CN-121991643-A - Heat absorbing material for lead storage battery electrolyte and low-temperature valve-controlled sealed lead storage battery

Abstract

The invention discloses a heat-absorbing material for lead storage battery electrolyte and a low-temperature valve-control sealed lead storage battery. The heat absorbing material for the lead storage battery electrolyte is prepared by mixing urea and anhydrous magnesium sulfate according to the mass ratio of 4-5:1 to prepare micron-sized particles, and then coating a polyvinyl alcohol film on the surface of the particles, wherein the coating rate of the polyvinyl alcohol film is 85% -95%, and the area of the surface of the particles, which is not coated with the polyvinyl alcohol film, is used as the area for the electrolyte to permeate into during use. By adopting an active heat absorption mechanism, the PVA coating material is continuously decomposed and absorbed within 1 hour after acid addition, the internal peak temperature of the battery is reduced from about 90 ℃ to about 65 ℃, the decomposition and dissolution of the organic expanding agent are greatly reduced, and the problem of high-temperature loss of the organic expanding agent in the traditional process is solved.

Inventors

• CHEN QUN
• NI QIANYONG
• GAO KUI
• CHEN YUTING
• LI GUIFA
• HU GUOZHU
• ZHANG GUOQIN
• SHE QIULI

Assignees

• 天能电池集团股份有限公司

Dates

Publication Date

20260508

Application Date

20251229

Claims (8)

1. 1. A heat absorbing material for lead storage battery electrolyte is characterized in that urea and anhydrous magnesium sulfate are mixed according to the mass ratio of 4-5:1 to prepare micron-sized particles, then polyvinyl alcohol films are partially coated on the surfaces of the particles, the coating rate of the polyvinyl alcohol films is 85% -95%, and the areas, which are not coated with the polyvinyl alcohol films, on the surfaces of the particles are used as areas for the electrolyte to permeate into during use.
2. 2. The heat absorbing material for lead storage battery electrolyte according to claim 1, wherein the coating thickness of the polyvinyl alcohol film is 2-8 μm.
3. 3. The heat absorbing material for lead storage battery electrolyte according to claim 1, wherein the particle size of the fine particles is 50 to 150 μm.
4. 4. The heat absorbing material for lead storage battery electrolyte according to claim 1, wherein when the polyvinyl alcohol film is prepared, polyvinyl alcohol is firstly dispersed in water according to the mass ratio of 5% -8% to obtain a polyvinyl alcohol mother solution, then boric acid is added into the polyvinyl alcohol mother solution as a cross-linking agent to crosslink the polyvinyl alcohol mother solution to obtain a polyvinyl alcohol cross-linked solution, the polyvinyl alcohol cross-linked solution is sprayed on the surfaces of the particles through a spraying method, and the particles coated with the polyvinyl alcohol film are formed by drying.
5. 5. The heat absorbing material for lead storage battery electrolyte according to claim 4, wherein after drying, the coated fine particles are sieved and the coated fine particles having a particle diameter in the range of 50 to 200 μm are collected.
6. 6. The low-temperature valve-controlled sealed lead storage battery comprises electrolyte and is characterized in that the heat-absorbing material for the lead storage battery electrolyte according to any one of claims 1-5 is added into the electrolyte, and the addition amount of the heat-absorbing material for the lead storage battery electrolyte is 0.5% -3% of the mass of the electrolyte.
7. 7. The low temperature valve-regulated sealed lead acid battery of claim 6, wherein said electrolyte is a sulfuric acid solution having a density of 1.20-1.25 g/ml.
8. 8. The low temperature valve-regulated sealed lead acid battery according to claim 6, wherein the heat absorbing material for the electrolyte of the lead acid battery is subjected to acid addition within 5-15 minutes after being added to the electrolyte.

Description

Heat absorbing material for lead storage battery electrolyte and low-temperature valve-controlled sealed lead storage battery Technical Field The invention belongs to the technical field of lead storage batteries, and particularly relates to a heat-absorbing material for a lead storage battery electrolyte and a low-temperature valve-control sealed lead storage battery. Background The lead storage battery is widely applied to various electric devices due to low cost and high safety, but the running performance under the low-temperature condition is always a core short plate, and is also the direction of continuous research and study of the industry. The existing acid storage battery manufacturing process generally adopts the process of 'pasting a raw polar plate to assemble a semi-finished product-adding acid to charge to prepare a finished product'. With the continuous application of new technology and new technology, the production mode of the green polar plate is changed from the traditional gravity casting mode to the mode that positive and negative are net punching, namely the so-called positive and negative double net punching battery. Research shows that the semi-finished battery can generate concentrated chemical reaction between sulfuric acid and various basic lead sulfate, lead oxide and the like in the green plate after acid is added to about 1 hour before charging, and the electrochemical oxidation-reduction reaction generated in the charging process is overlapped to release a large amount of heat in a short time. The existing internal formation charging supporting facilities mostly adopt process cooling modes such as air cooling, circulating water and the like, heat dissipation is mainly carried out in a conduction mode, a layer of plastic shell is arranged, the heat dissipation rate is low, the short-time concentrated heat generation condition at the stage cannot be dealt with, the internal temperature of the battery is rapidly increased, and the battery reaches a peak value after about 1 hour of charging by adding acid. The gravity casting polar plate production process has acid spraying or acid soaking process, the part of basic lead sulfate and lead oxide inside the consumed polar plate part, and the double-punching net polar plate adopts the production process without acid spraying or acid soaking, so the reaction after charging and acid adding is more intense, the temperature rise is more obvious, and the highest temperature of the central position of the polar group can reach 90-95 ℃. The high temperature can cause the key organic expansion agent (such as sodium lignin sulfonate and humic acid) in the negative plate and paste formula to be decomposed and separated out in a large amount. The organic expanding agent such as sodium lignin sulfonate, humic acid and the like added in the negative plate and paste formula is a core component for improving the low-temperature performance of the battery, and can improve the ion conduction efficiency in a low-temperature environment by maintaining the pore structure of the negative plate and inhibiting passivation of lead ions. However, the thermal stability of such organic materials is extremely sensitive to temperature changes, and high temperatures can directly lead to their decomposition and precipitation, and the higher the temperature, the more serious the decomposition. Research shows that at the conventional temperature (25 ℃), the decomposition rates of sodium lignosulfonate and humic acid are lower than 3%, the sodium lignosulfonate can play a role stably, when the temperature is raised to 60 ℃, the decomposition rate of sodium lignosulfonate is increased to 8% -10%, the decomposition rate of humic acid is increased to 5% -7%, and when the temperature reaches about 90 ℃ in the battery in the charging process, the decomposition rate of sodium lignosulfonate is increased to 35% -45%, and simultaneously, the dissolution rate of sodium lignosulfonate is increased to 25% -30%, and the dissolution rate of humic acid is about 20% -25%. Therefore, the organic expanding agents such as sodium lignin sulfonate, humic acid and the like are decomposed and dissolved in a large quantity at high temperature in the early stage of internal formation, so that the low-temperature discharge performance of the battery is damaged, the capacity is greatly attenuated (50% when 20% -30% are serious), the service life of the battery is shortened, the return rate of the battery in winter is greatly increased, and the battery becomes a technical pain point to be solved in the industry urgently. The method for controlling the temperature of the internal formation process has a plurality of descriptions, including the system control by an intelligent water cooling mode, the internal formation charging process control and the like. For example, the invention application with publication number CN117766890A discloses intelligent temperature control high-efficiency rapid