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CN-122025645-A - Zinc-based sodium-philic modified current collector, preparation method thereof and negative-electrode-free sodium metal battery

CN122025645ACN 122025645 ACN122025645 ACN 122025645ACN-122025645-A

Abstract

The invention relates to the technical field of non-negative sodium metal batteries, in particular to a zinc-based sodium-philic modified current collector, a preparation method thereof and a non-negative sodium metal battery with the current collector. The current collector comprises a zinc foil substrate and a sodium-philic Zn-M intermetallic phase modification layer formed on the surface of the zinc foil substrate, wherein M adopts one of Sb, sn and Bi, the modification layer is formed in situ by magnetron sputtering metallic antimony on the zinc foil and annealing treatment, and the best effect is achieved when the M metal is Sb. The method has the beneficial effects that the alloy layer is subjected to reversible and non-cracking alloying/dealloying reaction in the sodium deposition/stripping process, a continuous conductive framework and a stable sodium-philic interface are maintained, the sodium nucleation overpotential can be remarkably reduced, uniform deposition of sodium on the surface of a current collector is induced, and generation of dendrite and dead sodium is inhibited, so that the coulombic efficiency, the cycle life and the safety of the negative-electrode-free sodium metal battery are improved.

Inventors

  • WANG HAIYAN
  • DAI JIAWEN
  • TANG YONGQUAN
  • WANG PEIYU
  • QIU TIAN
  • SU YUEJIN

Assignees

  • 衢州东峰新材料集团股份有限公司

Dates

Publication Date
20260512
Application Date
20260207

Claims (10)

  1. 1. A zinc-based sodium-philic current collector is characterized by comprising a zinc foil matrix and a sodium-philic interface layer compounded on at least one surface of the zinc foil matrix; The sodium-philic interface layer is a metal modified layer containing Zn-M intermetallic phases, wherein M is one metal element of Sb, sn and Bi; the sodium-philic interface layer is metallurgically combined with the zinc foil matrix, and forms a continuous compact metal modification layer on the surface of the zinc foil matrix, so as to induce uniform deposition/stripping of sodium metal in the battery charging/discharging process.
  2. 2. The zinc-based sodium-philic current collector of claim 1, wherein M is Sb and the Zn-M intermetallic phase contained in the sodium-philic interface layer comprises Zn 4 Sb 3 intermetallic phases.
  3. 3. A zinc-based sodium-philic current collector as in claim 2, wherein the Zn 4 Sb 3 intermetallic phases are continuously distributed along the foil surface on the surface of the zinc foil substrate to form a continuous alloying interface layer covering the surface of the zinc foil substrate.
  4. 4. A zinc-based sodium-philic current collector as in any of claims 1-3, wherein the thickness of the sodium-philic interface layer is 100 nm-2000 nm.
  5. 5. A zinc-based sodium-philic current collector as in any of claims 1-3, characterized in that the zinc foil matrix has a thickness of 10 μm to 100 μm.
  6. 6. A method for preparing a zinc-based sodium philic current collector as in any one of claims 1-5, comprising the steps of: s1, cleaning and drying a zinc foil matrix; s2, in a vacuum magnetron sputtering device, performing sputter deposition on the surface of the zinc foil substrate in the step S1 by taking metal M as a target material, and forming a metal M plating layer on the surface of the zinc foil substrate, wherein the metal M adopts one of Sb, sn and Bi; And S3, performing heat treatment on the zinc foil substrate with the metal M plating layer formed on the surface in the step S2 in an inert atmosphere to enable the metal M plating layer to perform solid phase reaction with the zinc foil substrate, and forming a metal modified layer containing Zn-M intermetallic phases on the surface of the zinc foil substrate in situ to serve as a sodium-philic interface layer.
  7. 7. The method of claim 6, wherein the step S2 is performed in vacuum or inert atmosphere when using vacuum magnetron sputtering equipment to perform sputtering deposition, and the power of magnetron sputtering is 20-100W, and the sputtering time is 1-20 min, so as to obtain the metal M coating with the thickness of 100-2000 nm.
  8. 8. The method for preparing a zinc-based sodium-philic current collector as claimed in claim 6, wherein the temperature of the heat treatment in the step S3 is 300-450 ℃, the heat preservation time is 1-6 h, the temperature rising rate is 1-10 ℃ per minute, and the zinc-based sodium-philic current collector is naturally cooled to room temperature under the protection of inert atmosphere after the heat preservation is finished.
  9. 9. The preparation method of the zinc-based sodium-philic current collector according to any one of claims 6-8, wherein the metal M used in the step S2 is Sb, when sputtering deposition is carried out by using a vacuum magnetron sputtering device, the magnetron sputtering power is 50W, the sputtering time is 5min, the heat treatment temperature in the step S3 is 400 ℃, the heat preservation time is 4h, the heating rate is5 ℃ per min, and the Sb modified layer with a main phase Zn 4 Sb 3 is formed in situ on the surface of a zinc foil substrate to serve as a sodium-philic interface layer.
  10. 10. A non-negative sodium metal battery is characterized by comprising a positive electrode, a diaphragm, a negative electrode current collector and electrolyte which infiltrates the positive electrode, the diaphragm and the negative electrode current collector which are sequentially compounded, wherein the negative electrode current collector adopts the zinc-based sodium-philic modified current collector according to any one of claims 1-5, a metal sodium negative electrode is not preset in the non-negative sodium metal battery during assembly, all active sodium in the battery is sourced from the positive electrode, and sodium is deposited on the surface of the zinc-based sodium-philic modified current collector in a metal form during the first charging process.

Description

Zinc-based sodium-philic modified current collector, preparation method thereof and negative-electrode-free sodium metal battery Technical Field The invention relates to the technical field of non-negative sodium metal batteries, in particular to a zinc-based sodium-philic modified current collector, a preparation method thereof and a non-negative sodium metal battery with the current collector. Background The application scene represented by renewable energy grid connection, grid side peak shaving and novel transportation means provides comprehensive requirements of high energy density, low cost and long service life for an electrochemical energy storage system. The traditional lithium ion battery is limited by uneven distribution of lithium resources and cost pressure, and large-scale deployment faces a certain bottleneck, and compared with a sodium-based battery constructed based on sodium elements with higher crust abundance, the traditional lithium ion battery has natural advantages in terms of resource endowment and material cost, so the traditional lithium ion battery is gradually regarded as an important candidate technical route facing large-scale energy storage and medium energy density application. Among many sodium-based systems, sodium-metal batteries using metallic sodium as the negative electrode have the potential to build high energy density batteries by virtue of the theoretical specific capacity approaching 1160 mAh g –1 and lower electrode potential. However, the design of the conventional excessive sodium metal negative electrode not only increases the consumption of active metal and the manufacturing cost, but also easily induces serious dendrite growth, dead sodium accumulation and side reaction of combustible electrolyte in the circulating process, thereby causing the problems of low coulomb efficiency, rapid capacity decay, even safety accidents and the like. In order to achieve a better balance between energy density and safety, the proposed non-negative sodium metal battery in recent years is becoming a research hotspot. When the system is assembled, metal sodium or embedded anode materials are not preset, but only a metal current collector is used as an anode carrier, all available sodium ions are sourced from an anode and electrolyte, and are deposited on the surface of the current collector in situ in the primary charging process. The cathode-free configuration reduces the processing links of sodium metal, improves the volume/mass energy density, and is expected to reduce the cost and the carbon footprint of the whole life cycle. However, at the same time, because no extra sodium metal buffer exists in the system, the non-negative sodium metal battery is highly sensitive to the reversibility of the interface of each sodium deposition/stripping, on one hand, the solid electrolyte interface film continuously generated and repaired between the negative current collector and the electrolyte continuously consumes limited active sodium, so that the coulomb efficiency and the recyclable capacity gradually decrease, and on the other hand, the uneven ion/electron transmission at the interface is easy to induce the sodium to locally nucleate firstly and grow outwards in a dendrite mode, so that dead sodium and potential safety hazards are formed, and therefore, the inhibition of side reactions and the realization of uniform sodium deposition are key challenges facing the current non-negative electrode system. In the prior researches, sodium nucleation overpotential is reduced and uniform deposition is guided by introducing a sodium-philic metal or alloy coating (such as Sn, sb, bi, ag and the like) on a conventional metal current collector, and the interface modification method has certain advantages in cost and process and achieves positive effects in a sodium metal/non-negative electrode battery. As in the patent with publication number CN 117747847A, under the patent name "composite current collector with sodium-philic interface and its preparation and application in negative electrode-free sodium battery", it discloses a technical solution that Cu, fe, ni and Ti are used as matrix, and Sb, bi, in, ag, pb and Sn are combined with matrix to form sodium-philic interface layer. However, these sodium-philic coatings often accompany significant volume changes during repeated sodium alloying/dealloying, which can easily lead to cracking of the coating, interfacial debonding, and repeated cracking and reconstruction of the SEI film, thereby weakening long-term sodium philic and sodium deposition regulation and control capabilities, and making it difficult to compromise the long cycle life and process simplicity required for high energy density non-negative sodium batteries. This is because Cu, fe, ni and Ti conventionally used as a matrix are metals with high melting points (melting points are greater than 1000 ℃) and, when magnetic sputtering processing or conventional heat treatmen