KR20190019412A - Electrolyte for a lead storage battery and lead storage battery comprising it - Google Patents

Abstract

The present invention relates to an electrolyte for a lead storage battery and a lead storage battery comprising the same. More particularly, the present invention relates to an electrolyte for a lead storage battery and a lead storage battery comprising the same. According to the present invention, it is possible to obtain an effect for reducing a stratification phenomenon by adding a specific ionic liquid to an electrolyte containing distilled water and sulfuric acid (H_2SO_4) to lower the hydrogen and oxygen generation overvoltage and promote bubble generation.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrolytic solution for a lead-acid battery, and a lead-

The present invention relates to an electrolytic solution for a lead-acid battery and a lead-acid battery including the same, and more particularly, to an electrolytic solution for electrolytic solution containing hydrogen and oxygen generation overvoltage by adding a specific ionic liquid to an electrolytic solution containing distilled water and sulfuric acid (H ₂ SO ₄ ) To thereby reduce the stratification phenomenon. The present invention also relates to a lead-acid battery including the same.

Conventional lead-acid batteries for automobiles have mainly used SLI (Starting, Lighting, Ignition). Recently, due to an increase in fuel efficiency improvement needs, a charging control system (power generation control) for suppressing the generation amount of an idling stop system (ISG), an alternator and an engine efficiency is developed, and kinetic energy is converted into electric energy Such as a regenerative braking system (RBS), which accumulates a large amount of fuel. In particular, the lead-acid battery under the idling stop system (ISG) frequently experiences a deep discharge and frequent charging, and the state of partial charge (PSOC) which is not fully charged is mainly maintained. It decreases.

Lead batteries consist of lead dioxide (PbO ₂ ) in the anode, lead (Pb) in the cathode, and diluted sulfuric acid (H ₂ SO ₄ ) in the electrolyte. According to the discharge reaction of the lead-acid battery, lead sulfate (PbSO ₄ ) is produced in the positive electrode and the negative electrode, and water (H ₂ O) is produced in the electrolyte. According to the charging reaction of the lead-acid battery, lead sulfate (PbSO ₄ ) as a discharge product is returned to lead dioxide (PbO ₂ ) and lead (Pb) respectively in the positive electrode and negative electrode, and sulfuric acid (H ₂ SO ₄ ) is generated in the electrolyte .

[Chemical reaction at charge / discharge of lead accumulator]

PbO ₂ (anode) + Pb (cathode) + 2 H ₂ SO ₄ ↔ 2 PbSO ₄ + 2 H ₂ O

When the charge / discharge is repeated, the lead sulfate (PbSO ₄ ) produced in the discharge reaction is not completely decomposed to form a film on the electrode as lead sulfate (PbSO ₄ ) crystals, and lead sulfate (PbSO ₄ ) The voltage of the lead-acid battery is lowered, and the flow of the current is reduced, thereby deteriorating the performance of the lead-acid battery.

In addition, since lead sulfate (PbSO ₄ ) is heavier than water molecules, it precipitates to the bottom of the electrolyte due to gravity, thereby causing a phenomenon in which the concentration at the bottom of the electrolyte increases and the concentration at the top decreases. do.

The lead-acid battery stratification phenomenon is a phenomenon in which sulfuric acid ion (SO ₄ ^2- ) having a specific gravity larger than water (OH ^- ) sinks to the bottom of the battery due to gravity and a difference in electrolyte specific gravity between the battery and the lower battery occurs. Until the stratification phenomenon occurs, the specific gravity between the upper and lower portions of the battery is maintained uniformly. However, when stratification occurs, the upper portion becomes low specific gravity and the lower portion becomes high gravity. When the concentration of sulfuric acid in the lower portion of the electrolyte is increased, the charge / discharge reaction between the upper and lower portions becomes uneven. That is, the lower side reactivity is larger than the upper side reactivity. As a result, a large amount of lead sulfate (PbSO ₄ ), which is a reaction product, is generated in the lower portion of the upper portion, resulting in a reaction deviation between the upper portion and the lower portion. In addition, lead sulfate (PbSO ₄ ) produced in a large amount at the bottom accumulates without being restored to the original active material (anode: PbO ₂ , cathode: Pb) upon charging. A large amount of lead sulfate (PbSO ₄ ) is adhered to the lower part to become inactive in the charge / discharge reaction, and the overall reaction specific surface area is reduced. This results in a reduction in the reaction specific surface area, which leads to a decrease in the capacity, resulting in a reduction in the battery endurance life.

In order to solve the electrolytic solution stratification phenomenon which is the main life end of the lead acid battery, a method of laminating a separator of positive electrode, negative electrode and glass fiber as a method of suppressing stratification itself has been proposed (Patent Document 1). The method disclosed in Patent Document 1 has a structure in which a separator made of a glass fiber is laminated on the positive electrode and the negative electrode, which has a fatal disadvantage that the internal resistance of the battery increases sharply, and the effect of improving the stratification phenomenon is not significant.

Japanese Patent Application Laid-Open No. 2001-102027

The present invention is directed to a novel lead-acid battery electrolyte and a lead-acid battery containing the same, which can solve the problem that the performance of the battery is deteriorated and the service life is shortened due to lead sulfate (PbSO ₄ ) formed on the electrode of the lead- To provide,

In order to solve the above-described technical problem, the present invention provides an electrolytic solution for a lead-acid battery including distilled water and sulfuric acid (H ₂ SO ₄ ), wherein mono-butylammonium hydrogensulfate (mono-BAHS), di-butylammonium hydrogensulfate at least one ion selected from the group consisting of di-BAHS, tri-butylammonium hydrogensulfate (tri-BAHS), tetra-butylammonium hydrogensulfate (tetra-BAHS) and isopentylammonium hydrogensulfate (IPAHS) Thereby providing an electrolytic solution for a lead-acid battery.

According to a preferred embodiment of the present invention, the ionic liquid may be contained in an amount of 0.001 to 2% by weight in the electrolytic solution.

According to a more preferred embodiment of the present invention, the ionic liquid may be contained in an amount of 0.1 to 0.5% by weight in the electrolytic solution.

According to a more preferred embodiment of the present invention, mono-butylammonium hydrogen sulfate (BAHS) as the ionic liquid may be contained in an amount of 0.1 to 0.5% by weight in the electrolytic solution.

In order to solve the above-mentioned technical problem, the present invention provides a lead-acid battery including the electrolyte.

The electrolytic solution provided by the present invention further includes a specific ionic liquid, thereby lowering hydrogen and oxygen generation overvoltage, promoting bubble generation, and reducing the stratification phenomenon.

According to the present invention, improvement of the stratification phenomenon achieves an effect of improving the durability by 25% (evaluation criteria of the durability cycle performance) compared with the conventional lead-acid battery. By improving the durability of these lead acid batteries, it is possible to reduce the claim due to battery starting failure, and it is also possible to reduce the cost by replacing the expensive AGM battery applied to the power generation control system application vehicle.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a graph comparing hydrogen and oxygen generating potentials in a lead acid battery having a conventional electrolyte system or an electrolytic solution system containing an ionic liquid proposed by the present invention. FIG.
FIG. 2 is a graph showing the relationship between the amount of lead sulfate (PbSO ₄ ) present in the active material and the amount of lead sulfate (PbSO ₄ ) present in a lead acid battery having an electrolytic solution system containing (A) a conventional electrolytic solution system or (B) (TEM) photograph.
FIG. 3 is a graph showing the hydrogen generation overvoltage according to the kind and content of the ionic liquid contained in the electrolytic solution.
4 is a graph for confirming the change in the difference between the specific gravity of the electrolyte and the specific gravity of the electrolyte according to the type of the ionic liquid.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

In the present invention, a specific ionic liquid is further contained in an electrolytic solution for a lead-acid battery containing distilled water and sulfuric acid (H ₂ SO ₄ ) to improve a stratification phenomenon which is a durability deterioration factor of the lead-acid battery. In addition, the size of lead sulfate (PbSO ₄ ) crystals formed on the electrode plate during lead battery discharge was reduced to increase the reversibility to lead dioxide (PbO ₂ ) state during charging, thereby increasing overall durability.

The electrolyte according to the invention comprises distilled water, sulfuric acid (H ₂ SO ₄ ) and an ionic liquid of character. Specifically, sulfuric acid (H ₂ SO ₄ ) is added to distilled water to prepare a sulfuric acid solution, and an ionic liquid is added thereto to prepare an electrolytic solution. The sulfuric acid solution is prepared so as to have a concentration of 30 to 40 wt%.

The ionic liquids used in the present invention are mono-butylammonium hydrogensulfate (mono-BAHS), di-butylammonium hydrogen sulfate (di-BAHS), tri-butylammonium hydrogensulfate (tri- Butylammonium hydrogensulfate (tetra-BAHS) and isopentylammonium hydrogen sulfate (IPAHS). And more preferably mono-butylammonium hydrogen sulfate (mono-BAHS).

The ionic liquid does not form crystals due to the asymmetry of the sizes of cations and anions, is present in a liquid state, and maintains a liquid state in a wide temperature range. Further, the ionic liquid has a vapor pressure of almost zero, and is safely present in a liquid state even at a high temperature (400 DEG C) where the solvent usually evaporates. Further, the ionic liquid is chemically stable and nonflammable in spite of being an organic material because it is nonvolatile. High mobility of ions, high ionic conductivity, and electrochemically stable characteristics. The ionic liquid has high ionic conductivity, maintains liquid state in a wide temperature range, is nonflammable, has a wide potential window, and is electrochemically stable.

The ionic liquid may be contained in the electrolytic solution in the range of 0.001 to 2 wt%, preferably 1.0 to 0.5 wt%. If the content of the ionic liquid is less than 0.001% by weight and a small amount of the ionic liquid is contained, the effect of the additive can hardly be expected. On the other hand, if the content of the ionic liquid exceeds 2% by weight, the amount of - ions may be excessively increased and the electrochemical reaction rate may be lowered.

The present invention will now be described in more detail with reference to the following experimental examples, but the present invention is not limited thereto.

[Experimental Example]

Experimental Example 1. Comparison of the specific gravity difference between the upper and lower portions of the conventional sulfuric acid lead acid battery by the charge / discharge step

In Table 1, the specific gravity of the electrolyte of the lead-acid battery was measured and shown in each step during charging / discharging of the conventional lead acid battery having the electrolyte system of the 38 wt% sulfuric acid solution.

division Variation of electrolyte ratio by stages Step ① Step ② Step ③ Step (4) Top 1.280 1.185 1.187 1.252 bottom 1.280 1.192 1.215 1.342 Top / bottom deviation 0 0.007 0.028 0.127

According to the above Table 1, in the step (1) and the step (2) in which the lead-acid battery is a discharging process, the specific gravity deviation between the upper and lower portions of the battery hardly occurred. However, in step 3 and step 4, which are the charging processes, the deviation of the specific gravity between the upper and lower portions of the battery is accelerated and the stratification phenomenon progresses.

As a method for suppressing the stratification phenomenon, the electrolytic solution may be stirred so that the specific gravity of the electrolyte solution does not increase during the charging process. Further, as a method for suppressing the phenomenon of electrolyte stratification, a physical operation method such as applying a liquid circulation device or applying a PP + GLASS MAT separator is known. However, these physical manipulation methods have a disadvantage in that the manufacturing cost is excessively increased due to a change in the design structure, and the effect is insignificant compared to the rising cost. On the contrary, the present invention improves the stratification phenomenon by adding an ionic liquid to the electrolytic solution, so that it is unnecessary to change the design structure and manufacturing process separately, so that the cost increase can be minimized, .

Experimental Example 2 Comparison of Hydrogen and Oxygen Generating Potentials in Charging / Discharging Process of Lead Acid Batteries

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a graph comparing hydrogen and oxygen generation potentials in a battery charge / discharge reaction process for each of an electrolytic solution system containing an ionic liquid or a lead acid battery having a conventional sulfuric acid electrolytic solution proposed by the present invention.

In this experiment, an electrode plate coated with an active material on a Pb-Sn-2.1% Sb alloy substrate was used, and a cyclic voltammetry was performed under a 38 wt% sulfuric acid solution. A 38 wt% sulfuric acid solution was used as a conventional electrolyte solution system. The electrolytic solution system containing the ionic liquid proposed by the present invention is prepared by adding 1 g of mono-butylammonium hydrogen sulfate (BAHS) to 100 mL of a 38 wt% sulfuric acid solution. The electrolytic solution has an ionic liquid of 0.1 Weight%.

1, (1) is a region where lead (Pb) of the negative electrode is converted into lead sulfate (PbSO ₄ ) by discharge. ( ₂ ) is a region where lead dioxide (PbO ₂ ) of the anode is converted into lead sulfate (PbSO ₄ ) by discharge. ③ is a region where discharged lead sulfate (PbSO ₄ ) is reduced by lead (Pb) and lead dioxide (PbO ₂ ), respectively.

In the case of a lead acid battery having an electrolytic solution system containing an ionic liquid in contrast to the conventional sulfuric acid electrolytic solution system, it can be confirmed that the current density during the discharging process in the regions ① and ② is low. This means that the discharge product, lead sulfate (PbSO ₄ ), is formed of small particles compared to the conventional electrolyte system. In addition, in the case of a lead acid battery having an electrolyte system containing an ionic liquid in contrast to the conventional electrolyte system, it is confirmed that the reduction current density of lead sulfate (PbSO ₄ ) is lowered in the region ③ because the current density is low. These results show that the ionic liquid contained in the lead-acid battery electrolyte lowers the surface energy of the active material during the charging / discharging process, so that the current required for the chemical reaction is reduced by applying a uniform current between the particles. There is a reason that the durability of the battery is improved by reducing the energy required.

In addition, the hydrogen generation region on the left side of the graph of FIG. 1 shows that the hydrogen (H ₂ ) generation and overvoltage of the lead acid battery having the electrolyte system including the ionic liquid is low compared to the conventional sulfuric acid electrolyte system. As can be seen from the oxygen generating region on the right side of the graph of FIG. 1, it can be seen that the oxygen (O ₂ ) generation and overvoltage of the lead acid battery having the electrolytic solution system containing the ionic liquid is low in comparison with the conventional sulfuric acid electrolytic solution system. From these results, it can be seen that the electrolytic solution system containing the ionic liquid in the charging / discharging reaction of the lead accumulator accelerates the gas generation even at the lower overvoltage, thereby causing the electrolytic solution stirring effect and improving the stratification phenomenon.

Experimental Example 3. Comparison of lead sulfate (PbSO ₄ ) crystals in the active material

FIG. 2 is a photograph of the active material of the lead acid battery used in Experimental Example 2 by a transmission electron microscope (TEM). FIG.

The electrolytic solution system (B) including the ionic liquid proposed by the present invention lowers the surface energy of the active material during the charging / discharging reaction of the lead acid battery to help uniform current application so that the lead sulfate (PbSO ₄ ) It can be confirmed that the particles exist as fine and uniform particles. On the other hand, in the conventional sulfuric acid electrolyte system (A), lead sulfate (PbSO ₄ ), which is a discharge product of the active material, grew as coarse particles.

Therefore, it can be seen that the lead acid battery having the electrolyte system including the ionic liquid proposed by the present invention has an increased reaction specific surface area of the active material, thereby increasing the battery capacity and the durability cycle characteristics.

Experimental Example 4. Comparison of Hydrogen Generation Overvoltage According to Composition of Ionic Liquid

FIG. 3 is a graph showing the results of measuring the hydrogen generation overvoltage while adding the ionic liquid to the sulfuric acid solution and varying the addition amount of the ionic liquid to 0 to 20 mg / mL. As the ionic liquid, mono-butylammonium hydrogen sulfate (mono-BAHS), di-butylammonium hydrogen sulfate (di-BAHS), tri-butylammonium hydrogensulfate (tri-BAHS), tetra-butylammonium Hydrogen sulfates (tetra-BAHS), isopentylammonium hydrogen sulfate (IPAHS) were used.

3, it can be confirmed that the hydrogen generation voltage is decreased overall by the addition of the ionic liquid. When mono-butylammonium hydrogensulfate (mono-BAHS) was added in the ionic liquid, the hydrogen generation voltage was the lowest, and the lowest overvoltage was shown when the addition amount was 15 mg / mL.

From these results, it can be confirmed that the ionic liquid is added to the electrolyte system to lower the hydrogen generation overpotential during the charge / discharge cycle of the battery, thereby increasing the amount of bubbles generated, thereby maximizing the effect of stirring the electrolyte and improving the stratification.

Experimental Example 5. Comparison of Hydrogen Generation Overvoltage According to Composition of Ionic Liquid

The results of measurement of the difference in specific gravity between the upper and lower portions of the electrolyte in the charge / discharge reaction process for the electrolyte system including the ionic liquid and the lead acid battery having the conventional sulfuric acid electrolyte system proposed by the present invention are shown in Tables 2 and 4 Respectively.

division Ionic liquid Battery electrolyte up / down weight deviation measured by cycle number Kinds content
(weight%) 1 time Episode 2 3rd time 4 times 5 times 6 times 7 times 8 times 9 times 10 times Comparative Example
(Conventional lead acid battery) - - 0.131 0.134 0.142 0.154 0.178 0.185 0.194 0.202 0.218 0.232 Example 1 mono-BAHS 0.10 0.129 0.131 0.139 0.143 0.147 0.154 0.162 0.176 0.179 0.183 Example 2 mono-BAHS 0.15 0.129 0.132 0.134 0.138 0.136 0.139 0.142 0.149 0.151 0.159 Example 3 mono-BAHS 0.20 0.127 0.133 0.134 0.136 0.138 0.144 0.149 0.157 0.164 0.172 Example 4 IPAHS 0.10 0.126 0.129 0.133 0.141 0.142 0.149 0.157 0.164 0.182 0.179 Example 5 IPAHS 0.15 0.128 0.130 0.136 0.143 0.146 0.152 0.155 0.159 0.172 0.182 Example 6 IPAHS 0.20 0.132 0.036 0.139 0.142 0.149 0.154 0.162 0.179 0.186 0.196 Example 7 Tri-BAHS 0.10 0.136 0.134 0.146 0.148 0.155 0.159 0.167 0.174 0.189 0.201 Example 8 Tri-BAHS 0.15 0.132 0.138 0.144 0.149 0.153 0.163 0.175 0.192 0.189 0.198 Example 9 Tri-BAHS 0.20 0.129 0.134 0.147 0.156 0.163 0.179 0.194 0.202 0.212 0.224 Example 10 Di-BAHS 0.10 0.131 0.129 0.139 0.146 0.153 0.159 0.169 0.174 0.189 0.197 Example 11 Di-BAHS 0.15 0.134 0.132 0.149 0.147 0.153 0.159 0.164 0.174 0.184 0.199 Example 12 Di-BAHS 0.20 0.13 0.134 0.145 0.149 0.157 0.164 0.175 0.189 0.198 0.209 Example 13 Tetra-BAHS 0.10 0.134 0.142 0.149 0.158 0.166 0.176 0.189 0.194 0.204 0.215 Example 14 Tetra-BAHS 0.15 0.136 0.1390.146 0.152 0.166 0.178 0.182 0.197 0.201 0.209 0.221 Example 15 Tetra-BAHS 0.20 0.136 0.134 0.151 0.149 0.155 0.161 0.166 0.176 0.186 0.201

According to Table 2, the lead acid battery having the electrolyte system including the ionic liquid has a reduced specific gravity deviation between the electrolyte solution and the lower electrolyte solution compared to the conventional lead acid battery, and the degree of occurrence of the stratification phenomenon is reduced. Particularly, as shown in Example 2, when 0.15 wt% of mono-butylammonium hydrogensulfate (mono-BAHS) was added as an ionic liquid, it was confirmed that the progress of stratification development was improved by 32% compared to the comparative example.

Also, referring to the graph of FIG. 4, as the number of cycles increases, the specific gravity deviation between the electrolyte and the lower electrolyte tends to increase. In contrast to conventional lead acid batteries, lead acid batteries having an electrolyte system containing an ionic liquid, Is low. Particularly, in the case of Example 2 in which 0.15 wt% of mono-butylammonium hydrogensulfate (mono-BAHS) was added, it can be confirmed that the stratification reduction effect is most excellent even after 10 charge / discharge cycles.

Experimental Example 6. Initial Performance Comparison

The performance of each of the electrolytic solution system containing the ionic liquid proposed by the present invention and the lead acid battery having the conventional electrolytic solution system was evaluated in the following manner. The results are shown in Table 3 below.

<Performance evaluation method>

(1) Holding capacity (RC)

The storage capacity was allowed to stand for 1 hour or more after full charge, then discharged at a discharge current of 25 A at room temperature, and the discharge sustainable time until the end voltage of 10.5 V was measured. The storage capacity refers to the maximum time required to operate a load such as an electrical component in a state where startup is stopped.

(2) Cold startability (CCA)

The low temperature startability was a high rate discharge test for evaluating the starting ability of a car at low temperature and the voltage at a discharge time of 30 seconds at -18 ° C to 600 A after full charge was measured. The holding voltage at 30 seconds should be at least 7.2 V, and the higher the value, the better the cold startability.

(3) 20HR capacity

The 20HR capacity was used to evaluate low-rate discharge characteristics. The discharge capacity (AH) was measured until the battery capacity reached 10.5 V by continuously discharging at 3.5 A, which is a comparatively low current value.

division Ionic liquid Performance evaluation Kinds content
(weight%) Capacity
(RC) Cold startability
(CCA) 20HR capacity Requirement standard 130 minutes 7.2V or more 70AH Comparative Example
(Conventional lead acid battery) - - 130.44 7.23 70.2 Example 1 mono-BAHS 0.10 130.12 7.28 72.4 Example 2 mono-BAHS 0.15 131.8 7.43 75.3 Example 3 mono-BAHS 0.20 131.2 7.39 74.2 Example 4 IPAHS 0.10 131.2 7.32 73.6 Example 5 IPAHS 0.15 131.3 7.31 73.6 Example 6 IPAHS 0.20 130.46 7.26 71.4 Example 7 Tri-BAHS 0.10 130.5 7.25 73.2 Example 8 Tri-BAHS 0.15 130.82 7.29 70.8 Example 9 Tri-BAHS 0.20 131.2 7.31 71.4 Example 10 Di-BAHS 0.10 131.04 7.32 72.2 Example 11 Di-BAHS 0.15 130.88 7.28 72.8 Example 12 Di-BAHS 0.20 130.7 7.25 73.4 Example 13 Tetra-BAHS 0.10 130.64 7.36 73.6 Example 14 Tetra-BAHS 0.15 131.6 7.32 72.4 Example 15 Tetra-BAHS 0.20 131.2 7.28 71.8

According to the results shown in Table 3, the retention capacity RC is comparable to that of the Comparative Example and Examples 1 to 15. It can be seen that the lead-acid battery having an electrolytic solution system containing an ionic liquid has improved performance by 0.5 to 2.8% compared to the comparative example at low temperature start-up performance (CCA). It can be confirmed that the lead-acid battery having the electrolyte system including the ionic liquid improves the performance by about 1 to 7% as compared with the comparative example.

Experimental example 7. Comparison of charge / discharge cycle life

The charge / discharge cycle life (SAE J240 at 75 DEG C) of each of the electrolytic solution system containing the ionic liquid proposed by the present invention and the lead acid battery having the conventional electrolytic solution system was evaluated.

The charging / discharging cycle lifetime was evaluated by repeating a cycle of discharging at 25 A for 4 minutes and then charging for 10 minutes at a current limit of 14.8 V and a maximum current of 25 A for 1 unit (480 times) And the lifetime was determined by measuring the voltage for 30 seconds by discharging at a high rate. If the 30 second voltage was 7.2 V or more, the unit was further repeatedly operated. If the voltage was less than 7.2 V, it was determined that the life was over, and the test was terminated. The results are shown in Table 4 below.

division Ionic liquid 30 seconds Voltage (V) / number of cycles life span
Judgment Kinds content
(weight%) 480 960 1440 1920 2440 Comparative Example
(Conventional lead acid battery) - - 8.89 8.64 7.94 4.83 1920 Example 1 mono-BAHS 0.10 9.02 8.68 8.02 7.12 1920 Example 2 mono-BAHS 0.15 9.12 8.94 8.46 7.54 7.06 2440 Example 3 mono-BAHS 0.20 9.06 8.87 8.38 7.41 6.95 2440 Example 4 IPAHS 0.10 9.08 8.72 8.24 7.32 4.34 2440 Example 5 IPAHS 0.15 9.03 8.69 7.98 7.19 1920 Example 6 IPAHS 0.20 9.06 8.72 8.04 7.24 5.89 2440 Example 7 Tri-BAHS 0.10 9.04 8.74 8.06 7.29 6.02 2440 Example 8 Tri-BAHS 0.15 9.08 8.68 7.99 7.34 5.48 2440 Example 9 Tri-BAHS 0.20 9.04 8.76 8.05 7.16 1920 Example 10 Di-BAHS 0.10 9.10 8.79 8.14 7.22 6.89 2440 Example 11 Di-BAHS 0.15 9.08 8.84 8.21 7.32 6.42 2440 Example 12 Di-BAHS 0.20 9.06 8.82 8.19 7.28 6.74 2440 Example 13 Tetra-BAHS 0.10 9.04 8.78 8.06 7.21 5.65 2440 Example 14 Tetra-BAHS 0.15 9.02 8.90 8.16 7.20 5.92 2440 Example 15 Tetra-BAHS 0.20 9.06 8.92 8.22 7.27 6.24 2440

According to Table 4, it can be seen that the life of the lead acid battery having the electrolytic solution system containing the ionic liquid is improved compared to the comparative example. Particularly, in the case of Example 2, it was confirmed that the verify voltage was maintained at the highest level, and the performance improvement of the battery endurance was the most excellent.

Claims (5)

In an electrolytic solution for a lead-acid battery comprising distilled water and sulfuric acid (H ₂ SO ₄ )
(Mono-BAHS), di-butylammonium hydrogensulfate (di-BAHS), tri-butylammonium hydrogensulfate (tri-BAHS), tetra-butylammonium hydrogensulfate ) And isopentylammonium hydrogensulfate (IPAHS). &Lt; / RTI &gt;
The method according to claim 1,
Wherein the ionic liquid is contained in an amount of 0.001 to 2% by weight in the electrolytic solution.
The method according to claim 1,
Wherein the ionic liquid is contained in an amount of 0.1 to 0.5% by weight in the electrolytic solution.
The method according to claim 1,
Wherein the electrolytic solution contains mono-butylammonium hydrogensulfate (BAHS) in an amount of 0.1 to 0.5 wt%.
A lead-acid battery containing an electrolyte according to any one of claims 1 to 4.

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