A multilayer ceramic electrode tab and a method of manufacturing the same
By employing a multilayer ceramic electrode preparation method, using a stacked structure and ALD deposition technology, the problems of thermal runaway and insufficient energy density in lithium-ion batteries have been solved, thereby improving battery safety and performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- JIANG XI LI NENG NEW ENERGY TECH CO LTD
- Filing Date
- 2023-04-23
- Publication Date
- 2026-04-10
AI Technical Summary
Existing lithium-ion batteries are prone to thermal runaway during use, leading to heat accumulation and material decomposition, resulting in a high risk of combustion. Furthermore, the safety and energy density of these batteries need to be improved.
A method for preparing multilayer ceramic electrode sheets is adopted. After coating the current collector surface with a binder layer and an active composition layer, heat treatment is performed to deposit a ceramic layer. The above steps are repeated to form a multilayer structure. The ALD deposition technology avoids the use of solvents, thereby improving battery safety and energy density.
It improves the safety and energy density of lithium-ion batteries, effectively prevents lithium dendrite puncture, enhances battery cycle performance and utilization, and is suitable for large-scale applications.
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Figure BDA0004192950320000061
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of lithium ion batteries, in particular to a multilayer ceramic electrode tab and a preparation method thereof. BACKGROUND
[0002] With the acceleration of social progress, various energy problems have become increasingly prominent, of which the most serious is energy depletion. Therefore, the sustainable development of energy has become a key research issue. Among them, solar energy is the most direct energy, but its problems are large occupation area and low utilization rate; the main problem of wind energy is that it relies on specific geographical location and use conditions are limited. Therefore, batteries have become a key research direction, and the capacity and cycle performance of batteries are increasingly mature, but as the number of uses increases, it is found that thermal runaway phenomenon occurs inside the battery, which is mainly because a large amount of heat accumulates inside the battery, causing decomposition of various substances in the battery and eventually burning. Therefore, how to provide a safe battery for use has become a problem to be solved. SUMMARY
[0003] The present application aims to overcome the defects in the prior art and provide a multilayer ceramic electrode tab and a preparation method thereof.
[0004] In order to achieve the above-mentioned application purposes, the present application provides the following technical solutions:
[0005] The present application provides a preparation method of a multilayer ceramic electrode tab, comprising the following steps:
[0006] (1) sequentially coating a binder layer and an active composition layer on the surface of the current collector and then performing heat treatment to obtain a composite;
[0007] (2) depositing a ceramic layer on the surface of the active composition layer of the composite to obtain an intermediate;
[0008] (3) repeating steps (1) and (2) to obtain the multilayer ceramic electrode tab.
[0009] Preferably, the current collector in step (1) is a copper foil, an aluminum foil or a foamed copper;
[0010] The binder is polyvinylidene fluoride, sodium carboxymethyl cellulose and polyacrylic acid.
[0011] Preferably, the areal density of the binder layer in step (1) is 20-25 g / m 2 .
[0012] Preferably, the active composition in step (1) comprises an active substance, a conductive agent and an intermediate binder;
[0013] The active substance is a positive electrode active substance or a negative electrode active substance;
[0014] The conductive agent is conductive carbon black, carbon nanotube, acetylene black or graphene;
[0015] The intermediate binder is a polyvinyl fluoride binder;
[0016] The mass ratio of the active material, the conductive agent and the intermediate binder is 90-110:5-12:2-4.
[0017] As preferred, the preparation method of the active composition comprises the following steps:
[0018] After mixing the active material, the conductive agent and the intermediate binder, the active composition is obtained by pressing;
[0019] The single-pass deformation degree of the pressing is 50-65%, and the pressing passes are 3-5.
[0020] As preferred, the areal density of the active composition layer in step (1) is 120-130 g / m 2 ; the temperature of the heat treatment is 200-230℃, and the time is 2-4 min.
[0021] As preferred, the material of the ceramic layer in step (2) is alumina;
[0022] The aluminum source of the alumina is trimethylaluminum; and the oxygen source of the alumina is ozone;
[0023] The deposition flow rate of the trimethylaluminum is 110-130 sccm, and the deposition time is 5-10 s;
[0024] The ozone is introduced for 25-30 s.
[0025] As preferred, the temperature of the deposition in step (2) is 400-500℃, the pressure is 4-6.1 mbar, and the thickness of the ceramic layer is 0.4-0.6 nm.
[0026] As preferred, the number of repetitions in step (3) is 6-8.
[0027] The application further provides a multilayer ceramic electrode tab prepared by the preparation method.
[0028] The application provides a preparation method of a multilayer ceramic electrode tab, which comprises the following steps: DETAILED DESCRIPTION
[0029] The application provides a preparation method of a multilayer ceramic electrode tab, which comprises the following steps:
[0030] (1) sequentially coating a binder layer and an active composition layer on the surface of a current collector and then performing heat treatment to obtain a composite;
[0031] (2) depositing a ceramic layer on the surface of the active composition layer of the composite to obtain an intermediate;
[0032] (3) repeating steps (1) and (2), and thus the multilayer ceramic electrode tab is obtained.
[0033] In the application, the current collector in step (1) is preferably a copper foil, an aluminum foil or a foamed copper.
[0034] In the application, the binder is preferably polyvinylidene fluoride, sodium carboxymethyl cellulose and polyacrylic acid.
[0035] In the application, the areal density of the binder layer in step (1) is preferably 20-25 g / m 2 , further preferably 21-24 g / m 2 , and more preferably 22-23 g / m 2 .
[0036] In the application, the active composition in step (1) comprises an active substance, a conductive agent and an intermediate binder.
[0037] In the application, the active substance is preferably a positive electrode active substance or a negative electrode active substance.
[0038] In the application, the conductive agent is preferably conductive carbon black, a carbon nanotube, acetylene black or graphene.
[0039] In the application, the intermediate binder is preferably a polyperfluoroethylene binder.
[0040] In the present application, the mass ratio of the active material, the conductive agent and the intermediate binder is preferably 90-110:5-12:2-4, further preferably 94-106:6-11:2.5-3.5, and more preferably 98-102:8-9:2.8-3.2.
[0041] In the present application, the method for preparing the active composition comprises the following steps:
[0042] After mixing the active material, the conductive agent and the intermediate binder, the active composition is obtained by pressing;
[0043] In the present application, the single-pass deformation degree of the pressing is preferably 50-65%, further preferably 53-62%, and more preferably 55-60%, and the number of passes of the pressing is preferably 3-5, and further preferably 4.
[0044] In the present application, the areal density of the active composition layer in step (1) is preferably 120-130 g / m 2 , further preferably 122-128 g / m 2 , and more preferably 124-126 g / m 2 ; the temperature of the heat treatment is preferably 200-230°C, further preferably 205-225°C, and more preferably 210-220°C; and the time is preferably 2-4 min, further preferably 2.5-3.5 min, and more preferably 2.8-3.2 min.
[0045] In the present application, the active composition is pressed into a sheet, at which time the binder in the active composition layer plays a role in binding the active material and the conductive agent together; the sheet is placed above the binder layer, and after heat treatment, the active composition layer and the binder layer are bonded, preventing detachment.
[0046] In the present application, the material of the ceramic layer in step (2) is preferably alumina.
[0047] In the present application, the aluminum source of the alumina is preferably trimethylaluminum; and the oxygen source of the alumina is preferably ozone.
[0048] In the present application, the carrier of the trimethylaluminum is preferably nitrogen.
[0049] In the present application, the deposition flow rate of the trimethylaluminum is preferably 110-130 seem, further preferably 115-125 seem, and more preferably 118-123 seem; and the deposition time is preferably 5-10 s, further preferably 6-9 s, and more preferably 7-8 s.
[0050] In the present application, the time for the ozone to be introduced is preferably 25-30s, further preferably 26-29s, and more preferably 27-28s.
[0051] In the present application, when the deposition is performed, trimethylaluminum is first introduced, and after the deposition of the trimethylaluminum is completed, nitrogen is introduced for purging. The purging time of the nitrogen is preferably 10-15s, further preferably 11-14s, and more preferably 12-13s. Then, ozone is introduced, and the ozone and the trimethylaluminum are reacted to obtain aluminum oxide. After the introduction of the ozone is completed, nitrogen is introduced for purging. The purging time of the nitrogen is preferably 10-15s, further preferably 11-14s, and more preferably 12-13s. At this time, one cycle is completed, and multiple cycles are performed until the target thickness of the ceramic layer is reached.
[0052] In the present application, the temperature in step (2) is preferably 400-500℃, further preferably 420-480℃, and more preferably 440-460℃. The pressure is preferably 4-6.1mbar, further preferably 4.5-5.5mbar, and more preferably 4.8-5.2mbar. The thickness of the ceramic layer is preferably 0.4-0.6nm, further preferably 0.45-0.55nm, and more preferably 0.48-0.52nm.
[0053] In the present application, the number of repetitions in step (3) is preferably 6-8, and more preferably 7.
[0054] The present application also provides a multilayer ceramic electrode tab obtained by the preparation method.
[0055] The technical solutions provided by the present application are described in detail below in conjunction with examples, but they should not be understood as limiting the scope of protection of the present application.
[0056] Example 1
[0057] A polyvinylidene fluoride layer is coated on the surface of the copper foil, and the surface density is controlled to be 23g / m 2 Then, a positive electrode active composition is prepared, and the mass ratio of lithium iron phosphate, conductive carbon black, and polyperfluorinated ethylene binder is 100:8:3. After the positive electrode active composition is mixed sufficiently, it is pressed, and the deformation degree of a single pass is 60%. The positive electrode composition sheet is obtained by pressing 4 times. The positive electrode composition sheet is placed on the polyvinylidene fluoride layer, and the surface density is controlled to be 125g / m 2then heat treatment at 230℃ for 3min to obtain a composite; deposition on the surface of the active composition layer of the composite, control the deposition temperature to be 450℃, the pressure to be 5.5mbar, take nitrogen as the carrier gas, the flow rate of trimethylaluminum to be 120sccm, deposit for 8s; then nitrogen blowing for 15s, ozone input for 25s to react, then nitrogen blowing for 15s, complete the first cycle of deposition, the thickness of the ceramic layer to be 0.5nm to obtain an intermediate; repeat the above steps for 6 times to obtain a multilayer ceramic positive electrode tab.
[0058] In the same way, replace the lithium iron phosphate with artificial graphite to prepare a multilayer ceramic negative electrode tab.
[0059] Example 2
[0060] Coat the surface of the copper foil with carboxymethyl cellulose sodium, control the surface density to be 20g / m 2 then prepare the positive electrode active composition, the mass ratio of lithium iron phosphate, graphene and polyperfluoroethylene binder to be 90:11:4, mix the positive electrode active composition thoroughly and then press, the deformation degree of single pass to be 50%, press 3 times to obtain a positive electrode composition sheet, place the positive electrode composition sheet on the carboxymethyl cellulose sodium layer, control the surface density to be 120g / m 2 then heat treatment at 200℃ for 2min to obtain a composite; deposition on the surface of the active composition layer of the composite, control the deposition temperature to be 410℃, the pressure to be 6.0mbar, take nitrogen as the carrier gas, the flow rate of trimethylaluminum to be 110sccm, deposit for 10s; then nitrogen blowing for 10s, ozone input for 30s to react, then nitrogen blowing for 10s, complete the first cycle of deposition, the thickness of the ceramic layer to be 0.4nm to obtain an intermediate; repeat the above steps for 7 times to obtain a multilayer ceramic positive electrode tab.
[0061] In the same way, replace the lithium iron phosphate with artificial graphite to prepare a multilayer ceramic negative electrode tab.
[0062] Example 3
[0063] Coat the surface of the copper foil with polyacrylic acid, control the surface density to be 24g / m 2 then prepare the positive electrode active composition, the mass ratio of lithium iron phosphate, carbon nanotubes and polyperfluoroethylene binder to be 105:6:2, mix the positive electrode active composition thoroughly and then press, the deformation degree of single pass to be 63%, press 3 times to obtain a positive electrode composition sheet, place the positive electrode composition sheet on the polyacrylic acid layer, control the surface density to be 130g / m 2Then the composite is heat-treated at 220℃ for 3min; deposition is carried out on the surface of the active composition layer of the composite, the deposition temperature is controlled at 460℃, the pressure is 4.2mbar, nitrogen is used as the carrier gas, the flow rate of trimethylaluminum is 120sccm, the deposition time is 8s; then nitrogen is blown for 10s, ozone is introduced for 25s for reaction, then nitrogen is blown for 10s, the first deposition cycle is completed, the thickness of the ceramic layer is 0.5nm, and an intermediate is obtained; the above steps are repeated 8 times, and a multilayer ceramic positive electrode sheet is obtained.
[0064] The surface of the copper foil is coated with polyvinylidene fluoride, and the surface density is controlled at 21g / m 2 Then the negative active composition is prepared, the mass ratio of artificial graphite, acetylene black and polyvinylidene fluoride binder is 90:8:4, the negative active composition is mixed thoroughly and then pressed, the deformation degree of single pass is 55%, the negative active composition sheet is obtained after being pressed 4 times, and the negative active composition sheet is placed on the polyvinylidene fluoride layer, and the surface density is controlled at 125g / m 2 Then the composite is heat-treated at 205℃ for 2min; deposition is carried out on the surface of the active composition layer of the composite, the deposition temperature is controlled at 420℃, the pressure is 5.5mbar, nitrogen is used as the carrier gas, the flow rate of trimethylaluminum is 115sccm, the deposition time is 5s; then nitrogen is blown for 15s, ozone is introduced for 30s for reaction, then nitrogen is blown for 10s, the first deposition cycle is completed, the thickness of the ceramic layer is 0.6nm, and an intermediate is obtained; the above steps are repeated 8 times, and a multilayer ceramic negative electrode sheet is obtained.
[0065] The positive electrode sheets and the negative electrode sheets prepared in Examples 1-3 are subjected to winding, baking, liquid injection, sealing, etc. to prepare 18650 lithium ion batteries, and the batteries obtained in each example are subjected to performance testing, and the results are recorded in Table 1.
[0066] Table 1 Performance test results
[0067]
[0068] From the above embodiment, the application provides a multilayer ceramic electrode tab. The application adopts a laminated mode, which can further improve the use rate of the battery; the active composition layer is prepared by a dry method, and the ceramic layer is deposited by ALD deposition, thereby avoiding the use of solvent and reducing the occurrence of swelling. The application adopts a multilayer ceramic deposition mode, which improves the energy density and safety of the battery, and the multilayer ceramic layer effectively prevents direct puncture of lithium dendrites. The multilayer ceramic electrode tab provided by the application greatly improves the safety of the battery while ensuring the performance of the battery, and is suitable for large-scale use. According to the description of the embodiment, the electrode tab provided by the application has an energy density of 381 Wh / kg after being made into a battery, a cycle performance of 4371 times, a capacity retention rate of 99% after 100 cycles, and a capacity retention rate of 96% after 1000 cycles, and is an electrode tab with excellent performance.
[0069] The above only describes the preferred embodiments of the application, and it should be pointed out that those skilled in the art can make several improvements and refinements without departing from the principles of the application, and these improvements and refinements should also be considered as the protection scope of the application.
Claims
1. A method for preparing a multilayer ceramic electrode sheet, characterized in that, The preparation method comprises the following steps: (1) performing heat treatment after sequentially coating an adhesive layer and an active composition layer on the surface of a current collector to obtain a composite; (2) depositing a ceramic layer on the surface of the active composition layer of the composite to obtain an intermediate; (3) repeating steps (1) and (2) to obtain the multilayer ceramic electrode tab; The active composition in step (1) comprises an active material, a conductive agent and an intermediate binder; The active material is a positive electrode active material or a negative electrode active material; The conductive agent is conductive carbon black, carbon nanotubes or graphene; The intermediate binder is a polyperfluoroethylene binder; The mass ratio of the active material, the conductive agent and the intermediate binder is 90-110:5-12:2-4; The areal density of the active composition layer in step (1) is 120 to 130 g / m 2 ; the temperature of the heat treatment is 200 to 230 °C and the time is 2 to 4 min; The material of the ceramic layer in step (2) is alumina; The aluminum source of the alumina is trimethylaluminum; and the oxygen source of the alumina is ozone; The deposition flow rate of the trimethylaluminum is 110-130 sccm, and the deposition time is 5-10 s; The ozone is introduced for 25-30 s; The deposition temperature in step (2) is 400-500 DEG C, the pressure is 4-6.1 mbar, and the thickness of the ceramic layer is 0.4-0.6 nm.
2. The production method according to claim 1, wherein The current collector in step (1) is a copper foil, an aluminum foil or a foamed copper; The binder in the adhesive layer is polyvinylidene fluoride, sodium carboxymethyl cellulose and polyacrylic acid.
3. The production method according to claim 1 or 2, characterized by, The areal density of the adhesive layer in step (1) is 20 to 25 g / m 2 .
4. The production method according to claim 3, wherein The preparation method of the active composition comprises the following steps: Mixing the active material, the conductive agent and the intermediate binder and then pressing to obtain the active composition; The single-pass deformation degree of the pressing is 50-65%, and the pressing passes are 3-5 times.
5. The production method according to claim 4, wherein The number of repetitions in step (3) is 6-8 times.
6. The multilayer ceramic electrode tab obtained by the preparation method in any one of claims 1-5.
Citation Information
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