CN-122025852-A - Alkaline antifreeze electrolyte and preparation method of low-temperature nickel-zinc battery

CN122025852ACN 122025852 ACN122025852 ACN 122025852ACN-122025852-A

Abstract

The invention relates to the technical field of chemical power supplies and discloses an alkaline antifreeze electrolyte and a preparation method of a low-temperature nickel-zinc battery, wherein the alkaline antifreeze electrolyte comprises solvent water and solutes dissolved in the solvent water, the solutes comprise main electrolyte KOH, antifreeze conductive agent potassium formate, positive electrode stabilizer LiOH, basic zinc source ZnO, deposition regulator zinc acetate dihydrate and corrosion inhibitor KF, and the concentration of the potassium formate is 35-55wt%. The preparation method of the alkaline antifreeze electrolyte adopts a sectional temperature control dissolution process aiming at high-concentration potassium formate. The potassium formate damages a water molecule hydrogen bond network, reduces the solidifying point, improves the low-temperature conductivity, and cooperates with a functional auxiliary agent to induce zinc to be tiled and deposited and inhibit hydrogen evolution. The working temperature range of the battery is wide to minus 60 ℃ to 25 ℃, the problem of freezing electrolyte at low temperature is effectively solved, and the battery has excellent low-temperature discharge capability and cycle life.

Inventors

LIU YEYI
GUO JIAYANG
LIANG JUNHAO
WANG SHOUJUN
WANG WEIDONG

Assignees

深圳市量能科技有限公司

Dates

Publication Date: 20260512
Application Date: 20260127

Claims (10)

1. An alkaline antifreeze electrolyte is characterized by comprising solvent water and a solute dissolved in the solvent water, wherein the solute comprises a main electrolyte, an antifreeze conductive agent, a positive electrode stabilizer, a basic zinc source, a deposition regulator and a corrosion inhibitor; The antifreeze conductive agent is potassium formate, and the mass percentage concentration of the antifreeze conductive agent in the electrolyte is 35-55wt%.
2. The alkaline antifreeze electrolyte of claim 1, wherein the main electrolyte is potassium hydroxide and has a molar concentration of 3.5m to 4.5m in the electrolyte.
3. The alkaline antifreeze electrolyte of claim 1, wherein the positive electrode stabilizer is lithium hydroxide and has a molar concentration of 0.5m to 1.5m in the electrolyte.
4. The alkaline antifreeze electrolyte of claim 1, wherein the base zinc source is zinc oxide and the mass percent concentration of the zinc oxide in the electrolyte is 1.5-2.5 wt%.
5. The alkaline antifreeze electrolyte of claim 1, wherein the deposition regulator is zinc acetate dihydrate, the molar concentration of the zinc acetate dihydrate in the electrolyte is 0.01-0.1M, and the corrosion inhibitor is potassium fluoride, and the mass percentage concentration of the potassium fluoride in the electrolyte is 0.1-1.0 wt%.
6. The alkaline antifreeze electrolyte of claim 1, wherein the solvent water is deionized water and the positive electrode stabilizer is anhydrous lithium hydroxide.
7. The preparation method of the alkaline antifreeze electrolyte is characterized by comprising the following steps of: s1, adding weighed potassium formate into deionized water, and stirring for dissolution to obtain a potassium formate solution; s2, sequentially adding a positive electrode stabilizer, a main electrolyte, a corrosion inhibitor, a basic zinc source and a deposition regulator into the potassium formate solution, and stirring until the solution is completely dissolved to obtain the alkaline antifreeze electrolyte; In the step S1, the dissolution temperature is controlled according to the concentration of potassium formate, wherein when the mass percentage concentration of the potassium formate is less than or equal to 45wt%, stirring and dissolving are performed at room temperature, when the mass percentage concentration of the potassium formate is more than 45wt%, deionized water is preheated to 35-40 ℃, potassium formate is added, stirring and dissolving are performed, and after the solution is clarified, cooling is performed to room temperature, and then the step S2 is performed.
8. The method for preparing an alkaline antifreeze electrolyte according to claim 7, wherein in the step S2, the temperature of the system is controlled to be 25 ℃ or less.
9. A low temperature nickel zinc battery comprising a positive electrode, a negative electrode, a separator, and the alkaline antifreeze electrolyte of any of claims 1-6.
10. The low temperature nickel zinc cell of claim 9, wherein the low temperature nickel zinc cell has an operating temperature range of-60 ℃ to 25 ℃.

Description

Alkaline antifreeze electrolyte and preparation method of low-temperature nickel-zinc battery Technical Field The invention relates to the technical field of data processing, in particular to an alkaline antifreeze electrolyte and a preparation method of a low-temperature nickel-zinc battery. Background Currently, chemical power supplies are increasingly in demand for applications in the fields of alpine regions, aerospace and special equipment. The nickel-zinc battery is an energy storage device with high competitive power by virtue of the advantages of high energy density, high power output, low cost, environmental friendliness and the like. Compared with lead-acid batteries and lithium ion batteries, the nickel-zinc batteries are more excellent in safety, and the hidden danger of thermal runaway ignition is avoided. Industry is working to explore its operational potential in extreme climatic conditions to meet energy supply demands in harsh environments. Aiming at the application scene, the existing nickel-zinc battery mainly relies on an alkaline aqueous solution system for charge transmission. In the conventional technology, the electrolyte mostly adopts high-concentration potassium hydroxide or sodium hydroxide solution as a main solvent. The electrolyte provides abundant hydroxide ion carriers by utilizing hydroxide, and is matched with zinc oxide as a basic zinc source to construct an ion conduction network. In the charge and discharge process, hydroxide ions shuttle between the anode and the cathode, and oxidation reduction of the nickel electrode and dissolution deposition reaction of the zinc electrode are maintained, so that electric energy is stored and released. However, conventional alkaline electrolyte systems have short plates in terms of low temperature flexibility and interfacial stability. Firstly, the eutectic point of the traditional potassium hydroxide aqueous solution is higher, when the ambient temperature is reduced below-20 ℃, free water molecules are easy to associate to form ice crystals, so that an ion migration channel is blocked physically, the internal resistance is increased sharply, and the battery is failed rapidly. Secondly, some technologies attempt to introduce organic alcohols such as ethylene glycol as an antifreeze, but this often results in an increase in viscosity of the electrolyte, attenuation in ionic conductivity, and failure to support large-current discharge. Thirdly, the zinc cathode has inherent thermodynamic instability in a liquid phase environment, zinc ion deposition kinetics is uneven in a charging and discharging process, dendrite vertical growth is easy to be induced to pierce a diaphragm, and continuous hydrogen evolution corrosion and electrode passivation are accompanied. These problems are interwoven, and it is difficult to achieve both low temperature performance and long cycle life. Therefore, the invention provides an alkaline antifreeze electrolyte and a preparation method of a low-temperature nickel-zinc battery, which are used for solving the defects in the prior art. Disclosure of Invention Aiming at the defects of the prior art, the invention provides an alkaline antifreeze electrolyte and a preparation method of a low-temperature nickel-zinc battery, and solves the problems that the conventional nickel-zinc battery cannot work normally due to freezing or rapid increase of internal resistance of the electrolyte in an extremely low-temperature environment, and dendrites and corrosion of a zinc negative electrode are easy to generate, so that the cycle life of the battery is influenced. In order to achieve the above purpose, the invention is realized by the following technical scheme: In a first aspect, the invention provides an alkaline antifreeze electrolyte comprising solvent water and a solute dissolved in the solvent water, wherein the solute comprises a main electrolyte, an antifreeze conductive agent, a positive electrode stabilizer, a basic zinc source, a deposition regulator and a corrosion inhibitor; The antifreeze conductive agent is potassium formate, and the mass percentage concentration of the antifreeze conductive agent in the electrolyte is 35-55wt%. By adopting the technical scheme, potassium formate is used as a core antifreeze conductive component, and a stable solid-liquid coexisting system is constructed with water molecules. The formate ion has an asymmetric structure and higher charge density, and the original tetrahedral hydrogen bond network structure among water molecules is effectively destroyed by strong solvation in the solution, thereby preventing formation and growth of crystal nucleus of ice crystal and reducing the freezing point of the electrolyte. In the concentration range of 35-55wt%, the potassium formate can not only ensure that electrolyte is not completely frozen at the extremely low temperature of-60 ℃, and keeps a liquid or pasty ion transmission channel, but also has lower viscosity and higher io