CN-122025863-A - Quasi-solid-state water-based zinc ion battery based on ferroelectric coating and sodium alginate gel electrolyte

Abstract

The invention discloses a quasi-solid water system zinc ion battery based on a ferroelectric coating and sodium alginate gel electrolyte, and relates to the technical field of electrochemical energy storage. The battery comprises a positive electrode, a zinc negative electrode modified by a ferroelectric coating and sodium alginate-based gel electrolyte. The ferroelectric coating is formed by compounding a ferroelectric polymer and zinc salt, and utilizes a built-in electric field generated by spontaneous polarization to homogenize zinc ion flux, induce zinc to preferentially deposit, effectively inhibit dendrite growth and reduce side reactions, and the sodium alginate-based gel electrolyte has a three-dimensional network structure, has high ionic conductivity and excellent mechanical strength, can physically block dendrite penetration and eliminate leakage risk, and the synergistic effect of the two obviously improves the cycle stability and safety performance of the battery, solves the problems of easy short circuit and short service life of the water-based zinc ion battery, and is suitable for the field of high-safety energy storage.

Inventors

• QIN XIXIAN
• ZHAO DANYANG
• ZHU QIANCHENG
• SONG JIANMIN

Assignees

• 河北农业大学

Dates

Publication Date

20260512

Application Date

20260313

Claims (9)

1. 1. A quasi-solid water system zinc ion battery is characterized by comprising a positive electrode, a negative electrode and an electrolyte; The negative electrode is a zinc negative electrode modified by a ferroelectric coating and comprises a zinc matrix and the ferroelectric coating compounded on the surface of the zinc matrix; The electrolyte is sodium alginate-based gel electrolyte; Wherein the ferroelectric coating comprises a ferroelectric polymer and a zinc salt.
2. 2. The quasi-solid state aqueous zinc-ion battery of claim 1, wherein the positive electrode is a manganese dioxide positive electrode.
3. 3. The quasi-solid state water-based zinc-ion battery according to claim 1, wherein the ferroelectric polymer is polyvinylidene fluoride-trifluoroethylene copolymer, and the zinc salt in the ferroelectric coating is zinc trifluoromethane sulfonate.
4. 4. The quasi-solid state water-based zinc-ion battery according to claim 1, wherein the sodium alginate-based gel electrolyte is a gel with a three-dimensional network structure formed by ion crosslinking of sodium alginate, zinc salt and water.
5. 5. The quasi-solid state aqueous zinc-ion battery of claim 1, wherein the ferroelectric coating has a thickness of 10-120 μm.
6. 6. The quasi-solid state water-based zinc-ion battery according to claim 1, wherein the ferroelectric coating layer has a ferroelectric polymer mass ratio of 80% and a zinc salt mass ratio of 20%.
7. 7. The quasi-solid state aqueous zinc-ion battery of claim 1, wherein the ferroelectric coating modified zinc anode preparation method comprises the following steps: dissolving ferroelectric polymer and zinc salt in organic solvent to obtain ferroelectric slurry; and coating the ferroelectric slurry on the surface of a zinc matrix, and drying to obtain the zinc anode modified by the ferroelectric coating.
8. 8. The quasi-solid state water-based zinc-ion battery of claim 1, wherein the preparation method of the sodium alginate-based gel electrolyte comprises the following steps: And (3) immersing the porous carrier in sodium alginate solution, and transferring the immersed porous carrier into zinc salt solution for ionic crosslinking to obtain the sodium alginate-based gel electrolyte.
9. 9. The quasi-solid water-based zinc ion battery according to claim 8, wherein the mass fraction of the sodium alginate solution is 2% -5%, the zinc salt solution is zinc sulfate solution, and the concentration is 1-3 mol/L.

Description

Quasi-solid-state water-based zinc ion battery based on ferroelectric coating and sodium alginate gel electrolyte Technical Field The invention relates to the technical field of electrochemical energy storage, in particular to a quasi-solid water system zinc ion battery based on a ferroelectric coating and sodium alginate gel electrolyte. Background The water system zinc ion battery is used as an electrochemical energy storage device with great development potential, and by virtue of the outstanding advantages of abundant zinc resource reserves, low cost and high theoretical capacity, the water system has the advantages of safety, environmental protection and no explosion risk, and has wide application prospect in the fields of large-scale power grid energy storage, portable electronic equipment, new energy matched energy storage and the like, and becomes one of research hot spots in the energy storage field in recent years. Compared with a lithium ion battery, the water-based zinc ion battery does not need expensive lithium resources and a complex preparation process, avoids potential safety hazards caused by electrolyte, has natural advantages in the aspect of industrialization landing, and is considered as an important technical path for realizing low-cost and high-safety energy storage. However, the industrialization process of traditional aqueous zinc ion batteries is still limited by a series of key technical bottlenecks of zinc cathodes, and dendrite growth problems are particularly prominent. In the charge-discharge cycle process, the electric field distribution and the current density on the surface of the zinc cathode are uneven, so that zinc ions are easy to deposit preferentially at electrode defects, bulges and other points, needle-shaped or dendritic zinc dendrites are gradually formed, and the zinc dendrites continuously grow and pierce a battery diaphragm to cause internal short circuit of the battery, and the battery is directly caused to fail. Meanwhile, the zinc cathode in the water-based electrolyte can be accompanied with serious hydrogen evolution side reaction and zinc matrix corrosion, the hydrogen evolution reaction not only consumes active water in the electrolyte and damages the stability of an electrode/electrolyte interface, but also can generate gas to cause the increase of the internal pressure of the battery, and the zinc corrosion can cause the loss of cathode active substances, so that the capacity attenuation of the battery is increased and the cycle life of the battery is greatly shortened, and the traditional water-based zinc ion battery is difficult to meet the requirements of long cycle and high stability in practical application. In order to solve the above problems, various zinc anode modification and electrolyte optimization schemes have been proposed in the prior art, such as coating a polymer coating on the surface of a zinc anode, modifying the anode interface with a metal oxide, or using a gel electrolyte instead of a conventional liquid electrolyte. The conventional improvement means are mostly single-dimensional optimization, the comprehensive effects of dendrite growth inhibition, side reaction alleviation and interface stability improvement are difficult to realize, a simple polymer coating is easy to crack and fall off due to volume change in the zinc anode charge-discharge process, long-acting interface protection cannot be formed, a conventional metal oxide modification layer can regulate zinc ion deposition to a certain extent, but the preparation process is complex, the cost is high, the bonding force with a zinc matrix is insufficient, interface stripping is easy to occur in the circulation process, the extension of zinc dendrites can only be slightly limited from a physical layer by a common gel electrolyte, the active regulation capability of zinc ion migration dynamics is not available, the sprouting of dendrites cannot be radically avoided, and the core problem of zinc ion uneven deposition is still difficult to solve. In addition, the existing aqueous zinc ion battery has poor electrode/electrolyte interface compatibility, unstable interface contact of liquid electrolyte and a zinc cathode, easy formation of a loose zinc deposition layer and further aggravation of dendrite growth and side reaction, and the partially modified gel electrolyte has the problems of low ion conductivity and poor contact with an electrode interface, thereby leading to increase of battery polarization and poor capacity. In summary, the prior art has not developed a technical scheme capable of realizing uniform deposition of zinc ions, thoroughly inhibiting dendrite growth and side reaction and simultaneously considering ionic conductivity and interface stability from the dual angles of chemical regulation and physical limitation, which becomes a key obstacle for restricting the development of the water-based zinc ion battery in the directions of high stability and long se