A kind of sodium sulphur energy storage device capacity attenuation judgment method
Technical field
The present invention relates to a kind of sodium sulphur energy storage device capacity attenuation judgment methods in battery detecting field.
Background technique
Sodium-sulphur battery is a kind of large capacity, the high temperature secondary battery of long-life, in peak load shifting, new-energy grid-connected, intelligence
The fields such as power grid construction, which have, to be widely applied.Under normal circumstances with the continuous progress of charge and discharge cycles, capacity gradually slowly declines
Subtracting, sodium-sulphur battery has about 4500 cycle life, however since the material selection of sodium-sulphur battery monomer is improper or sodium sulphur
Perhaps charge and discharge system is unreasonable causes to abuse or the reason of other cannot not be predicted leads for the quality of materials problem of battery cell
It causes the improper decaying of sodium sulphur energy storage device capacity to limit the application of sodium-sulphur battery to a certain extent, therefore sodium sulphur energy storage is set
Standby capacity attenuation is carried out judgement and proposes to be of great significance using suggestion to user.
Summary of the invention
The purpose of the invention is to overcome the deficiencies of the prior art and provide a kind of sodium sulphur energy storage device capacity attenuation judgement
Method, with high sensitivity, enforceability is good, simple operation and other advantages.
Realizing a kind of technical solution of above-mentioned purpose is: a kind of 1. sodium sulphur energy storage device capacity attenuation judgment methods, including
The following steps:
First discharge step: constant-current discharge is carried out to running sodium sulphur energy storage device with nominal discharge current, and is discharged
To discharge cut-off voltage, shelve 1~for 24 hours;
Charge step: carrying out constant-current charge to the sodium sulphur energy storage device with specified charging current, and charges to charging and cut
Only voltage measures charging capacity Qc, shelve 1~for 24 hours;
Second discharge step: constant-current discharge is carried out to the sodium sulphur energy storage device with nominal discharge current, and is discharged to
Electric blanking voltage measures discharge capacity Qd;
Coulombic efficiency calculates step: coulombic efficiency η calculation formula are as follows:
Decay judgment step: when the sodium sulphur energy storage device coulombic efficiency be more than or equal to 101% or be less than or equal to 99%,
Judge that the capacity of the sodium sulphur energy storage device is decayed.
Further, in the charge step, after the voltage of the sodium sulphur energy storage device reaches charge cutoff voltage, after
Continuous constant-voltage charge, until charging current is decreased to the 10% of specified charging current.
Further, in the judgment step that decays, if the coulombic efficiency for the sodium sulphur energy storage device occur is more than or equal to 105%
Or it is less than or equal to 95%, judge that improper decaying occurs in the capacity of the sodium sulphur energy storage device, the sodium sulphur energy storage device is necessary
It is scrapped or is updated.
Further, there are also coulombic efficiency comparison steps after the judgment step that decays, i.e., the sodium sulphur measured n-th stores up
The coulombic efficiency η of energy equipmentn, the coulombic efficiency η of the sodium sulphur energy storage device measured with (n-1)th timen-1It is compared, if logical
Cross and compare to obtain | ηn-ηn-1| >=1%, then judge that improper decaying, the sodium sulphur storage occurs in the capacity of the sodium sulphur energy storage device
Energy equipment must be scrapped or be updated.
Further, the time interval that arbitrary neighborhood is detected twice between the coulombic efficiency of the sodium sulphur energy storage device is
One week to 1 year.
Further, when carrying out the detection of any coulombic efficiency to the sodium sulphur energy storage device, if the sodium
The coulombic efficiency of sulphur energy storage device is more than or equal to 101% or less than or equal to 99%, then shortens this time and next time stores up the sodium sulphur
Energy equipment carries out the interval time between coulombic efficiency detection.
Further, the sodium sulphur energy storage device is sodium-sulphur battery monomer, sodium-sulphur battery group, sodium-sulfur battery module or sodium sulphur
One of battery power station.
Using a kind of technical solution of sodium sulphur energy storage device capacity attenuation judgment method of the invention, including following step
It is rapid: the first discharge step: constant-current discharge being carried out to running sodium sulphur energy storage device with nominal discharge current, and is discharged to electric discharge
Blanking voltage, shelve 1~for 24 hours;Charge step: carrying out constant-current charge to the sodium sulphur energy storage device with specified charging current, and
Charge cutoff voltage is charged to, charging capacity Q is measuredc, shelve 1~for 24 hours;Second discharge step: with nominal discharge current to institute
It states sodium sulphur energy storage device and carries out constant-current discharge, and be discharged to discharge cut-off voltage, measure discharge capacity Qd;Coulombic efficiency calculates step
It is rapid: coulombic efficiency η calculation formula are as follows:Decay judgment step: when the coulombic efficiency of the sodium sulphur energy storage device
More than or equal to 101% or less than or equal to 99%, judge that the capacity of the sodium sulphur energy storage device is decayed.Its technical effect is that:
With having, high sensitivity, enforceability be good, simple operation and other advantages for it.
Detailed description of the invention
Fig. 1 is sodium-sulphur battery monomer in a kind of embodiment of sodium sulphur energy storage device capacity attenuation judgment method of the invention
Coulombic efficiency variation diagram.
Specific embodiment
Referring to Fig. 1, the present inventor in order to preferably understand technical solution of the present invention, is led to below
Specifically embodiment is crossed, and will be described in detail with reference to the accompanying drawings:
A kind of sodium sulphur energy storage device capacity attenuation judgment method of the present invention is to sodium-sulphur battery monomer, sodium-sulphur battery group or sodium
The sodium sulphur energy storage device such as sulphur battery module or sodium-sulphur battery power station is all suitable for.
As the basic component units of sodium sulphur energy-storage system, sodium-sulphur battery monomer is with β "-Al2O3Electrolyte ceramics Guan Wei electricity
Matter and diaphragm are solved, therefore does not have side reaction, without self discharge, the coulombic efficiency η of charge and discharge cycles is generally 100%, Huo Zhe
The range fluctuation of very little near 100%.But it often will appear charging capacity when the capacity of sodium-sulphur battery monomer is decayed
QcLess than discharge capacity QdOr discharge capacity QdLess than charging capacity QcThe phenomenon that, or charging capacity Q sometimescLess than electric discharge
Capacity Qd, discharge capacity Q sometimesdLess than charging capacity QcThe phenomenon that, above-mentioned three kinds of phenomenons are corresponding to be known as charging capacity decaying, puts
Capacitance fall-off and capacity attenuation, being embodied on coulombic efficiency η with regard to correspondence is that coulombic efficiency η is greater than 100% or coulombic efficiency
η is less than 100% or coulombic efficiency η big ups and downs occurs and is sometimes more than 100% sometimes again less than 100%.In conclusion logical
The coulombic efficiency η variation crossed in monitoring charge and discharge cycles can judge the capacity attenuation of sodium sulphur energy storage device.
The specific method is as follows, includes the following steps:
First discharge step: running sodium sulphur energy storage device is switched into off-network state, with nominal discharge current to institute
It states sodium sulphur energy storage device and carries out constant-current discharge, and be discharged to discharge cut-off voltage, shelve 1~for 24 hours, keep sodium sulphur energy storage device steady
It is fixed.
Charge step: carrying out constant-current charge to the sodium sulphur energy storage device with specified charging current, and charges to charging and cut
Only voltage measures charging capacity Qc, it shelves a period of time, such as 1~for 24 hours, so that sodium sulphur energy storage device is stablized.In sodium sulphur energy storage
The voltage of equipment reaches charging after voltage, measures charging capacity QcBefore, can also continue constant pressure to sodium sulphur energy storage device to fill
Electric a period of time, so that charging capacity QcIt is substantial access to the rated capacity of the sodium sulphur energy storage device.Constant-voltage charge is to the electricity that charges
Stream is that 10% or by specification of specified charging current carry out constant-voltage charge.
Second discharge step: constant-current discharge is carried out to the sodium sulphur energy storage device with nominal discharge current, and is discharged to
Electric blanking voltage measures discharge capacity Qd。
Coulombic efficiency calculates step: coulombic efficiency η calculation formula are as follows:
Decaying judgment step: when the coulombic efficiency η of the sodium sulphur energy storage device is more than or equal to 101% or is less than or equal to
99%, judge that the capacity of the sodium sulphur energy storage device is decayed, indicates the sodium sulphur energy storage device although also can be used, use
Family must be noted that the decaying that the capacity of sodium sulphur energy storage device occurs.
If the coulombic efficiency η of the sodium sulphur energy storage device is more than or equal to 105% or less than or equal to 95%, the sodium sulphur is judged
There is improper decaying in the capacity of energy storage device, and the sodium sulphur energy storage device must be scrapped or be updated.It include: sodium-sulphur battery
Monomer is scrapped, and sodium-sulphur battery group or sodium-sulfur battery module are integrally scrapped or carried out more to sodium-sulphur battery monomer in part therein
Newly.Part sodium-sulphur battery group or sodium-sulfur battery module in sodium-sulphur battery power station are updated.
Coulombic efficiency comparison step can be the fixed time interval between one week to 1 year at regular intervals, than
Such as 3 months, perhaps carried out when certain charge and discharge cycles number perhaps each scheduled maintenance or in needs any
When, the coulombic efficiency η of sodium sulphur energy storage device will be detected, and sodium sulphur energy storage detected by n-th is set
Standby coulombic efficiency ηn, the coulombic efficiency η of the sodium sulphur energy storage device measured with (n-1)th timen-1It is compared, if passing through ratio
Relatively obtain | ηn-ηn-1| >=1%, judge that improper decaying, the sodium sulphur energy storage device occurs in the capacity of the sodium sulphur energy storage device
It must be scrapped or be updated.Such as the coulombic efficiency η of the sodium sulphur energy storage device that n-th measuresnIt is 99.45%, (n-1)th
The coulombic efficiency η of the secondary sodium sulphur energy storage device measuredn-1It is 100.55%, although the sodium sulphur energy storage detected twice
The coulombic efficiency of equipment between 99%~101%, but because | ηn-ηn-1| >=1%, then still judge the sodium sulphur storage
There is improper decaying in energy equipment.
If carry out the detection of any coulombic efficiency η to the sodium sulphur energy storage device, if the sodium sulphur energy storage device
Coulombic efficiency η be more than or equal to 101% or be less than or equal to 99%, then shorten this time and next time to the sodium sulphur energy storage device progress
Interval time between coulombic efficiency η detection.
Embodiment 1:
A certain model sodium-sulphur battery monomer parameter is as follows: sodium-sulphur battery monomer capacity 350Ah, discharge cut-off voltage 1.75V,
Charge cutoff voltage 2.5V, nominal discharge current 50A, specified charging current 25A.
Wherein a section sodium-sulphur battery monomer carries out the charge and discharge cycles test under working condition, it is specified that carrying out at quarterly intervals
Coulombic efficiency η detection.
The initial charging capacity Q of the section sodium-sulphur battery monomercFor 355Ah, initial discharge capacity QdFor 355.1Ah, because
This initial coulombic efficiency
When the 3rd month coulombic efficiency to the section sodium-sulphur battery monomer detect for the first time, the section sodium-sulphur battery monomer
Charging capacity QcFor 354.9Ah, discharge capacity QdFor 355.1Ah, therefore the coulomb effect of the sodium-sulphur battery monomer measured for the first time
Rate are as follows:
When the 6th month coulombic efficiency to the section sodium-sulphur battery monomer carries out second of detection, the section sodium-sulphur battery monomer
Charging capacity QcFor 354.3Ah, discharge capacity QdFor 354.9Ah, therefore the coulomb effect of the sodium-sulphur battery monomer measured for the second time
Rate are as follows:
The coulombic efficiency η of 9th month sodium-sulphur battery monomer measured when third time detects3It is 100.1%.12nd month
The coulombic efficiency η of measured sodium-sulphur battery monomer when the 4th detection4It is 100.07%.15th month the 5th time detection when institute
The coulombic efficiency η of the sodium-sulphur battery monomer measured5It is 100.11%.
When carrying out the 6th detection to the coulombic efficiency of the section sodium-sulphur battery monomer within 18th month, the section sodium-sulphur battery monomer
Charging capacity QcFor 348Ah, discharge capacity QdFor 352.9Ah, therefore the coulombic efficiency of the 6th sodium-sulphur battery monomer measured
Are as follows:
Show that the capacity of the section sodium-sulphur battery monomer is decayed, battery management system needs to remind user's section sodium at this time
There is decaying in the capacity of sulphur battery cell, needs especially to pay close attention to.Therefore a coulombic efficiency detection is carried out every other week.
When carrying out the 7th detection to the coulombic efficiency of the section sodium-sulphur battery monomer when testing 18th month another week, the section
The charging capacity Q of sodium-sulphur battery monomercFor 332Ah, discharge capacity QdFor 315.3Ah, therefore the 7th sodium-sulphur battery measured
The coulombic efficiency of monomer are as follows:
Show that improper decaying occurs in the capacity of the section sodium-sulphur battery monomer, battery management system needs to remind user at this time
There is improper decaying in the capacity of the section sodium-sulphur battery monomer, needs to carry out the section sodium-sulphur battery monomer in conditions permit
Pressure is scrapped.
A kind of sodium sulphur energy storage device capacity attenuation judgment method of the invention, takes full advantage of the characteristic of sodium-sulphur battery, i.e.,
The charge and discharge cycles coulombic efficiency of normal sodium-sulphur battery is generally 100%, or the range of very little fluctuates near 100%, leads to
The variation of the coulombic efficiency of monitoring charge and discharge cycles is crossed to judge the decaying of sodium sulphur energy storage device capacity, there is high sensitivity, can
Feasibility is good, simple operation and other advantages.
Those of ordinary skill in the art it should be appreciated that more than embodiment be intended merely to illustrate the present invention,
And be not used as limitation of the invention, as long as the change in spirit of the invention, to embodiment described above
Change, modification will all be fallen within the scope of claims of the present invention.