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CN-122025719-A - Titanium/bismuth/carbon nano material composite additive, preparation method and application thereof, and all-vanadium redox flow battery electrolyte

CN122025719ACN 122025719 ACN122025719 ACN 122025719ACN-122025719-A

Abstract

The invention discloses a titanium/bismuth/carbon nano material composite additive, a preparation method and application thereof, and an all-vanadium redox flow battery electrolyte, wherein the composite additive comprises a titanium-containing compound, a bismuth-containing compound and a carbon nano material which are mixed and dispersed in a dispersion liquid; wherein the mass ratio of the titanium-containing compound to the bismuth-containing compound to the carbon nanomaterial is 0.8-2: 0.5-1: 5, a step of; according to the invention, the obtained composite additive is added into the electrolyte of the all-vanadium redox flow battery, the battery is assembled, and the composite additive can play a synergistic catalysis role on the electrode side and the proton exchange membrane side under the action of a flow field and an electric field along with continuous charge and discharge of the battery, so that the battery performance is improved.

Inventors

  • Lai Fuming
  • SUN XIUQIANG

Assignees

  • 四川晟坤新能科技有限公司

Dates

Publication Date
20260512
Application Date
20260403

Claims (9)

  1. 1. The titanium/bismuth/carbon nano material composite additive is characterized by comprising a titanium-containing compound, a bismuth-containing compound and a carbon nano material which are mixed and dispersed in a dispersion liquid, wherein the mass ratio of the titanium-containing compound to the bismuth-containing compound to the carbon nano material is 0.8-2:0.5-1:5.
  2. 2. The titanium/bismuth/carbon nanomaterial composite additive of claim 1, wherein the titanium-containing compound is obtained by mixing one or two or more of titanium dioxide, titanium chloride and titanium nitride in any proportion, the bismuth-containing compound is obtained by mixing one or two or more of bismuth nitrate, bismuth sulfate and bismuth oxide in any proportion, and the carbon nanomaterial is obtained by mixing one or two of carbon nanotubes and graphene in any proportion.
  3. 3. The preparation method of the titanium/bismuth/carbon nanomaterial composite additive of any one of claims 1 to 2, characterized by comprising the following steps: Adding a titanium-containing compound and a bismuth-containing compound into the carbon nanomaterial dispersion liquid, and carrying out ultrasonic treatment to obtain a uniform dispersion liquid; and carrying out hydrothermal reaction on the uniform dispersion liquid, and cooling to obtain the composite additive.
  4. 4. The method for preparing the titanium/bismuth/carbon nano material composite additive according to claim 3, wherein the hydrothermal reaction temperature is 150-200 ℃ and the reaction time is 5-12 h.
  5. 5. The use of the titanium/bismuth/carbon nanomaterial composite additive of any of claim 1, wherein the composite additive is used as an electrolyte additive for an all-vanadium flow battery.
  6. 6. The electrolyte of the all-vanadium redox flow battery containing the titanium/bismuth/carbon nano material composite additive is characterized in that the titanium/bismuth/carbon nano material composite additive according to any one of claims 1-2 is added into the electrolyte of the all-vanadium redox flow battery and fully and uniformly stirred, and the mass concentration of the composite additive in the electrolyte is 0.01-wt% to 0.5-wt%.
  7. 7. The titanium/bismuth/carbon nano material composite additive all-vanadium redox flow battery electrolyte according to claim 6, wherein the total vanadium ion concentration in the all-vanadium redox flow battery electrolyte is 1.5-4.0 mol/L.
  8. 8. The titanium/bismuth/carbon nano material composite additive all-vanadium redox flow battery electrolyte according to claim 6, wherein the concentration of sulfate radical in the all-vanadium redox flow battery electrolyte is 3.0-5.0 mol/L.
  9. 9. The electrolyte of the vanadium redox flow battery containing the titanium/bismuth/carbon nano material composite additive, which is disclosed in claim 6, wherein the mass concentration of the composite additive in the electrolyte is 0.04 wt%.

Description

Titanium/bismuth/carbon nano material composite additive, preparation method and application thereof, and all-vanadium redox flow battery electrolyte Technical Field The invention relates to the technical field of battery electrolyte, in particular to a titanium/bismuth/carbon nano material composite additive, a preparation method and application thereof, and an all-vanadium redox flow battery electrolyte. Background Electrochemical energy storage is a high-efficiency stable energy conversion energy storage system, and has become an indispensable bridge between clean renewable energy and stable energy output systems. Among the electrochemical energy storage technologies, the all-Vanadium Redox Flow Battery (VRFB) has excellent application prospect in the fields of large-scale renewable energy storage, peak clipping and valley filling of a power grid and the like due to the advantages of excellent cycle stability, cycle life, high safety, easy expansibility, environmental friendliness and the like. The vanadium redox flow battery is mainly based on reversible oxidation-reduction reaction of vanadium active materials among different valence states, wherein a VO 2+/VO2+ oxidation-reduction pair is arranged on the positive side, a V 2+/V3+ oxidation-reduction pair is arranged on the negative side, and electric energy storage and release are realized. The electrolyte of the all-vanadium redox flow battery is used as a core component of the system, and the performance of the electrolyte directly determines key parameters such as the overall capacity, the cycling stability, the service life and the like of the battery. Under the conditions of long-time operation and high temperature, high-valence vanadium ions are easy to hydrolyze, and V 2O5 precipitation is continuously generated, so that the vanadium active substances are irreversibly consumed, and the capacity of the battery is further reduced. Meanwhile, the problems of low conductivity of the electrolyte, slow oxidation-reduction reaction kinetics speed under high current density and serious electrode polarization condition exist. One of the improvement measures of the all-vanadium redox flow battery is to optimize and modify the electrolyte, and the conductivity, stability, reactivity and electrochemical reaction kinetic rate of the vanadium electrolyte can be fundamentally improved by introducing electrolyte additives, so that the overall performance of the battery is improved. In recent years, a transition metal compound has been attracting attention in the electrochemical field due to its excellent catalytic performance, and a titanium-containing compound, a bismuth-containing compound, or the like as a functional electrolyte additive can improve the rate of redox reaction kinetics of vanadium ions in an electrolyte. However, the transition metal compound used as the electrolyte additive of the all-vanadium redox flow battery can effectively catalyze vanadium active substances to accelerate the electrochemical reaction kinetics, but can still have negative effects on the electrolyte in other aspects. For example, additional metal ions (such as Ti and Bi) can occupy active sites of vanadium ions, so that the intrinsic stability of the electrolyte is reduced, and the internal resistance of the electrolyte is inevitably increased, so that the electrochemical polarization is increased, the voltage efficiency of the battery is reduced, and the overall capacity of the battery is affected. In order to improve the negative influence of the electrolyte additive in the charge and discharge process, a carbon nanomaterial can be introduced into the electrolyte, and the conductivity of the vanadium electrolyte can be improved, the internal resistance of the battery can be reduced, and the overall electrochemical performance of the electrolyte can be further improved due to the excellent electron conduction capability of the carbon nanomaterial. Disclosure of Invention Aiming at the problems existing in the prior art, the invention provides a titanium/bismuth/carbon nano material composite additive, a preparation method and application thereof, and an all-vanadium redox flow battery electrolyte. The technical scheme adopted by the invention is that the titanium/bismuth/carbon nano material composite additive is characterized by comprising a titanium-containing compound, a bismuth-containing compound and a carbon nano material which are mixed and dispersed in a dispersion liquid, wherein the mass ratio of the titanium-containing compound to the bismuth-containing compound to the carbon nano material is 0.8-2:0.5-1:5. Further, the titanium-containing compound is obtained by mixing one or two or more of titanium dioxide, titanium chloride and titanium nitride in any proportion, the bismuth-containing compound is obtained by mixing one or two or more of bismuth nitrate, bismuth sulfate and bismuth oxide in any proportion, and the carbon nanomaterial is obtained by mixing