CN-116404097-B - Three-dimensional zinc-philic current collector composite negative electrode constructed in electrochemical welding mode

CN116404097BCN 116404097 BCN116404097 BCN 116404097BCN-116404097-B

Abstract

The invention discloses a three-dimensional zinc-philic current collector composite negative electrode constructed by an electrochemical welding mode, the negative electrode structure connects a copper substrate and ZnO/C fibers prepared by electrostatic spinning in an electrochemical welding mode through zinc pre-electrodeposition. The method is characterized in that zinc-philic ZnO/C fibers are prepared by combining an electrostatic spinning process with high-temperature carbonization, and then ZnO/C and copper foil are subjected to electrochemical welding by utilizing a zinc electrochemical deposition technology, so that a Zn@ZnO/C-Cu anode material is obtained. According to the invention, zinc-philic site ZnO and high-conductivity copper foil are introduced into carbon fibers with large specific surface area, so that a negative electrode structure which is beneficial to more efficient operation of zinc ion batteries is designed. The prepared negative electrode material improves the cycle and the multiplying power performance of the zinc ion battery and promotes the further development of the negative electrode material of the zinc ion battery.

Inventors

WANG MINGSHAN
GAO YANG
Chu Yuanwei
LI XINPENG
FENG YUANLONG
CHEN JUNCHEN
LI XING

Assignees

西南石油大学

Dates

Publication Date: 20260508
Application Date: 20230412

Claims (7)

1. A three-dimensional zinc-philic current collector composite negative electrode constructed in an electrochemical welding mode is characterized in that an electrostatic spinning technology is adopted, znO/C-Cu@Zn composite negative electrode material is prepared through carbonization and electrochemical deposition, cu is used as a substrate, znO is uniformly dispersed in carbon fibers, and the substrate and the fibers are connected together in an electrochemical welding mode through Zn to form a three-dimensional zinc-philic current collector composite negative electrode structure.
2. The three-dimensional zinc-philic current collector composite negative electrode constructed by electrochemical welding according to claim 1, characterized by the specific steps of: (1) Adding a zinc precursor and a carbon source into an organic solvent, heating and stirring to obtain a uniformly mixed spinning solution, transferring the spinning solution into a spinning injector, and carrying out electrostatic spinning under proper parameters to obtain carbon fibers containing the zinc source; (2) Pre-oxidizing and carbonizing the spinning fiber obtained by electrostatic spinning to obtain ZnO/C fiber; (3) And (3) pre-electrodeposition, namely forming a button cell by a positive electrode, a negative electrode, a diaphragm between the positive electrode and the negative electrode and electrolyte, taking the material obtained in the step (2) and the copper foil as a substrate together, and then setting a program to deposit zinc on the substrate to obtain the three-dimensional zinc-philic current collector composite negative electrode structure.
3. The three-dimensional zinc-philic current collector composite anode constructed in an electrochemical welding mode according to claim 2 is characterized in that in the step (1), a carbon source is one or more of polyethylene oxide (PEO), polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), polyvinylidene fluoride (PVDF), polyacrylonitrile (PAN), polycaprolactone (PCL), polyurethane (PU), polylactic acid (PLA), polyethersulfone (PES), polystyrene (PS), polyamide (PA), cellulose Acetate (CA), chitosan (CS) and Silk Fibroin (SF), a zinc precursor is one or more of zinc sulfate, zinc chloride, zinc nitrate, zinc acetate, zinc fluoride, zinc hexafluoroate, zinc triflate and zinc gluconate, and an organic solvent is one or more of ethanol, N-N-Dimethylformamide (DMF), N-N-dimethylacetamide (DMAc), acetone, chloroform (TCM), dichloromethane (DCM), formic acid, hexafluoroisopropanol (HFIP) and Tetrahydrofuran (THF).
4. The three-dimensional zinc-philic current collector composite anode constructed by electrochemical welding according to claim 2, wherein in the step (1), the advancing speed of an electrostatic spinning injector is 15-30 mu L s -1 , the rotating speed of a collecting cylinder is 200-500r min -1 , the distance between the collecting cylinder and a spinneret is 10-20cm, and the voltage is set to be 15-22kV.
5. The three-dimensional zinc-philic current collector composite negative electrode constructed in an electrochemical welding mode according to claim 2 is characterized in that in the step (2), air is used as an atmosphere in pre-oxidation, N 2 or Ar is used as an atmosphere in carbonization, the heating rate in pre-oxidation is 1-3 ℃ min -1 , the heating rate in carbonization is 2-5 ℃ min -1 , the pre-oxidation heat preservation time is 2-5h, the carbonization heat preservation time is 2-5h, and the carbonization cooling rate is 2-5 ℃ min -1 .
6. The three-dimensional zinc-philic current collector composite negative electrode constructed by electrochemical welding according to claim 2, wherein in the step (3), the pre-electrodeposition selective diaphragm comprises one of non-woven fabric, glass fiber, polyacrylonitrile, polyamide, polyterephthalate, polyimide, polyethylene, polypropylene, polystyrene, polyvinyl chloride, acrylonitrile-butadiene-styrene copolymer, polypropylene, polytetrafluoroethylene, polyvinylidene fluoride and polycarbonate, and the pre-electrodeposition selective electrolyte comprises soluble zinc salt which is at least one of zinc sulfate, zinc chloride, zinc nitrate, zinc acetate, zinc fluoride, zinc hexafluoroate, zinc triflate and zinc gluconate.
7. The three-dimensional zinc-philic current collector composite negative electrode constructed by electrochemical welding according to claim 2, wherein in the step (3), the deposition current density of the pre-electrodeposited zinc is 1-10 mA/cm 2 , and the deposition capacity is 1-10 mAh/cm 2 .

Description

Three-dimensional zinc-philic current collector composite negative electrode constructed in electrochemical welding mode Technical Field The invention relates to a three-dimensional zinc-philic current collector composite negative electrode constructed in an electrochemical welding mode, and belongs to the technical field of zinc ion battery negative electrode materials. Background Lithium ion batteries are the most widely used energy storage devices due to their high energy density and long life. However, their widespread use and subsequent development is hampered by safety problems, high costs, limited lithium resources, and the like. The advent and development of aqueous zinc ion batteries has provided new opportunities for large scale energy storage applications, torsional energy crisis, and improved environmental pollution, because of their high safety, high stability, and low cost. Metallic zinc is considered the most common negative electrode in zinc ion batteries because of its unique advantages, including high theoretical capacity (820 mA h g –1), appropriate redox potential (-0.76 v vs. she, standard hydrogen electrode), abundant reserves and low toxicity. However, the most critical challenge for commercial zinc foil is uncontrolled non-uniform zinc deposition due to the presence of sharp points on the roughened surface of the zinc foil, and the large accumulation of zinc ions around it. In addition, due to continuous side reactions (such as competitive hydrogen evolution), zinc utilization is low, and with volume expansion, electrode corrosion and short-circuit failure, electrochemical performance of zinc ion batteries is deteriorated, even safety accidents are caused. Although zinc ion batteries have great advantages, development of high-efficiency anode materials for zinc ion batteries is still in an early stage. Extensive research has shown that zinc dendrite formation results mainly from non-uniformity of ion and electron distribution across the electrode, and that in order to slow zinc dendrite growth, uniform nucleation and Zn 2+ ion distribution must be achieved. Compared with a planar anode, the three-dimensional anode has a highly stable skeleton structure, can prevent the anode from shape change or structural collapse in the process of depositing and stripping zinc ions, can provide wider channels, is beneficial to the transportation of charges and ions, and can induce uniform distribution of zinc ions by providing a larger reaction surface area and rich nucleation sites. The invention application CN114937754A provides a dendrite-free cathode of a zinc ion battery and a 3D printing preparation method thereof, wherein a composite coating is deposited on one surface of zinc and stainless steel foil through a 3D printing technology for inhibiting the growth of zinc dendrites, and the invention CN112952053B provides a preparation method of a zinc/carbon nano tube foam composite material, which is used for inhibiting the growth of zinc dendrites by carbonizing carbon nano tubes, performing hydrophilic treatment and then electrochemically depositing zinc. However, the existing zinc ion battery cathode preparation technology has the following defects that the transmission speed of zinc ions is slow and the electrochemical activity is not high due to poor conductivity and large ion diffusion resistance, so that the capacity and the multiplying power performance of the battery are affected, the deposition area is small, the preparation process is complex and the cost is high. Therefore, the preparation process and the method of the existing three-dimensional zinc ion battery cathode are also required to be adjusted and improved. Disclosure of Invention The invention aims to solve the problems of the existing zinc ion battery cathode material and provides a preparation method for preparing a three-dimensional zinc-philic cathode material by utilizing an electrostatic spinning technology and through electrochemical welding. The method of the invention comprises the following steps: (1) Adding a zinc precursor and a carbon source into an organic solvent, heating and stirring to obtain a uniformly mixed spinning solution, transferring the spinning solution into a spinning injector, and carrying out electrostatic spinning under proper parameters to obtain carbon fibers containing the zinc source; (2) Pre-oxidizing and carbonizing the spinning fiber obtained by electrostatic spinning to obtain ZnO/C fiber; (3) And (3) pre-electrodeposition, namely forming a button cell by a positive electrode, a negative electrode, a diaphragm between the positive electrode and the negative electrode and electrolyte, taking the material obtained in the step (2) and the copper foil as a substrate together, and then setting a program to deposit zinc on the substrate to obtain the three-dimensional zinc-philic current collector composite negative electrode structure. Further, in the step (1), the carbon source is one or