Lead-acid storage battery electrolyte composite additive, electrolyte and preparation method thereof

Abstract

The invention relates to the technical field of a lead-acid storage battery electrolyte, and provides a lead-acid storage battery electrolyte composite additive, an electrolyte and a preparation method thereof. The electrolyte composite additive is prepared from the following components: hexadecyl trimethyl ammonium bromide, stannous mono-sulphate, organic sodium phosphonate and 1, 8-diazabicyclo [5.4. 0] undec-7-ene. The electrolyte composite additive provided by the invention solves the problems of fast battery capacity fading and short battery life of a lead-acid battery in a low-temperature environment, and improves the low-temperature resistance of the lead-acid battery.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of electrolyte of lead-acid storage batteries, and particularly relates to a composite additive for electrolyte of lead-acid storage batteries, electrolyte and a preparation method thereof. BACKGROUND

[0002] The lead-acid storage battery is widely applied in many fields such as automobile starting, communication base station and energy storage system due to low comprehensive cost, mature technology and high recovery rate. The electrolyte of the lead-acid storage battery is an important component of the lead-acid storage battery and plays a role in conducting ions and participating in electrochemical reactions.

[0003] The main components of the electrolyte are sulfuric acid and water, and generally, the mass fraction of the sulfuric acid is 25%-40%. The sulfuric acid concentration is different for lead-acid storage batteries with different purposes and types. In order to improve the performance and service life of the lead-acid battery, a suitable additive needs to be added to the electrolyte, and common additives include sodium sulfate, potassium sulfate, phosphoric acid, boric acid, organic compounds and the like. However, these additives cannot meet the demand of low-temperature working environment, so that the performance of the lead-acid battery is seriously reduced in the low-temperature environment, for example, the battery capacity is quickly attenuated and the battery service life is short. Therefore, a composite additive for electrolyte of lead-acid storage batteries which can improve the low-temperature resistance of the lead-acid battery needs to be developed. SUMMARY

[0004] In view of this, the application provides a composite additive for electrolyte of lead-acid storage batteries, electrolyte and a preparation method thereof. The additive can improve the problems of quick attenuation of battery capacity and short service life of the lead-acid battery in the low-temperature environment and improve the low-temperature resistance of the lead-acid battery.

[0005] The technical scheme of the application is achieved in the following manner. In a first aspect, the application provides a composite additive for electrolyte of lead-acid storage batteries, which comprises the following components: hexadecyl trimethyl ammonium bromide, stannous sulfate, organic phosphonate sodium salt and 1,8-diazabicyclo[5.4.0]undec-7-ene.

[0006] Specifically, the hexadecyl trimethyl ammonium bromide (CTAB) reduces the electrode / electrolyte interfacial tension, inhibits the deposition of lead sulfate (PbSO4) large crystals and optimizes the low-temperature ion migration rate. 2+ The Sn in the stannous sulfate (SnSO4) reacts with the lead electrode to generate a SnO2-Pb composite passivation layer, inhibits the hydrogen / oxygen evolution side reaction, reduces the plate corrosion and prolongs the service life of the battery. The organic phosphonate sodium salt is selectively adsorbed on the positive electrode PbO2 surface, avoids the irreversible PbSO4 conversion of the positive electrode, delays the consumption of the positive electrode active material and improves the service life; the organic phosphonate sodium salt complexes impurity ions (Fe 2+ , Cu 2+), reduce impurity erosion caused by dendritic growth and side reactions, and further stabilize performance. 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) complexes Pb 2+ Prevent the formation of dense lead sulfate deposits, while weakening the hydrogen bond network, reducing viscosity, and improving conductivity at low temperatures.

[0007] CTAB reduces the viscosity of the electrolyte, optimizes the reaction efficiency of the electrode surface, DBU destroys the hydrogen bond system and the complexation with metal ions enhances the ion migration rate, both of which synergistically improve the battery capacity and improve the ion migration rate in low temperature environment. At the same time, DBU limits the lead sulfate deposition, reduces the adverse effects of crystal size on electrode reaction activity under low temperature conditions. Organic phosphonate sodium salt protects the stability of the positive active material, slows down the irreversible conversion; SnSO4 forms a passivation layer to protect the negative electrode surface, both of which synergistically improve the battery cycle life. In addition, the passivation layer remains stable at low temperature, improves the utilization rate of active material, and further improves the low temperature performance.

[0008] On the basis of the above technical scheme, preferably, the mass ratio of the hexadecyl trimethyl ammonium bromide: stannous sulfate: organic phosphonate sodium salt: 1,8-diazabicyclo[5.4.0]undec-7-ene is 1-6: 2-9: 5-10: 2-8.

[0009] On the basis of the above technical scheme, preferably, the additive further comprises phosphatidylserine.

[0010] Specifically, although the above-mentioned additive can solve the low temperature resistance problem of lead-acid storage battery, the additive molecules will be detached from the electrode surface during multiple charge and discharge processes, resulting in insufficient regeneration ability of the protective layer. Therefore, the present application adds phosphatidylserine to the above-mentioned composite additive. The phospholipid molecules are anchored on the electrode surface through the hydrophobic chain, and the polar head group dynamically adjusts the orientation to form an interface film with self-repairing function. In addition, the ordered water molecule network in the phospholipid bilayer can reduce the ion migration activation energy and improve the discharge capacity of lead-acid storage battery in the environment.

[0011] On the basis of the above technical scheme, preferably, the concentration of the phosphatidylserine is: the mass ratio of hexadecyl trimethyl ammonium bromide is 4-8: 1-6.

[0012] On the basis of the above technical scheme, preferably, the organic phosphonate sodium salt is one of hydroxyethylidene diphosphonic acid disodium, ethylenediaminetetramethylene phosphonic acid pentasodium, diethylenetriamine pentamethylene phosphonic acid pentasodium and 2-phosphonobutane-1,2,4-tricarboxylic acid tetrasodium.

[0013] In a second aspect, the present application provides an electrolyte comprising an electrolyte composite additive.

[0014] On the basis of the above technical scheme, preferably, the solvent of the electrode liquid is a dilute sulfuric acid solution with a density of 1.2-1.5 g / cm 3 .

[0015] On the basis of the above technical scheme, preferably, in the electrolyte, the concentration of cetyltrimethylammonium bromide is 0.1wt%-0.6wt%, the concentration of stannous sulfate is 0.2wt%-0.9wt%, the concentration of organic phosphonate sodium salt is 0.5wt%-1.0wt%, the concentration of 1,8-diazabicyclo[5.4.0]undec-7-ene is 0.2wt%-0.8wt%, and the concentration of phosphatidylserine is 0.4wt%-0.8wt%.

[0016] In a third aspect, the application provides a preparation method of the electrolyte, comprising the following steps: preparing a dilute sulfuric acid solution with a density of 1.2-1.5 g / cm 3 , and sequentially adding cetyltrimethylammonium bromide, stannous sulfate, organic phosphonate sodium salt, 1,8-diazabicyclo[5.4.0]undec-7-ene and phosphatidylserine, stirring uniformly, and then filtering and removing impurities to obtain the electrolyte.

[0017] On the basis of the above technical scheme, preferably, in order to prevent stannous sulfate and 1,8-diazabicyclo[5.4.0]undec-7-ene from being oxidized or decomposed, when stannous sulfate is added, the temperature of the solution system is lower than 40℃; and when 1,8-diazabicyclo[5.4.0]undec-7-ene is added, the temperature of the solution system is lower than 50℃.

[0018] The lead-acid battery electrolyte composite additive, the electrolyte and the preparation method thereof have the following beneficial effects compared with the prior art: (1) The CTAB and DBU in the electrolyte composite additive of the application cooperatively improve the ion migration rate in a low-temperature environment and improve the battery capacity. The organic phosphonate sodium salt and SnSO4 cooperatively improve the battery cycle life, and in addition, the passivation layer remains stable at low temperature, which is conducive to improving the utilization rate of active substances and further improving the low-temperature performance.

[0019] (2) The phosphatidylserine in the composite additive of the application, the phospholipid molecules of which are anchored on the electrode surface through the hydrophobic chain, and the polar head group dynamically adjusts the orientation to form an interface film with self-repairing function. In addition, the ordered water molecule network in the phospholipid bilayer can reduce the ion migration activation energy, further improving the low-temperature resistance. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0021] The cetyltrimethylammonium bromide (CTAB), stannous sulfate, disodium hydroxyethylidene-1,1-diphosphonate, 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and phosphatidylserine described in the present application are all purchased from the market. Among them, the phosphatidylserine (CAS: 51446-62-9) is purchased from Jiangxi Ruwei Biological Technology Co., Ltd., and the organic phosphonate sodium salt is purchased from Shandong Kerry Chemical Co., Ltd.

[0022] Example 1 The electrolyte composite additive for improving the performance of lead-acid batteries in this embodiment comprises the following components: cetyltrimethylammonium bromide, stannous sulfate, disodium hydroxyethylidene-1,1-diphosphonate and 1,8-diazabicyclo[5.4.0]undec-7-ene.

[0023] The preparation method of the electrolyte is as follows: S1, add concentrated sulfuric acid into ultrapure water to prepare 1L of dilute sulfuric acid solution with a density of 1.347g / cm 3 ; S2, add 4g of cetyltrimethylammonium bromide into the dilute sulfuric acid, stir at 300 rpm for 10 min until completely dissolved; then add 5g of stannous sulfate at 30-40℃, continue to stir for 10 min; then add 8g of disodium hydroxyethylidene-1,1-diphosphonate, stir at 600 rpm for 15 min to ensure that it is completely dissolved in the acidic environment; then slowly add 5g of 1,8-diazabicyclo[5.4.0]undec-7-ene, control the temperature ≤50℃, stir for 20 min. Finally, remove the undissolved impurities through a 0.45 μm filter membrane to ensure that the electrolyte is transparent and free of particles.

[0024] Example 2 The electrolyte composite additive for improving the performance of lead-acid batteries in this embodiment comprises the following components: cetyltrimethylammonium bromide, stannous sulfate, disodium hydroxyethylidene-1,1-diphosphonate and 1,8-diazabicyclo[5.4.0]undec-7-ene and phosphatidylserine.

[0025] The preparation method of the electrolyte is as follows: S1, add concentrated sulfuric acid into ultrapure water to prepare 1L of dilute sulfuric acid solution with a density of 1.347g / cm 3 ; S2, 4 g of cetyltrimethylammonium bromide was added to dilute sulfuric acid, stirred at 300 rpm for 10 min to completely dissolve; then 5 g of stannous sulfate was added at 30-40 °C, and stirring was continued for 10 min; then 8 g of ethylenediaminetetra(methylene) phosphonic acid pentasodium was added, stirred at 600 rpm for 15 min to ensure complete dissolution in the acidic environment; then 5 g of 1,8-diazabicyclo[5.4.0]undec-7-ene was slowly added, the temperature was controlled to be ≤ 50 °C, and stirring was continued for 20 min; 6 g of phosphatidylserine was slowly added, and stirring was continued for 30 min until the system was uniform. Finally, the undissolved impurities were removed by a 0.45 μm filter membrane to ensure that the electrolyte was transparent and particle-free.

[0026] Example 3 The electrolyte composite additive for improving the performance of lead-acid batteries of this example comprises the following components: cetyltrimethylammonium bromide, stannous sulfate, ethylenediaminetetra(methylene) phosphonic acid pentasodium, and 1,8-diazabicyclo[5.4.0]undec-7-ene and phosphatidylserine.

[0027] The preparation method of the electrolyte is as follows: S1, concentrated sulfuric acid was added to ultrapure water to prepare 1 L of dilute sulfuric acid solution with a density of 1.347 g / cm 3 ; S2, 4 g of cetyltrimethylammonium bromide was added to dilute sulfuric acid, stirred at 300 rpm for 10 min to completely dissolve; then 5 g of stannous sulfate was added at 30-40 °C, and stirring was continued for 10 min; then 8 g of ethylenediaminetetra(methylene) phosphonic acid pentasodium was added, stirred at 600 rpm for 15 min to ensure complete dissolution in the acidic environment; then 5 g of 1,8-diazabicyclo[5.4.0]undec-7-ene was slowly added, the temperature was controlled to be ≤ 50 °C, and stirring was continued for 20 min; 6 g of phosphatidylserine was slowly added, and stirring was continued for 30 min until the system was uniform. Finally, the undissolved impurities were removed by a 0.45 μm filter membrane to ensure that the electrolyte was transparent and particle-free.

[0028] Example 4 The electrolyte composite additive for improving the performance of lead-acid batteries of this example comprises the following components: cetyltrimethylammonium bromide, stannous sulfate, ethylenediaminetetra(methylene) phosphonic acid pentasodium, and 1,8-diazabicyclo[5.4.0]undec-7-ene and phosphatidylserine.

[0029] The preparation method of the electrolyte is as follows: S1, concentrated sulfuric acid was added to ultrapure water to prepare 1 L of dilute sulfuric acid solution with a density of 1.347 g / cm 3 ; S2, 1 g of cetyltrimethylammonium bromide was added to dilute sulfuric acid, stirred at 300 rpm for 10 min to complete dissolution; then 3 g of stannous sulfate was added at 30-40 °C, and stirring was continued for 10 min; then 5 g of diethylenetriamine pentakis(methylene) phosphonic acid pentasodium was added, and stirring was carried out at 600 rpm for 15 min to ensure complete dissolution in the acidic environment; then 4 g of 1,8-diazabicyclo[5.4.0]undec-7-ene was slowly added, with the temperature controlled at ≤ 50 °C, and stirring was carried out for 20 min; 4 g of phosphatidylserine was pre-dissolved in water and then added to the electrolyte, and stirring was carried out for 30 min to ensure uniformity of the system. Finally, the undissolved impurities were removed by 0.45 μm filter membrane to ensure that the electrolyte was transparent and free of particles.

[0030] Example 5 The electrolyte composite additive for improving the performance of lead-acid batteries of this example comprises the following components: cetyltrimethylammonium bromide, stannous sulfate, organic phosphonate sodium salt (disodium hydroxyethylidene diphosphonate, ethylenediamine tetra(methylene) phosphonic acid pentasodium, diethylenetriamine pentakis(methylene) phosphonic acid pentasodium, and 2-phosphonobutane-1,2,4-tricarboxylic acid tetrasodium), and 1,8-diazabicyclo[5.4.0]undec-7-ene and phosphatidylserine.

[0031] The preparation method of the electrolyte is as follows: S1, concentrated sulfuric acid was added to ultrapure water to prepare 1 L of dilute sulfuric acid solution with a density of 1.347 g / cm 3 ; S2, 5 g of cetyltrimethylammonium bromide was added to dilute sulfuric acid, stirred at 300 rpm for 10 min to complete dissolution; then 2 g of stannous sulfate was added at 30-40 °C, and stirring was continued for 10 min; then 10 g of organic phosphonate sodium salt was added, and stirring was carried out at 600 rpm for 15 min to ensure complete dissolution in the acidic environment; then 2 g of 1,8-diazabicyclo[5.4.0]undec-7-ene was slowly added, with the temperature controlled at ≤ 50 °C, and stirring was carried out for 20 min; 5 g of phosphatidylserine was pre-dissolved in water and then added to the electrolyte, and stirring was carried out for 30 min to ensure uniformity of the system. Finally, the undissolved impurities were removed by 0.45 μm filter membrane to ensure that the electrolyte was transparent and free of particles.

[0032] Example 6 The electrolyte composite additive for improving the performance of lead-acid batteries of this example comprises the following components: cetyltrimethylammonium bromide, stannous sulfate, organic phosphonate sodium salt (disodium hydroxyethylidene diphosphonate, ethylenediamine tetra(methylene) phosphonic acid pentasodium, diethylenetriamine pentakis(methylene) phosphonic acid pentasodium, and 2-phosphonobutane-1,2,4-tricarboxylic acid tetrasodium), and 1,8-diazabicyclo[5.4.0]undec-7-ene and phosphatidylserine.

[0033] The preparation method of the electrolyte is as follows: S1, concentrated sulfuric acid was added to ultrapure water to prepare a dilute sulfuric acid solution 1 L with a density of 1.347 g / cm 3 ; S2, 6 g of cetyltrimethylammonium bromide was added to the dilute sulfuric acid and stirred at 300 rpm for 10 min until completely dissolved; then 8 g of stannous sulfate was added at 30-40 °C and stirred for another 10 min; then 10 g of organic phosphonate sodium salt was added and stirred at 600 rpm for 15 min to ensure complete dissolution in the acidic environment; then 7 g of 1,8-diazabicyclo[5.4.0]undec-7-ene was slowly added while controlling the temperature ≤ 50 °C and stirred for 20 min; 7 g of phosphatidylserine was pre-dissolved in water and then added to the electrolyte and stirred for 30 min until the system was uniform. Finally, the undissolved impurities were removed by a 0.45 μm filter membrane to ensure that the electrolyte was transparent and free of particles.

[0034] Example 7 The electrolyte composite additive for improving the performance of lead-acid batteries of this example includes the following components: cetyltrimethylammonium bromide, stannous sulfate, 2-phosphonobutane-1,2,4-tricarboxylic acid tetrasodium salt, and 1,8-diazabicyclo[5.4.0]undec-7-ene and phosphatidylserine.

[0035] The preparation method of the electrolyte is as follows: S1, concentrated sulfuric acid was added to ultrapure water to prepare a dilute sulfuric acid solution 1 L with a density of 1.347 g / cm 3 ; S2, 3 g of cetyltrimethylammonium bromide was added to the dilute sulfuric acid and stirred at 300 rpm for 10 min until completely dissolved; then 6 g of stannous sulfate was added at 30-40 °C and stirred for another 10 min; then 9 g of 2-phosphonobutane-1,2,4-tricarboxylic acid tetrasodium salt was added and stirred at 600 rpm for 15 min to ensure complete dissolution in the acidic environment; then 8 g of 1,8-diazabicyclo[5.4.0]undec-7-ene was slowly added while controlling the temperature ≤ 50 °C and stirred for 20 min; 8 g of phosphatidylserine was pre-dissolved in water and then added to the electrolyte and stirred for 30 min until the system was uniform. Finally, the undissolved impurities were removed by a 0.45 μm filter membrane to ensure that the electrolyte was transparent and free of particles.

[0036] Comparative Example 1 Comparative Example 1 is the same as Example 1 except that the electrolyte composite additive lacks cetyltrimethylammonium bromide.

[0037] Comparative Example 2 Comparative Example 2 is the same as Example 1 except that the electrolyte composite additive lacks stannous sulfate.

[0038] Comparative Example 3 Comparative Example 3 is the same as Example 1 except that the electrolyte composite additive lacks disodium hydroxyethylidene diphosphonate.

[0039] Comparative Example 4 Comparative Example 4 is the same as Example 1 except that the electrolyte composite additive lacks 1,8-diazabicyclo[5.4.0]undec-7-ene.

[0040] Comparative Example 5 The electrolyte of Comparative Example 5 contains no composite additive, but only a dilute sulfuric acid solution with a density of 1.347 g / cm 3 .

[0041] Comparative Example 6 Comparative Example 6 is the same as Example 1 except that the concentration of cetyltrimethylammonium bromide in the electrolyte composite additive exceeds the defined range, specifically 12 g / L.

[0042] Comparative Example 7 Comparative Example 7 is the same as Example 1 except that the concentration of stannous sulfate in the electrolyte composite additive exceeds the defined range, specifically 18 g / L.

[0043] Comparative Example 8 Comparative Example 8 is the same as Example 1 except that the concentration of disodium hydroxyethylidene diphosphonate in the electrolyte composite additive exceeds the defined range, specifically 20 g / L.

[0044] Comparative Example 9 Comparative Example 9 is the same as Example 1 except that the concentration of 1,8-diazabicyclo[5.4.0]undec-7-ene in the electrolyte composite additive exceeds the defined range, specifically 15 g / L.

[0045] Comparative Example 10 Comparative Example 10 is the same as Example 2 except that the concentration of phosphatidylserine in the electrolyte composite additive exceeds the defined range, specifically 16 g / L.

[0046] The lead-acid battery electrolytes prepared according to the examples and comparative examples were respectively added to prepared 5 Ah batteries, which were then subjected to formation using a battery test system ARBIN. Three batteries were prepared for each example and comparative example, and the cycle life and -30 °C low-temperature performance were tested.

[0047] -30 °C low-temperature discharge: the batteries were placed in a low-temperature chamber, the temperature of which was set to -30 °C. After 24 hours, the batteries were discharged at a current of 0.5 C in a -30 °C environment, and the time to 1 V was recorded.

[0048] -30℃ low temperature capacity: temperature set to -30℃, after 24 hours, discharge at 0.5C current in -30℃ environment, record the discharge capacity value.

[0049] Charge acceptance: charge acceptance discharge 5h with current value of maximum discharge capacity divided by 10, then put into low temperature box (0℃±1℃) for 20h, then take out the battery and charge at 2.4V constant voltage, record the charge acceptance current A after 10min.

[0050] The detection method of cycle life refers to GB / T5008.1-2013, and the test temperature is -30℃. When the discharge capacity of the battery is lower than 80% of the rated capacity, the cycle life ends.

[0051] Table 1 performance test results of lead-acid storage battery

[0052] As can be seen from Table 1, the charge-discharge capacity, capacity, and life of the lead-acid storage battery assembled using the electrolyte of the examples are all higher than those of the comparative examples, proving that the use of the composite additive of the application greatly improves the low-temperature resistance of the lead-acid storage battery.

[0053] As can be seen from Examples 1-2, the charge-discharge capacity, capacity, and life of the lead-acid storage battery are greatly improved after the addition of phosphatidylserine, indicating that phosphatidylserine inhibits the shedding of the active material film through its molecular film, and in addition, the hydrophobic chain of phosphatidylserine is complexed with DBU, improving the conductivity, optimizing the mass transfer at low temperature, and further improving the low-temperature resistance of the lead-acid storage battery.

[0054] As can be seen from Comparative Examples 1-4, the low-temperature resistance of the lead-acid storage battery is greatly reduced when any of cetyltrimethylammonium bromide, stannous sulfate, organic phosphonate sodium salt, and 1,8-diazabicyclo[5.4.0]undec-7-ene is absent, thereby proving the synergistic effect between the components. As can be seen from Comparative Examples 6-10, the amount of cetyltrimethylammonium bromide, stannous sulfate, organic phosphonate sodium salt, 1,8-diazabicyclo[5.4.0]undec-7-ene, and phosphatidylserine is not the higher the better. When the amount exceeds the limited range, the viscosity of the electrolyte increases, ion migration is blocked, in addition, electrochemical side reactions are also produced, thereby leading to a decrease in the low-temperature resistance of the lead-acid storage battery.

[0055] The above only describes the preferred embodiments of the application and is not intended to limit the application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the application shall be included in the protection scope of the application.

Claims

1. A composite additive for lead-acid battery electrolyte, characterized in that: The invention comprises the following components: hexadecyltrimethylammonium bromide, stannous sulfate, organic phosphonic acid sodium salt and 1,8-diazabicyclo[5.4.0]undec-7-ene; The organic phosphonic acid sodium salt is one of disodium hydroxyethylidene diphosphonate, pentasodium ethylenediaminetetramethylenephosphonate, pentasodium diethylenetriaminepentamethylenephosphonate and tetrasodium 2-phosphonobutane-1,2,4-tricarboxylate.

2. The lead-acid battery electrolyte composite additive according to claim 1, wherein: The mass ratio of hexadecyltrimethylammonium bromide:stannous sulfate:organic phosphonic acid sodium salt:1,8-diazabicyclo[5.4.0]undec-7-ene is 1-6:2-9:5-10:2-8.

3. The lead-acid battery electrolyte composite additive according to claim 2, wherein: The additive also includes phosphatidylserine.

4. The lead-acid battery electrolyte composite additive according to claim 3, wherein: The concentration of the phosphatidylserine is such that the mass ratio of hexadecyltrimethylammonium bromide is 4-8:1-6.

5. An electrolyte, characterized in that: The electrolyte composite additive comprises the electrolyte composite additive according to any one of claims 1 to 4.

6. An electrolyte according to claim 5, characterized in that: The electrolyte solvent has a density of 1.2-1.5 g / cm 3 of dilute sulfuric acid solution.

7. An electrolyte according to claim 6, characterized in that: In the electrolyte, the concentration of hexadecyltrimethylammonium bromide is 0.1wt%-0.6wt%, the concentration of stannous sulfate is 0.2wt%-0.9wt%, the concentration of organic phosphonic acid sodium salt is 0.5wt%-1.0wt%, the concentration of 1,8-diazabicyclo[5.4.0]undec-7-ene is 0.2wt%-0.8wt%, and the concentration of phosphatidylserine is 0.4wt%-0.8wt%.

8. The method for preparing an electrolyte according to any one of claims 5 to 7, wherein: The following steps are involved: Preparation density is 1.2-1.5g / cm 3 To a dilute sulfuric acid solution, cetyltrimethylammonium bromide, stannous sulfate, sodium salt of an organic phosphonate, 1,8-diazabicyclo[5.4.0]undec-7-ene and phosphatidylserine were added in that order, the mixture was stirred evenly, and the electrolyte was obtained by filtering and removing impurities.

9. The method for preparing an electrolyte according to claim 8, wherein: When stannous sulfate is added, the temperature of the solution system is lower than 40°C; when 1,8-diazabicyclo[5.4.0]undec-7-ene is added, the temperature of the solution system is lower than 50°C.

Images