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CN-122025432-A - Mo-Fe co-doped MnO2Ag-CNTs composite electrode and preparation method and application thereof

CN122025432ACN 122025432 ACN122025432 ACN 122025432ACN-122025432-A

Abstract

The application belongs to the technical field of preparation of new energy materials and super capacitors, and particularly relates to a Mo-Fe co-doped MnO 2 /Ag-CNTs composite electrode, and a preparation method and application thereof. The method comprises the steps of preparing an activated carbon cloth substrate, a deposition solution A and a deposition solution B, mixing the deposition solution A and the deposition solution B to obtain a Mo-Fe-MnO 2 deposition solution, preparing an Ag-CNTs deposition solution, and finally performing electrodeposition alternately in the Mo-Fe-MnO 2 deposition solution and the Ag-CNTs deposition solution. The preparation process provided by the application is simple and controllable, and is easy to prepare the high-performance composite electrode in a large scale. The electrode has unique structure and excellent performance, and the assembled flexible solid PSCSC device has high energy storage density and high-efficiency mechanical energy self-charging capability, and has great application potential in the field of self-energy wearable/implantable microelectronics.

Inventors

  • PENG XINYUAN
  • LIU XINYU
  • YE ZHIGUO

Assignees

  • 南昌航空大学

Dates

Publication Date
20260512
Application Date
20260211

Claims (10)

  1. 1. The preparation method of the Mo-Fe co-doped MnO 2/ Ag-CNTs composite electrode is characterized by comprising the following steps of: placing carbon cloth in concentrated nitric acid for acid activation treatment to obtain an activated carbon cloth substrate; Dissolving MnC 4 H 6 O 4 ·4H 2 O、Na 2 SO 4 and (NH 4 ) 2 Fe(SO 4 ) 2 ·6H 2 O in water to obtain a deposition solution A; Na 2 MoO 4 ·2H 2 O is dissolved in the H 2 SO 4 solution to obtain a deposition solution B; mixing the deposition solution A and the deposition solution B to obtain Mo-Fe-MnO 2 deposition solution; Dispersing agent TNWDIS, carbon nano tube, potassium carbonate and potassium iodide are dissolved in water in turn to obtain black suspension; Adding silver nitrate into the black suspension under the condition of avoiding light until the silver nitrate is completely dissolved, so as to obtain Ag-CNTs deposition solution; And adopting a three-electrode system, taking the carbon cloth substrate as a working electrode, and alternately performing electrodeposition in the Mo-Fe-MnO 2 deposition solution and the Ag-CNTs deposition solution under a constant current condition to obtain the Mo-Fe co-doped MnO 2 /Ag-CNTs composite electrode.
  2. 2. The method according to claim 1, wherein the atomic ratio of Mn, mo and Fe in the Mo-Fe-MnO 2 deposition solution is 210:30:1-5.
  3. 3. The method according to claim 2, wherein the atomic ratio of Mn, mo and Fe in the Mo-Fe-MnO 2 deposition solution is 210:30:2.
  4. 4. The method of claim 1, wherein the mass ratio of carbon dispersant TNWDIS to nanotubes is 0.3-1.2:1; the concentration ratio of iodide ions to silver ions in the Ag-CNTs deposition solution is 200-500:1.
  5. 5. The method according to claim 1, wherein the specific process of electrodeposition alternately in the Mo-Fe-MnO 2 deposition solution and the Ag-CNTs deposition solution is as follows: Taking a carbon cloth substrate as a working electrode, a saturated calomel electrode as a reference electrode, and a carbon rod as a counter electrode, and sequentially and alternately depositing the carbon cloth substrate and the counter electrode in the Mo-Fe-MnO 2 deposition solution for 8min-15min and the Ag-CNTs deposition solution for 1min-3min; the anode deposition times are 3-6 times, and the cathode deposition times are 2-5 times.
  6. 6. The method according to claim 5, wherein the current density at the time of electrodeposition is 1-3 mA/cm 2 and the deposition temperature is 60-80 ℃.
  7. 7. A Mo-Fe co-doped MnO 2 /Ag-CNTs composite electrode prepared by the method of any one of claims 1-6.
  8. 8. The flexible solid-state piezoelectric self-charging asymmetric supercapacitor is characterized by comprising a positive electrode, a negative electrode, a gel electrolyte positioned between the positive electrode and the negative electrode and a flexible packaging layer; The positive electrode is the Mo-Fe co-doped MnO 2 /Ag-CNTs composite electrode of claim 7.
  9. 9. The flexible solid state piezoelectric self-charging asymmetric supercapacitor according to claim 8, wherein the negative electrode is activated carbon cloth, and the gel electrolyte is sodium carboxymethyl cellulose/sodium sulfate gel doped with BaTiO 3 particles; The flexible packaging layer is polyurethane, polyethylene terephthalate or polyimide.
  10. 10. Use of the flexible solid state piezoelectric self-charging asymmetric supercapacitor of any one of claims 8-9 in a wearable electronic device, an implantable medical device, or a self-powered microsystem.

Description

Mo-Fe co-doped MnO 2/Ag-CNTs composite electrode and preparation method and application thereof Technical Field The application belongs to the technical field of preparation of new energy materials and super capacitors, and particularly relates to a Mo-Fe co-doped MnO 2/Ag-CNTs composite electrode, and a preparation method and application thereof. Background The rapid development of flexible wearable/implantable electronic devices has created an urgent need for a miniaturized, high energy density, sustainable power supply system that matches it. The flexible solid super capacitor is regarded as an ideal miniature energy storage device because of the advantages of high power density, rapid charge and discharge, long cycle life, safety, reliability and the like. However, the energy density of the existing super capacitor still needs to be improved, and the energy density of the existing super capacitor depends on an external power supply for periodic charging, so that the application of the super capacitor in a continuous power supply scene is limited. The energy collection function (such as piezoelectric effect) and the energy storage function are integrated into a single device, and the piezoelectric self-charging super capacitor (PSCSC) is constructed, so that the piezoelectric self-charging super capacitor is an effective way for realizing spontaneous collection and storage of mechanical energy. In PSCSC, the properties of the positive electrode material directly determine the energy storage capacity and overall efficiency of the device. Manganese dioxide (MnO 2) is a potential positive electrode material because of the advantages of high theoretical specific capacitance, environmental friendliness, low cost and the like. However, the MnO 2 has low intrinsic conductivity, and under the condition of high active material loading, the utilization rate of active sites is low, and the ion transmission kinetics is slow, so that the actual specific capacitance is far lower than a theoretical value, and the application of the MnO 2 in high-performance PSCSC is severely restricted. Therefore, how to realize uniform and tight combination of the active material and the conductive network on the nano scale under high load by a simple and controllable process, avoid interface resistance, and simultaneously maximize and improve the electrochemical active area and the ion transmission efficiency of the material is still a technical problem facing the field. Disclosure of Invention The invention aims to solve the defects of the prior art, and particularly overcomes the defects of poor conductivity, slow ion transmission and low specific capacitance of MnO 2 -based electrode materials under high load in the prior art, and provides a Mo-Fe co-doped MnO 2/Ag-CNTs composite electrode, and a preparation method and application thereof, wherein the technical scheme is as follows: In a first aspect, the invention provides a preparation method of a Mo-Fe co-doped MnO 2/Ag-CNTs composite electrode, which comprises the following steps: placing carbon cloth in concentrated nitric acid for acid activation treatment to obtain an activated carbon cloth substrate; Dissolving MnC 4H6O4·4H2O、Na2SO4 and (NH 4)2Fe(SO4)2·6H2 O in water to obtain a deposition solution A; Na 2MoO4·2H2 O is dissolved in the H 2SO4 solution to obtain a deposition solution B; mixing the deposition solution A and the deposition solution B to obtain Mo-Fe-MnO 2 deposition solution; Dispersing agent TNWDIS, carbon nano tube, potassium carbonate and potassium iodide are dissolved in water in turn to obtain black suspension; Adding silver nitrate into the black suspension under the condition of avoiding light until the silver nitrate is completely dissolved, so as to obtain Ag-CNTs deposition solution; And adopting a three-electrode system, taking the carbon cloth substrate as a working electrode, and alternately performing electrodeposition in the Mo-Fe-MnO 2 deposition solution and the Ag-CNTs deposition solution under a constant current condition to obtain the Mo-Fe co-doped MnO 2/Ag-CNTs composite electrode. As a further preferred embodiment, the atomic ratio of Mn, mo and Fe in the Mo-Fe-MnO 2 deposition solution in the Mo-Fe-MnO 2 deposition solution is 210:30:1-5. As a further preferred embodiment, the atomic ratio of Mn, mo and Fe in the Mo-Fe-MnO 2 deposition solution is 210:30:2. The invention optimizes the electronic structure and ion transmission path and reduces the charge transfer resistance by introducing proper Fe doping into beneficial structural defects (such as Mn 3+ and oxygen vacancy), thereby improving the redox reaction kinetics, but excessive doping causes serious lattice distortion and possibly generates impurity phases, so that the ion transmission is blocked and the active sites are reduced, and the energy storage performance is deteriorated. As a further preferred embodiment, the mass ratio of carbon dispersant TNWDIS to nanotubes is 0.3-1.