Pre-adsorbed anionic ferroelectric material and preparation method thereof, functional layer and application thereof

Abstract

The application discloses a pre-adsorbed anionic ferroelectric material and a preparation method thereof, a functional layer and application of the pre-adsorbed anionic ferroelectric material. The preparation method comprises the following steps: adding a target salt into water and stirring to dissolve the target salt, adding ferroelectric powder into the target salt solution, performing high-energy ball milling, vacuum filtration or centrifugal treatment to obtain a solid product, baking, cooling, crushing and grinding the solid product to obtain a primary product powder, heating the primary product powder to 100-120 DEG C at a speed of 1-5 DEG C / min under an inert atmosphere, heating the primary product powder to 250-350 DEG C at a speed of 1-2 DEG C / min after heat preservation, and cooling the primary product powder after heat preservation to obtain the pre-adsorbed anionic ferroelectric material. The pre-adsorbed anionic ferroelectric material can be used for preparing the functional layer. The pre-adsorbed anionic ferroelectric material and the functional layer can effectively inhibit interface side reactions and dendrites, improve interface stability and kinetic performance, prolong the service life of a battery, and can be widely applied in the field of rechargeable batteries.

Description

Technical Field

[0001] This invention belongs to the field of rechargeable battery technology, and relates to a pre-adsorbed anion-type ferroelectric material, its preparation method, functional layer and its application. Background Technology

[0002] Rechargeable batteries, as a core technology for energy storage, play a vital role in electric vehicles, portable electronic devices, and renewable energy storage. However, with the diversification of application scenarios and the increasing performance requirements of end devices, higher demands are being placed on rechargeable batteries in terms of cycle life, fast charging capability, energy density, and safety. Researchers are addressing these challenges through novel electrode designs, electrolyte engineering, and interface engineering. Among these, interface functional layer design is an effective means of studying battery interface science and regulating battery performance.

[0003] Studies have shown that poor ion transport performance at the electrode / electrolyte interface directly affects the battery's kinetic performance and interfacial stability, ultimately leading to poor cycle life and fast-charging capability. For example, in lithium metal batteries, uncontrollable side reactions and lithium dendrite growth at the lithium electrode / electrolyte interface result in a thickened, poor-quality solid electrolyte interphase (SEI) and the accumulation of "dead" lithium, causing a sharp increase in interfacial impedance and ultimately leading to widespread lithium dendrite formation, severely impacting battery interfacial stability and kinetic transport. Recent research indicates that the structure and composition of the SEI are closely related to battery performance. The initially formed SEI is often solvent-derived, rich in organic matter, and exhibits uneven thickness, porosity, and fragility, resulting in poor chemical stability, electron tunneling resistance, and mechanical properties. Therefore, it is necessary to seek an interfacial phase modulation method to achieve precise control over the SEI composition and structure.

[0004] Beyond lithium metal batteries, the electrolyte interphase (SEI) plays a crucial role in other battery systems such as lithium-ion, lithium-sulfur, sodium-ion, and zinc-ion rechargeable batteries. For example, one of the goals of researchers in forming commercial lithium-ion batteries is to generate a stable SEI. The SEI in lithium-sulfur, sodium-ion, and zinc-ion batteries serves a similar purpose to that in lithium metal batteries, primarily suppressing interfacial side reactions and dendrite growth. Furthermore, another important interfacial phase in the battery system, the cathode / electrolyte interface (CEI), also plays a vital role in achieving excellent battery electrochemical performance. Therefore, precise control of the CEI is equally important. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a pre-adsorbed anionic ferroelectric material, its preparation method, functional layer and application, which can effectively suppress interfacial side reactions and dendrites, improve interfacial stability and kinetic performance, and extend battery life.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution.

[0007] A method for preparing a pre-adsorbed anion-type ferroelectric material includes the following steps:

[0008] (1) Add the target salt to water and mix and stir until dissolved to obtain the target salt solution;

[0009] (2) Add the ferroelectric powder to the above target salt solution to obtain a mixture, wherein the mass fraction of the ferroelectric powder in the mixture is 20% to 50%, and ball mill the mixture with a ball-to-material ratio (mass ratio, material being ferroelectric powder) of 4 to 8:1 and a ball milling speed of 600 r / min to 1200 r / min. After ball milling, vacuum filter or centrifuge to obtain a solid product.

[0010] (3) The solid product obtained above is baked at 80℃~120℃, cooled, crushed and ground to obtain primary product powder;

[0011] (4) The primary product powder obtained above is heated to 100℃~120℃ at a heating rate of 1℃ / min~5℃ / min under an inert atmosphere and held for 2h~12h. Then, it is heated to 250℃~350℃ at a heating rate of 1℃ / min~2℃ / min and held for 10h~24h. After cooling, a pre-adsorbed anion ferroelectric material is obtained.

[0012] In the above-described method for preparing pre-adsorbed anionic ferroelectric materials, preferably, in step (1), the target salt is one or more (including one) anionic salts, and the anionic salt is NO3. - NO2 - NO - SO4 2- SO3 2- PO4 3- PO3 3- PO2 3- BO3 3- BO2 3- SiO3 2- SiO2 2- ClO4 - ClO3 - ClO2 - ,ClO - BrO4 -, BrO3 - , BrO2 - , BrO - , IO4 - , IO3 - , IO2 - and IO - or one of the following.

[0013] For the preparation method of the pre-adsorbed anionic ferroelectric material described above, preferably, in step (2), the ferroelectric powder includes barium titanate (BaTiO3), lithium niobate (LiNbO3), bismuth ferrite (BiFeO3), bismuth titanate (Bi4Ti3O 12 ), (Ba x1 Ca y1 Sr z1 )(Ti x2 Zr y2 Sn z2 )O3, Na x3 K y3 NbO3 (sodium potassium niobate), PbZr x4 Ti y4 O3 (lead zirconate titanate), and KTa x5 Nb y5 O3 (potassium tantalum niobate), or one or more of them. Among them, in (Ba x1 Ca y1 Sr z1 )(Ti x2 Zr y2 Sn z2 )O3, 0.5 < x1 < 1, y1 > 0, z1 > 0, y1 + z1 = 1 - x1, 0.5 < x2 < 1, y2 > 0, z2 > 0, y2 + z2 = 1 - x2. In Na x3 K y3 [[ID=|59]]NbO3, 0 < x3 < 1, y3 = 1 - x3. In PbZr x4 Ti y4 O3, 0 < x4 < 1, y4 = 1 - x4. In KTa x5 Nb y5 O3, 0 < x5 < 1, y5 = 1 - x5.

[0014] For the preparation method of the pre-adsorbed anionic ferroelectric material described above, preferably, in step (2), the ball milling medium used for ball milling includes one or more of zirconia balls, tungsten carbide balls, stainless steel balls, corundum balls, nylon balls, and polytetrafluoroethylene balls. The ball milling time is 1 h to 5 h, and the rotation speed of the centrifugal treatment is 5000 r / min to 15000 r / min.

[0015] In the above-mentioned method for preparing pre-adsorbed anionic ferroelectric materials, preferably, in step (3), the baking time is 2h to 24h.

[0016] In the above-mentioned method for preparing pre-adsorbed anionic ferroelectric materials, preferably, in step (4), the inert atmosphere is high-purity argon and / or high-purity nitrogen, wherein the purity of the high-purity argon is ≥99.999% and the purity of the high-purity nitrogen is ≥99.999%.

[0017] As a general technical concept, the present invention also provides a pre-adsorbed anionic ferroelectric material prepared by the above-mentioned method for preparing pre-adsorbed anionic ferroelectric materials.

[0018] As a general technical concept, the present invention also provides a functional layer, which is a layered structure made by mixing the above-mentioned pre-adsorbed anionic ferroelectric material with a binder.

[0019] As a general technical concept, the present invention also provides an application of the above-mentioned functional layer in the field of rechargeable batteries.

[0020] In the above-described applications, preferably, the rechargeable battery includes one or more of lithium-ion batteries, lithium metal batteries, lithium-sulfur batteries, sodium-ion batteries, and zinc-ion batteries. The functional layer is typically integrated onto various battery separators, copper foil, aluminum foil, carbon foil, carbon-coated copper foil, carbon-coated aluminum foil, lithium foil, zinc foil, and various electrode sheets, etc.

[0021] The main innovative ideas of this invention are as follows:

[0022] As a component that directly contacts both the electrolyte and the electrode, the interfacial functional layer facilitates the control of the electrode / electrolyte interface phase. This invention involves the targeted pre-adsorption of target anions on the surface of a ferroelectric material and its integration into the electrode / electrolyte interface as a functional layer. The functional layer utilizes the polarization dipoles of the ferroelectric material to polarize and activate the adsorbed anions, thereby promoting their preferential reduction and decomposition. This ferroelectric material pre-adsorbed target anion functional layer allows for precise design of the electrode / electrolyte interface phase, generating a uniform and dense SEI rich in various inorganic components derived from anions. This suppresses interfacial side reactions and lithium dendrite formation, improving interfacial stability and kinetic transport performance.

[0023] The preparation of pre-adsorbed anionic ferroelectric materials typically faces two major challenges. The first challenge is how to adsorb and capture more anions on the ferroelectric material surface. To address this, this invention employs high-energy ball milling, synergistically controlling parameters such as salt solution concentration, suspension solids content, ball-to-particle ratio, milling speed, and milling time to construct a stress-induced piezoelectric potential on the ferroelectric particle surface, thereby promoting the directional migration and efficient capture of charged anions in solution. The second challenge is maintaining the stability of anions adsorbed on the ferroelectric material surface and reducing their natural loss. To address this, this invention explores a low-temperature reheating process, combining low temperature, slow heating, and long-term heat preservation to form a strong bond between anions and the ferroelectric material surface, significantly improving their stability.

[0024] Compared with the prior art, the advantages of the present invention are as follows:

[0025] 1. In the preparation method of the present invention, the target salt solution is prepared by dissolving inorganic salt in pure water. The entire technical solution uses water (preferably deionized water) as the reaction solvent, which is more green, environmentally friendly and pollution-free than organic solvents. More importantly, the present invention uses pre-adsorbed inorganic anions as the control medium. Compared with the organic anion strategy in organic electrolytes, its reduction and decomposition process is often cleaner and more thorough, which can avoid the introduction of too many incompletely decomposed intermediate products (the reduction and decomposition path of organic salts is often longer and more complex, with more intermediate products), thereby accurately controlling the target inorganic components and content of the interface phase.

[0026] The technical solution of this invention allows for the design of salt solutions of different types, combinations, and concentrations to regulate the type, combination, and adsorption amount of anions pre-adsorbed on the surface of ferroelectric materials. This invention controls the content of anions adsorbed on the surface of ferroelectric materials by designing the concentration of the mixture, the ball-to-particle ratio in high-energy ball milling, the milling speed, and the milling time. By controlling the high-energy ball milling process, it ensures that the ball milling impact on the ferroelectric particles induces a strong piezoelectric potential on their surface without causing agglomeration or pulverization of the ferroelectric material. This promotes the directional migration and aggregation of loaded anions in the solution, facilitates the efficient capture and adsorption of anions on the surface of the ferroelectric particles, and allows for the controllable pre-adsorption of target anions on the surface of the ferroelectric material to obtain a pre-adsorbed anion-type ferroelectric material. The technical solution of this invention allows for the selection of different types of ferroelectric powders to regulate the adsorption and polarization ability of the ferroelectric material for target anions. This invention regulates the properties of the generated pre-adsorbed anionic ferroelectric powder through a specific combination of the above technical features, including the type, combination, and quantity of adsorbed anions, as well as the polarization and activation ability of polarized dipoles on target anions, providing a basis for subsequent preparation of functional layers to finely regulate the composition and structure of the interface phase.

[0027] This invention uses a low-temperature reheating process to firmly fix and stabilize anions adsorbed on the surface of ferroelectric materials. The slow heating and long-term low-temperature holding process not only avoids the thermal decomposition and disappearance of adsorbed anions caused by local overheating, but also ensures that the migration of reactants on the surface and the rearrangement of chemical bonds have sufficient time to occur, thereby causing a slow solid-phase interface reaction and forming stable chemical bonds to ensure the stable existence of surface anions.

[0028] 2. The pre-adsorbed anion-type ferroelectric material of the present invention has the following advantages compared with the original ferroelectric material without pre-adsorbed anions:

[0029] (1) The pre-adsorbed anion-type ferroelectric material of the present invention has higher flexibility in the control of interfacial phase (such as SEI, CEI) composition. Although the original ferroelectric material without pre-adsorbed anions can control the interfacial phase composition by adsorbing and capturing anions in the electrolyte, it is limited to anions present in the electrolyte. When using the original ferroelectric material, if it is desired to artificially and precisely introduce certain target anions or control the coexistence of multiple anions, it is necessary to introduce target additives or multiple anion additives into the electrolyte. This will bring many disadvantages such as additive solubility compatibility, electrolyte performance degradation caused by additives, and increased cost. The pre-adsorbed anion-type ferroelectric material of the present invention can flexibly select and pre-adsorb target anions and can achieve the coexistence of multiple target anions, thereby flexibly controlling the composition and properties of the interfacial phase.

[0030] (2) The pre-adsorbed anionic ferroelectric material of the present invention has particularly significant advantages in high-voltage ester electrolyte systems, for example, pre-adsorbed NO3 - Anionic ferroelectric materials exhibit significant performance improvements in high-voltage battery systems at the 4.7 V level, NO3 - Anions are excellent electrolyte additives for regulating the SEI composition at the interface and thus improving the performance of lithium-based batteries. However, NO3... - It is readily soluble in low-voltage ether electrolytes and poorly soluble in high-voltage ester electrolyte systems, thus limiting the dissolution of NO3. - Or the application of nitrogen-containing SEI in high-voltage battery systems, pre-adsorbing NO3. - The use of anionic ferroelectric materials breaks this limitation, enabling precise control of the nitrogen-containing SEI in high-voltage battery systems, thereby improving the cycle life of high-voltage batteries.

[0031] 3. The pre-adsorbed anionic ferroelectric material of the present invention can be used to prepare functional layers. When the functional layers are applied to the interface components of rechargeable batteries (including lithium-ion batteries, lithium metal batteries, lithium-sulfur batteries, sodium-ion batteries, and zinc-ion batteries, etc.), the composition and structure of the interface phases (SEI and CEI) can be precisely customized, and the stability and kinetic transport performance of interface ion migration can be controlled, thereby achieving high-rate fast charging and long-life cycle performance of rechargeable batteries. Attached Figure Description

[0032] Figure 1 SEM images and corresponding EDS elemental mapping diagrams of the pre-adsorbed anionic ferroelectric material prepared in Example 1 of this invention.

[0033] Figure 2 The graph shows the results of the apparent zeta potential test of the original BaTiO3 powder.

[0034] Figure 3 The graph shows the apparent zeta potential test results of the pre-adsorbed anionic ferroelectric material prepared in Example 1 of this invention.

[0035] Figure 4 The images show SEM images and corresponding EDS elemental mapping diagrams of the pre-adsorbed anionic ferroelectric material functional layer prepared in Example 1 of this invention.

[0036] Figure 5 The original lithium-copper battery sample and the BaTiO3-NO3 containing Example 1 of this invention. - CV curve of a lithium-copper battery with functional layers.

[0037] Figure 6 To use the original lithium-copper battery (a) and the BaTiO3-NO3 containing Example 1 of this invention, respectively. - SEM image of lithium deposition surface obtained from lithium-copper battery with functional layer (b).

[0038] Figure 7 To use the original lithium-lithium battery sample and the BaTiO3-NO3 containing Example 1 of this invention, respectively. - Lithium deposition / stripping lifetime diagram of a lithium-ion battery with functional layers.

[0039] Figure 8 BaTiO3-NO3 prepared in Example 1 of this invention - Cycle performance diagram of a high-voltage full cell assembled with functional separators in the functional layer.

[0040] Figure 9 SEM images and corresponding EDS elemental mapping diagrams of the pre-adsorbed anionic ferroelectric material prepared in Example 2 of this invention.

[0041] Figure 10The XPS full spectrum of the pre-adsorbed anionic ferroelectric material prepared in Example 2 of this invention is shown.

[0042] Figure 11 The graph shows the apparent zeta potential test results of the pre-adsorbed anionic ferroelectric material prepared in Example 2 of this invention.

[0043] Figure 12 The images show SEM images and corresponding EDS elemental mapping diagrams of the pre-adsorbed anionic ferroelectric material functional layer prepared in Example 2 of this invention.

[0044] Figure 13 To use the original lithium-copper battery (a) and the BaTiO3-SiO3 containing Example 2 of this invention, respectively. 2- SEM image of lithium deposition cross section obtained from lithium-copper battery with functional layer (b).

[0045] Figure 14 To use the original lithium-lithium battery sample and the BaTiO3-SiO3 sample from Example 2 of this invention, respectively. 2- Lithium deposition / stripping lifetime diagram of a lithium-ion battery with functional layers.

[0046] Figure 15 Pre-adsorbed NO3 prepared for Comparative Example 1 - Surface SEM image of the BaTiO3-based functional layer.

[0047] Figure 16 Pre-adsorbed NO3 prepared for Comparative Example 1 - Cross-sectional SEM image of the BaTiO3-based functional layer.

[0048] Figure 17 Pre-adsorbed NO3 prepared for Comparative Example 2 - SEM image of the surface of the BaTiO3-based functional layer.

[0049] Figure 18 Pre-adsorbed NO3 prepared for Comparative Example 2 - Cross-sectional SEM image of the BaTiO3-based functional layer.

[0050] Figure 19 The pre-adsorbed NO3 prepared for Comparative Example 2 - Cyclic performance of a high-voltage full cell assembled with a functional membrane based on a BaTiO3 functional layer.

[0051] Figure 20 The pre-adsorbed NO3 prepared for Comparative Example 3 - Cyclic performance of a high-voltage full cell assembled with a functional membrane based on a BaTiO3 functional layer. Detailed Implementation

[0052] The present invention will be further described below with reference to the accompanying drawings and specific preferred embodiments, but this does not limit the scope of protection of the present invention. The materials and instruments used in the following embodiments are commercially available, and room temperature typically refers to 25°C to 30°C.

[0053] Example 1

[0054] A method for preparing a pre-adsorbed anionic ferroelectric material according to the present invention includes the following steps:

[0055] (1) Weigh the target salt LiNO3 powder and add it to deionized water. Mix and stir until the target salt is completely dissolved to obtain LiNO3 aqueous solution with a concentration of 0.5 g / mL.

[0056] (2) The ferroelectric powder was added to the above-mentioned LiNO3 aqueous solution to obtain a mixed solution. The ferroelectric powder was BaTiO3 powder, and the mass fraction of the ferroelectric powder in the mixed solution was 40%. The mixed solution was subjected to high-energy ball milling using a planetary ball mill. The ball milling media was zirconia balls, the ball-to-material ratio was 5:1, and the ball milling speed was 800 r / min. After ball milling for 4 hours, the mixture was subjected to high-speed centrifugation at a speed of 8000 r / min to obtain a solid product, namely solid BaTiO3-NO3. - product.

[0057] (3) The solid product obtained above was baked in a forced-air oven at 100°C for 12 hours to preliminarily remove the remaining solvent. After cooling, the product was crushed and ground in a mortar and pestle to obtain pre-adsorbed NO3. - Primary product powder of anionic BaTiO3 ferroelectric materials.

[0058] (4) The primary product powder obtained above is placed in a tubular atmosphere furnace. The sintering atmosphere is high-purity Ar gas (purity ≥ 99.999%). The temperature is first increased from room temperature to 120°C at a heating rate of 3°C / min and held for 8 hours. Then, the temperature is increased to 300°C at a heating rate of 1°C / min and held for 12 hours. Finally, it is naturally cooled to room temperature to obtain the pre-adsorbed anion ferroelectric material, i.e., pre-adsorbed NO3. - Anionic BaTiO3 ferroelectric material powder.

[0059] The pre-adsorbed anionic ferroelectric material prepared in this embodiment was characterized by SEM combined with EDS, and the results are as follows: Figure 1 As shown. The results indicate that, in addition to containing Ba, Ti, and O elements, the surface of this pre-adsorbed anionic ferroelectric material is also modified with N-containing species. For example... Figure 2 and Figure 3As shown, the apparent zeta potentials of the original BaTiO3 powder and the pre-adsorbed anionic ferroelectric material prepared in this embodiment were tested respectively. The results showed that the apparent zeta potential of the original BaTiO3 powder was -14.1 mV, while the apparent zeta potential of the pre-adsorbed anionic ferroelectric material prepared in this embodiment decreased to -20.2 mV. This indicates that a negatively charged species was adsorbed onto the powder surface. Based on the results, the adsorbed species was determined to be negatively charged NO3. - .

[0060] The pre-adsorbed anionic ferroelectric material prepared in this embodiment was prepared into a slurry. Specifically, the pre-adsorbed anionic ferroelectric material and PVDF (polyvinylidene fluoride) binder were mixed at a mass ratio of 9:1 and dissolved in an appropriate amount of NMP (N-methylpyrrolidone) solution. The mixture was stirred until a uniform slurry was obtained, which was then coated onto the surface of a PP membrane. After drying, a pre-adsorbed anionic ferroelectric material-based functional layer, i.e., pre-adsorbed NO3, was obtained on the surface of the PP membrane. - The type of BaTiO3-based functional layer can be simply referred to as BaTiO3-NO3. - The functional layer was then used to prepare a functional membrane coated with a pre-adsorbed anion-based ferroelectric material functional layer. Figure 4 As shown, SEM and EDS together demonstrate that the synthesized functional layer contains BaTiO3 and NO3. - .

[0061] The aforementioned functional separator, including the functional layer, is assembled into a lithium-copper battery. For example... Figure 5 As shown, the CV curve of the lithium-copper battery indicates that, compared to the original lithium-copper battery, the use of a battery containing BaTiO3-NO3... - The lithium-copper battery with the functional layer showed a significant new reduction current peak near 1.75V, which is mainly attributed to the promotion of pre-adsorbed NO3 by BaTiO3. - The reductive decomposition of anions. This will allow for the introduction of inorganic species (such as Li3N, Li2O, etc.) into the SEI during subsequent interfacial phase regulation, thereby improving interfacial phase stability and kinetic performance. For example... Figure 6 As shown in a, the deposition regime is 0.5 mA / cm³. 2 The current density deposited on the copper foil is 1 mAh / cm². 2 The lithium deposited in the original lithium-copper battery exhibits a poor lithium dendrite morphology, characterized by loose and porous structure. For example... Figure 6 As shown in b, using BaTiO3-NO3 - The lithium deposited in the functional layer of the lithium-copper battery lacks dendrites and exhibits a uniform and dense morphology. For example... Figure 7As shown, the lithium deposition / stripping long-cycle performance of lithium-ion batteries was evaluated using a test regime of 0.5 mA / cm². 2 Deposition / exfoliation at current density of 1 mAh / cm 2 The original lithium-to-lithium battery had a cycle life of only about 300 hours, while the battery using BaTiO3-NO3... - The lithium-ion battery with the functional layer exhibited a significantly extended cycle life of nearly 1000 hours. High-voltage full cells assembled with the functional separator containing the functional layer of this embodiment were assembled and evaluated. The charge / discharge voltage range of the full cells was 2.0 V to 4.7 V. The batteries were first formed by cycling 3 times at a low rate of 0.1C, and then subjected to long-term cycle testing at a 1C rate. Figure 8 As shown, its lithium-rich manganese-based cathode / lithium metal anode battery exhibits excellent cycling performance, retaining 83.7% of its capacity after 450 cycles at 1C rate. The above data comprehensively demonstrate the superior cycling performance of BaTiO3-NO3. - By regulating the composition and structure of the battery interface phase, the functional layer significantly suppresses the formation of lithium dendrites and improves the stability of lithium deposition / stripping at the interface, thereby extending the battery's lifespan.

[0062] Example 2

[0063] A method for preparing a pre-adsorbed anionic ferroelectric material according to the present invention includes the following steps:

[0064] (1) Weigh the target salt Li2SiO3 and add it to deionized water. Mix and stir until the target salt is completely dissolved to obtain an aqueous solution of Li2SiO3 with a concentration of 0.3 g / mL.

[0065] (2) The ferroelectric powder was added to the above-mentioned Li2SiO3 aqueous solution to obtain a mixed solution. The ferroelectric powder was BaTiO3 powder, and the mass fraction of the ferroelectric powder in the mixed solution was 30%. The mixed solution was subjected to high-energy ball milling using a planetary ball mill. The ball milling media was zirconia balls, the ball-to-material ratio was 6:1, and the ball milling speed was 1000 rpm. After ball milling for 2 hours, high-speed centrifugation was performed at a speed of 10000 r / min to obtain a solid product, namely solid BaTiO3-SiO3. 2- product.

[0066] (3) The solid product obtained above was baked in a forced-air oven at 120°C for 15 hours to remove the remaining solvent. After cooling, the product was crushed and ground in a mortar and pestle to obtain pre-adsorbed SiO3. 2- Primary product powder of anionic BaTiO3 ferroelectric materials.

[0067] (4) The primary product powder obtained above is placed in a tube furnace with a high-purity nitrogen atmosphere (purity ≥ 99.999%). The temperature is first increased from room temperature to 120°C at a heating rate of 4°C / min and held for 10 hours. Then, the temperature is increased to 280°C at a heating rate of 2°C / min and held for 20 hours. Finally, it is naturally cooled to room temperature to obtain the pre-adsorbed anionic ferroelectric material, i.e., pre-adsorbed SiO3. 2- Anionic BaTiO3 ferroelectric material powder.

[0068] The pre-adsorbed anionic ferroelectric material prepared in this embodiment was characterized by SEM combined with EDS, and the results are as follows: Figure 9 As shown in the figure. The results indicate that, in addition to Ba, Ti, and O elements, the pre-adsorbed anionic ferroelectric material is also modified with Si-containing species on the surface of the powder particles. Surface XPS analysis of this pre-adsorbed anionic ferroelectric material yielded the following full spectrum: Figure 10 As shown, in addition to Ba, Ti, and O peaks, the full spectrum also exhibits a significant Si peak, further verifying the adsorption of Si-containing species on its surface. The apparent zeta potential was measured for both the original BaTiO3 powder and the pre-adsorbed anionic ferroelectric material prepared in this example, and the results are as follows: Figure 11 As shown, the apparent zeta potential of the pre-adsorbed anionic ferroelectric material prepared in this embodiment is -20.8 mV, which is significantly lower than that of the original BaTiO3 powder. This indicates the presence of negatively charged SiO3. 2- The species were adsorbed onto the surface of the BaTiO3 powder.

[0069] The pre-adsorbed anionic ferroelectric material prepared in this embodiment was prepared into a slurry. Specifically, the pre-adsorbed anionic ferroelectric material and PVDF binder were mixed at a mass ratio of 9:1 and dissolved in an appropriate amount of NMP solution. The mixture was stirred until a uniform slurry was obtained, which was then coated onto the surface of a PP membrane. After drying, a pre-adsorbed anionic ferroelectric material-based functional layer, namely pre-adsorbed SiO3, was obtained on the surface of the PP membrane. 2- BaTiO3-based functional layer, abbreviated as BaTiO3-SiO3 2- The functional layer was then used to prepare a functional membrane coated with a pre-adsorbed anion-based ferroelectric material functional layer. Figure 12 As shown, SEM and EDS together demonstrate that the synthesized functional layer contains BaTiO3 and SiO3. 2- .

[0070] The functional membrane containing the functional layer described above is assembled into a lithium-copper battery. The cross-sectional morphology of the deposited lithium is as follows. Figure 13 As shown, the deposition regime was 3 mA / cm². 2The current density deposited on the copper foil is 3 mAh / cm². 2 Lithium, such as Figure 13 As shown in Figure a, the deposited lithium in the original lithium-copper battery exhibits an uneven morphology, such as... Figure 13 As shown in b, using BaTiO3-SiO3 2- The lithium deposited in the functional layer of the lithium-copper battery exhibits a uniform and dense morphology. Furthermore, the lithium-lithium battery was evaluated at an ultra-high current density (10 mA / cm²). 2 The lithium deposition / stripping long-cycle performance under the following conditions was tested at 10 mA / cm². 2 Deposition / exfoliation at current density of 1 mAh / cm 2 Lithium, such as Figure 14 As shown, compared to the original lithium-ion battery sample, the use of BaTiO3-SiO3... 2- The functional layer of the lithium-ion battery exhibited a significantly extended cycle life. The above data collectively demonstrate that BaTiO3-SiO3... 2- The functional layer significantly improves the stability of lithium deposition / stripping at the interface by regulating the composition structure of the battery interface phase, thereby extending the battery's lifespan.

[0071] Comparative Example 1

[0072] A method for preparing a pre-adsorbed anionic ferroelectric material is basically the same as the preparation method in Example 1, except that in step (2), the ball-to-material ratio is 10:1.

[0073] The pre-adsorbed anionic ferroelectric material prepared in this comparative example was used to prepare a slurry according to the method in Example 1, and then coated onto the surface of a PP membrane to prepare pre-adsorbed NO3. - The surface and cross-sectional morphology of the BaTiO3-based functional layer are as follows: Figure 15 and Figure 16 As shown, pre-adsorbed NO3 - The BaTiO3 powder exhibited severe agglomeration and could not be uniformly and densely distributed on the surface of the PP membrane.

[0074] Comparative Example 2

[0075] A method for preparing a pre-adsorbed anionic ferroelectric material is basically the same as the preparation method in Example 1, except that in step (2), the ball-to-material ratio is 2:1.

[0076] The pre-adsorbed anionic ferroelectric material prepared in this comparative example was used to prepare a slurry according to the method in Example 1, and then coated onto the surface of a PP membrane to prepare pre-adsorbed NO3. - The surface and cross-sectional morphology of the BaTiO3-based functional layer are as follows: Figure 17 and Figure 18 As shown, pre-adsorbed NO3- The BaTiO3 powder did not exhibit significant agglomeration and could be uniformly distributed on the surface of the PP membrane.

[0077] High-voltage full cells with functional separators incorporating the aforementioned functional layers were assembled and evaluated. The charge / discharge voltage range of the full cells was 2.0V to 4.7V. The cells were first formed by cycling three times at a low rate of 0.1C, and then subjected to long-term cycle testing at a 1C rate. Figure 19 As shown, its lithium-rich manganese-based cathode / lithium metal anode battery exhibited 83.4% capacity retention after 250 cycles at 1C rate. Compared to Example 1, its relatively poor cycling performance may be attributed to the lower ball-to-material ratio (2:1) during planetary ball milling, resulting in insufficient and weak piezoelectric potential on the ferroelectric material surface, thus affecting its resistance to NO3. - Anion capture.

[0078] Comparative Example 3

[0079] A method for preparing a pre-adsorbed anionic ferroelectric material is basically the same as the preparation method in Example 1, except that in step (4), the temperature is first increased from room temperature to 120°C at a heating rate of 3°C / min and held for 8 hours, then increased to 400°C at a heating rate of 3°C / min and held for 12 hours, and then naturally cooled to room temperature to finally obtain the pre-adsorbed anionic ferroelectric material, namely, pre-adsorbed NO3. - Anionic BaTiO3 ferroelectric materials.

[0080] The pre-adsorbed anionic ferroelectric material prepared in this comparative example was used to prepare a slurry according to the method in Example 1, and then coated onto the surface of a PP membrane to prepare pre-adsorbed NO3. - A BaTiO3-based functional layer was used. High-voltage full cells with functional separators containing this layer were assembled and evaluated. The charge / discharge voltage range of the full cells was 2.0V–4.7V. The cells were first formed by cycling three times at a low rate of 0.1C, and then subjected to long-term cycling tests at a 1C rate. Figure 20 As shown, its lithium-rich manganese-based cathode / lithium metal anode battery exhibited 81.2% capacity retention after 300 cycles at 1C rate. Compared to Example 1, its relatively poor cycling performance may be attributed to the excessively high heating rate (3°C / min) and excessively high temperature (400°C), leading to the adsorption of NO3 on the ferroelectric material surface. - They disappear upon thermal decomposition, thereby reducing the content of pre-adsorbed anions on the surface of ferroelectric materials.

[0081] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention using the methods and techniques disclosed above, or modify them into equivalent embodiments with equivalent changes, without departing from the spirit and technical essence of the present invention. Therefore, any simple modifications, equivalent substitutions, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall still fall within the protection scope of the technical solutions of the present invention.

Claims

1. A method for preparing a pre-adsorbed anion-type ferroelectric material, characterized in that, Includes the following steps: (1) Add the target salt to water and mix and stir until dissolved to obtain the target salt solution; (2) Add the ferroelectric powder to the above target salt solution to obtain a mixture, wherein the mass fraction of the ferroelectric powder in the mixture is 20% to 50%, and the mixture is ball-milled at a ball-to-material ratio of 4 to 8:1 and a ball-milling speed of 600 r / min to 1200 r / min. After ball milling, vacuum filtration or centrifugation is performed to obtain a solid product. (3) The solid product obtained above is baked at 80℃~120℃, cooled, crushed and ground to obtain primary product powder; (4) The primary product powder obtained above is heated to 100℃~120℃ at a heating rate of 1℃ / min~5℃ / min under an inert atmosphere and held for 2h~12h. Then, it is heated to 250℃~350℃ at a heating rate of 1℃ / min~2℃ / min and held for 10h~24h. After cooling, a pre-adsorbed anion ferroelectric material is obtained. In step (1), the target salt is one or more salts containing anions, and the anion is NO3. - NO2 - NO - SO4 2- SO3 2- PO4 3- PO3 3- PO2 3- BO3 3- BO2 3- SiO3 2- SiO2 2- ClO4 - ClO3 - ClO2 - ,ClO - BrO4 - BrO3 - BrO2 - BrO - IO4 - IO3 - IO2 - and IO - One of them.

2. The method for preparing pre-adsorbed anionic ferroelectric materials according to claim 1, characterized in that, In step (2), the ferroelectric powder includes one or more of barium titanate, lithium niobate, bismuth ferrite, bismuth titanate, (Ba x1 Ca y1 Sr z1 )(Ti x2 Zr y2 Sn z2 )O3, Na x3 K y3 NbO3, PbZr x4 Ti y4 O3, and KTa x5 Nb y5 O3, where in (Ba x1 Ca y1 Sr z1 )(Ti x2 Zr y2 Sn z2 )O3, 0.5 < x1 < 1, y1 > 0, z1 > 0, y1 + z1 = 1 - x1, 0.5 < x2 < 1, y2 > 0, z2 > 0, y2 + z2 = 1 - x2, in Na x3 K y3 NbO3, 0 < x3 < 1, y3 = 1 - x3, in PbZr x4 Ti y4 O3, 0 < x4 < 1, y4 = 1 - x4, and in KTa x5 Nb y5 O3, 0 < x5 < 1, y5 = 1 - x5.

3. The method for preparing pre-adsorbed anionic ferroelectric materials according to claim 1 or 2, characterized in that, In step (2), the ball milling media used includes one or more of zirconium oxide balls, tungsten carbide balls, stainless steel balls, corundum balls, nylon balls and polytetrafluoroethylene balls. The ball milling time is 1h to 5h, and the centrifugal treatment speed is 5000r / min to 15000r / min.

4. The method for preparing pre-adsorbed anionic ferroelectric materials according to claim 1 or 2, characterized in that, In step (3), the baking time is 2h to 24h.

5. The method for preparing pre-adsorbed anionic ferroelectric materials according to claim 1 or 2, characterized in that, In step (4), the inert atmosphere is high-purity argon and / or high-purity nitrogen, wherein the purity of the high-purity argon is ≥99.999% and the purity of the high-purity nitrogen is ≥99.999%.

6. A pre-adsorbed anionic ferroelectric material prepared by the method described in any one of claims 1 to 5.

7. A functional layer, characterized in that, The functional layer is a layered structure made by mixing the pre-adsorbed anionic ferroelectric material as described in claim 6 with an adhesive.

8. The application of the functional layer as described in claim 7 in the field of rechargeable batteries.

9. The application according to claim 8, characterized in that, The rechargeable battery includes one or more of the following: lithium-ion battery, lithium metal battery, lithium-sulfur battery, sodium-ion battery, and zinc-ion battery.

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