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CN-121990541-A - Silane modified zirconium phosphate electrolyte additive and preparation method thereof

CN121990541ACN 121990541 ACN121990541 ACN 121990541ACN-121990541-A

Abstract

The invention relates to the technical field of electrolyte additives, in particular to a preparation method of a silane modified zirconium phosphate electrolyte additive, which comprises the following steps of S1, introducing a zirconium source and a phosphorus source into a high-pressure synthesis kettle, fully stirring and mixing, and performing hydrothermal reaction to obtain nano zirconium phosphate; S2, dispersing the nano zirconium phosphate of the adjusting mechanism obtained in the step S1 in absolute ethyl alcohol, then introducing the absolute ethyl alcohol into a main chamber of a surface modification device, adding a silane coupling agent into the main chamber of the adjusting mechanism to enable a mixed solution to be primarily mixed in the main chamber of the adjusting mechanism, S3, after primary mixing, enabling the mixed solution at the bottom of the main chamber of the adjusting mechanism to be modified under the combined action of an electric field and ultrasound in an acousto-electric coupling module of the adjusting mechanism, and S4, after modification is completed, obtaining the silane modified zirconium phosphate electrolyte additive. The preparation method provided by the invention can efficiently and stably obtain the silane modified zirconium phosphate with greatly reduced surface hydroxyl coverage rate, and has good application value.

Inventors

  • LU ZHIJUN
  • WU HUIZHEN
  • CAO YONGQING
  • ZHANG XU
  • ZOU QIANQIAN
  • SHI DONGYI

Assignees

  • 福建瑞森新材料股份有限公司

Dates

Publication Date
20260508
Application Date
20260210

Claims (10)

  1. 1. The preparation method of the silane modified zirconium phosphate electrolyte additive is characterized by comprising the following steps of: S1, introducing a zirconium source and a phosphorus source into a high-pressure synthesis kettle, fully stirring and mixing, performing hydrothermal reaction for 12-24 hours at 160-200 ℃, and centrifugally washing, filtering and drying reaction products to obtain nano zirconium phosphate; S2, dispersing the nano zirconium phosphate obtained in the S1 in absolute ethyl alcohol, then introducing the absolute ethyl alcohol into a main chamber (11) of a surface modification device, and adding a silane coupling agent into the main chamber (11), so that the mixed solution is primarily mixed under the action of a microwave stirring module (2) in the main chamber (11) at 60-80 ℃; S3, after preliminary mixing, the microwave stirring module (2) continuously operates, and meanwhile, mixed solution at the bottom of the main cavity (11) continuously flows through the acoustic-electric coupling module (3) from bottom to top and then flows back into the main cavity (11) from the upper part of the main cavity (11), and the mixed solution is modified in the acoustic-electric coupling module (3) under the combined action of an electric field and ultrasound; and S4, after modification is finished, centrifugally drying the mixed solution obtained in the step S3 to obtain the silane modified zirconium phosphate electrolyte additive.
  2. 2. The method according to claim 1, wherein the surface modifying means comprises; -a main body (1), the centre of which has said main chamber (11); The microwave stirring module (2) is arranged at the top of the main body (1), extends into the cavity from the top of the main body (1) and is used for stirring and microwave heating of the mixed solution in the main cavity (11); The acoustic-electric coupling module (3) comprises an ultrasonic assembly (31), an electric field generating assembly (32) and a plurality of reaction tubes (33), wherein the reaction tubes (33) are distributed in the vertical direction and are arranged at the outer side of the main body (1) at intervals, the bottom and the top of each reaction tube (33) are communicated with the main cavity (11) through a conveying pipeline (34), the ultrasonic assembly (31) is correspondingly arranged at the top of each reaction tube (33) and is used for carrying out ultrasonic treatment on mixed solution in each reaction tube (33), the electric field generating assembly (32) is sleeved on each reaction tube (33), arc-shaped electrodes (321) distributed in the vertical direction in the electric field generating assembly (32), and a plurality of arc-shaped electrodes (321) are arranged, and the polarities of the adjacent arc-shaped electrodes (321) are opposite.
  3. 3. The method according to claim 2, wherein the electric field generating assembly (32) comprises a fixed ring sleeve (322), the arc-shaped electrode (321), a sliding frame plate (323) and an adjusting mechanism (324), the fixed ring sleeve (322) comprises an inner ring wall (3221) and an outer ring wall (3222), a mounting cavity (3223) is formed between the inner ring wall (3221) and the outer ring wall (3222), one end of the sliding frame plate (323) is hinged with the inner ring wall (3221), the other end of the sliding frame plate (323) is in sliding connection with the outer ring wall (3222), the arc-shaped electrode (321) is arranged in the mounting cavity (3223) at intervals, the adjusting mechanism (324) is arranged at two ends of the arc-shaped electrode (321) and is in sliding connection with one side, close to the outer ring wall (3222), of the sliding frame plate (323), and the adjusting mechanism (324) drives the sliding frame plate (323) to rotate so as to adjust the mounting position of the arc-shaped electrode (321) in the mounting cavity (3223).
  4. 4. The method according to claim 3, wherein the adjusting mechanism (324) comprises a spacing sliding wall (3241), an adjusting rod (3242) and a connecting rod (3243), the arc-shaped electrode (321) is connected with the middle of the spacing sliding wall (3241), an extending column (3244) is arranged on one side of the spacing sliding wall (3241) in the length direction, a sliding groove (3245) is correspondingly arranged on the sliding frame plate (323), the extending column (3244) is in sliding connection with the sliding groove (3245), the adjusting rod (3242) extends into the mounting cavity (3223) from the outer side of the outer annular wall (3222), and two ends of the connecting rod (3243) are hinged with one side of the spacing sliding wall (3241) where the extending column (3244) is arranged and one end of the adjusting rod (3242) extending into the mounting cavity (3223) respectively.
  5. 5. The method of claim 4, wherein the adjusting rod (3242) is a screw, a rotatable connecting sleeve (3246) is disposed at one end of the adjusting rod (3242) extending into the mounting cavity (3223), and the connecting rod (3243) is hinged to the connecting sleeve (3246).
  6. 6. The method of manufacturing a semiconductor device according to claim 4, wherein the adjusting rod (3242) is connected to two connecting rods (3243) simultaneously, and the partition walls (3241) connected to adjacent connecting rods (3243) are connected to the sides of the arc-shaped electrodes (321) having different polarities.
  7. 7. The preparation method of the microwave stirring module (2) is characterized by comprising a stirring assembly (21), a microwave assembly (22), a driving motor (23) and a driving rod (24), wherein the driving motor (23) is arranged at the top of the main body (1), the driving rod (24) is connected with the output end of the driving motor (23) and extends into the main cavity (11), the microwave assembly (22) extends into the main cavity (11) from the top of the main body (1) and is sleeved on the outer edge of the driving rod (24), and the stirring assembly (21) is provided with one end, far away from the driving motor (23), of the driving rod (24) and extends upwards along the outer wall of the microwave assembly (22).
  8. 8. The method according to claim 7, wherein the microwave assembly (22) comprises a microwave annular wall (221), a microwave generator (222), a spiral duct (223) and a transmitting window (224), the microwave annular wall (221) extends downwards from the top of the main chamber (11), the microwave generator (222) is arranged on the top of the microwave annular wall (221), the spiral duct (223) is embedded in the microwave annular wall (221), the transmitting window (224) is arranged on the microwave annular wall (221), and the spiral duct (223) conducts microwaves generated by the microwave generating assembly into the main chamber (11) through the transmitting window (224); The stirring assembly (21) comprises a main frame plate (211), a support plate (212), abutting plates (213) and connecting plates (214), wherein the middle part of the main frame plate (211) is connected with the driving rod (24), the support plate (212) vertically extends upwards from two ends of the main frame plate (211), the abutting plates (213) vertically extend upwards from the middle part of the main frame plate (211) along the two sides of the outer edge of the microwave annular wall (221), the connecting plates (214) are arranged between the support plate (212) and the abutting plates (213), and when the driving rod (24) drives the main frame plate (211) to rotate, the abutting plates (213) are driven to rotate around the outer surface of the microwave annular wall (221).
  9. 9. The preparation method of the nano zirconium phosphate, as set forth in claim 1, characterized in that in the step S1, the zirconium source comprises any one of zirconium oxychloride or zirconium oxynitrate, the phosphorus source comprises any one of diammonium hydrogen phosphate or monoammonium dihydrogen phosphate, the molar ratio of the zirconium source to the phosphorus source is 1:1-2.5, and in the step S2, the silane coupling agent comprises gamma-aminopropyl triethoxysilane, and the addition amount of the silane coupling agent is 12% -20% of the mass of the nano zirconium phosphate.
  10. 10. A silane modified zirconium phosphate electrolyte additive prepared by the preparation method according to any one of claims 1 to 9, which is characterized in that the particle size is 30 to 80nm.

Description

Silane modified zirconium phosphate electrolyte additive and preparation method thereof Technical Field The invention relates to the technical field of electrolyte additives, in particular to a silane modified zirconium phosphate electrolyte additive and a preparation method thereof. Background Film forming additives such as traditional Vinylene Carbonate (VC) and fluoroethylene carbonate (FEC) can effectively optimize SEI/CEI film structure and improve interface stability, but the effect is limited to the surface of an electrode, and thermal decomposition reaction of LiPF 6 at above 60 ℃ cannot be inhibited from the source. PF 5 generated by thermal dissociation of LiPF 6 reacts with trace water to generate HF, which causes dissolution of transition metal of positive electrode and corrosion of interface, resulting in capacity loss of generally not less than 5% after 7 days of high-temperature storage, which becomes a common bottleneck of high-energy density battery system such as high-nickel ternary system. The current mainstream scheme for inhibiting the decomposition of LiPF 6 in industry is to adopt soluble organosilicon/phosphorus compounds (such as TTSPI and TMSNCS), but the additive is subjected to irreversible coordination reaction with PF 5 through Si-O/P/B bond (such as TTSPI+PF 5 →product), is continuously consumed and cannot be regenerated, and under the working condition of long-term storage at 60 ℃ for more than 14 days or over 80 ℃, the decomposition of LiPF 6 is accelerated after the additive is consumed, and a capacity fading curve shows a characteristic of 'slow before steep', so that the 10-year service life requirement of a vehicle battery is difficult to meet. Meanwhile, in order to avoid the interface compatibility risks (such as adsorption deactivation and agglomeration sedimentation) with inorganic fillers, pure organic additive systems are commonly adopted in industry, but the key performance gain brought by inorganic matters is sacrificed, namely, the high heat capacity heat absorption and physical barrier capability of the fillers such as Al 2O3、Mg(OH)2 are lacked, the initial temperature rise inhibition effect of thermal runaway is limited, the 'rigid framework' formed in SEI/CEI by the particles such as SiO 2 and zirconium phosphate is lacked, the interfacial film modulus is low (< 1 GPa), the film rupture under the conditions of lithium dendrite penetration and high volume expansion is difficult to inhibit, the non-consumption buffer effect of inorganic surface P-OH/Al-OH groups on HF is lost, and the acidity rebound after long-term storage accelerates the positive electrode corrosion. These deficiencies make the cell significantly performance ceiling in terms of thermal safety, long cycling (especially silicon negative electrode systems), and wide temperature range adaptability. Zirconium phosphate itself has a regulatable interlayer structure, and can be embedded into SEI/CEI film to form a rigid mechanical skeleton, so as to effectively inhibit lithium dendrite penetration and film rupture under high volume expansion. Meanwhile, the zirconium phosphate is electrochemically inert, so that the zirconium phosphate is still stable in a high-voltage window, and is suitable for a high-nickel/high-voltage system. Thus, zirconium phosphate has potential as an electrolyte additive. However, the zirconium phosphate is easy to form hydrogen bonds with the solvent to cause serious agglomeration due to the rich P-OH groups on the surface of the zirconium phosphate, sedimentation (the sedimentation rate is more than 70%) occurs after standing for 24 hours, a stable dispersion system cannot be formed, and micron-sized agglomerates formed by the zirconium phosphate are difficult to embed into an SEI/CEI film when the zirconium phosphate is directly applied, and can block electrode pores to increase interface impedance, so that the battery performance is adversely affected. Accordingly, there is a need for further improvements in zirconium phosphate that can accommodate inorganic filler systems and inhibit decomposition of LiPF 6. Disclosure of Invention The invention aims to solve the technical problem of providing a silane modified zirconium phosphate electrolyte additive and a preparation method thereof, and solves the problem that the existing electrolyte additive cannot adapt to an inorganic filler system. In order to solve the technical problems, the technical scheme adopted by the invention is that the preparation method of the silane modified zirconium phosphate electrolyte additive comprises the following steps: S1, introducing a zirconium source and a phosphorus source into a high-pressure synthesis kettle, fully stirring and mixing, performing hydrothermal reaction for 12-24 hours at 160-200 ℃, and centrifugally washing, filtering and drying reaction products to obtain nano zirconium phosphate; s2, dispersing the nano zirconium phosphate obtained in the step S1 in absolute ethyl a