) of the module during thermal runaway way of extensive experimentation is heated_III, using T, " (t) demarcates the 3rd mathematics Model T (t)_III, the 3rd Mathematical Modeling T (t)_IIIIt is that first power battery module is heating thermal runaway way of extensive experimentation mistake The at a time temperature of t in journey；

S7：In the 3rd Mathematical Modeling T (t)_IIIBattery cell between a thermal insulation layer is set, using the 3rd mathematical modulo Type T (t)_IIISimulation calculation is carried out, acquisition can suppress the ginseng of the thermal insulation layer of the first power battery module thermal runaway extension Number；And

S8：One second power battery module is chosen, second power battery module is the phase in first power battery module The thermal insulation layer is set between adjacent battery cell to obtain, and thermal runaway way of extensive experimentation is carried out to second power battery module, should Thermal runaway triggering form in second power battery module is identical with the thermal runaway triggering form of first power battery module, Using the experimental result of the second power battery module thermal runaway way of extensive experimentation to step S7 in the thermal insulation layer parameter Experimental verification is carried out, is determined to suppress the design parameter of the thermal insulation layer that thermal runaway extends, obtained and suppress power battery module heat The design of extension out of control.

2. it is according to claim 1 to suppress the method for designing that power battery module thermal runaway extends, it is characterised in that described First Mathematical Modeling T (t)_ISet up further comprising the steps：

S21：Obtain the summation Q of the heat power that the reaction of the first electrokinetic cell monomer internal chemical is produced_IThe calculating formula of (t), it is described Q_I(t)=Q_r(t)+Q_e(t), Q_rT () represents the first electrokinetic cell monomer internal material chemical reaction heat power, Q_e(t) Represent the electrical power of battery internal short-circuit release；

S22：According to Q_IT () sets up first section triggering battery cellCalculating formula；And

S23：According toSet up the T (t) of first section triggering battery cell_ICalculating formula.

3. it is according to claim 2 to suppress the method for designing that power battery module thermal runaway extends, it is characterised in that described Q_rT the calculating formula of () is：

Q_r(t)=Q_SEI+Q_anode+Q_separator+Q_cathode+Q_electrolyte+Q_PVDF,

Wherein, Q_SEIRepresent the quantity of heat production of SEI film decomposition reactions；Q_anodeRepresent the quantity of heat production of negative pole and electrolyte reaction； Q_separatorRepresent the caloric receptivity of barrier film decomposition；Q_cathodeThe quantity of heat production of positive polar decomghtion；Q_electrolyteThe heat production of electrolyte decomposition Amount；Q_PVDFRepresent the quantity of heat production of bonding agent decomposition reaction, the Q_SEICalculating formula be：

$Q_{SEI}=H_{SEI}\·\frac{{\mathrm{dc}}_{SEI}\left(t\right)}{dt}=H_{SEI}\·A_{SEI}\·c_{SEI}\left(t\right)\·\exp \left(-\frac{E_{a,SEI}}{{\mathrm{RT}}_i\left(t\right)}\right),$

Wherein, H_SEIThe releasable gross energy of SEI films decomposition reaction institute is represented, unit is J；c_SEIT () represents the normalization of SEI films Concentration；A_SEIThe frequency factor of SEI film reactions is represented, unit is s^-1；E_{A, SEI}It is the activation energy of chemical reaction, unit is J/ mol；R is perfect gas constant；T_iT () is that battery cell is the temperature of t, the Q in the time_anode, Q_separator, Q_cathode, Q_electrolyteAnd Q_PVDFCalculating formula by by the Q_SEIThe subscript of calculating formula is respectively modified as anode, separator, Cathode, electrolyte or PVDF are obtained.

4. it is according to claim 2 to suppress the method for designing that power battery module thermal runaway extends, it is characterised in that described Q_eT the calculating formula of () is：

$Q_e\left(t\right)=\left\{\begin{array}{cc}{Q}_{short}\left(t\right)=A_{short}{\left(T\left(t\right)/273\right)}^b,& \left(T_i\left(t\right)\≤T_{onset}\right)\\ \frac{1}{\mathrm{\Δ}t}\left(\mathrm{\Δ}H-{\∫}_{T\≤T_{short}}{Q}_{short}\left(t\right)dt-{\∫}_{T>T_{short}}{Q}_e\left(t\right)\right),& \left(T_i\left(t\right)>T_{onset}\right)\end{array}\right.,$

Wherein, A_shortIt is the rate factor of weak shorts, b is the exponential term of short circuit, and Δ H represents the gross energy of short circuit release, Δ t Represent average reaction time,The energy of the weak shorts that representative has occurred and that.

5. it is according to claim 4 to suppress the method for designing that power battery module thermal runaway extends, it is characterised in that described Formula

It is further simplified as

6. it is according to claim 1 to suppress the method for designing that power battery module thermal runaway extends, it is characterised in that described Second Mathematical Modeling T (t)_IIFoundation comprise the following steps：

S41：Set up the second electrokinetic cell monomer heat production power Q in thermal runaway trigger process_IIThe calculating formula of (t), it is described Q_II(t)=Q_r(t)+Q_{e_in}(t)-Q_h(t), Q_rSecond electrokinetic cell monomer thermal chemical reaction release when () is heat triggering experiment t Reaction thermal power, Q_{e_in}T () is thermal power of the internal short-circuit by abrupt release out, Q_hT () is the second electrokinetic cell monomer The power of radiating；

S42：According to Q_IIT () drawsCalculating formula；And

S43：According toDraw the calculating formula of T (t) II.

7. it is according to claim 6 to suppress the method for designing that power battery module thermal runaway extends, it is characterised in that the Q_r(t) Calculating formula and Q in the first electrokinetic cell monomer_rT () calculating formula is identical；It is described Wherein, Δ H represent the second electrokinetic cell monomer occur thermal runaway triggering short-circuit process in, due to short circuit release electric energy it is total With Δ H is a known quantity, ∫ Q_{e_in}T () dt represents the electric energy released when the time is as t, v represents reaction rate in finger Number form formula；The Q_h(t)=h_II·A_II·(T(t)_II-T_amb(t)), wherein, h_IIThe second electrokinetic cell monomer is represented to environment The coefficient of heat transfer, unit is W/ (m²K), A_IIThe surface radiating area of the second electrokinetic cell monomer is represented, unit is m², T (t)_II The simulation model temperature of the second electrokinetic cell monomer is represented, unit is K, T_ambT () represents the temperature of surrounding environment, unit is K.

8. it is according to claim 7 to suppress the method for designing that power battery module thermal runaway extends, it is characterised in that describedCan be further simplified as

9. it is according to claim 1 to suppress the method for designing that power battery module thermal runaway extends, it is characterised in that by institute State and save triggering battery headed by the battery cell definition that thermal runaway triggering experiment is carried out in power battery module, by the electrokinetic cell Other battery cells in module outside first section triggering battery are defined as partial node extension battery, and the power battery module is further Including multiple metal connecting sheets, multiple metal fixtures and multiple thermal insulation layers, the 3rd Mathematical Modeling T (t)_IIIFoundation bag Include following steps：

S61：First section triggering battery, partial node extension battery, battery electrode column and fixture are set up respectively in heating thermal runaway expansion condition Under energy gradient Q_i(t) calculating formula, it is described

Wherein, Q_ijRepresent the heat radiation power that node i is conducted heat to node j；Q_ihT () represents node i and is dissipated to surrounding environment The heat radiation power of heat；

S62：According to Q_iFirst section triggering battery, partial node extension battery, battery electrode column and fixture is set up respectively to expand in heating thermal runaway Under the conditions of exhibitionCalculating formula；And

S63：According toFirst section triggering battery, partial node extension battery, battery electrode column and fixture are set up respectively in heating heat T under expansion condition out of control_i(t)_IIICalculating formula.

10. it is according to claim 1 to suppress the method for designing that power battery module thermal runaway extends, it is characterised in that institute The parameter for stating thermal insulation layer refers to the thickness and thermal conductivity factor of thermal insulation layer.