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CN-122025859-A - Water system zinc metal secondary battery based on silver halide positive electrode

CN122025859ACN 122025859 ACN122025859 ACN 122025859ACN-122025859-A

Abstract

The invention discloses a water-based zinc metal secondary battery based on a silver halide positive electrode, which belongs to the technical field of electrochemical energy storage and comprises an electrolyte, a positive electrode, a negative electrode and a diaphragm, wherein the electrolyte is an aqueous solution containing zinc salt and halogen ions, the positive electrode is a silver halide material and is used for carrying out silver halide redox reaction at an interface between the positive electrode and the electrolyte, the negative electrode is a zinc sheet and is used for carrying out zinc metal redox reaction at an interface between the negative electrode and the electrolyte, and the diaphragm is arranged between the positive electrode and the negative electrode. The water-based zinc metal secondary battery based on the silver halide anode fundamentally solves the core problems that the traditional zinc-silver battery anode material is easy to dissolve and has poor cycle performance, and provides a feasible technical path for large-scale energy storage application.

Inventors

  • ZHU ZHENGXIN
  • LI HUANWEI

Assignees

  • 南华大学

Dates

Publication Date
20260512
Application Date
20260305

Claims (9)

  1. 1. A water-based zinc metal secondary battery based on a silver halide positive electrode is characterized by comprising an electrolyte, a positive electrode, a negative electrode and a diaphragm, wherein: the electrolyte is an aqueous solution containing zinc salt and halogen ions; the positive electrode is made of silver halide material and is used for carrying out silver halide redox reaction at the interface of the positive electrode and the electrolyte; the negative electrode is zinc metal and is used for carrying out zinc metal oxidation-reduction reaction at the interface of the negative electrode and the electrolyte; and a separator interposed between the positive electrode and the negative electrode.
  2. 2. The aqueous zinc metal secondary battery according to claim 1, wherein the zinc salt concentration is in the range of 0.1 to 4mol/kg and the halogen ion concentration is in the range of 0.05 to 2mol/kg.
  3. 3. The aqueous zinc metal secondary battery according to claim 1, wherein the silver halide material comprises silver halide, a binder, and a carbon material, and the silver halide has the carbon material and the binder supported thereon.
  4. 4. The positive electrode aqueous zinc metal secondary battery according to claim 1, wherein the zinc salt is one of zinc sulfate, zinc chloride, zinc nitrate, zinc gluconate, zinc lactate, zinc perchlorate, zinc tetrafluoroborate, zinc trifluoromethane sulfonate, zinc acetate, and zinc carbonate.
  5. 5. The aqueous zinc metal secondary battery according to claim 1, wherein the halogen ion is one of iodide ion, bromide ion and chloride ion.
  6. 6. The aqueous zinc metal secondary battery according to claim 2, wherein the silver halide is one of silver bromide, silver chloride and silver iodide.
  7. 7. The aqueous zinc metal secondary battery according to claim 2, wherein the binder is one of CMC, PVDF, PTFE.
  8. 8. The aqueous zinc metal secondary battery based on silver halide anode as set forth in claim 2, wherein the carbon material is one or more of graphite, graphene, carbon cloth, carbon paper, activated carbon, carbon fiber, carbon felt, graphite felt, acetylene black, ketjen black.
  9. 9. The aqueous zinc metal secondary battery based on silver halide anode according to claim 1, wherein the aqueous zinc metal secondary battery has one of button cell type, cylindrical cell type, prismatic cell type and abnormal cell type.

Description

Water system zinc metal secondary battery based on silver halide positive electrode Technical Field The invention relates to the technical field of electrochemical energy storage, in particular to a water-based zinc metal secondary battery based on a silver halide anode. Background With the acceleration of global energy structure transformation and the advancement of "two-carbon" targets, the development of high-safety, low-cost, environmentally friendly large-scale electrochemical energy storage technologies has become an urgent need. The water-based zinc metal battery is regarded as an important candidate of the next-generation energy storage system because of the advantages of non-combustible water-based electrolyte, abundant zinc resources, high theoretical capacity (820 mAh g -1), low electrode potential (-0.76V vs. SHE) and simple manufacturing process. Among the many aqueous zinc metal battery systems, traditional zinc silver batteries have been of interest due to their high operating voltage (typically > 1.5V) and high energy density. However, the traditional zinc-silver battery is faced with a serious technical bottleneck in practical application, namely, the positive electrode silver oxide active substance of the traditional zinc-silver battery is easy to generate irreversible conversion and dissolution reaction in the charge and discharge process, and particularly, the traditional zinc-silver battery is in a neutral or weak acid electrolyte environment. This dissolution behavior is mainly due to the limited solubility product (K sp) of the silver oxide anode at low pH. The continuous loss of the anode material not only leads to rapid capacity decay, but also finally leads to remarkable shortening of the cycle life of the battery (usually less than 100 times), and severely restricts the popularization of the battery in large-scale application scenes such as long-time energy storage, power grid peak shaving and the like. Based on the above, the traditional zinc-silver battery mostly adopts a strong alkaline electrolyte (such as KOH solution), although the ionic conductivity can be improved and the dissolution of the silver oxide anode can be inhibited, the dendrite growth and hydrogen evolution side reaction of the zinc cathode can be aggravated, and the coulomb efficiency and the safety of the battery are reduced. In order to overcome the above problems, researchers have tried to inhibit the dissolution of silver oxide positive electrode through strategies such as positive electrode structural design (such as carbon coating, nano-confinement), halogen ion electrolyte additive regulation or development of novel salt systems. However, these methods often have difficulty in achieving high reversibility, long cycle life, and high energy density, and lack systematic utilization of halogen ion redox reactions. Disclosure of Invention The invention aims to provide a water-based zinc metal secondary battery based on a silver halide positive electrode, which skillfully utilizes halogen ions to reversibly participate in multivalent conversion in the charge-discharge process to construct a positive electrode reaction path taking the silver halide positive electrode as an initial active substance and taking a compound conversion mechanism as a basis, and can inhibit excessive dissolution of the silver halide positive electrode caused by concentration driving on one hand and can realize a high-efficiency and reversible redox process by forming a stable polyhalide intermediate on the other hand by introducing halogen ions with a certain concentration into electrolyte, and adopts neutral or weak acid zinc salt aqueous solution as a basic electrolyte, thereby avoiding corrosion of a zinc negative electrode by a strong alkaline environment and effectively improving an electrochemical stability window and cycle durability of the whole battery system. In order to achieve the above object, the present invention provides a silver halide positive electrode-based aqueous zinc metal secondary battery comprising an electrolyte, a positive electrode, a negative electrode and a separator, wherein: the electrolyte is an aqueous solution containing zinc salt and halogen ions; the positive electrode is made of silver halide material and is used for carrying out silver halide redox reaction at the interface of the positive electrode and the electrolyte; the negative electrode is zinc metal and is used for carrying out zinc metal oxidation-reduction reaction at the interface of the negative electrode and the electrolyte; and a separator interposed between the positive electrode and the negative electrode. Preferably, the zinc salt concentration is in the range of 0.1 to 4mol/kg and the halide ion concentration is in the range of 0.05 to 2mol/kg. Preferably, the silver halide material comprises silver halide, a binder, and a carbon material, the silver halide carrying the carbon material and the binder thereon. Preferably, the zi