CN-122025851-A - Electrolyte for improving float performance of nickel-zinc battery and application thereof

CN122025851ACN 122025851 ACN122025851 ACN 122025851ACN-122025851-A

Abstract

The application relates to the technical field of secondary batteries, in particular to an electrolyte for improving the float performance of a nickel-zinc battery and application thereof, wherein the electrolyte comprises a basic alkaline electrolyte and a composite additive, the composite additive consists of a quaternary ammonium salt derivative, an organic phosphate compound and borate, the mass of the basic alkaline electrolyte is 100%, the addition amount of the quaternary ammonium salt derivative is 0.1-0.5% by weight, the addition amount of the organic phosphate compound is 0.05-0.3% by weight, and the addition amount of the borate is 0.03-0.2% by weight. The three additives cooperate to jointly inhibit the degradation of the battery under the floating charge condition by forming an adsorption film on the surface of the negative electrode, regulating and controlling the ion behaviors of the positive electrode and the negative electrode and stabilizing the electrolyte chemical environment. The nickel-zinc battery prepared by the application has the characteristics of small floating charge voltage fluctuation, high capacity retention rate after long-term circulation and long cycle life, and is suitable for long-term floating charge scenes such as uninterruptible power supplies, communication standby power supplies and the like.

Inventors

GUO JIAYANG
WANG WEIDONG
WANG SHOUJUN
LIU YEYI
CAI JUN
LIANG JUNHAO
ZHANG CHENGLIN

Assignees

深圳市量能科技有限公司

Dates

Publication Date: 20260512
Application Date: 20260110

Claims (10)

1. The electrolyte for improving the float performance of the nickel-zinc battery is characterized by comprising basic alkaline electrolyte and a composite additive; the basic alkaline electrolyte consists of potassium hydroxide, sodium hydroxide, lithium hydroxide and deionized water; The composite additive consists of quaternary ammonium salt derivatives, organic phosphate compounds and borates; The addition amount of the quaternary ammonium salt derivative is 0.1-0.5 wt%, the addition amount of the organic phosphate compound is 0.05-0.3 wt%, and the addition amount of the borate is 0.03-0.2 wt%.
2. The electrolyte of claim 1 wherein the quaternary ammonium salt derivative is selected from tetrabutylammonium chloride or tetrapropylammonium bromide.
3. The electrolyte according to claim 1, wherein the organic phosphate compound is one or more selected from the group consisting of diethyl phosphite, tributyl phosphate, and dodecyl phosphate.
4. The electrolyte of claim 1, wherein the borate is selected from one or more of potassium borate, potassium metaborate, sodium borate, sodium metaborate.
5. The electrolyte according to claim 1, wherein the total concentration of potassium hydroxide, sodium hydroxide and lithium hydroxide in the basic alkaline electrolyte is 6-8 mol/L, wherein the molar ratio of potassium hydroxide, sodium hydroxide and lithium hydroxide is a: b: c, wherein a is 10-15, b is 0.5-2.0, and c is 0.5-1.5.
6. The electrolyte of claim 1 wherein the composite additive consists of tetrabutylammonium chloride, diethyl phosphite and potassium borate.
7. A method for preparing the electrolyte for improving the float performance of the nickel-zinc battery according to any one of claims 1 to 6, comprising the following steps: S1, preparing basic alkaline electrolyte; S2, adding the quaternary ammonium salt derivative, the organic phosphate compound and the borate into the basic alkaline electrolyte, and stirring and uniformly mixing to obtain the electrolyte for improving the float charging performance of the nickel-zinc battery.
8. The method according to claim 7, wherein the step S1 is to add the potassium hydroxide, sodium hydroxide and lithium hydroxide into deionized water, and mix the mixture with stirring to obtain the basic alkaline electrolyte.
9. The preparation method according to claim 8, wherein the step S1 of stirring and mixing is performed at a rotation speed of 300 r/min; and in the step S2, stirring and mixing are carried out at the rotating speed of 250 r/min.
10. Use of the electrolyte for improving the float performance of a nickel zinc battery according to any of claims 1-6 for the preparation of uninterruptible power supplies, communication backup power supplies or emergency energy storage devices.

Description

Electrolyte for improving float performance of nickel-zinc battery and application thereof Technical Field The invention relates to the technical field of secondary batteries, in particular to electrolyte for improving the floating charge performance of a nickel-zinc battery and application thereof. Background The nickel-zinc battery is considered to be one of ideal choices for replacing the traditional lead-acid battery and nickel-cadmium battery due to the advantages of high working voltage, high energy density, excellent power characteristics, relatively low cost, environmental friendliness and the like, and particularly has great application potential in the fields of uninterruptible power supplies, standby power supplies of communication base stations, emergency energy storage and the like. A common feature of these applications is that the battery is in a floating state of charge for a long period of time, i.e. continuously connected to the charging source to maintain full power, thereby ensuring instantaneous power supply when the main power supply is interrupted. However, nickel zinc batteries face serious technical challenges in commercial applications, particularly where long-term float-over is required. The performance bottleneck is mainly caused by the instability of the zinc cathode in alkaline electrolyte. Under the floating charge condition, the continuous charging voltage can aggravate corrosion and hydrogen evolution side reaction of the zinc electrode, so that not only are active substances and water in electrolyte consumed, but also the internal pressure of the battery can be increased, and potential safety hazards such as shell bulge and the like are caused. Meanwhile, the problems of dendrite growth and electrode deformation inherent in the zinc electrode in the circulation process can be continuously accumulated in a floating state of long-term tiny current, and the battery is extremely easy to puncture a diaphragm to cause internal short circuit of the battery, so that the battery suddenly fails. In addition, the electrolyte itself has stability problems such as carbonization caused by absorbing carbon dioxide in the air, lowering the ionic conductivity of the electrolyte and affecting the electrode performance. While the prior art attempts to suppress a particular problem, such as dendrite suppression alone or corrosion rate reduction, by adding single or dual component additives to the electrolyte, it is often difficult to address the complex coexistence of multiple degradation mechanisms under float conditions. These degradation factors are mutually interwoven and mutually promoted, so that the floating performance of the existing nickel-zinc battery is generally poor, the voltage fluctuation is large, the capacity attenuation is rapid, and the actual service life is far lower than the theoretical expectation, thereby limiting the wide application of the nickel-zinc battery in the field of key standby power supplies. Therefore, developing a comprehensive technical scheme capable of cooperatively solving the above technical problems and remarkably improving the float performance of the nickel-zinc battery has become a technical problem to be solved in the art. Disclosure of Invention Aiming at the defects of the prior art, the invention provides the electrolyte for improving the floating performance of the nickel-zinc battery and the application thereof, which solve the problems that the floating performance is poor and the cycle life is short due to the synergistic effect of various degradation mechanisms such as zinc negative pole dendrite growth, hydrogen evolution corrosion, electrolyte instability and the like in the application of the nickel-zinc battery requiring long-term floating in the uninterrupted power supply and the like in the prior art, and the existing additive scheme is difficult to provide a comprehensive solution. In order to achieve the aim, the invention is realized by the following technical scheme that the electrolyte for improving the float charging performance of the nickel-zinc battery comprises basic alkaline electrolyte and a composite additive; the basic alkaline electrolyte consists of potassium hydroxide, sodium hydroxide, lithium hydroxide and deionized water; The composite additive consists of quaternary ammonium salt derivatives, organic phosphate compounds and borates; The addition amount of the quaternary ammonium salt derivative is 0.1-0.5 wt%, the addition amount of the organic phosphate compound is 0.05-0.3 wt%, and the addition amount of the borate is 0.03-0.2 wt%. Preferably, the quaternary ammonium salt derivative is selected from tetrabutylammonium chloride or tetrapropylammonium bromide. Preferably, the organic phosphate compound is selected from one or more of diethyl phosphite, tributyl phosphate and dodecyl phosphate. Preferably, the borate is selected from one or more of potassium borate, potassium metaborate, sodium borate and sodium