CN114335417B - Pre-lithiated negative electrode plate, preparation method thereof and lithium battery - Google Patents
Pre-lithiated negative electrode plate, preparation method thereof and lithium battery Download PDFInfo
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- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 title claims abstract description 243
- 229910052744 lithium Inorganic materials 0.000 title claims abstract description 243
- 238000002360 preparation method Methods 0.000 title abstract description 20
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- 238000012986 modification Methods 0.000 claims abstract description 92
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- 238000000034 method Methods 0.000 claims abstract description 45
- 238000006138 lithiation reaction Methods 0.000 claims abstract description 34
- 230000008569 process Effects 0.000 claims abstract description 31
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 claims description 74
- 229910001416 lithium ion Inorganic materials 0.000 claims description 74
- 238000000151 deposition Methods 0.000 claims description 35
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- 239000002184 metal Substances 0.000 claims description 21
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- 238000007738 vacuum evaporation Methods 0.000 claims description 17
- 238000001755 magnetron sputter deposition Methods 0.000 claims description 13
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 claims description 11
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- 239000004332 silver Substances 0.000 claims description 10
- 238000005507 spraying Methods 0.000 claims description 8
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- ZVLDJSZFKQJMKD-UHFFFAOYSA-N [Li].[Si] Chemical compound [Li].[Si] ZVLDJSZFKQJMKD-UHFFFAOYSA-N 0.000 claims description 4
- 229910052782 aluminium Inorganic materials 0.000 claims description 4
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 4
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- 229910001020 Au alloy Inorganic materials 0.000 claims description 3
- 229910000521 B alloy Inorganic materials 0.000 claims description 3
- 229910000952 Be alloy Inorganic materials 0.000 claims description 3
- 229910000925 Cd alloy Inorganic materials 0.000 claims description 3
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 claims description 3
- 229910000881 Cu alloy Inorganic materials 0.000 claims description 3
- 229910000861 Mg alloy Inorganic materials 0.000 claims description 3
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 claims description 3
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims description 3
- 229910001297 Zn alloy Inorganic materials 0.000 claims description 3
- JFBZPFYRPYOZCQ-UHFFFAOYSA-N [Li].[Al] Chemical compound [Li].[Al] JFBZPFYRPYOZCQ-UHFFFAOYSA-N 0.000 claims description 3
- 229910052797 bismuth Inorganic materials 0.000 claims description 3
- JCXGWMGPZLAOME-UHFFFAOYSA-N bismuth atom Chemical compound [Bi] JCXGWMGPZLAOME-UHFFFAOYSA-N 0.000 claims description 3
- PPTSBERGOGHCHC-UHFFFAOYSA-N boron lithium Chemical compound [Li].[B] PPTSBERGOGHCHC-UHFFFAOYSA-N 0.000 claims description 3
- ADCXHZZSUADYMI-UHFFFAOYSA-N cadmium lithium Chemical compound [Li].[Cd] ADCXHZZSUADYMI-UHFFFAOYSA-N 0.000 claims description 3
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- 229910052804 chromium Inorganic materials 0.000 claims description 3
- 239000011651 chromium Substances 0.000 claims description 3
- 229910017052 cobalt Inorganic materials 0.000 claims description 3
- 239000010941 cobalt Substances 0.000 claims description 3
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 claims description 3
- OPHUWKNKFYBPDR-UHFFFAOYSA-N copper lithium Chemical compound [Li].[Cu] OPHUWKNKFYBPDR-UHFFFAOYSA-N 0.000 claims description 3
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 claims description 3
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- 239000003353 gold alloy Substances 0.000 claims description 3
- RRMGGYGDQCMPKP-UHFFFAOYSA-N gold lithium Chemical compound [Li].[Au] RRMGGYGDQCMPKP-UHFFFAOYSA-N 0.000 claims description 3
- 229910052742 iron Inorganic materials 0.000 claims description 3
- GCICAPWZNUIIDV-UHFFFAOYSA-N lithium magnesium Chemical compound [Li].[Mg] GCICAPWZNUIIDV-UHFFFAOYSA-N 0.000 claims description 3
- KUJOABUXCGVGIY-UHFFFAOYSA-N lithium zinc Chemical compound [Li].[Zn] KUJOABUXCGVGIY-UHFFFAOYSA-N 0.000 claims description 3
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 claims description 3
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- LEONUFNNVUYDNQ-UHFFFAOYSA-N vanadium atom Chemical compound [V] LEONUFNNVUYDNQ-UHFFFAOYSA-N 0.000 claims description 3
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- AMWRITDGCCNYAT-UHFFFAOYSA-L hydroxy(oxo)manganese;manganese Chemical compound [Mn].O[Mn]=O.O[Mn]=O AMWRITDGCCNYAT-UHFFFAOYSA-L 0.000 description 2
- GELKBWJHTRAYNV-UHFFFAOYSA-K lithium iron phosphate Chemical compound [Li+].[Fe+2].[O-]P([O-])([O-])=O GELKBWJHTRAYNV-UHFFFAOYSA-K 0.000 description 2
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- 102000004310 Ion Channels Human genes 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
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- 238000000089 atomic force micrograph Methods 0.000 description 1
- GPBUGPUPKAGMDK-UHFFFAOYSA-N azanylidynemolybdenum Chemical compound [Mo]#N GPBUGPUPKAGMDK-UHFFFAOYSA-N 0.000 description 1
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- UQSXHKLRYXJYBZ-UHFFFAOYSA-N iron oxide Inorganic materials [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 1
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- 238000007254 oxidation reaction Methods 0.000 description 1
- NDLPOXTZKUMGOV-UHFFFAOYSA-N oxo(oxoferriooxy)iron hydrate Chemical compound O.O=[Fe]O[Fe]=O NDLPOXTZKUMGOV-UHFFFAOYSA-N 0.000 description 1
- GNRSAWUEBMWBQH-UHFFFAOYSA-N oxonickel Chemical compound [Ni]=O GNRSAWUEBMWBQH-UHFFFAOYSA-N 0.000 description 1
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Classifications
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- 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
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- Battery Electrode And Active Subsutance (AREA)
- Secondary Cells (AREA)
Abstract
The application discloses a pre-lithiated negative electrode plate, a preparation method thereof and a lithium battery, wherein the pre-lithiated negative electrode comprises a negative electrode current collector, an active material layer covered on the surface of the negative electrode current collector, a plurality of modification layers covered on part of the surface of the active material layer, and a lithium-containing layer covered on the residual surface of the active material layer and the surfaces of the modification layers, wherein the modification layers are distributed on the surface of the active material layer at intervals, and the coverage rate is 30-75%. The modification layer/lithium-containing layer interface in the pre-lithiated cathode is used as an artificial electronic path and is responsible for stabilizing the electronic transmission between two phase interfaces in the pre-lithiation process, so that the damage of interface stress fluctuation to the electronic path structure is avoided, the reaction depth of contact pre-lithiation is obviously enhanced, the utilization rate of the lithium-containing layer is improved, the yield of inert lithium formation is reduced, and the capacity retention rate and the cycling stability of the battery are improved.
Description
Technical Field
The application relates to the technical field of lithium ion batteries, in particular to a pre-lithiated negative plate, a preparation method thereof and a lithium battery.
Background
In the first charging process of the lithium ion battery, a solid electrolyte film (SEI film) can be spontaneously formed on the surface of the negative electrode, so that a part of reversible lithium ion capacity is lost, and the lithium ion battery further shows lower first coulomb efficiency, so that the lithium ion inventory of the positive electrode is free, and the reversible circulating capacity of the lithium ion battery is reduced.
Contact prelithiation is a method for effectively improving the first coulombic efficiency of a lithium ion battery and improving the cycle performance of the battery. Specifically, a lithium-containing layer is compounded on the surface of a negative electrode to trigger a contact pre-lithiation process of an internal short-circuit electrochemical reaction, so that a certain amount of lithium ions are stored in the negative electrode structure in advance to compensate capacity vacancies generated when the battery circulates for the first time.
In the contact prelithiation reaction process, the direct contact site of the lithium-containing layer and the negative electrode serves as an electron path to transfer electrons, and the electrolyte adsorbed at the contact interface of the lithium-containing layer and the negative electrode serves as an ion path to transfer lithium ions. However, due to the nature of the internal short-circuit electrochemical reaction, the growth of the solid electrolyte film on the surface of the negative electrode is accompanied in the contact prelithiation process, and the electron path structure is easily damaged by the expansion of the solid electrolyte film due to the fact that the electron path is loaded with a larger electron density, so that the electron path blocking phenomenon is caused, the contact prelithiation reaction is stopped in advance, and the utilization rate of the lithium-containing layer is too low. At this time, the lithium-containing layer left on the surface of the negative electrode becomes "dead" lithium inert to electrons due to the loss of an effective electron transfer path, and excessive inert lithium not only reduces the utilization rate of the lithium-containing layer, but also can prevent diffusion and migration of lithium ions in the operation process of the battery, and improves electrochemical polarization phenomenon, thereby reducing the capacity retention rate and the cycling stability of the battery and possibly triggering lithium precipitation behavior of the negative electrode.
Disclosure of Invention
The application provides a pre-lithiated negative electrode plate, a preparation method thereof and a lithium battery, and aims to solve the problem that a lithium-containing layer cannot be fully utilized due to unstable electronic paths in the pre-lithiation process, so that the lithium-containing layer becomes inert lithium.
On one hand, the embodiment of the application provides a pre-lithiated anode sheet, which comprises an anode current collector, an active material layer covered on the surface of the anode current collector, a plurality of modification layers covered on part of the surface of the active material layer, and a lithium-containing layer covered on the rest surface of the active material layer and the surfaces of the modification layers, wherein the modification layers are distributed on the surface of the active material layer at intervals, and the coverage rate is 30-75%; the plurality of modification layers includes one or more of a lithium-philic metal, a lithium-philic metal oxide, and a lithium-philic metal nitride.
Alternatively, the mass per unit area of the plurality of modification layers is 0.1 to 5% of the mass per unit area of the active material layer.
Optionally, the average area of the single modification layer of the plurality of modification layers is 100-1000000 nm 2 。
Optionally, the lithium-philic metal includes one or more of gold, silver, copper, iron, titanium, aluminum, manganese, tin, cobalt, nickel, chromium, bismuth, vanadium, molybdenum, and niobium.
Optionally, the lithium-containing layer includes one or more of metallic lithium, lithium silicon alloy, lithium magnesium alloy, lithium copper alloy, lithium silver alloy, lithium beryllium alloy, lithium zinc alloy, lithium cadmium alloy, lithium aluminum alloy, lithium gold alloy, and lithium boron alloy.
In another aspect, an embodiment of the present application provides a method for preparing the pre-lithiated negative electrode sheet, including the following steps:
(1) Manufacturing a lithium ion battery anode, wherein the lithium ion battery anode comprises an anode current collector and an active material layer covered on the surface of the anode current collector;
(2) Depositing a plurality of modification layers on the surface of the lithium ion battery cathode at intervals, so that part of the surface of the active material layer covers the modification layers to obtain a lithium ion battery cathode plate;
(3) Depositing a lithium-containing layer on the surface of the lithium ion battery negative electrode plate, so that the surface of the rest part of the active material layer and the surfaces of the plurality of modification layers are covered with a lithium-containing layer to obtain a lithium-loaded negative electrode plate;
(4) And placing the lithium-loaded negative plate in electrolyte to complete the contact pre-lithiation reaction, so as to obtain the pre-lithiated negative plate. Optionally, the surface of the negative electrode of the lithium ion battery is covered with a lithium-containing layer.
Optionally, in the step (2), the method of depositing a plurality of modification layers on the surface of the negative electrode of the lithium ion battery at intervals comprises one or a combination of several of magnetron sputtering, vacuum evaporation, knife coating, spraying and chemical vapor deposition.
Optionally, in the step (3), the method of depositing the lithium-containing layer on the surface of the negative plate of the lithium ion battery comprises one or a combination of several of vacuum evaporation, mechanical rolling, knife coating and spray coating.
Optionally, the step (3) is followed by a rolling press treatment of the lithium-loaded negative electrode sheet, wherein the rolling press treatment has a pressure range of 20-50Mpa.
In yet another aspect, an embodiment of the present application provides a lithium battery, including a positive electrode sheet, a separator, an electrolyte, and the above-described pre-lithiated negative electrode sheet.
The pre-lithiated negative electrode sheet provided by the application comprises a plurality of modification layers covered on part of the surface of an active material layer and a lithium-containing layer covered on the residual surface of the active material layer and the surface of the modification layers, wherein the modification layers comprise one or more of a lithium-philic metal, an oxide of the lithium-philic metal and a nitride of the lithium-philic metal. The prelithiation negative electrode sheet with the multilayer structure forms three interfaces, namely: an active material layer/modification layer interface, a modification layer/lithium-containing layer interface, and an active material layer/lithium-containing layer interface. The active material layer/modification layer interface and the modification layer/lithium-containing layer interface are used as artificial electronic paths and are responsible for stabilizing the electron transmission between two phase interfaces in the pre-lithiation process; the interface of the active material layer/the lithium-containing layer is used as an ion passage and is responsible for the diffusion and migration of ions in a two-phase structure in the pre-lithiation process.
The artificial electronic path can effectively avoid the formation of the morphology of lithium dendrite in the pre-lithiation reaction process, thereby improving the effective contact site of the lithium-containing layer and the cathode and promoting the reaction rate of contact pre-lithiation. Meanwhile, the morphology of the lithium dendrite is inhibited, namely the area of the lithium-containing layer exposed in the electrolyte is reduced, and the side reaction is reduced to improve the utilization rate of the lithium-containing layer.
The artificial electronic path effectively stabilizes the electronic conductivity between the lithium-containing layer and the anode interface in the pre-lithiation reaction process, avoids the damage of interface stress fluctuation caused by solid electrolyte film growth, lithium-containing layer dissolution and anode lithiation to an electronic path structure, remarkably enhances the reaction depth of contact pre-lithiation, improves the utilization rate of the lithium-containing layer, reduces the yield of inert lithium formation, and improves the capacity retention rate and the cycling stability of the battery. Meanwhile, the artificial electronic path can avoid spontaneous chemical reaction of the lithium-loaded negative electrode in a dry state environment, so that the physical and chemical stability of the lithium-containing layer in a non-pre-lithiation process is further improved.
Drawings
Features, advantages, and technical effects of exemplary embodiments of the present application will be described below with reference to the accompanying drawings.
Fig. 1 is a schematic structural view of a pre-lithiated negative electrode sheet of the present application;
FIG. 2 is an atomic force microscope image of the surface of example 1 of the present application after deposition of a modification layer on the negative electrode of a lithium ion battery;
FIG. 3 is a scanning electron microscope image of the surface of example 1 of the present application after deposition of a modification layer on the negative electrode of a lithium ion battery;
fig. 4 is a scanning electron microscope image of the lithium-loaded negative electrode sheet of example 1 of the present application after a contact prelithiation reaction;
fig. 5 is a graph of electrical performance results of lithium batteries disclosed in examples 1 to 10 and comparative example 1 of the present application.
In the accompanying drawings:
10-pre-lithiating the negative electrode sheet; 11-a lithium ion battery negative electrode; 12-a finishing layer; 13-a lithium-containing layer; 20-electrolyte.
Detailed Description
In order to make the objects, technical solutions and advantageous technical effects of the present invention clearer, the present invention will be further described in detail with reference to examples. It should be understood that the examples described in this specification are for the purpose of illustrating the invention only and are not intended to limit the invention.
For simplicity, only a few numerical ranges are explicitly disclosed herein. However, any lower limit may be combined with any upper limit to form a range not explicitly recited; and any lower limit may be combined with any other lower limit to form a range not explicitly recited, and any upper limit may be combined with any other upper limit to form a range not explicitly recited. Furthermore, each point or individual value between the endpoints of the range is included within the range, although not explicitly recited. Thus, each point or individual value may be combined as a lower or upper limit on itself with any other point or individual value or with other lower or upper limit to form a range that is not explicitly recited.
In the description herein, unless otherwise indicated, "above" and "below" are intended to include the present number, "one or more" means two or more, and "one or more" means two or more.
The above summary of the present invention is not intended to describe each disclosed embodiment or every implementation of the present invention. The following description more particularly exemplifies illustrative embodiments. Guidance is provided throughout this application by a series of embodiments, which may be used in various combinations. In various embodiments, the list is merely a representative group and should not be construed as exhaustive.
In the contact prelithiation process of the negative electrode of the lithium ion battery, an electron path structure between the negative electrode and the lithium-containing layer is a key factor influencing the prelithiation effect and the utilization rate of the lithium-containing layer. Therefore, the interface modification method can be used for stabilizing the electronic path structure so as to improve the traditional contact prelithiation behavior, improve the reaction depth of prelithiation, improve the utilization rate of the lithium-containing layer and reduce the formation and yield of inert lithium. In order to better utilize the high specific capacity advantage of the high-capacity negative electrode, further promote the application of the high-capacity negative electrode in commercial lithium ion batteries, improve the environmental protection value and the price advantage of the contact pre-lithiation technology, develop an interface modification method for the lithium ion battery negative electrode contact pre-lithiation, and be very important and urgent to apply to the lithium ion batteries.
Pre-lithiated negative electrode sheet
An embodiment of a first aspect of the present application provides a prelithiated anode sheet, including an anode current collector, an active material layer covered on the surface of the anode current collector, a plurality of modification layers (artificial electronic path layers) covered on part of the surface of the active material layer, and a lithium-containing layer covered on the remaining surface of the active material layer and the surfaces of the plurality of modification layers, wherein the plurality of modification layers are distributed at intervals on the surface of the active material layer, and the coverage rate is 30-75%; the plurality of modification layers includes one or more of a lithium-philic metal, a lithium-philic metal oxide, and a lithium-philic metal nitride.
According to an embodiment of the present application, the structure of the pre-lithiated negative electrode plate includes three two-phase interfaces, which are respectively: the unit area ratio of the three two-phase interfaces is 30-75%, 30-75% and 25-70% respectively.
The active material layer/modification layer interface and the modification layer/lithium-containing layer interface are used as artificial electronic paths and are responsible for stabilizing the electron transmission between two phase interfaces in the pre-lithiation process; the interface of the active material layer/the lithium-containing layer is used as an ion passage and is responsible for the diffusion and migration of ions in a two-phase structure in the pre-lithiation process.
The contact interface between the active material layer and the lithium-containing layer can cause dissolution of the lithium-containing layer (even if electrolyte is not added) due to the chemical potential difference, so that a pore structure is formed to contain the electrolyte, and the active material layer and the lithium-containing layer further serve as ion channels to transfer lithium ions.
The artificial electronic path can effectively avoid the formation of the morphology of lithium dendrite in the pre-lithiation reaction process, thereby improving the effective contact site of the lithium-containing layer and the cathode and promoting the reaction rate of contact pre-lithiation. Meanwhile, the morphology of the lithium dendrite is inhibited, namely the area of the lithium-containing layer exposed in the electrolyte is reduced, and the side reaction is reduced to improve the utilization rate of the lithium-containing layer.
The artificial electronic path effectively stabilizes the electronic conductivity between the lithium-containing layer and the anode interface in the pre-lithiation reaction process, avoids the damage of interface stress fluctuation caused by solid electrolyte film growth, lithium-containing layer dissolution and anode lithiation to an electronic path structure, remarkably enhances the reaction depth of contact pre-lithiation, improves the utilization rate of the lithium-containing layer, reduces the yield of inert lithium formation, and improves the capacity retention rate and the cycling stability of the battery. Meanwhile, the artificial electronic path can avoid spontaneous chemical reaction of the lithium-loaded negative electrode in a dry state environment, so that the physical and chemical stability of the lithium-containing layer in a non-pre-lithiation process is further improved.
According to the embodiment of the application, when the coverage rate of the plurality of modification layers on the surface of the active material layer is lower than 30%, the artificial electron paths are fewer, the electron transmission paths are too fewer, and the improvement on the prelithiation is not obvious; when the coverage rate of the plurality of modification layers on the surface of the active material layer is higher than 75%, the electrolyte infiltration degree in the contact interface is reduced, adverse reaction is caused, and the utilization rate, the first coulombic efficiency and the reversible capacity of the lithium-containing layer are reduced.
According to embodiments of the present application, the modification layer comprises one or more of a lithium-philic metal, a lithium-philic metal oxide and a lithium-philic metal nitride, and is included to ensure that it forms a stable interface layer with the active material layer after deposition on the surface of the active material layer; and also to ensure that the lithium-containing layer forms a stable interfacial layer with the surface of the lithium-containing layer after it has been deposited.
In embodiments of the present application, the lithium-philic metal includes one or more of gold, silver, copper, iron, titanium, aluminum, manganese, tin, cobalt, nickel, chromium, bismuth, vanadium, molybdenum, and niobium.
In the embodiment of the present application, the mass per unit area of the plurality of modification layers is 0.1 to 5% of the mass per unit area of the active material layer, and the calculation method is as follows: the mass per unit area of the plurality of modification layers/the mass per unit area of the active material layer.
According to embodiments of the present application, the improvement in prelithiation is not significant when the mass per unit area of the plurality of modification layers is less than 0.1%; when the mass per unit area of the plurality of modified layers is higher than 5%, the actual energy density of the battery is lowered.
In the embodiment of the application, the average area of the single modification layer in the plurality of modification layers is 100-1000000 nm 2 . The average area of the single modification layer is less than 100nm 2 When the stable electronic path structure is lost, the serious interface fluctuation phenomenon in the pre-lithiation process can cause the structural collapse of the electronic path, and the improvement on the pre-lithiation is not obvious. When the average area of the single modification layer is more than 1000000nm 2 In this case, the ion path density between the contact interface of the content layer and the negative electrode layer is low, which results in blocking of lithium ion diffusion and is unfavorable for the progress of the pre-lithiation reaction.
In embodiments of the present application, the lithium-containing layer includes one or more of metallic lithium, lithium silicon alloy, lithium magnesium alloy, lithium copper alloy, lithium silver alloy, lithium beryllium alloy, lithium zinc alloy, lithium cadmium alloy, lithium aluminum alloy, lithium gold alloy, and lithium boron alloy.
The lithium-containing layer material has a lower electrochemical potential than the negative electrode active layer, which is one of the requirements for triggering the contact prelithiation reaction. In addition, the theoretical unit mass capacity of the lithium-containing layer material is higher than that of the negative electrode active layer material, so that an effective pre-lithiation effect is achieved.
In the lithiation reaction process, the lithium-containing layer is subjected to oxidation reaction and the negative electrode layer is subjected to reduction reaction due to potential difference between the lithium-containing layer and the negative electrode layer. During this time, the lithium-containing layer is oxidized to give lithium ions and electrons, the electrons flow to the negative electrode layer through an electron path, and the lithium ions flow to the negative electrode layer through an electrolyte (ion path), and lithiation reaction of the negative electrode occurs after contacting the electrons and the negative electrode layer.
Preparation method of pre-lithiated negative electrode plate
An embodiment of a second aspect of the present application provides a method for preparing the pre-lithiated negative electrode sheet, including the following steps:
(1) Manufacturing a lithium ion battery anode, wherein the lithium ion battery anode comprises an anode current collector and an active material layer covered on the surface of the anode current collector;
(2) Depositing a plurality of modification layers on the surface of the lithium ion battery cathode at intervals, so that part of the surface of the active material layer covers the modification layers to obtain a lithium ion battery cathode plate;
(3) Depositing a lithium-containing layer on the surface of the lithium ion battery negative electrode plate, so that the surface of the rest part of the active material layer and the surfaces of the plurality of modification layers are covered with a lithium-containing layer to obtain a lithium-loaded negative electrode plate;
(4) And placing the lithium-loaded negative plate in electrolyte to complete the contact pre-lithiation reaction, so as to obtain the pre-lithiated negative plate. Optionally, the surface of the negative electrode of the lithium ion battery is covered with a lithium-containing layer.
In the embodiment of the present application, in the step (2), the method of depositing a plurality of modification layers on the surface of the negative electrode of the lithium ion battery at intervals includes one or a combination of several of magnetron sputtering, vacuum evaporation, knife coating, spraying and chemical vapor deposition.
According to the embodiment of the application, by controlling the parameters of the physical deposition process in the step (2), a plurality of modification layers can be deposited on the surface of the lithium ion battery cathode, the modification layers are distributed at intervals, and the coverage rate is 30-75%.
By controlling the parameters of the physical deposition process in the step (2), the mass per unit area of the plurality of modification layers can be 0.1 to 5% of the mass per unit area of the active material layer.
The average area of the single modification layer in the plurality of modification layers can be 100-1000000 nm by controlling the parameters of the physical deposition process in the step (2) 2 。
In the embodiment of the application, in the step (3), the method for depositing the lithium-containing layer on the surface of the negative plate of the lithium ion battery comprises one or a combination of several of vacuum evaporation, mechanical rolling, blade coating and spraying.
As shown in fig. 1, according to the embodiment of the present application, parameters of the physical deposition process in the step (3) are controlled, so that the surface of the original uncovered modification layer can be filled with the lithium-containing layer and uniformly covered on the surface of the negative electrode plate of the lithium ion battery.
In an embodiment of the present application, after step (3), the method further includes performing a roll pressing treatment on the lithium-loaded negative electrode sheet, where the roll pressing treatment has a pressure ranging from 20Mpa to 50Mpa.
According to the embodiment of the application, the lithium-loaded negative electrode after the pressure rolling pressing treatment has stable structure in the processes of storage, transportation, packaging and the like of the lithium-loaded negative electrode.
Lithium battery
An embodiment of a third aspect of the present application provides a lithium battery, including a positive electrode sheet, a separator, an electrolyte, and the above-mentioned pre-lithiated negative electrode sheet.
The pre-lithiated negative electrode plate not only comprises a silicon negative electrode plate, but also comprises lithium battery negative electrode plates of graphite, hard carbon, soft carbon and other active substances.
The lithium battery containing the pre-lithiated negative electrode plate not only has higher first-time coulomb efficiency, but also has higher capacity retention rate and cycle stability. The battery can be applied to rechargeable batteries of portable electronic products, electric tools, electric automobiles and the like.
Examples
Example 1
The embodiment provides a pre-lithiated negative electrode plate, a preparation method thereof and a lithium battery, comprising the following steps:
(1) And manufacturing a lithium ion battery anode, wherein the lithium ion battery anode comprises an anode current collector and an active material layer covered on the surface of the anode current collector.
(2) Depositing an artificial electronic passage layer which is made of metallic silver on the surface of the negative electrode in the step (1) by a magnetron sputtering technology, wherein the unit area mass of the artificial electronic passage layer is 0.1% of the unit area active substance mass of the negative electrode, and the average area of a single modification layer in the plurality of modification layers is 2500nm 2 。
(3) And (3) depositing a lithium-containing layer on the surface of the negative electrode in the step (2) through a vacuum evaporation technology to obtain metal lithium, and carrying out rolling treatment under the pressure of 20Mpa to obtain the lithium-loaded negative electrode plate. The unit area ratio of the negative electrode/artificial electronic path interface, the negative electrode/lithium-containing layer interface and the artificial electronic path/lithium-containing layer interface in the obtained lithium-loaded negative electrode structure is 50%, 50% and 50% respectively.
(4) And (3) soaking the lithium-loaded negative electrode in the step (3) in electrolyte to complete a contact prelithiation reaction, and assembling the battery for testing.
The test result shows that after magnetron sputtering treatment, atomic force microscope pictures show that nano-sized metal silver particles are formed on the surface of the negative electrode (figure 2), and scanning electron microscope shows that the nano-silver particles are uniformly and singly dispersed on the upper surface of the negative electrode active particles (figure 3). Wherein, the raised metallic silver particles are used as an artificial electronic path, and the exposed active particle surface of the negative electrode is used as an ion path in the pre-lithiation reaction process. As shown in fig. 5, half cell testing indicated (the counter electrode was a metallic lithium sheet) that the lithium-containing layer was 85.4% utilized and no significant inert lithium formation was observed on the negative electrode surface (fig. 4). Full cell testing showed that the initial coulombic efficiency of the pre-lithiated cell was 98.1% with a reversible capacity of 141mAh/g and a capacity retention after 300 cycles of 95.4% (fig. 5).
Example 2
The embodiment provides a pre-lithiated negative electrode plate, a preparation method thereof and a lithium battery, comprising the following steps:
(1) And manufacturing a lithium ion battery anode, wherein the lithium ion battery anode comprises an anode current collector and an active material layer covered on the surface of the anode current collector.
(2) Depositing an artificial electronic passage layer which is made of metallic silver on the surface of the negative electrode in the step (1) by a magnetron sputtering technology, wherein the unit area mass of the artificial electronic passage layer is 0.5% of the unit area active substance mass of the negative electrode, and the average area of a single modification layer in the plurality of modification layers is 100nm 2 。
(3) And (3) depositing a lithium-containing layer on the surface of the negative electrode in the step (2) through a vacuum evaporation technology, wherein the lithium-containing layer is metallic lithium, and carrying out rolling treatment under the pressure of 30 Mpa. The unit area ratio of the negative electrode/artificial electronic path interface, the negative electrode/lithium-containing layer interface and the artificial electronic path/lithium-containing layer interface in the obtained lithium-loaded negative electrode structure is 30%, 70% and 30% respectively.
(4) And (3) soaking the lithium-loaded negative electrode in the step (3) in electrolyte to complete a contact prelithiation reaction, and assembling the battery for testing. As shown in fig. 3, half-cell tests showed that the lithium-containing layer utilization was 90.2% (for the counter electrode as a metallic lithium sheet), full-cell tests showed that the first coulombic efficiency of the pre-lithiated cell was 97.5%, the reversible capacity was 139mAh/g, and the capacity retention after 300 cycles was 96.3%.
Example 3
The embodiment provides a pre-lithiated negative electrode plate, a preparation method thereof and a lithium battery, comprising the following steps:
(1) And manufacturing a lithium ion battery anode, wherein the lithium ion battery anode comprises an anode current collector and an active material layer covered on the surface of the anode current collector.
(2) Depositing an artificial electronic passage layer on the surface of the negative electrode in the step (1) through a magnetron sputtering technology, wherein the material is metallic copper, the unit area mass of the artificial electronic passage layer is 0.1% of the unit area active substance mass of the negative electrode, and a plurality of repairing processes are performedThe average area of the single decorative layer in the decorative layer is 900nm 2 。
(3) And (3) depositing a lithium-containing layer on the surface of the negative electrode in the step (2) through a vacuum evaporation technology to obtain a lithium silicon alloy, and carrying out rolling treatment under the pressure of 40 Mpa. The unit area ratio of the negative electrode/artificial electronic path interface, the negative electrode/lithium-containing layer interface and the artificial electronic path/lithium-containing layer interface in the obtained lithium-loaded negative electrode structure is 45%, 55% and 45% respectively.
(4) And (3) soaking the lithium-loaded negative electrode in the step (3) in electrolyte to complete a contact prelithiation reaction, and assembling the battery for testing. As shown in fig. 3, half-cell tests showed that the lithium-containing layer utilization was 88.2% (for the counter electrode as a metallic lithium sheet), full-cell tests showed that the initial coulombic efficiency of the pre-lithiated cell was 98.5%, the reversible capacity was 145mAh/g, and the capacity retention after 300 cycles was 93.7%.
Example 4
The embodiment provides a pre-lithiated negative electrode plate, a preparation method thereof and a lithium battery, comprising the following steps:
(1) And manufacturing a lithium ion battery anode, wherein the lithium ion battery anode comprises an anode current collector and an active material layer covered on the surface of the anode current collector.
(2) Depositing an artificial electronic passage layer which is made of metal aluminum on the surface of the negative electrode in the step (1) by a vacuum evaporation technology, wherein the unit area mass of the artificial electronic passage layer is 1.0% of the unit area active substance mass of the negative electrode, and the average area of a single modification layer in the plurality of modification layers is 900nm 2 。
(3) And (3) depositing a lithium-containing layer on the surface of the negative electrode in the step (2) through a vacuum evaporation technology, wherein the lithium-containing layer is metallic lithium, and carrying out rolling treatment under the pressure of 25 Mpa. The unit area ratio of the negative electrode/artificial electronic path interface, the negative electrode/lithium-containing layer interface and the artificial electronic path/lithium-containing layer interface in the obtained lithium-loaded negative electrode structure is 45%, 55% and 45% respectively.
(4) And (3) soaking the lithium-loaded negative electrode in the step (3) in electrolyte to complete a contact prelithiation reaction, and assembling the battery for testing. As shown in fig. 3, half-cell tests showed that the lithium-containing layer utilization was 84.7% (for the counter electrode as a metallic lithium sheet), full-cell tests showed that the initial coulombic efficiency of the pre-lithiated cell was 96.1%, the reversible capacity was 136mAh/g, and the capacity retention after 300 cycles was 93.8%.
Example 5
The embodiment provides a pre-lithiated negative electrode plate, a preparation method thereof and a lithium battery, comprising the following steps:
(1) And manufacturing a lithium ion battery anode, wherein the lithium ion battery anode comprises an anode current collector and an active material layer covered on the surface of the anode current collector.
(2) Loading an artificial electron passage layer made of manganese oxide on the surface of the negative electrode in the step (1) by a spraying technology, wherein the unit area mass of the artificial electron passage layer is 2.5% of the unit area active substance mass of the negative electrode, and the average area of a single modification layer in the plurality of modification layers is 40000nm 2 。
(3) And (3) depositing a lithium-containing layer on the surface of the negative electrode in the step (2) through a vacuum evaporation technology, wherein the lithium-containing layer is metallic lithium, and carrying out rolling treatment under the pressure of 30 Mpa. The unit area ratio of the negative electrode/artificial electronic path interface, the negative electrode/lithium-containing layer interface and the artificial electronic path/lithium-containing layer interface in the obtained lithium-carrying negative electrode structure is 75%, 25% and 75% respectively.
(4) And (3) soaking the lithium-loaded negative electrode in the step (3) in electrolyte to complete a contact prelithiation reaction, and assembling the battery for testing. As shown in fig. 3, half cell tests showed that the lithium-containing layer utilization was 81.3% (for the counter electrode as a metallic lithium sheet), full cell tests showed that the first coulombic efficiency of the pre-lithiated cell was 94.8%, the reversible capacity was 131mAh/g, and the capacity retention after 300 cycles was 91.2%.
Example 6
The embodiment provides a pre-lithiated negative electrode plate, a preparation method thereof and a lithium battery, comprising the following steps:
(1) And manufacturing a lithium ion battery anode, wherein the lithium ion battery anode comprises an anode current collector and an active material layer covered on the surface of the anode current collector.
(2) Loading an artificial electronic passage layer made of nickel oxide on the surface of the negative electrode in the step (1) by a spraying technology, wherein the unit area mass of the artificial electronic passage layer is 1.4% of the unit area active substance mass of the negative electrode, and the average area of a single modification layer in the plurality of modification layers is 40000nm 2 。
(3) And (3) attaching a lithium-containing layer to the surface of the negative electrode in the step (2) through a mechanical rolling technology to obtain a lithium silver alloy, and carrying out rolling treatment under the pressure of 50Mpa. The unit area ratio of the negative electrode/artificial electronic path interface, the negative electrode/lithium-containing layer interface and the artificial electronic path/lithium-containing layer interface in the obtained lithium-loaded negative electrode structure is 67%, 33% and 67% respectively.
(4) And (3) soaking the lithium-loaded negative electrode in the step (3) in electrolyte to complete a contact prelithiation reaction, and assembling the battery for testing. As shown in fig. 3, half-cell tests showed that the lithium-containing layer utilization was 87.8% (for the counter electrode as a metallic lithium sheet), full-cell tests showed that the initial coulombic efficiency of the pre-lithiated cell was 95.1%, the reversible capacity was 132mAh/g, and the capacity retention after 300 cycles was 97.6%.
Example 7
The embodiment provides a pre-lithiated negative electrode plate, a preparation method thereof and a lithium battery, comprising the following steps:
(1) And manufacturing a lithium ion battery anode, wherein the lithium ion battery anode comprises an anode current collector and an active material layer covered on the surface of the anode current collector.
(2) Depositing an artificial electronic passage layer made of molybdenum nitride on the surface of the negative electrode in the step (1) by magnetron sputtering, wherein the unit area mass of the artificial electronic passage layer is 5.0% of the unit area active substance mass of the negative electrode, and the average area of a single modification layer in the plurality of modification layers is 360000nm 2 。
(3) And (3) attaching a lithium-containing layer to the surface of the negative electrode in the step (2) through a mechanical rolling technology to obtain metallic lithium, and carrying out rolling treatment under the pressure of 50Mpa. The unit area ratio of the anode/artificial electronic path interface, the anode/lithium-containing layer interface and the artificial electronic path/lithium-containing layer interface in the obtained lithium-loaded anode structure is 70%, 30% and 70% respectively.
(4) And (3) soaking the lithium-loaded negative electrode in the step (3) in electrolyte to complete a contact prelithiation reaction, and assembling the battery for testing. As shown in fig. 3, half-cell tests showed that the lithium-containing layer utilization was 87.3% (for the counter electrode as a metallic lithium sheet), full-cell tests showed that the initial coulombic efficiency of the pre-lithiated cell was 95.9%, the reversible capacity was 134mAh/g, and the capacity retention after 300 cycles was 97.1%.
Example 8
The embodiment provides a pre-lithiated negative electrode plate, a preparation method thereof and a lithium battery, comprising the following steps:
(1) And manufacturing a lithium ion battery anode, wherein the lithium ion battery anode comprises an anode current collector and an active material layer covered on the surface of the anode current collector.
(2) Depositing an artificial electronic passage layer which is made of metallic silver on the surface of the negative electrode in the step (1) through magnetron sputtering, wherein the unit area mass of the artificial electronic passage layer is 5.0% of the unit area active substance mass of the negative electrode, and the average area of a single modification layer in the plurality of modification layers is 2500nm 2 。
(3) And (3) attaching a lithium-containing layer to the surface of the negative electrode in the step (2) through a mechanical rolling technology to obtain metallic lithium, and carrying out rolling treatment under the pressure of 40 Mpa. The unit area ratio of the negative electrode/artificial electronic path interface, the negative electrode/lithium-containing layer interface and the artificial electronic path/lithium-containing layer interface in the obtained lithium-loaded negative electrode structure is 55%, 45% and 55% respectively.
(4) And (3) soaking the lithium-loaded negative electrode in the step (3) in electrolyte to complete a contact prelithiation reaction, and assembling the battery for testing. As shown in fig. 3, half-cell tests showed that the lithium-containing layer utilization was 85.2% (for the counter electrode as a metallic lithium sheet), full-cell tests showed that the first coulombic efficiency of the pre-lithiated cell was 97.2%, the reversible capacity was 140mAh/g, and the capacity retention after 300 cycles was 95.8%.
Example 9
The embodiment provides a pre-lithiated negative electrode plate, a preparation method thereof and a lithium battery, comprising the following steps:
(1) And manufacturing a lithium ion battery anode, wherein the lithium ion battery anode comprises an anode current collector and an active material layer covered on the surface of the anode current collector.
(2) Coating an artificial electronic passage layer made of ferric oxide on the surface of the negative electrode in the step (1) by a blade coating technology, wherein the unit area mass of the artificial electronic passage layer is 0.5% of the unit area active substance mass of the negative electrode, and the average area of a single modification layer in the plurality of modification layers is 100nm 2 。
(3) And (3) coating a lithium-containing layer on the surface of the negative electrode in the step (2) through a blade coating technology to obtain a lithium silver alloy, and carrying out rolling treatment under the pressure of 30 Mpa. The unit area ratio of the negative electrode/artificial electronic path interface, the negative electrode/lithium-containing layer interface and the artificial electronic path/lithium-containing layer interface in the obtained lithium-loaded negative electrode structure is 30%, 70% and 30% respectively.
(4) And (3) soaking the lithium-loaded negative electrode in the step (3) in electrolyte to complete a contact prelithiation reaction, and assembling the battery for testing. As shown in fig. 3, half-cell tests showed that the lithium-containing layer utilization was 82.1% (for the counter electrode as a metallic lithium sheet), full-cell tests showed that the initial coulombic efficiency of the pre-lithiated cell was 94.9%, the reversible capacity was 135mAh/g, and the capacity retention after 300 cycles was 92.8%.
Example 10
The embodiment provides a pre-lithiated negative electrode plate, a preparation method thereof and a lithium battery, comprising the following steps:
(1) And manufacturing a lithium ion battery anode, wherein the lithium ion battery anode comprises an anode current collector and an active material layer covered on the surface of the anode current collector.
(2) Depositing an artificial electronic passage layer made of metallic molybdenum on the surface of the negative electrode in the step (1) by a magnetron sputtering technology, wherein the unit area mass of the artificial electronic passage layer is 3.0% of the unit area active substance mass of the negative electrode, and the average area of a single modification layer in the plurality of modification layers is 10000nm 2 。
(3) And (3) depositing a lithium-containing layer on the surface of the negative electrode in the step (2) through a vacuum evaporation technology, wherein the lithium-containing layer is metallic lithium, and carrying out rolling treatment under the pressure of 40 Mpa. The unit area ratio of the negative electrode/artificial electronic path interface, the negative electrode/lithium-containing layer interface and the artificial electronic path/lithium-containing layer interface in the obtained lithium-loaded negative electrode structure is 55%, 45% and 55% respectively.
(4) And (3) soaking the lithium-loaded negative electrode in the step (3) in electrolyte to complete a contact prelithiation reaction, and assembling the battery for testing. As shown in fig. 3, half-cell tests showed that the lithium-containing layer utilization was 81.6% (for the counter electrode as a metallic lithium sheet), full-cell tests showed that the initial coulombic efficiency of the pre-lithiated cell was 92.5%, the reversible capacity was 133mAh/g, and the capacity retention after 300 cycles was 90.9%.
Comparative example
Comparative example 1
The comparative example provides a pre-lithiated negative electrode sheet, a preparation method thereof and a lithium battery, comprising the following steps:
(1) And manufacturing a lithium ion battery anode, wherein the lithium ion battery anode comprises an anode current collector and an active material layer covered on the surface of the anode current collector.
(2) And (3) depositing a lithium-containing layer on the surface of the negative electrode in the step (1) through a vacuum evaporation technology, wherein the lithium-containing layer is metallic lithium, and carrying out rolling treatment under the pressure of 20 Mpa.
(3) And (3) soaking the lithium-loaded negative electrode in the step (2) in electrolyte to complete a contact prelithiation reaction, and assembling the battery for testing. As shown in fig. 3, half-cell tests showed that the lithium-containing layer utilization was 64.5% (the counter electrode was a metallic lithium sheet), full-cell tests showed that the initial coulombic efficiency of the pre-lithiated cell was 79.9%, and the capacity retention after 300 cycles was 81.4%.
Comparative example 2
The comparative example provides a pre-lithiated negative electrode sheet, a preparation method thereof and a lithium battery, comprising the following steps:
(1) And manufacturing a lithium ion battery anode, wherein the lithium ion battery anode comprises an anode current collector and an active material layer covered on the surface of the anode current collector.
(2) Depositing an artificial electronic passage layer made of metallic molybdenum on the surface of the negative electrode in the step (1) by a magnetron sputtering technology, wherein the unit area mass of the artificial electronic passage layer is 10.0% of the unit area active substance mass of the negative electrode, and the average area of a single modification layer in the plurality of modification layers is 90000nm 2 。
(3) And (3) depositing a lithium-containing layer on the surface of the negative electrode in the step (2) through a vacuum evaporation technology, wherein the lithium-containing layer is metallic lithium, and carrying out rolling treatment under the pressure of 30 Mpa. The unit area ratio of the negative electrode/artificial electronic path interface, the negative electrode/lithium-containing layer interface and the artificial electronic path/lithium-containing layer interface in the obtained lithium-loaded negative electrode structure is 65%, 35% and 65% respectively.
(4) And (3) soaking the lithium-loaded negative electrode in the step (3) in electrolyte to complete a contact prelithiation reaction, and assembling the battery for testing. Half-cell tests show that the utilization rate of the lithium-containing layer is 83.2 percent (the counter electrode is a metal lithium sheet), full-cell tests show that the first coulomb efficiency of the pre-lithiated battery is 89.5 percent (the counter electrode is a lithium iron phosphate), and the reversible capacity of the pre-lithiated battery is 115mAh/g, which indicates that the actual unit mass capacity of the battery is reduced due to excessive electron path content.
Comparative example 3
The comparative example provides a pre-lithiated negative electrode sheet, a preparation method thereof and a lithium battery, comprising the following steps:
(1) And manufacturing a lithium ion battery anode, wherein the lithium ion battery anode comprises an anode current collector and an active material layer covered on the surface of the anode current collector.
(2) Depositing an artificial electronic passage layer which is made of metallic silver on the surface of the negative electrode in the step (1) by a magnetron sputtering technology, wherein the unit area mass of the artificial electronic passage layer is 5.0% of the unit area active substance mass of the negative electrode, and the average area of a single modification layer in the plurality of modification layers is 4000000nm 2 。
(3) And (3) depositing a lithium-containing layer on the surface of the negative electrode in the step (2) through a vacuum evaporation technology, wherein the lithium-containing layer is metallic lithium, and carrying out rolling treatment under the pressure of 30 Mpa. The unit area ratio of the negative electrode/artificial electronic passage interface, the negative electrode/lithium-containing layer interface and the artificial electronic passage/lithium-containing layer interface in the obtained lithium-loaded negative electrode structure is 100%, 0% and 100%, respectively, namely the artificial electronic passage layer completely covers the upper surface of the negative electrode.
(4) And (3) soaking the lithium-loaded negative electrode in the step (3) in electrolyte to complete a contact prelithiation reaction, and assembling the battery for testing. Half-cell tests show that the utilization rate of the lithium-containing layer is 54.3 percent (the counter electrode is a metal lithium sheet), and full-cell tests show that the first coulombic efficiency of the pre-lithiated battery is 76.8 percent (the counter electrode is lithium iron phosphate), and the reversible capacity is 109mAh/g.
Comparative example 4
The comparative example provides a pre-lithiated negative electrode sheet, a preparation method thereof and a lithium battery, comprising the following steps:
(1) And manufacturing a lithium ion battery anode, wherein the lithium ion battery anode comprises an anode current collector and an active material layer covered on the surface of the anode current collector.
(2) Depositing an artificial electronic passage layer which is made of metallic silver on the surface of the negative electrode in the step (1) by a magnetron sputtering technology, wherein the unit area mass of the artificial electronic passage layer is 0.1% of the unit area active substance mass of the negative electrode, and the average area of a single modification layer in the plurality of modification layers is 16nm 2 。
(3) And (3) depositing a lithium-containing layer on the surface of the negative electrode in the step (2) through a vacuum evaporation technology, wherein the lithium-containing layer is metallic lithium, and carrying out rolling treatment under the pressure of 30 Mpa. The unit area ratio of the negative electrode/artificial electronic path interface, the negative electrode/lithium-containing layer interface and the artificial electronic path/lithium-containing layer interface in the obtained lithium-loaded negative electrode structure is 15%, 85% and 15% respectively.
(4) And (3) soaking the lithium-loaded negative electrode in the step (3) in electrolyte to complete a contact prelithiation reaction, and assembling the battery for testing. Half-cell tests showed that the lithium-containing layer utilization was 67.1% (the counter electrode was a metallic lithium sheet), full-cell tests showed that the primary coulombic efficiency of the pre-lithiated cell was 75.4%, and the capacity retention after 300 cycles was 83.8%.
The pre-lithiated negative electrode sheet in comparative example 1 does not contain a modification layer, and its lithium-containing layer utilization, first coulombic efficiency, and cycling stability are lower than those of the lithium battery of example.
The mass per unit area of the modified layer of the pre-lithiated negative electrode sheet in comparative example 2 was 10.0% of the mass of the active material per unit area of the negative electrode, and the result showed that the excessive electron path content caused a decrease in the actual capacity per unit mass of the battery.
The coverage rate of the multiple modification layers of the pre-lithiated negative electrode sheet on the surface of the active material layer in comparative example 3 was 100% (i.e., the active material layer/modification layer interface unit area ratio was 100%, the modification layer/lithium-containing layer interface ratio was 100%, and the active material layer/lithium-containing layer interface ratio was 0%), and as a result, it was shown that the lithium-containing layer utilization rate, the first coulombic efficiency and the cycling stability of the battery were reduced after the modification layers completely covered the active material layer.
The coverage of the multiple modified layers of the pre-lithiated negative electrode sheet in comparative example 4 on the surface of the active material layer was 15% (the average area of the individual modified layers was 16 nm) 2 ) The result shows that serious interface structure fluctuation in the pre-lithiation process easily causes collapse of the modification layer structure, and promotes early termination of the pre-lithiation process. Meanwhile, the lower coverage of the modification layer by the occupied area leads to lower electron path density, so that the prelithiation rate is slower, and the overall appearance of the prelithiation process is not ideal.
While the invention has been described with reference to certain preferred embodiments, it will be understood by those skilled in the art that various changes and substitutions of equivalents may be made and equivalents will be apparent to those skilled in the art without departing from the scope of the invention. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.
Claims (7)
1. The pre-lithiated negative electrode plate is characterized by comprising a negative electrode current collector, an active material layer covered on the surface of the negative electrode current collector, a plurality of modification layers covered on part of the surface of the active material layer, and a lithium-containing layer covered on the residual surface of the active material layer and the surfaces of the modification layers,
the plurality of modification layers are distributed on the surface of the active material layer at intervals, and the coverage rate is 30-75%; the plurality of modification layers includes one or more of a lithium-philic metal, an oxide of the lithium-philic metal, and a nitride of the lithium-philic metal;
the mass of the unit area of the plurality of modification layers is 0.1-5% of the mass of the unit area of the active material layer;
the average area of the single modification layer in the plurality of modification layers is 100-1000000 nm 2 ；
The lithium-containing layer comprises one or more of metal lithium, lithium silicon alloy, lithium magnesium alloy, lithium copper alloy, lithium silver alloy, lithium beryllium alloy, lithium zinc alloy, lithium cadmium alloy, lithium aluminum alloy, lithium gold alloy and lithium boron alloy.
2. The pre-lithiated negative electrode pad of claim 1, wherein the lithium-philic metal comprises one or more of gold, silver, copper, iron, titanium, aluminum, manganese, tin, cobalt, nickel, chromium, bismuth, vanadium, molybdenum, and niobium.
3. A method for preparing a pre-lithiated negative electrode sheet as claimed in any one of claims 1 to 2, comprising the steps of:
(1) Manufacturing a lithium ion battery anode, wherein the lithium ion battery anode comprises an anode current collector and an active material layer covered on the surface of the anode current collector;
(2) Depositing a plurality of modification layers on the surface of the lithium ion battery cathode at intervals, so that part of the surface of the active material layer covers the modification layers to obtain a lithium ion battery cathode plate;
(3) Depositing a lithium-containing layer on the surface of the lithium ion battery negative electrode plate, so that the surface of the rest part of the active material layer and the surfaces of the plurality of modification layers are covered with a lithium-containing layer to obtain a lithium-loaded negative electrode plate;
(4) And placing the lithium-loaded negative plate in electrolyte to complete the contact pre-lithiation reaction, so as to obtain the pre-lithiated negative plate.
4. The method of claim 3, wherein in step (2), the method of depositing a plurality of modification layers on the surface of the negative electrode of the lithium ion battery at intervals comprises one or a combination of magnetron sputtering, vacuum evaporation, knife coating, spraying and chemical vapor deposition.
5. The method of claim 3, wherein in step (3), the method of depositing the lithium-containing layer on the surface of the negative electrode sheet of the lithium ion battery comprises one or a combination of vacuum evaporation, mechanical rolling, blade coating and spray coating.
6. The method of claim 3, further comprising, after the step (3), subjecting the lithium-loaded negative electrode sheet to a roll-pressing process, wherein the roll-pressing process is performed under a pressure ranging from 20Mpa to 50Mpa.
7. A lithium battery, comprising a positive plate, a separator, an electrolyte, and the pre-lithiated negative plate of any one of claims 1-2.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20200076006A (en) * | 2018-12-18 | 2020-06-29 | 한양대학교 산학협력단 | Anode for lithium secondary battery comprising lithiophilic coating layer, method for producing the same, and lithium secondary battery comprising the same |
| CN112072077A (en) * | 2020-09-11 | 2020-12-11 | 昆山宝创新能源科技有限公司 | Pre-lithiated negative plate and preparation method and application thereof |
| CN112750982A (en) * | 2020-12-30 | 2021-05-04 | 复旦大学 | Laminated lithium metal battery negative electrode material, preparation method thereof and lithium metal secondary battery |
| CN113410424A (en) * | 2021-06-17 | 2021-09-17 | 昆山宝创新能源科技有限公司 | Lithium silicon-based negative electrode plate and preparation method and application thereof |
-
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- 2021-12-21 CN CN202111586304.7A patent/CN114335417B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20200076006A (en) * | 2018-12-18 | 2020-06-29 | 한양대학교 산학협력단 | Anode for lithium secondary battery comprising lithiophilic coating layer, method for producing the same, and lithium secondary battery comprising the same |
| CN112072077A (en) * | 2020-09-11 | 2020-12-11 | 昆山宝创新能源科技有限公司 | Pre-lithiated negative plate and preparation method and application thereof |
| CN112750982A (en) * | 2020-12-30 | 2021-05-04 | 复旦大学 | Laminated lithium metal battery negative electrode material, preparation method thereof and lithium metal secondary battery |
| CN113410424A (en) * | 2021-06-17 | 2021-09-17 | 昆山宝创新能源科技有限公司 | Lithium silicon-based negative electrode plate and preparation method and application thereof |
Non-Patent Citations (1)
| Title |
|---|
| Pre-Lithiation Strategies for Next-Generation Practical Lithium-Ion Batteries;Liming Jin;《Adv. Sci.》 * |
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