CN105527581B - The discrimination method of mixed type anode material lithium ion battery key parameter and capacity attenuation mechanism - Google Patents
The discrimination method of mixed type anode material lithium ion battery key parameter and capacity attenuation mechanism Download PDFInfo
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Abstract
The invention discloses a kind of discrimination methods of mixed type anode material lithium ion battery key parameter, include being discharged the mesuring battary of full power state with constant current；Obtain the balanced potential curve of each component active material and the dQ/dV curves of each component active material in the balanced potential curve of anode, cathode equilibrium potential curve, mixed type anode material of battery；The estimated value of the terminal voltage of battery is calculated according to the initial set value of the key parameter of the dQ/dV curves of each component active material, constant discharge current and battery in each component active material equilibrium potential, mixed type anode in cathode equilibrium potential, mixed type anode material；The initial set value of the key parameter is modified, until the root-mean-square error RMSE between the estimated value and actual value of battery terminal voltage reaches minimum value, obtains the final correction result of key parameter.The invention also discloses a kind of discrimination methods of mixed type anode material lithium ion battery capacity attenuation mechanism identification.
Description
Technical field
The invention belongs to technical field of battery management, and in particular to mixed type anode material lithium ion battery key parameter
The discrimination method of discrimination method and capacity attenuation mechanism.
Background technology
Lithium ion battery has the characteristics that high power/energy density, long-life, and what is obtained on electric vehicle answers on a large scale
With.Lithium ion battery is generally made of positive electrode, negative material, diaphragm and electrolyte etc., and wherein positive electrode is to battery
Performance has a great impact.The positive electrode active materials of common lithium ion battery have LiFePO4 (LFP), cobalt acid lithium (LCO), manganese
Sour lithium (LMO) and the ternary materials such as nickel cobalt manganese (NCM) or nickel cobalt aluminium (NCA).However, single positive electrode active materials can not make electricity
The performance in pond is optimal, and in actual production, two different positive electrode active materials are mixed, and forms mixed type anode
Material realizes the mutual supplement with each other's advantages of different positive electrode active materials, becomes a kind of method promoting lithium ion battery chemical property.
By the experiment and screening of long period, LMO-NCM (NCA) mixed type anodes material, LFP-NCM (NCA) mixed type anode material
The practical application that the mixed type anodes materials such as material, LCO-NCM (NCA) mixed type anode material all obtain.
The health status SOH of battery such as passes through capacity definition, i.e. SOH=C/C there are many method of definition0, wherein C is electricity
Pond current capacities, C0For the initial capacity of battery.Simultaneously can also according to the parameters such as internal resistance, the energy/power density of battery come
Define the health status of battery.However, the method for estimation of cell health state SOH at this stage is only to estimate that battery capacity declines
Subtract how many, rather than has analyzed the mechanism of battery capacity decaying to determine the Trueattenuation situation of inside battery.
The capacity attenuation mechanism of battery may be lost due to positive electrode active materials, negative electrode active material loses or available
Caused by the reasons such as the loss of lithium ion.For the lithium ion battery of mixed type anode material, due to mixed type anode material
Material includes different active material component, and the loss of active material is more complicated.With the damage of LMO-NCM mixed type anode materials
For mistake.The loss of LMO active materials and the loss of NCM active materials can all cause the damage of LMO-NCM mixed type anode materials
It loses.During battery use, two kinds of positive electrode active materials of LMO, NCM may also will present out different rate of decay.
The research for the mechanism that decays for battery capacity, generally requires to disassemble on battery, utilizes XRD (X-Ray
Diffraction, X-ray diffraction), the methods of SEM (Scanning Electron Micorscope, scanning electron microscope)
It is analyzed, but this is completely infeasible on the practical electric vehicle.Chinese patent application CN103576097A proposes a kind of nothing
The health state of lithium ion battery SOH methods of estimation of damage, but this method is only applicable to the battery of single positive electrode active materials.
Invention content
In view of this, it is necessory to provide a kind of mixed type anode material lithium ion battery key parameter discrimination method and
The discrimination method of capacity attenuation mechanism.
Present invention firstly provides a kind of discrimination method of mixed type anode material lithium ion battery key parameter, including it is as follows
Step：
S1：It is discharged the mesuring battary of full power state with constant current, and records the constant-current discharge in discharge process
Voltage curve obtains the actual value of different moments battery terminal voltage, is denoted as V (t)；
S2：In the balanced potential curve of anode, cathode equilibrium potential curve, mixed type anode material that obtain the mesuring battary
The balanced potential curve of each component active material and electricity increment (dQ/dV) curve of each component active material；
S3：According to each component active material equilibrium potential, mixed type anode in cathode equilibrium potential, mixed type anode material
The initial set value meter of the key parameter of the dQ/dV curves of middle each component active material, constant discharge current and mesuring battary
The estimated value for calculating the terminal voltage of mesuring battary, is denoted as Vsim(t)；
S4：The initial set value of the key parameter is modified, until the estimated value V of the mesuring battary terminal voltagesim
(t) the root-mean-square error RMSE between actual value V (t) reaches minimum value, obtains the final correction result of key parameter.
The present invention also provides a kind of mixed type anode material lithium ion battery capacity attenuation mechanism discrimination method, including it is as follows
Step：
S1：It is discharged the mesuring battary of full power state with constant current, and records the constant-current discharge in discharge process
Voltage curve obtains the actual value of different moments battery terminal voltage, is denoted as V (t)；And
S2：In the balanced potential curve of anode, cathode equilibrium potential curve, mixed type anode material that obtain the mesuring battary
The balanced potential curve of each component active material and the dQ/dV curves of each component active material；
S3：According to each component active material equilibrium potential, mixed type anode in cathode equilibrium potential, mixed type anode material
The initial set value meter of the key parameter of the dQ/dV curves of middle each component active material, constant discharge current and mesuring battary
The estimated value for calculating the terminal voltage of mesuring battary, is denoted as Vsim(t)；
S4：The initial set value of the key parameter is modified, until the estimated value V of the mesuring battary terminal voltagesim
(t) the root-mean-square error RMSE between actual value V (t) reaches minimum value, obtains the final correction result of key parameter；And
S5：The capacity attenuation mechanism of battery is obtained according to the final correction result of key parameter.
Compared with prior art, the present invention is directed to the lithium ion battery of mixed type anode material, it is contemplated that due to mixed type
The attenuation law of each component active material is different in positive electrode and the mass ratio of each component active material can with decaying and
Changed factor, it is proposed that be suitable for the discrimination method and capacity of the lithium ion battery key parameter of mixed type anode material
Decaying mechanism discrimination method.The outstanding advantage of this method is nondestructively recognize to obtain the lithium ion of mixed type anode material
The attenuation of inside battery each component active material.
Description of the drawings
Fig. 1 be one embodiment of the invention using LMO-NCM mixed types material as positive electrode active materials, graphite be cathode live
Property material lithium ion battery differential declines cycle after constant-current discharge voltage curve.
Fig. 2 is the balanced potential curve of the graphite cathode of one embodiment of the invention.
Fig. 3 is the LMO-NCM mixed type anodes material of one embodiment of the invention and its balanced potential of component LMO, NCM
Curve.
Fig. 4 is the LMO-NCM mixed type anodes material of one embodiment of the invention and its dQ/dV songs of component LMO, NCM
Line.
It by positive electrode active materials, graphite of LMO-NCM mixed type anodes material is negative that Fig. 5, which is one embodiment of the invention,
The inside lithium ion cell Mechanism of electrochemical behaviors of anhydrous schematic diagram of pole active material.
Fig. 6 is that the LMO-NCM mixed type anode material internal lithium ions (electric current) of one embodiment of the invention distribute mechanism
Schematic diagram.
It by positive electrode active materials, graphite of LMO-NCM mixed type anodes material is negative that Fig. 7, which is one embodiment of the invention,
The change curve of positive and negative anodes equilibrium potential in the lithium ion battery discharge process of pole active material.
It by positive electrode active materials, graphite of LMO-NCM mixed type anodes material is negative that Fig. 8, which is one embodiment of the invention,
The comparison diagram of the estimated value and actual value of battery terminal voltage of the lithium ion battery of pole active material after differential declines recycles.
It by positive electrode active materials, graphite of LMO-NCM mixed type anodes material is negative that Fig. 9, which is one embodiment of the invention,
The identification result figure of the inside key parameter of the lithium ion battery of pole active material.
Specific implementation mode
Below with reference to attached drawing to the present invention mixed type anode material lithium ion battery key parameter discrimination method and
The discrimination method of capacity attenuation mechanism is described in further detail.
First choice explains some nouns involved in description of the invention.
" electricity " (the electric charge) mentioned in description of the invention refers to the reality that battery at a time has
Border electricity.
" capacity " (capacity) that is mentioned in description of the invention refers to the reality that battery has in fully charged state
Electricity, that is, maximum electricity that battery can store.
" active material " mentioned in description of the invention refers to participating in charge and discharge in lithium ion battery plus-negative plate
The material of lithium ion intercalation/deintercalation reaction in journey, common positive electrode active materials include LiFePO4 (LFP), cobalt acid lithium
(LCO), LiMn2O4 (LMO) and nickel-cobalt-manganese ternary material (NCM) or nickel cobalt aluminium ternary material (NCA) etc., common negative electrode active
Material includes graphite and lithium titanate etc..
" the mixed type anode material " mentioned in description of the invention refer to positive electrode include two kinds or two kinds with
On positive electrode active materials, be different from only include single positive electrode active materials a positive electrode.Specifically, the mixed type anode material
Material may include two or more arbitrary positive electrode active materials in the prior art.Common mixed type anode material include but
It is not limited to LMO-NCM mixed type anodes material currently on the market, LMO-NCA mixed type anodes material, LFP-NCM mixed types just
Pole material, LFP-NCA mixed type anodes material, LCO-NCM mixed type anodes material and LCO-NCA mixed type anode materials.
In " the mixed type anode material lithium ion battery " mentioned in description of the invention, positive electrode be the mixed type just
Pole material, i.e. anode include two or more positive electrode active materials, and cathode preferably only includes a kind of negative electrode active
Material.
It is embedding that " the balanced potential " mentioned in description of the invention refers to that slow lithium ion occurs for battery plus-negative plate material
Enter/deviate from electrode potential when reaction (i.e. very small current charging and discharging), at this time it is believed that electrode material is constantly in accurate put down
Weighing apparatus state.The balanced potential of lithium ion battery plus-negative plate material and the lithium ion score of material correspond, generally with to lithium electricity
Gesture indicates.
" the electricity increment " mentioned in description of the invention refer at different voltages V, the electricity dQ that battery is released with
The ratio of corresponding cell voltage decreasing value dV.For example, when cell voltage is V, electricity dQ is released, cell voltage is caused to reduce
DV, then corresponding electricity increment is dQ/dV.
" the lithium ion score " mentioned in description of the invention refers to the normalization of lithium ion in positive and negative anodes active material
Content, interval are [0,1].By taking cathode as an example, the chemical formula of negative electrode active material is LixC6, x therein is that cathode is lived
Property material lithium ion score, negative electrode active material completely embedding full lithium when, x is equal to 1, completely de- lithium when, x is equal to 0.
The present invention provides a kind of discrimination method of mixed type anode material lithium ion battery key parameter, including following step
Suddenly：
S1：It is discharged the mesuring battary of full power state with constant current, and records the constant-current discharge in discharge process
Voltage curve obtains the actual value of any time battery terminal voltage, is denoted as V (t)；
S2：In the balanced potential curve of anode, cathode equilibrium potential curve, mixed type anode material that obtain the mesuring battary
Electricity increment (dQ/dV) curve of each component active material equilibrium potential curve and each component active material；
S3：According to each component active material equilibrium potential, mixed type anode in cathode equilibrium potential, mixed type anode material
The initial set value of the key parameter of the dQ/dV curves of middle each component active material, constant discharge current and battery calculates electricity
The estimated value of the terminal voltage in pond, is denoted as Vsim(t)；
S4：The initial set value of key parameter is modified, until the estimated value V of battery terminal voltagesim(t) and it is true
Standard error RMSE between value V (t) reaches minimum value, obtains the final correction result of key parameter.
In step S1, which is t from full power state to the entire discharge time of emptying state1To tn, share n
Sampled point, n are positive integer, any moment tk.The voltage curve can be voltage-time curve or voltage-capacity curve.
In step S2, the balanced potential of each component material of battery plus-negative plate equilibrium potential curve and mixed type anode material
Curve can be obtained by carrying out the methods of low current (being less than 0.04C) charge and discharge to half-cell, and this will not be repeated here.
The mesuring battary anode may include the first positive electrode active materials, is denoted as A and the second positive electrode active materials, is denoted as B.
Step S2 can obtain the first positive electrode active materials equilibrium potential curve and dQ/dV curves and the second positive-active respectively
The balanced potential curve and dQ/dV curves of material.
The key parameter may include the capacity and lithium ion score of a certain composition activity material in mixed type anode material, bear
The capacity of pole active material, the lithium ion score of negative electrode active material and the internal resistance of the mesuring battary.
The dQ/dV curves can reflect the chemical reaction process of inside battery, can be obtained (such as by the methods of several methods
Chinese Patent Application Publication CN103698714A), it also repeats no more herein.At the same voltage, mixed type anode material
DQ/dV values are the sum of the dQ/dV values of the dQ/dV values and the second positive electrode active materials of the first positive electrode active materials.This is because
In the charge and discharge process of battery, first positive electrode active materials and both active materials of the second positive electrode active materials are in parallel connection
Connection status.In lithium ion battery discharge process, lithium ion is deviate from from cathode, by electrolyte and diaphragm, is embedded into positive material
In material.In mixed type anode material, two kinds of component moment of first positive electrode active materials and the second positive electrode active materials are in
It in equal balanced potential, is equivalent to the two and is connected in parallel, lithium ion divides according to the proportion of dQ/dV values both under the equilibrium potential
It Qian Ru not be in first positive electrode active materials and the second positive electrode active materials, to ensure first positive electrode active materials and second just
The balanced potential of pole active material keeps equal.
In an embodiment of the present invention, the estimated value V of the terminal voltage of the mesuring battarysim(tk)=Vp(tk)-Vn(x(tk))-
I × R, wherein Vp(tk) it is tkThe balanced potential of anode at moment, Vn(x(tk)) it is tkMoment lithium ion score is x (tk) cathode
Balanced potential, R be the internal resistance of cell initial set value, I be the constant current, i.e., per time instance insertion positive electrode in lithium from
Sub- total amount.
In an embodiment of the present invention, the Vp(tk) meet Vp(tk)=Vp,A(yA(tk))=Vp,B(yB(tk)), yA(tk) be
tkThe lithium ion score of the first positive electrode active materials of moment, Vp,A(yA(tk)) it is tkMoment lithium ion score is yA(tk) first
The balanced potential of positive electrode active materials, yB(tk) it is tkThe lithium ion score of the second positive electrode active materials of moment, Vp,B(yB(tk)) be
tkMoment lithium ion score is yB(tk) the second positive electrode active materials balanced potential.
The yA(tk) and x (tk) can meet respectively：
x(tk)=x0-I×tk/CN；
Wherein, x (tk) it is tkThe lithium ion score of moment negative electrode active material, x0For the lithium ion point of negative electrode active material
Several initial set values, CNFor the initial set value of the capacity of negative electrode active material, P (tk) it is tkMoment is embedded in first anode
Lithium ion quantity in active material accounts for the proportion of whole lithium ion quantity, y0,AFor the lithium ion point of the first positive electrode active materials
Several initial set values, CAFor the initial set value of the capacity of the first positive electrode active materials, Δ t is sampling time interval.
P (the tk) can meet：
Wherein dQA/ dV is the electricity increment of the first positive electrode active materials, dQB/ dV is the electricity of the second positive electrode active materials
Increment, c are the mass ratio (m of the second positive electrode active materials and the first positive electrode active materialsB/mA)。
The terminal voltage estimated value V of the mesuring battarysim(t) the root-mean-square error RMSE between actual value V (t) is：
The present invention further provides a kind of discrimination method of mixed type anode material lithium ion battery capacity attenuation mechanism, packets
Above-mentioned steps S1~S4 is included, and further comprises step S5：The capacity of battery is obtained according to the final correction result of key parameter
Decay mechanism.
Step S5 may include obtaining the key parameter after the mesuring battary undergoes not homogeneous charge and discharge cycles respectively
Final correction result, to obtain the attenuation rate that the key parameter changes with the mesuring battary charge and discharge cycles number.The decaying
Rate is the initial set value X of a certain key parameter0Difference and initial set value between final correction result X ' ratio (=
(X0-X’)/X0× 100%), according to the key parameter with the increase of charge and discharge cycles number ever-reduced attenuation rate, can be with
The attenuation degree for analyzing the key parameter, to judge whether the capacity attenuation of the battery is caused by the decaying of the key parameter.
Step S5 can further comprise being obtained inside the mesuring battary according to the final correction result of the key parameter
Amount Σ (the Li/Li of lithium ion can be used+),
Σ(Li/Li+)=x '0C’N+y’0,AC’A+y’0,BC’B,
Wherein x '0For t0The correction value of the lithium ion score of moment negative electrode active material, C 'NFor the appearance of negative electrode active material
The correction value of amount, y '0,AFor t0The correction value of the lithium ion score of the first positive electrode active materials of moment, C 'AFor the first positive-active
The correction value of the capacity of material, y '0,BFor t0The correction value of the lithium ion score of the second positive electrode active materials of moment, C 'BIt is second
The correction value of the capacity of positive electrode active materials, y '0,BAccording to Vp,A(y’0,A)=Vp,B(y’0,B)y’0,AIt is calculated, C 'B=c × k0
×C’A。k0For the initial capacity of the first positive electrode active materials and the second positive electrode active materials ratio, i.e. CA/CB
Step S5 can further comprise according to the amount Σ (Li/Li for obtaining can be used lithium ion+) attenuation rate, combining step
The key parameter of mesuring battary is obtained in S5 and can use the attenuation rate of the amount of lithium ion, and the inside that can obtain the mesuring battary is declined
Subtract mechanism.
Below with positive electrode for LMO-NCM mixed type anode materials, negative electrode active material is the lithium ion battery of graphite
As mesuring battary, the discrimination method of discrimination method and capacity attenuation mechanism to lithium ion battery key parameter of the present invention is made more
It is further to be described in detail.
In step S1, Fig. 1 is that positive electrode is LMO-NCM mixed type anode materials, and negative electrode active material is the lithium of graphite
Constant-current discharge voltage curve in the case of ion battery differential declines.The constant-current discharge voltage of the new battery of 0 cyclic representation is bent in Fig. 1
Line, 120 cycles, 240 cycles, 360 cyclic representation the batteries perseverance after 120 times, 240 times and 360 times durabilities recycle respectively
Flow discharge voltage profile.From figure 1 it appears that in differential declines, the constant-current discharge voltage curve of battery has very greatly
Difference, and not for simple Pan and Zoom relationship.The present invention is directed to according to mesuring battary certain cycle after perseverance
Banish the capacity attenuation mechanism and SOH of the piezoelectric voltage tracing analysis mesuring battary.
In step S2, Fig. 2 is the balanced potential curve of the graphite cathode of lithium ion battery in the present embodiment.Graphite cathode
Balanced potential changes with the variation of internal lithium ion score, and for lithium ion score closer to 1, the potential of graphite is lower.It needs
It should be noted that lithium ion score here refers to equivalent lithium ion score, and when definition graphite equilibrium potential is 0.05V, lithium
Ionic fraction is 1, and when balanced potential is 1.5V, lithium ion score is 0.In battery charge and discharge process, lithium ion is in negative material
Intercalation/deintercalation reaction occurs for inside, and lithium ion score changes in 0 to 1 section, and correspondingly, cathode equilibrium potential is also arrived 0
Change in the sections 1.5V.
Fig. 3 be the present embodiment in lithium ion battery LMO-NCM mixed type anodes material and its component LMO and NCM it is equal
Weigh potential curve.Likewise, lithium ion score here refers to being also equivalent lithium ion score, it is 3V to define balanced potential
When, lithium ion score is 1, and when balanced potential is 4.3V, lithium ion score is 0.In battery charge and discharge process, lithium ion is in anode
Intercalation/deintercalation reaction occurs for material, and lithium ion score changes in 0 to 1 section, and correspondingly, anode equilibrium potential is also arrived 3
Change in the sections 4.3V.From figure 3, it can be seen that the slope of the balanced potential curve of NCM materials is relatively steep, and LMO materials
The balanced potential curve of material is relatively flat, and the balanced potential curve of LMO-NCM mixed type anode materials is therebetween.
Fig. 4 is the electricity increment (dQ/dV) of LMO-NCM mixed type anodes material and its component LMO and NCM in the present embodiment
Curve.Figure 4, it is seen that at the same voltage, the dQ/dV values of LMO-NCM mixed type anode materials are the dQ/ of LMO
The sum of the dQ/dV values of dV values and NCM.This is because in the charge and discharge process of battery, two kinds of active materials of LMO and NCM are in
It is connected in parallel state, as shown in Figure 5.By taking electric discharge as an example, in lithium ion battery discharge process, lithium ion is deviate from from cathode, passes through
Electrolyte and diaphragm, are embedded into positive electrode.In mixed type anode material, two kinds of component moment of LMO and NCM are in equal
Balanced potential in, both be equivalent to and to be connected in parallel, lithium ion is embedding according to the ratio reassignment of dQ/dV values both under the equilibrium potential
Enter wherein, to ensure that the balanced potential of LMO and NCM keeps equal.Analysis lithium ion is embedding by taking the potential change of NCM as an example in Fig. 6
The process for entering mixed type anode material, in tkMoment, the lithium ion score in NCM are yNCM(tk), corresponding equilibrium potential is
Vp,NCM(yNCM(tk)), at this time according to the dQ/dV values of LMO and NCM, the lithium ion that can be calculated in embedded NCM materials accounts for entirely
Proportion (the number ratio of lithium ion) in portion's lithium ion is P (tk)：
Wherein, c is in mixed type anode material, and the mass ratio of LMO and NCM, initial value are set as 1.tk+1Moment, NCM materials
The incrementss of middle lithium ion score are Δ yNCM(tk), and
ΔyNCM(tk)=P (tk)·I·Δt/CNCM,
Wherein I is discharge current, i.e. lithium ion total amount in per time instance insertion positive electrode, and Δ t is between the sampling time
Every CNCMFor the capacity of NCM active materials.T can be obtained accordinglyk+1The lithium ion score y of moment NCMNCM(tk+1)=yNCM(tk)
+ΔyNCM(tk).The rest may be inferred, and the lithium ion score in each moment NCM can be calculated.
In step S3, according to each component active material equilibrium potential, mixing in cathode equilibrium potential, mixed type anode material
The initial set value of the key parameter of the dQ/dV curves of each component active material, constant discharge current and battery in type anode
The estimated value for calculating the terminal voltage of battery, is denoted as Vsim(t).Key parameter includes the capacity of NCM, the lithium ion score of NCM, stone
The capacity of black cathode, the lithium ion score and the internal resistance of cell of graphite cathode.Here, the initial set value of the capacity of NCM is
CNCM, the initial value of the lithium ion score of NCM is set as y0,NCM, the initial set value of the capacity of graphite cathode is CN, graphite cathode
The initial value of lithium ion score is set as x0, the initial value of the internal resistance of cell is set as R, constant current I.Discharge process, tkMoment, NCM
Lithium ion score yNCM, the calculation formula of the lithium ion score x of graphite cathode is：
x(tk)=x0-I×tk/CN (3)
As shown in fig. 6, the terminal voltage V of batterysim(tk) it is equal to the difference of positive and negative anodes equilibrium potential, while subtracting internal resistance and causing
The loss of voltage, calculation formula is as follows：
Vsim(tk)=Vp(tk)-Vn(x(tk))-I×R (4)
Wherein the balanced potential of mixed type anode material is equal to the balanced potential of NCM, as follows：
Vp(tk)=Vp,NCM(yNCM(tk))=Vp,LMO(yLMO(tk))
In step S4, if entire discharge time t1To tn, share n sampled point, the terminal voltage estimated value V of batterysim(t) and
Root-mean-square error RMSE between actual value V (t) is calculated by following formula：
Given different [x0,CN,y0,NCM,CNCM, c, R], different battery terminal voltage estimated value V can be obtainedsim(t),
Corresponding root-mean-square error RMSE can be calculated by formula (6).Key is joined using the optimal estimations such as genetic algorithm algorithm
Number [x0,CN,y0,NCM,CNCM, c, R] and it is modified, optimal key parameter can be found so that the estimated value of battery terminal voltage
Vsim(t) the root-mean-square error RMSE between actual value V (t) is minimum, as shown in Figure 7.
It compared the estimated value and actual value curve of battery terminal voltage of the battery after the cycle of different numbers in Fig. 8.
Compare for convenience, corresponding positive and negative anodes equilibrium potential curve is also depicted in figure.It is 1. the comparison result of new battery in Fig. 8,
2., 3. and 4. be respectively terminal voltage estimated value and actual value that battery have passed through after 120,240,360 durabilities cycles ratio
Compared with, it can be seen that after the durability of different numbers cycle, the estimated value and actual value of battery terminal voltage are identical very good,
The root-mean-square error of the two is always held within 6mV.
The present invention further provides a kind of discrimination method of mixed type anode material lithium ion battery capacity attenuation mechanism, packets
Above-mentioned steps S1~S4 is included, and further comprises step S5：The capacity of battery is obtained according to the final correction result of key parameter
Decay mechanism.
In step S5, according to the optimal correction result of key parameter, the capacity attenuation mechanism of lithium ion battery can be obtained.
Obtained key parameter [x0,CN,y0,NCM,CNCM, c, R] in, CNCMAnd CNIt can directly reflect the change of the capacity of NCM and graphite cathode
Change, R can reflect the variation of the internal resistance of cell.In addition, the capacity C of LMOLMOIt can be calculated with following formula, wherein k0For
The initial capacity ratio of NCM and LMO, can be calculated according to dQ/dV curves.
CLMO=c × k0×CNCM (7)
The decaying of lithium ion battery is it is also possible that as caused by available lithium ion loss, according to obtained key parameter,
The amount of the available lithium ion of inside battery can be calculated with following formula：
Σ(Li/Li+)=x0CN+y0, NCMCNCM+y0, LMOCLMO (8)
Fig. 9 is the identification result for the internal mechanism key parameter that battery is obtained according to one embodiment of the present of invention, including
The capacity of LMO, NCM, graphite cathode capacity, the amount and the internal resistance of cell that lithium ion can be used.
Pass through embodiment, it can be seen that mixed type anode material lithium ion battery decaying mechanism identification proposed by the present invention
Method can obtain the attenuation of each component material in the decaying mechanism of inside battery, especially mixed type anode material, have
Help fully understand the health status of battery.
In addition, those skilled in the art can also do other variations in spirit of that invention, these are spiritual according to the present invention
The variation done should be all included in scope of the present invention.
Claims (9)
1. a kind of discrimination method of mixed type anode material lithium ion battery key parameter, includes the following steps：
S1：It is discharged the mesuring battary of full power state with constant current, and records the constant-current discharge voltage in discharge process
Curve obtains the actual value of different moments battery terminal voltage, and the entire discharge time of the discharge process is t1To tn, shared n are adopted
Sampling point, n are positive integer, any moment tk, the actual value of the battery terminal voltage is denoted as V (tk)；
S2：Obtain each group in the balanced potential curve of anode, cathode equilibrium potential curve, mixed type anode material of the mesuring battary
Divide the balanced potential curve of active material and the electricity incremental rate curve of each component active material；
S3：According to each in each component active material equilibrium potential, mixed type anode in cathode equilibrium potential, mixed type anode material
The initial set value of the key parameter of the electricity incremental rate curve of composition activity material, constant discharge current and mesuring battary calculates
The estimated value of the terminal voltage of mesuring battary, is denoted as Vsim(tk), the estimated value V of battery terminal voltagesim(tk) it is equal to the balanced electricity of positive and negative anodes
The difference of gesture subtracts the loss of voltage caused by internal resistance simultaneously, wherein the key parameter of the mesuring battary includes mixed type anode material
In a certain composition activity material capacity and lithium ion score, the capacity of negative electrode active material, the lithium ion of negative electrode active material
The internal resistance of score and the mesuring battary；
S4：The initial set value of the key parameter is modified, until the estimated value V of the mesuring battary terminal voltagesim(tk) and
Actual value V (tk) between root-mean-square error RMSE reach minimum value, obtain the final correction result of key parameter.
2. the discrimination method of mixed type anode material lithium ion battery key parameter as described in claim 1, which is characterized in that
The estimated value V of the terminal voltage of the mesuring battarysim(tk)=Vp(tk)-Vn(x(tk))-I × R, wherein Vp(tk) it is tkMoment is just
Extremely balanced potential, Vn(x(tk)) it is tkMoment lithium ion score is x (tk) cathode equilibrium potential, R be the internal resistance of cell it is initial
Setting value, I are the constant current.
3. the discrimination method of mixed type anode material lithium ion battery key parameter as claimed in claim 2, which is characterized in that
The mesuring battary anode includes the first positive electrode active materials, is denoted as A and the second positive electrode active materials, is denoted as B, the Vp(tk) full
Foot：
Vp(tk)=Vp,A(yA(tk))=Vp,B(yB(tk)),
Wherein yA(tk) it is tkThe lithium ion score of the first positive electrode active materials of moment,
Vp,A(yA(tk)) it is tkMoment lithium ion score is yA(tk) the first positive electrode active materials balanced potential,
yB(tk) it is tkThe lithium ion score of the second positive electrode active materials of moment,
Vp,B(yB(tk)) it is tkMoment lithium ion score is yB(tk) the second positive electrode active materials balanced potential.
4. the discrimination method of mixed type anode material lithium ion battery key parameter as claimed in claim 3, which is characterized in that
The yA(tk) and x (tk) meet respectively：
x(tk)=x0-I×tk/CN；
Wherein, x (tk) it is tkThe lithium ion score of moment negative electrode active material,
x0For the initial set value of the lithium ion score of negative electrode active material,
CNFor the initial set value of the capacity of negative electrode active material,
P(tk) it is tkThe lithium ion quantity that moment is embedded in first positive electrode active materials accounts for the proportion of whole lithium ion quantity,
y0,AFor the initial set value of the lithium ion score of the first positive electrode active materials,
CAFor the initial set value of the capacity of the first positive electrode active materials,
Δ t is sampling time interval.
5. the discrimination method of mixed type anode material lithium ion battery key parameter as claimed in claim 4, which is characterized in that
P (the tk) meet：
Wherein dQA/ dV is the electricity increment of the first positive electrode active materials, dQB/ dV is the electricity increment of the second positive electrode active materials,
C is the mass ratio of the second positive electrode active materials and the first positive electrode active materials.
6. the discrimination method of mixed type anode material lithium ion battery key parameter as described in claim 1, which is characterized in that
The terminal voltage estimated value V of the mesuring battarysim(tk) and actual value V (tk) between root-mean-square error RMSE be：
7. a kind of mixed type anode material lithium ion battery capacity attenuation mechanism discrimination method, including in claim 1~6 arbitrarily
Step S1~S4 in one, and further comprise step S5：The appearance of battery is obtained according to the final correction result of key parameter
Amount decaying mechanism.
8. mixed type anode material lithium ion battery capacity attenuation mechanism discrimination method as claimed in claim 7, feature exist
In step S5, which is included in after the mesuring battary undergoes not homogeneous charge and discharge cycles respectively, obtains the final amendment of the key parameter
As a result, to obtain the attenuation rate that the key parameter changes with the mesuring battary charge and discharge cycles number.
9. mixed type anode material lithium ion battery capacity attenuation mechanism discrimination method as claimed in claim 7, feature exist
In, step S5 further comprise the final correction result according to the key parameter obtain available lithium inside the mesuring battary from
Amount Σ (the Li/Li of son+)：
Σ(Li/Li+)=x '0C’N+y’0,AC’A+y’0,BC’B,
Wherein x '0For the correction value of the lithium ion score of negative electrode active material,
C’NFor the correction value of the capacity of negative electrode active material,
y’0,AFor the correction value of the lithium ion score of the first positive electrode active materials,
C’AFor the correction value of the capacity of the first positive electrode active materials,
y’0,BFor the correction value of the lithium ion score of the second positive electrode active materials,
C’BFor the correction value of the capacity of the second positive electrode active materials.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101144850A (en) * | 2007-10-29 | 2008-03-19 | 清华大学 | Fuel cell voltage attenuation quick determination method and device |
| CN103576097A (en) * | 2013-11-19 | 2014-02-12 | 清华大学 | Method and system for estimating SOH of battery |
| CN103698714A (en) * | 2014-01-02 | 2014-04-02 | 清华大学 | Identifying method and system for battery capacity fading mechanism |
| CN103907030A (en) * | 2011-10-07 | 2014-07-02 | 日本康奈可株式会社 | Battery state-of-charge estimation device and state-of-charge estimation method |
| CN104678317A (en) * | 2015-03-05 | 2015-06-03 | 普天新能源车辆技术有限公司 | Method and device for detecting capacity fading of power lithium battery |
| CN104865536A (en) * | 2015-06-16 | 2015-08-26 | 天津力神电池股份有限公司 | Method for testing and diagnosing performance degradation reasons of lithium ion battery |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002305038A (en) * | 2001-04-05 | 2002-10-18 | Japan Storage Battery Co Ltd | Defect determining method of lead-acid battery and charging method of lead-acid battery |
| JP3714214B2 (en) * | 2001-09-05 | 2005-11-09 | 日産自動車株式会社 | Secondary battery charge rate estimation device |
-
2016
- 2016-01-30 CN CN201610067282.6A patent/CN105527581B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101144850A (en) * | 2007-10-29 | 2008-03-19 | 清华大学 | Fuel cell voltage attenuation quick determination method and device |
| CN103907030A (en) * | 2011-10-07 | 2014-07-02 | 日本康奈可株式会社 | Battery state-of-charge estimation device and state-of-charge estimation method |
| CN103576097A (en) * | 2013-11-19 | 2014-02-12 | 清华大学 | Method and system for estimating SOH of battery |
| CN103698714A (en) * | 2014-01-02 | 2014-04-02 | 清华大学 | Identifying method and system for battery capacity fading mechanism |
| CN104678317A (en) * | 2015-03-05 | 2015-06-03 | 普天新能源车辆技术有限公司 | Method and device for detecting capacity fading of power lithium battery |
| CN104865536A (en) * | 2015-06-16 | 2015-08-26 | 天津力神电池股份有限公司 | Method for testing and diagnosing performance degradation reasons of lithium ion battery |
Non-Patent Citations (3)
| Title |
|---|
| A comparative study of commercial lithium ion battery cycle life in electric vehicle: Capacity loss estimation;Xuebing Han et.al;《Journal of Power Sources》;20141231(第268期);第658-669页 * |
| A comparative study of commercial lithium ion battery cycle life in electrical vehicle: Aging mechanism identification;Xuebing Han et.al;《Journal of Power Sources》;20141231(第251期);第38-54页 * |
| A review of SOH estimation methods in Lithium-ion batteries for electric vehicle applications;Cheng Lin et.al;《Energy Procedia》;20151231(第75期);第1920-1925页 * |
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