CN-122000275-A - Preparation method of zinc-iodine battery anode, product and application thereof

CN122000275ACN 122000275 ACN122000275 ACN 122000275ACN-122000275-A

Abstract

The invention relates to the technical field of zinc-iodine soft-package batteries, in particular to a preparation method of a zinc-iodine battery positive electrode, a product and application thereof. Dissolving a polyamide thermoplastic elastomer in a lithium bis (trifluoromethylsulfonate) solution to obtain a mixed solution, mixing elemental iodine and carbon powder, heating to obtain carbon-iodine composite powder, adding the carbon-iodine composite powder into the solution dissolved with TPAE, stirring uniformly to obtain slurry, pouring the slurry into a mold, putting a conductive current collector between feeding operations, finally immersing the mold into deionized water, reversing the slurry phase, dissolving LiTFSI into water from the slurry, solidifying the TPAE and the carbon-iodine composite and the current collector to form a whole, taking out a pole piece, washing with water, and cutting to obtain the positive pole piece which can be directly used for assembling the high-load zinc-iodine soft-package battery. The invention can realize the characteristics of high load, long service life and flexibility of the soft package battery, and LiTFSI used in the preparation process can be recycled.

Inventors

LI XUE
XU YUTING
ZHU ZIYI
LI JUN
ZHANG YIYONG
YANG WENHAO
CHEN HAOYU
LIU JINPENG

Assignees

昆明理工大学

Dates

Publication Date: 20260508
Application Date: 20260202

Claims (10)

1. The preparation method of the positive electrode of the zinc-iodine battery is characterized by comprising the following steps: S1, preparing a solution A, namely mixing a polyamide thermoplastic elastomer TPAE, a lithium bistrifluoromethyl sulfoacid imine LiTFSI solution and ultrapure water according to a certain proportion, heating and stirring until the TPAE is completely dissolved to obtain the solution A; s2, preparing mixed carbon powder B, namely uniformly mixing active carbon powder and conductive carbon powder according to a certain mass ratio to obtain mixed carbon powder B; s3, preparing carbon-iodine composite powder C, namely mixing elemental iodine powder with mixed carbon powder B according to a certain mass ratio, packaging the mixture in a glass bottle, and heating the mixture to obtain carbon-iodine composite powder C; s4, preparing slurry D, namely weighing the mixture C and the solution A according to a certain mass ratio, and uniformly stirring to obtain slurry D; S5, preparing a Teflon mold with corresponding size according to the size of the designed soft-packaged battery, wherein the thickness of the mold is required to be larger than that of the designed positive electrode plate, pouring half of the weighed slurry D into the mold according to the design capacity of the positive electrode of the zinc-iodine battery, then placing a cut current collector on the surface of the slurry, pouring the other half of the slurry D, transferring the slurry into a container containing enough deionized water together with the Teflon mold after the slurry is flatly soaked, immersing the mold in water, dissolving LiTFSI into the external deionized water from the slurry in the phase inversion process, concentrating the aqueous solution for repeated use, solidifying the TPAE, carbon-iodine composite powder and the current collector to form a whole after the slurry is solidified, taking out the pole plate, washing the pole plate with water, and cutting to obtain the positive electrode plate which can be directly used for assembling the high-load zinc-iodine soft-packaged battery.
2. The method for preparing the positive electrode of the zinc-iodine battery according to claim 1, wherein the positive electrode material comprises a composite material of polyamide thermoplastic elastomer, elemental iodine and carbon powder; the mass ratio of the polyamide thermoplastic elastomer in the composite material is 10% -30% of the total mass, and the mass ratio of the elemental iodine to the carbon powder is 1:0.3-1.2.
3. The preparation method of the zinc-iodine battery anode according to claim 1, wherein the polyamide thermoplastic elastomer contains polyamide functional groups, the relative molecular weight of the polyamide thermoplastic elastomer is 20000-100000, the mass fraction of TPAE in the mixture of TPAE, liTFSI and ultrapure water is 5% -10%, the mass fraction of LiTFSI is 60% -80%, and the mass fraction of ultrapure water is 20% -30%.
4. The preparation method of the zinc-iodine battery anode according to claim 1, wherein the carbon powder is a mixture of activated carbon and conductive carbon, the specific surface area of the activated carbon is 2000-3500 m 2 /g, the activated carbon powder with high specific surface area is mainly used for adsorbing iodine simple substance, the conductive carbon powder is one or more of carbon black SP, acetylene black, graphene and carbon nano tubes, and the mass ratio of the activated carbon to the conductive carbon is 1:0.3-1.0.
5. The preparation method of the zinc-iodine battery anode according to claim 1 is characterized in that the mass ratio of elemental iodine powder to mixed carbon powder B is 1:0.3-1:1.2, the heating temperature after mixing is 70-90 ℃, the heating time is 2-3 h, and the mass ratio of composite powder C to solution A is 1:3-1:5.
6. The preparation method of the zinc-iodine battery anode according to claim 1 is characterized in that the current collector is titanium foil, titanium mesh, stainless steel foil, stainless steel mesh, carbon cloth or carbon paper, the size of the Teflon mold is adjusted according to the size and the load of a pole piece, and the length and the width range are 5-25 cm.
7. The method for preparing a positive electrode of a zinc-iodine battery according to claim 1, wherein the slurry D is required to be phase-inverted in deionized water, liTFSI is dissolved from the slurry into external deionized water, and the aqueous solution can be reused after being concentrated.
8. The method for preparing the positive electrode of the zinc-iodine battery according to claim 1, wherein the time for the positive electrode plate to be solidified in water is 5-8 hours.
9. A zinc-iodine battery positive electrode, characterized by being obtained by the preparation method of any one of the above claims 1 to 8.
10. The application of the positive electrode of the zinc-iodine battery is characterized by comprising the step of preparing a high-load zinc-iodine soft package battery.

Description

Preparation method of zinc-iodine battery anode, product and application thereof Technical Field The invention relates to the technical field of zinc-iodine soft-package batteries, in particular to a preparation method of a zinc-iodine battery positive electrode, a product and application thereof. Background The battery is used as a high-efficiency and flexible electrochemical energy storage technology, is one of important development directions of the energy storage system at present, and the main current lithium ion battery is limited by the flammability of an organic electrolyte and relatively high production cost of the organic electrolyte, and has certain limitation in large-scale application. Compared with organic electrolyte, the aqueous electrolyte has higher safety and lower production cost, and is expected to be used for developing novel environment-friendly aqueous secondary batteries. Among the numerous aqueous secondary batteries currently under study, aqueous Zinc Ion Batteries (AZIBs) have received attention because of the low redox potential (-0.76V vs. SHE) of zinc metal anodes, high compatibility, and low cost of reserves. The positive electrode material for AZIBs mainly comprises manganese oxide, vanadium oxide, prussian blue analogues, halogen and the like, wherein iodine has favorable working potential (0.536V vs. SHE), high theoretical capacity (211 mAh g-1) and high natural abundance (55 mug L-1 in the ocean), so that the water-based zinc-iodine battery has wide application prospect in the aspect of energy storage on the power grid scale due to inherent safety and low cost. Elemental iodine itself is poorly conductive and therefore requires the use of high specific surface area Activated Carbon (AC) as a host material to provide a conductive network and redox reaction sites. The nonpolar, hydrophobic surface of the activated carbon is conducive to adsorption of nonpolar iodine molecules by van der waals forces, while its porous structure is effective in trapping iodine within its pores. The solubility in water is very low (only 0.33 g.l -1) due to the non-polar nature of the elemental iodine. In an aqueous medium, the system promotes iodine molecules to migrate from the aqueous phase to the surface of the activated carbon, thereby achieving directional migration and efficient anchoring. In contrast, negatively charged polyiodides (e.g., I 3-、I5-) are more polar, have reduced affinity for activated carbon, and have significantly improved solubility in polar aqueous electrolytes. This results in their spontaneous dissociation from the binding of the activated carbon and an increase in solubility in the electrolyte, thus creating a shuttle effect. In the process of charging and discharging the battery, the dissolution and shuttling of multi-iodine intermediates (such as I 3-、I5-) can cause irreversible capacity loss and zinc cathode corrosion, which seriously hampers practical application of AZIBs, meanwhile, the conductivity of elemental iodine per se is poor, high specific surface area Activated Carbon (AC) is required to be used as a carrier to provide a conductive network and redox reaction sites, and the adsorption effect of carbon materials on iodine is limited, so that the shuttling effect cannot be inhibited in long circulation. In addition, from the application point of view, the use of a low surface area positive electrode (< 20mg/cm 2) results in a higher proportion of inactive ingredients in the finished battery, thus significantly reducing the overall energy density, and if a slurry is prepared using a conventional aqueous binder (such as CMC, SBR, PAA/PAN) or the like, when the positive electrode load is increased, a significant binder migration phenomenon occurs during the drying process of the pole piece, resulting in internal cracking or delamination from the current collector, which ultimately limits the production of high load electrodes, and the current reported aqueous zinc-iodine battery does not substantially reach the 1Ah capacity. Disclosure of Invention Aiming at the problems in the prior art, the first technical purpose of the invention is to provide a preparation method of a zinc-iodine battery anode. The second technical purpose of the invention is to provide a zinc-iodine battery anode aiming at the problems existing in the prior art. Aiming at the problems in the prior art, the third technical aim of the invention is to provide an application of the positive electrode of the zinc-iodine battery. The first technical purpose of the invention is realized by the following scheme: a preparation method of a zinc-iodine battery anode comprises the following steps: S1, preparing a solution A, namely mixing a polyamide thermoplastic elastomer TPAE, a lithium bistrifluoromethyl sulfoacid imine LiTFSI solution and ultrapure water according to a certain proportion, heating and stirring until the TPAE is completely dissolved to obtain the solution A; s2, preparing mixed