CN115548482A - Lithium supplementing method, battery preparation method and battery - Google Patents
Lithium supplementing method, battery preparation method and battery Download PDFInfo
- Publication number
- CN115548482A CN115548482A CN202211508274.2A CN202211508274A CN115548482A CN 115548482 A CN115548482 A CN 115548482A CN 202211508274 A CN202211508274 A CN 202211508274A CN 115548482 A CN115548482 A CN 115548482A
- Authority
- CN
- China
- Prior art keywords
- lithium
- battery
- active material
- negative pole
- supplement
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 229910052744 lithium Inorganic materials 0.000 title claims abstract description 197
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 title claims abstract description 195
- 238000000034 method Methods 0.000 title claims abstract description 46
- 230000001502 supplementing effect Effects 0.000 title claims abstract description 26
- 238000002360 preparation method Methods 0.000 title claims abstract description 12
- 239000013589 supplement Substances 0.000 claims abstract description 195
- 239000007774 positive electrode material Substances 0.000 claims abstract description 66
- 238000012360 testing method Methods 0.000 claims abstract description 46
- 239000007773 negative electrode material Substances 0.000 claims abstract description 44
- 238000004519 manufacturing process Methods 0.000 claims abstract description 32
- 239000003795 chemical substances by application Substances 0.000 claims description 114
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 27
- 238000011056 performance test Methods 0.000 claims description 24
- 229910002804 graphite Inorganic materials 0.000 claims description 22
- 239000010439 graphite Substances 0.000 claims description 22
- GELKBWJHTRAYNV-UHFFFAOYSA-K lithium iron phosphate Chemical compound [Li+].[Fe+2].[O-]P([O-])([O-])=O GELKBWJHTRAYNV-UHFFFAOYSA-K 0.000 claims description 20
- 239000002002 slurry Substances 0.000 claims description 8
- IDBFBDSKYCUNPW-UHFFFAOYSA-N lithium nitride Chemical compound [Li]N([Li])[Li] IDBFBDSKYCUNPW-UHFFFAOYSA-N 0.000 claims description 7
- JXGGISJJMPYXGJ-UHFFFAOYSA-N lithium;oxido(oxo)iron Chemical compound [Li+].[O-][Fe]=O JXGGISJJMPYXGJ-UHFFFAOYSA-N 0.000 claims description 6
- 229910000572 Lithium Nickel Cobalt Manganese Oxide (NCM) Inorganic materials 0.000 claims description 5
- FBDMTTNVIIVBKI-UHFFFAOYSA-N [O-2].[Mn+2].[Co+2].[Ni+2].[Li+] Chemical compound [O-2].[Mn+2].[Co+2].[Ni+2].[Li+] FBDMTTNVIIVBKI-UHFFFAOYSA-N 0.000 claims description 5
- QHGJSLXSVXVKHZ-UHFFFAOYSA-N dilithium;dioxido(dioxo)manganese Chemical compound [Li+].[Li+].[O-][Mn]([O-])(=O)=O QHGJSLXSVXVKHZ-UHFFFAOYSA-N 0.000 claims description 5
- 229910021385 hard carbon Inorganic materials 0.000 claims description 5
- ILXAVRFGLBYNEJ-UHFFFAOYSA-K lithium;manganese(2+);phosphate Chemical compound [Li+].[Mn+2].[O-]P([O-])([O-])=O ILXAVRFGLBYNEJ-UHFFFAOYSA-K 0.000 claims description 5
- 239000002931 mesocarbon microbead Substances 0.000 claims description 5
- 229910021389 graphene Inorganic materials 0.000 claims description 4
- 238000005520 cutting process Methods 0.000 claims description 3
- 238000001035 drying Methods 0.000 claims description 3
- 238000005096 rolling process Methods 0.000 claims description 3
- 239000002153 silicon-carbon composite material Substances 0.000 claims description 3
- 210000004027 cell Anatomy 0.000 description 47
- 230000000052 comparative effect Effects 0.000 description 41
- 238000007600 charging Methods 0.000 description 16
- 238000007599 discharging Methods 0.000 description 13
- 238000001556 precipitation Methods 0.000 description 13
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 description 12
- 229910001416 lithium ion Inorganic materials 0.000 description 12
- CASZBAVUIZZLOB-UHFFFAOYSA-N lithium iron(2+) oxygen(2-) Chemical group [O-2].[Fe+2].[Li+] CASZBAVUIZZLOB-UHFFFAOYSA-N 0.000 description 10
- 230000008569 process Effects 0.000 description 10
- 239000011149 active material Substances 0.000 description 7
- 230000000694 effects Effects 0.000 description 5
- 238000002161 passivation Methods 0.000 description 5
- 238000004364 calculation method Methods 0.000 description 4
- 238000006138 lithiation reaction Methods 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- HMDDXIMCDZRSNE-UHFFFAOYSA-N [C].[Si] Chemical class [C].[Si] HMDDXIMCDZRSNE-UHFFFAOYSA-N 0.000 description 3
- 230000001351 cycling effect Effects 0.000 description 3
- 239000007772 electrode material Substances 0.000 description 3
- 239000003792 electrolyte Substances 0.000 description 3
- 239000011888 foil Substances 0.000 description 3
- 238000009830 intercalation Methods 0.000 description 3
- 230000002035 prolonged effect Effects 0.000 description 3
- 239000002904 solvent Substances 0.000 description 3
- 239000000654 additive Substances 0.000 description 2
- 230000000996 additive effect Effects 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 210000001787 dendrite Anatomy 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 230000003631 expected effect Effects 0.000 description 2
- 230000002427 irreversible effect Effects 0.000 description 2
- DVATZODUVBMYHN-UHFFFAOYSA-K lithium;iron(2+);manganese(2+);phosphate Chemical compound [Li+].[Mn+2].[Fe+2].[O-]P([O-])([O-])=O DVATZODUVBMYHN-UHFFFAOYSA-K 0.000 description 2
- 230000014759 maintenance of location Effects 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 230000010287 polarization Effects 0.000 description 2
- 239000007784 solid electrolyte Substances 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- -1 Lithium iron phosphate Lithium manganese iron phosphate Lithium manganese phosphate Lithium nickel cobalt manganese oxide Chemical compound 0.000 description 1
- HFCVPDYCRZVZDF-UHFFFAOYSA-N [Li+].[Co+2].[Ni+2].[O-][Mn]([O-])(=O)=O Chemical compound [Li+].[Co+2].[Ni+2].[O-][Mn]([O-])(=O)=O HFCVPDYCRZVZDF-UHFFFAOYSA-N 0.000 description 1
- QZOVMCPHIQVUGV-UHFFFAOYSA-N [Si].[C].[Si] Chemical compound [Si].[C].[Si] QZOVMCPHIQVUGV-UHFFFAOYSA-N 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 239000006183 anode active material Substances 0.000 description 1
- 230000002238 attenuated effect Effects 0.000 description 1
- 230000006399 behavior Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000003575 carbonaceous material Substances 0.000 description 1
- 239000006182 cathode active material Substances 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 239000002482 conductive additive Substances 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 238000010280 constant potential charging Methods 0.000 description 1
- 239000011889 copper foil Substances 0.000 description 1
- 125000004122 cyclic group Chemical group 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000002950 deficient Effects 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 238000003487 electrochemical reaction Methods 0.000 description 1
- 230000034964 establishment of cell polarity Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 239000012212 insulator Substances 0.000 description 1
- 230000002687 intercalation Effects 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 239000005486 organic electrolyte Substances 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000002441 reversible effect Effects 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000012795 verification Methods 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
- H01M10/4235—Safety or regulating additives or arrangements in electrodes, separators or electrolyte
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/058—Construction or manufacture
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Materials Engineering (AREA)
- Battery Electrode And Active Subsutance (AREA)
Abstract
The invention provides a lithium supplementing method, a battery preparation method and a battery, wherein the lithium supplementing method comprises the following steps: testing the positive active material and the negative active material by adopting a half-cell, and determining the mass m of the negative active material required by the cell according to a preset N/P value Negative pole Mass m of positive electrode active material Is just The first proportionality of (a); calculating the mass m of the lithium supplement agent in the battery Supplement device And m is as described Is just Based on the second proportional relation and the m Is just Determining said m Supplement device Adding the lithium supplement agent with the mass within the value range in the manufacturing process of the positive pole piece. Need not to pass through many repetition tests, easy operation, practical high-efficient can calculate the mass range who obtains the lithium supplement agent rapidly according to the demand.
Description
Technical Field
The invention relates to the technical field of battery manufacturing and application, in particular to a lithium supplementing method, a battery preparation method and a battery.
Background
With the continuous expansion of new energy vehicle market, the requirements on the performance of batteries, such as high energy, high safety, low cost, long service life, and the like, are more and more strict. In order to further improve the lifetime and energy density of lithium ion batteries, prelithiation is an important technical means among them. Compared with the cathode pre-lithiation technology, the process difficulty is high, the anode pre-lithiation technology is simpler, more convenient and more efficient, and the method is compatible with the existing battery production line and has high industrial feasibility. However, the pre-lithiation effect of the positive electrode is influenced by various factors such as the type of a lithium supplement agent, gram capacity of the positive electrode and the negative electrode, the first coulombic efficiency, the ratio of the negative electrode capacity to the positive electrode capacity and the like, the addition amount of the lithium supplement agent is very important in the lithium supplement process, and even serious problems such as lithium precipitation and the like can be caused by excessive lithium supplement, so that the key of the pre-lithiation of the positive electrode is to find a proper lithium supplement amount, and the expected effect is achieved more accurately.
It should be noted that the above background description is only for the convenience of clear and complete description of the technical solutions of the present application and for the understanding of those skilled in the art. These solutions are not considered to be known to the person skilled in the art merely because they are set forth in the background section of the present application.
Disclosure of Invention
In view of the above disadvantages of the prior art, an object of the present invention is to provide a lithium supplementing method, a battery manufacturing method and a battery, which are used to solve the problems in the prior art that repeated experiments are required to verify the upper and lower limits of the required lithium supplementing agent, so that the calculation process of the required lithium supplementing agent is complicated and the efficiency is low.
In order to achieve the above and other related objects, the present invention provides a lithium replenishing method, which at least comprises:
1) Testing the positive active material and the negative active material by adopting a half-cell to determine the first charge gram capacity Q of the positive active material Is just First charge gram capacity q of negative electrode active material Negative pole The gram discharge capacity q of the positive electrode active material Is just And the discharge gram capacity Q of the negative electrode active material Negative pole And first coulombic efficiency eta of positive electrode active material Is just First coulombic efficiency eta of negative electrode active material Negative pole ；
2) Determining the mass m of the negative active material required by the battery according to the preset N/P value Negative pole Mass m with positive electrode active material Is just Wherein N/P = (q) Negative pole *m Negative pole /S)/(q Is just for *m Is just S), wherein S is the facing area of the positive active material and the negative active material in the battery;
3) Calculating the mass m of the lithium supplement agent in the battery Supplement device And m is as described Is just The second proportional relationship of (c), wherein the second proportional relationship satisfies: (m) Negative pole *Q Negative pole *(1-η Negative pole )/m Is just - Q Is just *(1-η Is just ))/ q Supplement device ≤m Supplement device /m Is just ≤(m Negative pole *Q Negative pole /m Is just - Q Is just )/ q Supplement device Wherein q is Supplement device The capacity is the discharge gram capacity of the lithium supplement agent;
4) Based on the second proportional relation and the m Is just Determining said m Supplement device Adding the lithium supplement agent with the mass within the value range in the manufacturing process of the positive pole piece.
In a possible implementation manner, the preset N/P value of the lithium supplementing method provided in the embodiment of the present application ranges from 1.03 to 1.30.
In a possible implementation manner, in the lithium supplement method provided in this embodiment of the present application, the positive electrode active material is at least one of lithium iron phosphate, lithium manganese phosphate, and lithium nickel cobalt manganese oxide; the negative active material is at least one of graphite, graphene oxide, hard carbon, mesocarbon microbeads and a silicon-carbon composite.
In a possible implementation manner, the lithium supplement method provided in the examples of the present application, the lithium supplement agent is at least one of lithium ferrate, lithium nitride, lithium nickelate, and lithium-rich lithium manganate.
To achieve the above and other related objects, the present invention provides a method for preparing a battery, comprising:
51 A positive pole piece is manufactured based on any one of the lithium supplement methods;
52 Preparing a negative pole piece, and preparing the negative pole piece and the positive pole piece into a battery.
In a possible implementation manner, in the battery manufacturing method provided in the embodiment of the present application, the step of manufacturing the positive electrode sheet includes: will have a mass m Is just for The positive electrode active material and the mass of m Supplement device The lithium supplement agent is mixed and prepared into slurry, then the slurry is coated on a current collector, and the positive pole piece is formed through drying, rolling and cutting.
In a possible implementation manner, the method for manufacturing a battery provided in the embodiment of the present application further includes performing a performance test on the battery, where the step of performing the performance test on the battery includes: carrying out capacity test on a reference battery and the battery, and comparing the actual capacities of the reference battery and the battery; and carrying out cycle performance test on the reference battery and the battery, then disassembling the reference battery and the battery after the cycle performance test is finished, and respectively checking the interface conditions of a negative pole piece and a positive pole piece in the reference battery and the battery.
In a possible implementation manner, the battery manufacturing method provided in the examples of the present application is different from the reference battery only in that the mass of the lithium supplement agent of the positive electrode plate of the reference battery is not in the m Supplement device The value range of (a).
In a possible implementation manner, in the battery manufacturing method provided in the example of the present application, the number of cycles of the cycle performance test is a natural number greater than or equal to 100.
To achieve the above and other related objects, the present invention provides a battery fabricated based on the battery fabrication method.
As described above, the lithium supplementing method, the battery preparation method and the battery of the invention have the following beneficial effects:
the lithium supplementing method, the battery preparation method and the battery do not need repeated tests, are simple to operate, practical and efficient, and can quickly calculate the mass range of the lithium supplementing agent according to the requirement.
Drawings
FIG. 1 is a schematic diagram showing a functional flow of a lithium supplementing method according to the present invention.
FIG. 2 is a functional flow diagram of a method for preparing a battery according to the present invention.
Detailed Description
The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention.
Please refer to fig. 1 and fig. 2. It should be noted that the drawings provided in the present embodiment are only for illustrating the basic idea of the present invention, and the drawings only show the components related to the present invention rather than the number, shape and size of the components in actual implementation, and the type, quantity and proportion of the components in actual implementation may be changed arbitrarily, and the layout of the components may be more complicated.
As shown in fig. 1, the present embodiment provides a lithium supplementing method, including:
s1: testing the positive active material and the negative active material by adopting a half-cell to determine the first charge gram capacity Q of the positive active material Is just First charge gram capacity q of negative electrode active material Negative pole The gram discharge capacity q of the positive electrode active material Is just And the discharge gram capacity Q of the negative electrode active material Negative pole And first coulombic efficiency η of the positive electrode active material Is just First coulombic efficiency eta of negative electrode active material Negative pole 。
Specifically, as an example, a half cell may be a button half cell, the rate of the half cell for performing the first charge gram capacity and discharge gram capacity test is between 0.1C and 0.15C, 1C represents the current intensity of the cell when the cell is completely discharged for one hour, if the rate is too large, the polarization of the half cell is severe (the polarization refers to a phenomenon that when the cell has current flowing through it, the electrode of the cell deviates from the equilibrium electrode potential, and is called as cell polarization, and in general, the larger the current flowing through the electrode per unit area, the more serious the deviation from the equilibrium electrode potential is, which results in the capacity performance of the half cell being deficient, thereby affecting the calculation accuracy; if the magnification is too small, the charge and discharge time is too long, which affects the efficiency.
In this embodiment, the multiplying factor is between 0.1C and 0.15C, and the test environment requirements of the first gram charge capacity, the first gram discharge capacity and the first coulombic efficiency of the positive electrode active material and the negative electrode active material can be met. It should be noted that the setting of the magnification ratio should be set according to a specific use environment, and a compromise between accuracy and efficiency is required, which is not limited to this embodiment. It should be further noted that the button half cell is called a button half cell because it is long like a button, and mainly comprises a positive electrode shell, a negative electrode shell, a positive electrode plate, a negative electrode plate, an isolating membrane, a gasket, an elastic sheet and electrolyte. If the button half cell is a lithium ion button half cell, when the cell is discharged, lithium ions are intercalated from the negative electrode into the positive electrode, and the more lithium ions that return to the positive electrode, the higher the discharge capacity.
Gram capacity refers to the ratio of the amount of capacitance that can be released by the active material inside the battery to the mass of the active material. The unit of gram volume is usually expressed in milliampere-hour/gram (mA × h/g), and sometimes, the calculated gram volume also includes the mass of all inactive materials such as conductive additives and adhesives, so the specific gram volume calculation logic should consider the actual application scenario.
Initial Coulomb Efficiency (ICE) is a performance index used to quantify positive and negative active materials of a lithium ion battery, and is defined as the ratio of discharge capacity to charge capacity of the lithium ion battery in the first charge-discharge cycle.
In one possible embodiment, the positive active material is at least one of lithium iron phosphate, lithium manganese phosphate, and lithium nickel cobalt manganese oxide; the negative active material is at least one of graphite, graphene oxide, hard carbon, mesocarbon microbeads and silicon-carbon composites. The positive active material and the negative active material can directly influence the charge and discharge behaviors of the lithium battery, the rheological property of the related battery slurry can directly influence the storage, coating and processing stability of the slurry, and the positive active material and the negative active material can be selected according to requirements in the actual use process. It should be further noted that the positive active material includes, but is not limited to, lithium iron phosphate, lithium manganese phosphate, lithium nickel cobalt manganese oxide; the negative active material includes, but is not limited to, graphite, graphene oxide, hard carbon, mesocarbon microbeads, and silicon carbon, and any positive active material and negative active material are suitable as long as the first gram charge capacity, gram discharge capacity, and first coulombic efficiency test can be performed, which is not limited to this embodiment.
Specifically, as an example, the following table 1 and table 2 show test data of the positive electrode active material and the negative electrode active material in the half cell test, respectively.
Table 1 positive active material test data
| Positive electrode active material | Lithium iron phosphate | Lithium manganese iron phosphate | Lithium manganese phosphate | Lithium nickel cobalt manganese oxide |
| Half cell test 1C reference capacity (mAh/g) | 154 | 145 | 145 | 185 |
| Half cell test charge cutoff voltage (V) | 3.75 | 4.45 | 4.45 | 4.45 |
| Half cell test discharge cutoff voltage (V) | 2.0 | 2.5 | 2.5 | 2.5 |
Table 2 negative active material test number
| Negative electrode active material | Graphite | Hard carbon | Mesocarbon microbeads | Silicon | Silicon carbon |
| Half cell test 1C reference capacity (mAh/g) | 350 | 350 | 350 | 1400 | 350-1400 |
| Half cell test charge cutoff voltage (V) | 1.5 | 1.5 | 1.5 | 1.5 | 1.5 |
| Half cell test discharge cutoff voltage (V) | 0.005 | 0.005 | 0.005 | 0.005 | 0.005 |
Wherein, the multiplying power of the half cell test is 0.1C, and the 1C reference capacity of the silicon-carbon material is different along with different mass ratios of silicon and carbon.
S2: determining the mass m of the negative active material required by the battery according to the preset N/P value Negative pole Mass m of positive electrode active material Is just The first proportional relationship of (1).
Wherein, N/P = (q) Negative pole *m Negative pole /S)/(q Is just *m Is just And S) is the facing area of the positive electrode active material and the negative electrode active material in the battery. Where N/P = negative electrode capacity per unit area/positive electrode capacity per unit area, N/P in one possible embodimentThe range may be between 1.03 and 1.30.
In battery capacity design, an important indicator is that the negative electrode has a larger reversible capacity than the positive electrode. If the N/P ratio is too large, shallow charge and discharge of a negative electrode and deep charge and discharge of a positive electrode can be caused, so that the positive electrode and the negative electrode of the battery are unbalanced; if the N/P ratio is too small, the utilization rate of the negative electrode is too low, the exertion of gram capacity is influenced, lithium separation is caused, and negative influence is generated on the capacity performance and the safety of the battery. Further, the value range of N/P includes but is not limited to 1.03 to 1.30, and any value range of N/P is applicable as long as the test safety and the battery performance are ensured, and is not limited to this embodiment.
Q is a preset value due to N/P Negative pole And q is Is just Obtained by the test in the step S1, then passes N/P = (q) Negative pole *m Negative pole /S)/(q Is just for *m Is just S), m can be confirmed Negative pole And m Is just A first proportional relationship between, i.e. m Negative pole =(N/P)*q Is just *m Is just for /q Negative pole 。
S3: calculating the mass m of the lithium supplement agent in the battery Supplement device And m is as described Is just The second proportional relationship of (c), wherein the second proportional relationship satisfies: (m) Negative pole *Q Negative pole *(1-η Negative pole )/m Is just - Q Is just *(1-η Is just for ))/ q Supplement device ≤m Supplement device /m Is just ≤(m Negative pole *Q Negative pole /m Is just - Q Is just )/ q Supplement device 。
In addition, the amount of the lithium ion-replenishing agent m is determined by the mass of the lithium ion-replenishing agent Supplement device Mass m of positive electrode active material Is just The second proportional relationship of (2) enables determination of the mass relationship between the addition amounts of the different types of lithium-supplementing agents and the addition amount of the positive electrode active material. The selection of the kind of the lithium supplement agent can be selected according to the requirements of battery preparation, and the embodiment of the application does not limit the requirements, and can be realized in a possible wayIn an embodiment, the lithium supplement agent is at least one of lithium ferrite, lithium nitride, lithium nickelate and lithium-rich lithium manganate. The material of the lithium supplement agent includes, but is not limited to, lithium ferrite, lithium nitride, lithium nickelate, and lithium-rich lithium manganate, and any material of the lithium supplement agent is applicable as long as the lithium supplement operation can be performed on the positive electrode, and the material is not limited to this embodiment.
Aiming at different types of lithium supplement agents, the gram capacity q of discharge corresponding to different lithium supplement agents Supplement device ，q Supplement device The information may be provided by a report of a purchasing manufacturer, or may be obtained by other methods, which is not limited in this embodiment of the present application.
S4: based on the second proportional relation and the m Is just Determining said m Supplement device Adding the lithium supplement agent with the mass within the value range in the manufacturing process of the positive pole piece.
Based on the second proportional relation and m Is just M can be determined Supplement device The value range of (A) is in accordance with: (m) Negative pole *Q Negative pole *(1-η Negative pole )- m Is just *Q Is just (1-η Is just ))/ q Supplement device ≤m Supplement device ≤(m Negative pole *Q Negative pole - m Is just *Q Is just )/ q Supplement device In the process of manufacturing the positive pole piece, m is Supplement device Optionally selecting a certain mass of lithium supplement agent within the value range of (2) to supplement lithium for the positive pole piece.
When m is Supplement device =(m Negative pole *Q Negative pole - m Is just *Q Is just for )/ q Supplement device The amount of the lithium replenishing agent added is just enough to allow the negative electrode active material to fully accept the lithium removal amount of the positive electrode active material and the lithium replenishing agent.
When m is Supplement device ＞(m Negative pole *Q Negative pole - m Is just *Q Is just for )/ q Supplement device When the lithium is excessively supplemented, lithium is supplemented, and the negative electrode does not have enough sites for accepting lithium ions in the first charging process, so that electrons are obtained on the surface of the negative electrode to form lithium metal, lithium precipitation is caused, the lithium ions of the positive electrode are irreversibly consumed, and the capacity of the battery is irreversibly attenuated, and if the lithium metal grows into lithium dendrites, the lithium dendrites can be generatedCan pierce through the diaphragm, lead to the positive negative contact, the battery short circuit. Therefore, the quality of the lithium replenishing agent needs to be strictly controlled to avoid the phenomenon of lithium precipitation.
When m is Supplement device = (m Negative pole *Q Negative pole *(1-η Negative pole )- m Is just *Q Is just (1-η Is just ))/ q Supplement device The addition amount of the lithium supplement agent can be leveled with the first effect difference between the positive electrode active material and the negative electrode active material, and irreversible lithium loss caused by SEI film formation in the first charging process can be compensated. The SEI film is generally defined as a passivation layer covering the surface of an electrode material formed by the reaction between the electrode material and an electrolyte at a solid-liquid interface during the first charge and discharge of a lithium ion battery. This passivation layer is an interfacial layer, which is characterized by a solid electrolyte, is an electronic insulator but is an excellent conductor of lithium ions, and lithium ions can freely intercalate and deintercalate through the passivation layer, so the passivation film is called a "solid electrolyte interfacial film" (SEI film for short). The SEI film has organic solvent insolubility and can stably exist in an organic electrolyte solution, and solvent molecules can pass through the passivation film, so that the co-intercalation of the solvent molecules can be effectively prevented, the damage to an electrode material caused by the co-intercalation of the solvent molecules is avoided, the cycle performance of the electrode is greatly improved, and the service life of the electrode is greatly prolonged.
When m is Supplement device ＜ (m Negative pole *Q Negative pole *(1-η Negative pole )- m Is just for *Q Is just for (1-η Is just for ))/ q Supplement device In this case, the effect of the addition amount of the lithium-supplementing agent is not expected, and the battery performance is not substantially improved.
By determining m Supplement device The value range of (2) is not required to repeatedly verify the upper and lower limits of the lithium supplement amount, so that the operation process is simplified, and m is used in the operation process Supplement device The limitation of the value range of (1) can avoid lithium precipitation caused by excessive addition of a lithium supplement agent; and the capacity and the cycle performance of the battery can not be improved due to insufficient addition of the lithium supplement agent, so that the expected effect can not be achieved, and the lithium supplement battery has wide application scenes.
In summary, the lithium supplementing method provided by the embodiment of the application does not need repeated tests, is simple to operate, is practical and efficient, and can quickly calculate the mass range of the lithium supplementing agent according to the requirement.
As shown in fig. 2, this embodiment provides a method for preparing a battery, including:
s51: and (4) manufacturing the positive pole piece based on the lithium supplement method in the steps S1-S4.
Specifically, as an example, the step of manufacturing the positive electrode plate includes: with mass m Is just The positive electrode active material and the mass of m Supplement device The lithium supplement agent is mixed and prepared into slurry, then the slurry is coated on a current collector, and the positive pole piece is formed through drying, rolling and cutting. The positive active material is at least one of lithium iron phosphate, lithium manganese phosphate and lithium nickel cobalt manganese oxide; the lithium supplement agent is at least one of lithium ferrite, lithium nitride, lithium nickelate and lithium-rich lithium manganate.
It should be noted that the current collector refers to a structure or a part for collecting current, and in the lithium ion battery, mainly refers to a metal foil, such as a copper foil or an aluminum foil, and the positive electrode is preferably an aluminum foil, and the function of the current collector is mainly to collect current generated by the active material of the battery so as to form a larger current to be output to the outside, so that the current collector should be in full contact with the active material, and the internal resistance of the battery should be as small as possible.
S52: and manufacturing a negative pole piece, and manufacturing the negative pole piece and the positive pole piece into a battery.
The quality of the negative active material of the negative pole piece is determined by utilizing the N/P, the negative pole piece is manufactured, then the negative pole piece and the positive pole piece are manufactured into the battery, wherein the steps of manufacturing the negative pole piece and manufacturing the positive pole piece and the positive pole piece into the battery can be realized by utilizing the scheme in the prior art.
In a possible implementation manner, the method for manufacturing a battery provided in the embodiment of the present application further includes performing a performance test on the battery, where the step of performing the performance test on the battery includes: carrying out capacity test on a reference battery and the battery, and comparing the actual capacities of the reference battery and the battery; and carrying out cycle performance test on the reference battery and the battery, then disassembling the reference battery and the battery after the cycle performance test is finished, and respectively checking the interface conditions of a negative pole piece and a positive pole piece in the reference battery and the battery. And judging whether the prepared battery meets the requirements or not by performing performance test on the battery.
It should be noted that, because the lithium supplement operation is performed on the positive electrode plate of the battery, the added lithium supplement agent can effectively supplement the irreversible consumption (such as electrolyte decomposition, active material dissolution, metal lithium deposition and the like) of the lithium supplement agent in the active material in the charging and discharging processes of the battery, so as to increase the actual available capacity of the battery; cycle performance tests can further verify the improvement of the added lithium supplement agent on the service life of the battery, and as a part of the lithium supplement agent is stored in the negative electrode and is circulated, the consumption of active materials is gradually supplemented, so that the service life of the battery is prolonged; for the disassembly of the reference battery and the battery, the interface between the negative electrode plate and the positive electrode plate is observed by comparison to verify whether the added lithium supplement agent has a negative effect on the original electrochemical reaction of the battery, for example, whether a foreign substance (mainly referred to as lithium) is generated on the positive electrode or the negative electrode plate, if lithium is generated, it is indicated that the lithium supplement agent is added too much, which results in insufficient capacity of the negative electrode of the battery, therefore, the addition amount of the lithium supplement agent needs to be reduced, and if no lithium is generated on the interface, it is indicated that the addition amount of the lithium supplement agent is proper Supplement device The value range of (2) is set, and the following requirements are met:
(m negative pole *Q Negative pole *(1-η Negative pole )- m Is just for *Q Is just (1-η Is just for ))/ q Supplement device ≤m Supplement device ≤(m Negative pole *Q Negative pole - m Is just *Q Is just )/ q Supplement device In the embodiment of the lithium supplementing method provided by the present application, it can be known that the added lithium supplementing agent does not cause lithium precipitation of the battery.
In one possible embodiment, a reference battery is subjected to a capacity test with a battery, comprising: and (2) placing the reference battery or the battery in a thermostat, keeping the temperature at 25 +/-3 ℃, standing for 30min, charging to 4.35V at a constant current of 0.33C, carrying out constant voltage charging at the voltage until the current is reduced to 0.05C, standing for 1h, discharging to 2.5V at a constant current of 1C, recording the discharge capacity, namely the actual capacity of the reference battery or the battery, and comparing the actual capacities of the reference battery and the battery.
And (3) carrying out cycle performance test on the reference battery and the battery, wherein the cycle performance test comprises the following steps: the reference cell or cell is placed in a thermostat, the temperature is 25 +/-3 ℃, the cell is charged to a specified voltage at 1C (the first discharge capacity is 1C), the cell is charged at a constant voltage under the voltage until the current is reduced to 0.05C, the cell is kept stand for 30min, the cell is discharged to 2.5V at a constant current of 1C, and the cell is kept stand for 30min, so that a one-week cycle is realized. And (4) cycling the charging and discharging steps for 500 weeks, fully charging and disassembling the battery, and checking the interface condition of the negative pole piece.
In the embodiment of the application, the positive active material of the reference battery is the same as the positive active material of the battery, the negative active material is the same as the negative active material of the battery, and the difference between the reference battery and the battery lies in that the positive pole piece of the reference battery is not subjected to lithium supplement operation or the lithium supplement additive amount of the positive pole piece of the reference battery is not m Supplement device The value range of (a). The number of cycles of the cycle performance test is a natural number greater than or equal to 100, wherein the number of cycles of the cycle performance test includes, but is not limited to, greater than or equal to 100, and any setting of the number of cycles is applicable as long as the performance of the battery can be verified, and is not limited to this embodiment.
Illustratively, the performance of the battery is tested by selecting a suitable reference battery in the above-described exemplary performance test manner, wherein examples 1, 2 and 3 are compared with comparative examples 1, 2 and 8, except that the lithium supplement agent is added in a different amount or is not added; example 6 was compared with comparative example 3, except that the amount of the lithium supplement agent added was different; example 7 was compared with comparative example 4, except that the amount of the lithium supplement agent added was different; example 8 was compared with comparative example 5, except that the amount of the lithium supplementing agent added was different; the examples 9 and 10 are compared with the comparative examples 6 and 7, the difference is that the value of N/P is different, and the specific implementation is as follows:
example 1: half ofThe positive electrode active material of the battery is lithium iron phosphate, the negative electrode is graphite, and after the tests of first charging gram capacity, first discharging gram capacity and first coulombic efficiency are completed, a lithium supplement agent is added to the positive electrode to prepare the battery, wherein N/P =1.12, and the lithium supplement agent is lithium iron oxide; m is Supplement device The value range of (1.6%) and (5.0%)]The addition amount of the lithium supplement agent is set to be 2.0 percent;
example 2: the positive electrode active material of the half-cell is lithium iron phosphate, the negative electrode is graphite, after the test of the first charging gram capacity, the first discharging gram capacity and the first coulombic efficiency is completed, a lithium supplement agent is added to the positive electrode to prepare the cell, wherein N/P =1.12, and the lithium supplement agent is lithium iron oxide; m is Supplement device The value range of (1.6%) and (5.0%)]The addition amount of the lithium supplement agent is 5.0 percent;
example 3: the positive electrode active material of the half-cell is lithium iron phosphate, the negative electrode is graphite, after the test of the first charging gram capacity, the first discharging gram capacity and the first coulombic efficiency is completed, a lithium supplement agent is added to the positive electrode to prepare the cell, wherein N/P =1.12, and the lithium supplement agent is lithium iron oxide; m is a unit of Supplement device The value range of (1.6%) and (5.0%)]The addition amount of the lithium supplement agent is 1.6 percent;
comparative example 1: the positive electrode active material of the half-cell is lithium iron phosphate, the negative electrode is graphite, after the first charging gram capacity, the first discharging gram capacity and the first coulombic efficiency are tested, a lithium supplement agent is added to the positive electrode to prepare the cell, wherein N/P =1.12, and the lithium supplement agent is lithium iron oxide; the addition amount of the lithium supplement agent is 6.0 percent and exceeds m Supplement device The upper limit value of the value range of (1) is 5.0 percent;
comparative example 2: the positive electrode active material of the half-cell is lithium iron phosphate, the negative electrode is graphite, after the test of the first charging gram capacity, the first discharging gram capacity and the first coulombic efficiency is completed, a lithium supplement agent is added to the positive electrode to prepare the cell, wherein N/P =1.12, and the lithium supplement agent is lithium iron oxide; the addition amount of the lithium supplement agent is set to be 0.5 percent and is less than m Supplement device The lower limit value of the value range of (1.6 percent);
example 4: the positive active material of the half-cell is lithium iron phosphate, the negative electrode is graphite, after the first charge gram capacity, discharge gram capacity and first coulombic efficiency test are completed, the lithium supplement agent is added to the positive electrode to prepare the cell, wherein the positive active material of the half-cell is lithium iron phosphate, and the negative active material of the half-cell is graphiteN/P =1.23, and the lithium supplement agent is lithium ferrate; m is Supplement device The value range of (1.8%) and (8.4%)]The addition amount of the lithium supplement agent is 3.0 percent;
example 5: the positive electrode active material of the half-cell is lithium iron phosphate, the negative electrode is graphite, after the test of the first charging gram capacity, the first discharging gram capacity and the first coulombic efficiency is completed, a lithium supplement agent is added to the positive electrode to prepare the cell, wherein N/P =1.23, and the lithium supplement agent is lithium iron oxide; m is a unit of Supplement device The value range of (1.8%) and (8.4%)]The addition amount of the lithium supplement agent is 6.5 percent;
example 6: the positive electrode active material of the half-cell is lithium manganese iron phosphate, the negative electrode is graphite, after the first charge gram capacity, the first discharge gram capacity and the first coulombic efficiency are tested, a lithium supplement agent is added to the positive electrode to prepare the cell; wherein N/P =1.10, and the lithium supplement agent is lithium ferrate; m is Supplement device The value range of (1) is (0.3%; 3.0%; C)]The addition amount of the lithium supplement agent is 1.5 percent;
comparative example 3: the positive electrode active material of the half-cell is lithium manganese iron phosphate, the negative electrode is graphite, after the first charging gram capacity, the first discharging gram capacity and the first coulombic efficiency are tested, a lithium supplement agent is added to the positive electrode to prepare the cell, wherein N/P =1.10, and the lithium supplement agent is lithium iron oxide; the addition amount of the lithium supplement agent is 4.0 percent and exceeds m Supplement device The upper limit value of the value range of (1) is 3.0 percent;
example 7: the positive active material of the half-cell is lithium iron phosphate, the negative electrode is graphite, after the first charge gram capacity, discharge gram capacity and first coulombic efficiency test are completed, a lithium supplement agent is added to the positive electrode to prepare the cell, wherein N/P =1.12, and the lithium supplement agent is lithium nitride; m is Supplement device The value range of (1.0%) and (3.2%)]The addition amount of the lithium supplement agent is set to be 2.0 percent;
comparative example 4: the positive electrode active material of the half-cell is lithium iron phosphate, the negative electrode is graphite, after the test of the first gram-charge capacity, the first gram-discharge capacity and the first coulombic efficiency is completed, a lithium supplement agent is added to the positive electrode to prepare the cell, wherein N/P =1.12, and the lithium supplement agent is lithium nitride; the addition amount of the lithium supplement agent is 3.5 percent and exceeds m Supplement device The upper limit value of the value range of (2) is 3.2%;
example 8: positive electrode of half cellAfter the first charge gram capacity, the first discharge gram capacity and the first coulombic efficiency are tested, adding a lithium supplement agent to the positive electrode to prepare the battery, wherein N/P =1.10, and the lithium supplement agent is lithium ferrite; m is Supplement device The value range of (1) is (0.1%) and (3.3%)]The addition amount of the lithium supplement agent is 1.8%;
comparative example 5: the positive electrode active material of the half-cell is nickel cobalt lithium manganate, the negative electrode is graphite, after the tests of first charge gram capacity, first discharge gram capacity and first coulombic efficiency are completed, a lithium supplement agent is added to the positive electrode to prepare the cell, wherein N/P =1.10, and the lithium supplement agent is lithium ferrite; the addition amount of the lithium supplement agent is 4.5 percent and exceeds m Supplement device The upper limit value of the value range of (1) is 3.3 percent;
example 9: the positive electrode active material of the half-cell is lithium iron phosphate, the negative electrode is graphite, after the test of the first charging gram capacity, the first discharging gram capacity and the first coulombic efficiency is completed, a lithium supplement agent is added to the positive electrode to prepare the cell, wherein N/P =1.30, and the lithium supplement agent is lithium iron oxide; m is a unit of Supplement device The value range of (1.9%) and (10.6%)]The addition amount of the lithium supplement agent is set to be 2.5 percent;
example 10: the positive electrode active material of the half-cell is lithium iron phosphate, the negative electrode is graphite, after the test of the first charging gram capacity, the first discharging gram capacity and the first coulombic efficiency is completed, a lithium supplement agent is added to the positive electrode to prepare the cell, wherein N/P =1.03, and the lithium supplement agent is lithium iron oxide; m is a unit of Supplement device The value range of (1.4%) and (2.3%)]The addition amount of the lithium supplement agent is 1.5 percent;
comparative example 6: the positive electrode active material of the half-cell is lithium iron phosphate, the negative electrode is graphite, after the first charging gram capacity, discharging gram capacity and first coulombic efficiency test are completed, a lithium supplement agent is added to the positive electrode to prepare the cell, wherein N/P =1.40, and the lithium supplement agent is lithium iron oxide; calculated m Supplement device The value range of (1) is [2.2%,13.7% ]]The addition amount of the lithium supplement agent is set to be 2.5 percent;
comparative example 7: the positive electrode active material of the half-cell is lithium iron phosphate, the negative electrode is graphite, after the tests of first charge gram capacity, first discharge gram capacity and first coulombic efficiency are completed, the positive electrode is added with a lithium supplement agent to prepare the cell, wherein N/P=1.01, the lithium supplement agent is lithium ferrate; calculated m Supplement device The value range of (1.3%) and (1.6%)]The addition amount of the lithium supplement agent is 1.5 percent;
comparative example 8: the positive electrode active material of the half-cell is lithium iron phosphate, the negative electrode is graphite, and after the tests of the first gram-charge capacity, the first gram-discharge capacity and the first coulombic efficiency are completed, a lithium supplement agent is not added to prepare the cell, wherein N/P =1.12;
specific parameters of examples 1 to 10 and comparative examples 1 to 8 are shown in table 3 below.
TABLE 3 lithium supplement amounts
| Examples | Q Is just for | q Is just for | Q Negative pole | q Negative pole | q Supplement device | η Is just for | η Negative pole | N/P | Lithium supplement additive amount/%) | Calculating the addition ratio range/% of a lithium supplementing agent |
| Example 1 | 160 | 156 | 375 | 350 | 540 | 97.5% | 93.3% | 1.12 | 2.0 | 1.6-5.0 |
| Example 2 | 160 | 156 | 375 | 350 | 540 | 97.5% | 93.3% | 1.12 | 5.0 | 1.6-5.0 |
| Example 3 | 160 | 156 | 375 | 350 | 540 | 97.5% | 93.3% | 1.12 | 1.6 | 1.6-5.0 |
| Example 4 | 160 | 156 | 375 | 350 | 540 | 97.5% | 93.3% | 1.23 | 3.0 | 1.8-8.4 |
| Example 5 | 160 | 156 | 375 | 350 | 540 | 97.5% | 93.3% | 1.23 | 6.5 | 1.8-8.4 |
| Example 6 | 147 | 138 | 375 | 350 | 540 | 93.9% | 93.3% | 1.10 | 1.5 | 0.3-3.0 |
| Example 7 | 160 | 156 | 375 | 350 | 840 | 97.5% | 93.3% | 1.12 | 2.0 | 1.0-3.2 |
| Example 8 | 185 | 172 | 375 | 350 | 540 | 93.0% | 93.3% | 1.10 | 1.8 | 0.1-3.3 |
| Example 9 | 160 | 156 | 375 | 350 | 540 | 97.5% | 93.3% | 1.30 | 2.5 | 1.9-10.6 |
| Example 10 | 160 | 156 | 375 | 350 | 540 | 97.5% | 93.3% | 1.03 | 1.5 | 1.4-2.3 |
| Comparative example 1 | 160 | 156 | 375 | 350 | 540 | 97.5% | 93.3% | 1.12 | 6.0 | 1.6-5.0 |
| Comparative example 2 | 160 | 156 | 375 | 350 | 540 | 97.5% | 93.3% | 1.12 | 0.5 | 1.6-5.0 |
| Comparative example 3 | 147 | 138 | 375 | 350 | 540 | 93.9% | 93.3% | 1.10 | 4.0 | 0.3-3.0 |
| Comparative example 4 | 160 | 156 | 375 | 350 | 840 | 97.5% | 93.3% | 1.12 | 3.5 | 1.0-3.2 |
| Comparative example 5 | 185 | 172 | 375 | 350 | 540 | 93.0% | 93.3% | 1.10 | 4.5 | 0.1-3.3 |
| Comparative example 6 | 160 | 156 | 375 | 350 | 540 | 97.5% | 93.3% | 1.40 | 2.5 | 2.2-13.7 |
| Comparative example 7 | 160 | 156 | 375 | 350 | 540 | 97.5% | 93.3% | 1.01 | 1.5 | 1.3-1.6 |
| Comparative example 8 | 160 | 156 | 375 | 350 | / | 97.5% | 93.3% | 1.12 | / | / |
The batteries of examples 1 to 10 and comparative examples 1 to 8 were subjected to performance tests in which cycle test voltages were as in table 4 below.
TABLE 4 Cyclic measurement of Charge-discharge cutoff Voltage
| Battery number | Cycling test charge cutoff voltage/V | Discharge cut-off voltage/V of cycle test |
| Example 1 | 3.65 | 2.5 |
| Example 2 | 3.65 | 2.5 |
| Example 3 | 3.65 | 2.5 |
| Example 4 | 3.65 | 2.5 |
| Example 5 | 3.65 | 2.5 |
| Example 6 | 4.35 | 2.5 |
| Example 7 | 3.65 | 2.5 |
| Example 8 | 4.35 | 2.5 |
| Example 9 | 3.65 | 2.5 |
| Example 10 | 3.65 | 2.5 |
| Comparative example 1 | 3.65 | 2.5 |
| Comparative example 2 | 3.65 | 2.5 |
| Comparative example 3 | 4.35 | 2.5 |
| Comparative example 4 | 3.65 | 2.5 |
| Comparative example 5 | 4.35 | 2.5 |
| Comparative example 6 | 3.65 | 2.5 |
| Comparative example 7 | 3.65 | 2.5 |
| Comparative example 8 | 3.65 | 2.5 |
And disassembling the battery after the performance test, the specific results are shown in the following table 5.
TABLE 5 results of Performance test
| Battery number | Initial discharge capacity Ah | Cell discharge capacity/Ah after 500 weeks of cycling | Capacity retention rate | Battery disassembly condition after 500 cycles |
| Example 1 | 9.53 | 9.12 | 95.7% | Interface Normal |
| Example 2 | 9.59 | 9.13 | 95.3% | Interface Normal |
| Example 3 | 9.50 | 9.03 | 95.0% | Interface Normal |
| Example 4 | 9.48 | 8.84 | 93.2% | Interface Normal |
| Example 5 | 9.53 | 9.15 | 96.0% | Interface Normal |
| Example 6 | 9.04 | 8.20 | 90.7% | Interface Normal |
| Example 7 | 9.56 | 8.80 | 92.1% | Interface Normal |
| Example 8 | 11.45 | 11.01 | 96.2% | Interface Normal |
| Example 9 | 9.45 | 9.03 | 95.6% | Interface Normal |
| Example 10 | 9.43 | 8.91 | 94.5% | Interface Normal |
| Comparative example 1 | 9.50 | 7.97 | 83.9% | Interfacial lithium precipitation |
| Comparative example 2 | 9.27 | 8.19 | 88.4% | Interface Normal |
| Comparative example 3 | 8.78 | 7.15 | 81.4% | Interfacial lithium precipitation |
| Comparative example 4 | 9.49 | 7.85 | 82.7% | Interfacial lithium precipitation |
| Comparative example 5 | 10.81 | 8.88 | 82.1% | Interfacial lithium precipitation |
| Comparative example 6 | 9.20 | 8.16 | 88.7% | The interface is darker in color |
| Comparative example 7 | 9.14 | 6.74 | 73.7% | Interfacial lithium precipitation |
| Comparative example 8 | 9.21 | 7.85 | 85.3% | Interface Normal |
Through the verification of corresponding examples and comparative examples, if the addition amount of the lithium supplementing agent is m Supplement device Within the value range of (a), the cycle life of the battery can be greatly prolonged, and lithium precipitation basically does not occur after 500 weeks of cycle; if the addition amount of the lithium supplement exceeds m Supplement device When the battery is disassembled, lithium precipitation occurs on an interface (the interface refers to a negative pole piece interface), namely a large number of grey-white spots appear on the interface, the capacity retention rate is obviously reduced, and the cycle life is greatly shortened; if the addition amount of the lithium supplement agent is less than m Supplement device Lower limit of (b), the performance of the comparative example cell is inferior compared to the example (first of allPoor performance in both sub-discharge capacity and cycle life); in addition, if the N/P is less than 1.03, lithium precipitation can occur on the interface of the negative pole piece; if the N/P is more than 1.30, the lithium intercalation of the negative electrode is insufficient, and the color of the interface of the negative electrode plate is dark.
The embodiment also provides a battery, and the battery is manufactured based on the battery manufacturing method of the embodiment.
In summary, the lithium supplement method, the battery preparation method and the battery of the present invention at least comprise: testing the positive active material and the negative active material by adopting a half-cell to determine the first charge gram capacity Q of the positive active material Is just First charge gram capacity q of negative electrode active material Negative pole The gram discharge capacity q of the positive electrode active material Is just And the discharge gram capacity Q of the negative electrode active material Negative pole And first coulombic efficiency η of the positive electrode active material Is just for First coulombic efficiency eta of negative electrode active material Negative pole (ii) a Determining the mass m of the negative active material required by the battery according to the preset N/P value Negative pole Mass m with positive electrode active material Is just The first proportionality of (a); wherein, N/P = (q) Negative pole *m Negative pole /S)/(q Is just *m Is just S), wherein S is the facing area of the positive active material and the negative active material in the battery; calculating the mass m of the lithium supplement agent in the battery Supplement device And m is as described Is just The second proportional relationship of (c), wherein the second proportional relationship satisfies: (m) Negative pole *Q Negative pole *(1-η Negative pole )/m Is just - Q Is just *(1-η Is just ))/ q Supplement device ≤m Supplement device /m Is just ≤ (m Negative pole *Q Negative pole /m Is just - Q Is just )/ q Supplement device Wherein q is Supplement device The capacity is the discharge gram capacity of the lithium supplement agent; based on the second proportional relation and the m Is just Determining said m Supplement device Adding the lithium supplement agent with the mass within the value range in the manufacturing process of the positive pole piece. The lithium supplementing method, the battery preparation method and the battery are simple to operate, practical and efficient, and the quality data of the lithium supplementing agent can be rapidly calculated according to the requirements. The invention relates to a lithium supplementing method, a battery preparation method and a battery,the upper and lower mass limits of the lithium supplement agent are obtained without repeated test calculation, and the mass of various anode and cathode active materials and the mass of the lithium supplement agent can be calculated according to the value range of the lithium supplement agent in the lithium supplement method. Therefore, the invention effectively overcomes various defects in the prior art and has high industrial utilization value.
The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Those skilled in the art can modify or change the above-described embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which may be made by those skilled in the art without departing from the spirit and scope of the present invention as defined in the appended claims.
Claims (10)
1. A lithium supplementing method is characterized by at least comprising the following steps:
1) Testing the positive active material and the negative active material by adopting a half-cell to determine the first charge gram capacity Q of the positive active material Is just for First charge gram capacity q of negative electrode active material Negative pole Positive electrode active material discharge capacity q Is just The discharge gram capacity Q of the negative electrode active material Negative pole And first coulombic efficiency eta of positive electrode active material Is just for First coulombic efficiency eta of the negative electrode active material Negative pole ；
2) Determining the mass m of the negative active material required by the battery according to the preset N/P value Negative pole Mass m of positive electrode active material Is just for A first proportional relationship of (a); wherein, N/P = (q) Negative pole *m Negative pole /S)/(q Is just *m Is just S), wherein S is the facing area of the positive active material and the negative active material in the battery;
3) Calculating the mass m of the lithium supplement agent in the battery Supplement device And m is as described Is just Wherein the second proportional relationship satisfies: (m) Negative pole *Q Negative pole *(1-η Negative pole )/m Is just for - Q Is just for *(1-η Is just ))/ q Supplement device ≤m Supplement device /m Is just ≤(m Negative pole *Q Negative pole /m Is just for - Q Is just )/ q Supplement device Wherein q is Supplement device The capacity is the discharge gram capacity of the lithium supplement agent;
4) Based on the second proportional relation and the m Is just for Determining said m Supplement device Adding the lithium supplement agent with the mass within the value range in the manufacturing process of the positive pole piece.
2. The lithium replenishing method according to claim 1, characterized in that: the preset N/P value is between 1.03 and 1.30.
3. The lithium replenishing method according to claim 1, characterized in that: the positive active material is at least one of lithium iron phosphate, lithium manganese phosphate and lithium nickel cobalt manganese oxide; the negative active material is at least one of graphite, graphene oxide, hard carbon, mesocarbon microbeads and a silicon-carbon composite.
4. The lithium replenishing method according to claim 1, characterized in that: the lithium supplement agent is at least one of lithium ferrite, lithium nitride, lithium nickelate and lithium-rich lithium manganate.
5. A battery preparation method is characterized in that: the battery preparation method at least comprises the following steps:
51 Manufacturing a positive pole piece based on the lithium supplementing method according to any one of claims 1 to 4;
52 Manufacturing a negative pole piece, and manufacturing the negative pole piece and the positive pole piece into a battery.
6. The battery production method according to claim 5, characterized in that: the steps of manufacturing the positive pole piece comprise: with mass m Is just The positive electrode active material and the mass of m Supplement device The lithium supplement agent is mixed and prepared into slurry, then the slurry is coated on a current collector, and the positive pole piece is formed by drying, rolling and cutting。
7. The battery production method according to claim 5, characterized in that: the method also comprises the step of carrying out performance test on the battery, and the step of carrying out performance test on the battery comprises the following steps: carrying out capacity test on a reference battery and the battery, and comparing the actual capacities of the reference battery and the battery; and carrying out cycle performance test on the reference battery and the battery, then disassembling the reference battery and the battery after the cycle performance test is finished, and respectively checking the interface conditions of a negative pole piece and a positive pole piece in the reference battery and the battery.
8. The battery production method according to claim 7, characterized in that: the reference battery is different from the battery only in that the mass of the lithium supplement agent of the positive pole piece of the reference battery is not in the m Supplement device Within the range of (a).
9. The battery production method according to claim 7, characterized in that: the cycle times of the cycle performance test are natural numbers which are more than or equal to 100.
10. A battery, characterized by: the battery is manufactured based on the battery manufacturing method according to any one of claims 5 to 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211508274.2A CN115548482A (en) | 2022-11-29 | 2022-11-29 | Lithium supplementing method, battery preparation method and battery |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211508274.2A CN115548482A (en) | 2022-11-29 | 2022-11-29 | Lithium supplementing method, battery preparation method and battery |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115548482A true CN115548482A (en) | 2022-12-30 |
Family
ID=84722758
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211508274.2A Pending CN115548482A (en) | 2022-11-29 | 2022-11-29 | Lithium supplementing method, battery preparation method and battery |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115548482A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116759535A (en) * | 2023-08-22 | 2023-09-15 | 宁德新能源科技有限公司 | Electrochemical device and electronic apparatus |
| CN117129888A (en) * | 2023-03-03 | 2023-11-28 | 荣耀终端有限公司 | Method for determining lithium supplementing amount of negative electrode, verification method, battery and terminal device |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106450481A (en) * | 2016-12-07 | 2017-02-22 | 清华大学深圳研究生院 | Lithium ion battery and preparation method thereof |
| CN113161602A (en) * | 2021-06-01 | 2021-07-23 | 湖南立方新能源科技有限责任公司 | Lithium ion battery cell, lithium ion battery and preparation method |
| CN114141981A (en) * | 2021-11-24 | 2022-03-04 | 蜂巢能源科技有限公司 | Positive pole piece and preparation method and application thereof |
| CN114597350A (en) * | 2022-02-23 | 2022-06-07 | 湖南立方新能源科技有限责任公司 | Calculation method of lithium supplementing time of lithium supplementing electrode, lithium supplementing method and lithium ion battery |
| CN115312774A (en) * | 2022-07-26 | 2022-11-08 | 南昌大学 | Method for determining and controlling pre-lithium amount of negative electrode lithium supplement electrode piece |
-
2022
- 2022-11-29 CN CN202211508274.2A patent/CN115548482A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106450481A (en) * | 2016-12-07 | 2017-02-22 | 清华大学深圳研究生院 | Lithium ion battery and preparation method thereof |
| CN113161602A (en) * | 2021-06-01 | 2021-07-23 | 湖南立方新能源科技有限责任公司 | Lithium ion battery cell, lithium ion battery and preparation method |
| CN114141981A (en) * | 2021-11-24 | 2022-03-04 | 蜂巢能源科技有限公司 | Positive pole piece and preparation method and application thereof |
| CN114597350A (en) * | 2022-02-23 | 2022-06-07 | 湖南立方新能源科技有限责任公司 | Calculation method of lithium supplementing time of lithium supplementing electrode, lithium supplementing method and lithium ion battery |
| CN115312774A (en) * | 2022-07-26 | 2022-11-08 | 南昌大学 | Method for determining and controlling pre-lithium amount of negative electrode lithium supplement electrode piece |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117129888A (en) * | 2023-03-03 | 2023-11-28 | 荣耀终端有限公司 | Method for determining lithium supplementing amount of negative electrode, verification method, battery and terminal device |
| CN116759535A (en) * | 2023-08-22 | 2023-09-15 | 宁德新能源科技有限公司 | Electrochemical device and electronic apparatus |
| CN116759535B (en) * | 2023-08-22 | 2024-01-05 | 宁德新能源科技有限公司 | Electrochemical device and electronic apparatus |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Mao et al. | Identifying the limiting electrode in lithium ion batteries for extreme fast charging | |
| Han et al. | A review on the key issues of the lithium ion battery degradation among the whole life cycle | |
| CN109581240B (en) | Lithium ion battery failure analysis method based on alternating current impedance method | |
| US10605870B2 (en) | Method for predicting battery charge limit, and method and apparatus for rapidly charging battery using same | |
| Kang et al. | Comparison of comprehensive properties of Ni-MH (nickel-metal hydride) and Li-ion (lithium-ion) batteries in terms of energy efficiency | |
| CN115548482A (en) | Lithium supplementing method, battery preparation method and battery | |
| CN112240986B (en) | Evaluation method for lithium separation and uniformity of large-size soft-package lithium ion battery | |
| CN106997960B (en) | Formation and capacity grading method for lithium ion battery | |
| CN105759213A (en) | Method for measuring storage battery residual capacity SOC | |
| CN112689934B (en) | Charging method, electronic device, and storage medium | |
| CN112180278B (en) | Electric vehicle power battery performance nondestructive testing method considering voltage hysteresis characteristic | |
| CN106908737A (en) | A kind of lithium ion battery life-span prediction method based on electrochemical reaction mechanism emulation | |
| CN111438077A (en) | Method for rapidly screening and detecting echelon utilization performance of retired ternary soft package battery | |
| CN113533981B (en) | Lithium ion battery self-discharge detection method, equipment and computer readable storage medium | |
| Kang et al. | How electrode thicknesses influence performance of cylindrical lithium-ion batteries | |
| Liu et al. | Electrochemical impedance analysis of C/LiFePO4 batteries in cycling process | |
| CN115128467A (en) | Method and device for estimating negative electrode capacity of lithium battery | |
| CN108680863B (en) | Method for measuring maximum charging current of lithium ion battery | |
| Zheng et al. | Influence of charge rate on the cycling degradation of LiFePO 4/mesocarbon microbead batteries under low temperature | |
| Xu et al. | Understanding the process of lithium deposition on a graphite anode for better lithium-ion batteries | |
| CN116430257B (en) | Method for representing electrical performance of lithium battery and application thereof | |
| Xiao et al. | State of charge effects on the parameters of electrochemical impedance spectroscopy equivalent circuit model for lithium ion batteries | |
| CN114778633B (en) | Single-layer particle electrode for electrochemical analysis and electrochemical analysis method | |
| CN111948554B (en) | Method for reducing mechanical degradation of lithium ion battery | |
| CN112768782A (en) | Lithium ion battery and preparation method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| REG | Reference to a national code |
Ref country code: HK Ref legal event code: DE Ref document number: 40077994 Country of ref document: HK |
|
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20221230 |
|
| RJ01 | Rejection of invention patent application after publication |