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CN-122025816-A - Functionalized MOF (metal oxide film) limited lithium nitrate additive and application thereof in lithium metal battery electrolyte

CN122025816ACN 122025816 ACN122025816 ACN 122025816ACN-122025816-A

Abstract

The invention discloses a functionalized MOF domain-limited lithium nitrate additive and application thereof in lithium metal battery electrolyte, and belongs to the technical field of lithium metal batteries. The modified electrolyte of the additive can obviously improve the multiplying power performance, long-cycle stability and low-temperature adaptability of the lithium metal battery, can still stably circulate at the extremely low temperature of minus 30 ℃ and provides a new scheme for the practical application of the lithium metal battery with high energy density.

Inventors

  • CAI GUORUI
  • ZHAO YULONG

Assignees

  • 中国科学技术大学

Dates

Publication Date
20260512
Application Date
20260319

Claims (9)

  1. 1. The preparation method of the lithium nitrate additive of the functionalized MOF limit domain is characterized by comprising the following steps: Adding zirconium tetrachloride and 2-amino-1, 4-dicarboxylic acid into a mixed system of N, N-dimethylformamide and acetic acid, adding deionized water after ultrasonic dispersion is uniform, reacting for 12-48 hours at 100-150 ℃, cooling, centrifugally collecting a product, washing with DMF and ethanol, drying, and vacuum-activating at 150-200 ℃ to obtain an amino-functional MOF material UIO-66-NH 2 ; Step 2, performing ultrasonic dispersion on the UiO-66-NH 2 obtained in the step 1 in an organic solvent dissolved with LiNO 3 to obtain a mixed system; Step 3, stirring the mixed system obtained in the step 2 at 20-60 ℃ for 6-48 hours to enable LiNO 3 to enter MOF pore channels; And 4, vacuum drying the solid powder obtained in the step 3 at 80-120 ℃ for 6-24 hours to obtain the UiO-66-NH 2 -LiNO 3 composite material, namely the lithium nitrate additive of the functionalized MOF limit domain.
  2. 2. The process according to claim 1, wherein in step 1, the molar ratio of zirconium tetrachloride to 2-amino-1, 4-dicarboxylic acid is 1:1.
  3. 3. The preparation method according to claim 2, wherein the consumption of the raw materials in the step 1 is that 50-75 mL of N, N-dimethylformamide, 8.85-17.7 mL of acetic acid and 50 mu L of deionized water are added to 1 mmol zirconium tetrachloride based on the molar ratio of 1:1 of zirconium tetrachloride to 2-amino-1, 4-dicarboxylic acid.
  4. 4. The preparation method of claim 1, wherein in the step 2, the mass ratio of UiO-66-NH 2 to LiNO 3 is 0.25-19:1.
  5. 5. The method according to claim 1 or 4, wherein in step 2, the concentration of LiNO 3 in the organic solvent is 0.1 to 2.0M.
  6. 6. The preparation method according to claim 1, wherein in the step 2, the organic solvent is one or more selected from ethylene glycol dimethyl ether and acetonitrile.
  7. 7. A functionalized MOF domain limited lithium nitrate additive, characterized in that the additive is prepared by the preparation method of any one of claims 1-6.
  8. 8. The lithium metal battery electrolyte is characterized by comprising an ester solvent, a lithium salt and the functionalized MOF domain-limited lithium nitrate additive according to claim 7, wherein the additive accounts for 0.1-20wt% of the total mass of the electrolyte.
  9. 9. A lithium metal battery comprising a lithium metal anode, a cathode, and the electrolyte of claim 8.

Description

Functionalized MOF (metal oxide film) limited lithium nitrate additive and application thereof in lithium metal battery electrolyte Technical Field The invention belongs to the technical field of lithium metal batteries, and particularly relates to a lithium nitrate additive for a functionalized metal-organic framework (MOF) limit domain and application of the lithium nitrate additive in lithium metal battery electrolyte. Background With the increasing demands of electric vehicles, portable electronic devices, large-scale energy storage and other fields for high-energy-density energy storage devices, lithium metal batteries are recognized as the core development direction of the next-generation high-specific-energy battery system by virtue of the ultrahigh theoretical capacity (3830 mAh g -1) of lithium metal cathodes and the lowest electrochemical reduction potential (-3.04V vs. SHE). However, the inherent problem of poor interfacial stability between the lithium metal negative electrode and the electrolyte severely restricts the commercial application of lithium metal batteries. In the charge-discharge cycle process, lithium metal is easy to generate continuous and uncontrollable side reaction with the traditional commercial ester electrolyte, so that Solid Electrolyte Interface (SEI) on the surface of an electrode is repeatedly broken, unevenly grows and is continuously reconstructed, active lithium and the electrolyte are consumed in a large amount, and a series of problems of rapid capacity decay, obviously shortened cycle life and the like of the battery are caused. Electrolyte additives are efficient technical means for regulating and controlling SEI composition and structure and improving electrode/electrolyte interface compatibility. Lithium nitrate (LiNO 3) is used as a classical and efficient film forming additive, so that a lithium metal anode interface can be effectively stabilized, and the cycle performance of the battery is improved. However, the solubility of LiNO 3 in an ester electrolyte is extremely low, and the root of LiNO 3 is that a very strong electrostatic interaction exists between Li + and NO 3-, so that the LiNO 3 is difficult to fully dissociate in an ester system. The intrinsic defect greatly limits the practical application of LiNO 3 in commercial ester electrolyte, so that the LiNO 3 is difficult to fully play the roles of film forming and interface modification. The existing technical route for improving the solubility of LiNO 3 has obvious limitations that 1) simple physical load can only realize surface adsorption and can not fundamentally solve the problem of intrinsic low solubility of LiNO 3 in ester electrolyte, and 2) high-donor-number cosolvent (such as dimethyl sulfoxide and the like) is introduced to improve the solubility to a certain extent, but the cosolvent has high chemical activity, and is easy to cause severe side reaction with a lithium metal cathode to damage the interface stability, so that the performance attenuation of the battery is aggravated. Therefore, on the premise of not introducing a high-activity cosolvent and not damaging the interface stability, the development of an electrolyte additive capable of remarkably improving the solubility and the utilization rate of LiNO 3 in an ester electrolyte is a key technical problem to be solved in the current lithium metal battery field. Disclosure of Invention In order to overcome the problems of the prior art, the invention provides a functionalized MOF domain-limited lithium nitrate (LiNO 3) additive and application thereof in lithium metal battery electrolyte. According to the invention, liNO 3 is limited in the sub-nanometer pore canal of the amino functional MOF, and the dissociation behavior of LiNO 3 is accurately regulated and controlled by means of weak interaction between the amino functional group modified on the surface of the pore canal and NO 3-, so that the problem of intrinsic low solubility of LiNO 3 in an ester electrolyte is fundamentally solved, and the interface side reaction risk caused by introducing a high-activity cosolvent is avoided. The invention aims to provide an electrolyte additive with excellent performance, which improves the stability of an electrode-electrolyte interface of a lithium metal battery, further remarkably improves the cycle stability and the rate capability of the lithium metal battery, and enhances the suitability of the lithium metal battery in an extremely low-temperature environment. The invention adopts the following technical scheme for realizing the purpose: The invention firstly provides a preparation method of a LiNO 3 additive of a functionalized MOF (metal oxide semiconductor field) limiting domain, which comprises the following steps: step 1 preparation of UiO-66-NH 2 Material Adding zirconium tetrachloride and 2-amino-1, 4-dicarboxylic acid into a mixed system of N, N-Dimethylformamide (DMF) and acetic acid, performing ultrasonic dispersion unti