A battery electrolyte, a battery and a method of increasing the power platform of a battery

Abstract

The application relates to the technical field of lead-acid storage batteries, and discloses a battery electrolyte, a storage battery and a method for improving the power platform of the storage battery. The battery electrolyte comprises the following components in a weight ratio: (26.0-30.0) wt % of sulfuric acid H2SO4, (0.08-0.13) wt % of anhydrous sodium sulfate, (2.0-3.0) wt % of fumed silica dispersion liquid, (0.04-0.15) wt % of polyvinyl alcohol, 0.05 wt % of sodium dodecyl benzene sulfonate, and the rest is distilled water, and the sum of the percentage contents of the components is 100%. The storage battery uses the battery electrolyte of the technical solution; and the method for improving the power platform of the storage battery is to add (2.0-3.0) wt % of fumed silica dispersion liquid, (0.04-0.15) wt % of polyvinyl alcohol and 0.05 wt % of sodium dodecyl benzene sulfonate into the sulfuric acid electrolyte of the storage battery. The electrolyte can improve the discharge capacity platform of the rich-liquid type parking storage battery by 6-10% during 100% deep cycle process, and the cycle number is improved by 19-31%.

Description

Technical Field

[0001] This invention belongs to the field of lead-acid battery technology, and particularly relates to a battery electrolyte, a storage battery, and a method for improving the storage battery's capacity platform. Background Technology

[0002] In recent years, heavy-duty truck parking air conditioners have developed rapidly and become widespread. Flooded parking batteries dominate the market due to their low price, safety, reliability, and ease of installation. As the main power source for starting and powering the parking air conditioner, the battery operates in a 100% deep discharge (100% DoD) mode for extended periods.

[0003] Heavy-duty trucks use the same charging mode as commercial vehicles, with an output voltage of 27.6V to 28.0V. This is suitable for charging a single 12V battery at 13.8V to 14.0V, which is a low-voltage constant-voltage charging mode. However, after deep discharge, flooded batteries experience poor charging efficiency and insufficient charge intake under this low-voltage charging condition, directly resulting in a low battery discharge capacity plateau and shortened parking air conditioning usage time. This is a common pain point in the industry, failing to meet users' needs for extended parking. Tests show that the 100% DoD cycle capacity plateau of this type of battery is only 53±3% Cn, indicating a short deep-cycle lifespan. Therefore, improving the discharge capacity plateau of flooded parking air conditioning batteries under low-voltage charging mode is an urgent problem to be solved and an important aspect of meeting user expectations. Summary of the Invention

[0004] One of the objectives of this invention is to provide a battery electrolyte that can increase the discharge capacity plateau of a flooded parking battery by 6% to 10% and increase the number of cycles by 19% to 31% during a 100% deep cycle.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A battery electrolyte, characterized in that it comprises the following components in the following weight ratios: (26.0-30.0) wt% sulfuric acid (H2SO4), (0.08-0.13) wt% anhydrous sodium sulfate, (2.0-3.0) wt% fumed silica dispersion, (0.04-0.15) wt% polyvinyl alcohol, 0.05 wt% sodium dodecylbenzenesulfonate, and the remainder being distilled water, wherein the sum of the percentages of each component is 100%.

[0007] Preferably, the content of pure SiO2 in the fumed silica dispersion is 13% to 20%.

[0008] The second objective of this invention is to provide a storage battery, which includes a battery casing and contains a sulfuric acid electrolyte. The sulfuric acid electrolyte contains a positive electrode group and a negative electrode group. The sulfuric acid electrolyte is the storage battery electrolyte described in any of the above technical solutions.

[0009] Preferably, the density of the sulfuric acid electrolyte is 1.200 g / cm³. 3 ~1.240g / cm 3 .

[0010] Preferably, after the sulfuric acid electrolyte is poured into the battery casing and the battery is assembled, battery formation is performed, and the battery is charged with a capacity of 4.8-5.6Cn.

[0011] The third objective of this invention is to provide a method for improving the power platform of a storage battery, wherein (2.0-3.0) wt% fumed silica dispersion, (0.04-0.15) wt% polyvinyl alcohol, and 0.05 wt% sodium dodecylbenzenesulfonate are added to the sulfuric acid electrolyte of the storage battery.

[0012] Compared with the existing technology, the present technical solution has the following beneficial effects:

[0013] This invention adds a certain proportion of fumed silica dispersion to a sulfuric acid electrolyte. Fumed silica has excellent gelling properties, high specific surface area, and a negative surface charge. The surface layer of silica is rich in siloxy groups (-Si-O-Si) and silanol groups (-OH). These groups cross-link with each other through hydrogen bonds to form a dense three-dimensional network structure that encapsulates sulfuric acid and water. In this way, the battery can suppress the stratification of sulfuric acid electrolyte under deep discharge conditions. Furthermore, the gaps in the gel structure allow ions to pass through freely, ensuring normal charging and discharging of the battery. Thus, during the 100% DoD deep cycle of a flooded parking battery, the charging capacity is increased under low-voltage constant-voltage charging conditions, which increases the discharge capacity plateau, extends parking time, and prolongs the deep cycle life of the battery.

[0014] Due to the extremely high specific surface area and surface free energy of fumed silica, this gel system is thermodynamically metastable, inherently exhibiting a tendency to spontaneously decrease surface energy and coalesce. The three main factors—zeta potential, Brownian motion, and steric hindrance of solvent molecules—contribute to its coalescence and kinetic stability. If any one of these three main stabilizing factors is weakened, it will spontaneously coalesce, forming a gel or sediment. When the anionic surfactant sodium dodecylbenzenesulfonate (SDBS) is introduced, it contains the hydrophilic sulfonate anion (-SO3). － The sulfonate group (SDBS) and the hydrophobic dodecylphenyl group adsorb onto the silica particle surface via van der Waals forces, while the hydrophilic end faces the aqueous phase, forming an adsorption layer at the solid-liquid interface. The adsorbed sulfonate group increases the negative charge density on the particle surface, enhancing electrostatic repulsion between particles and effectively inhibiting particle aggregation. The introduced water-soluble polymeric stabilizer, polyvinyl alcohol (PVA), contains numerous hydroxyl groups (-OH) on its molecular chain, forming stable hydrogen-bonded complexes with the silanol groups on the silica surface, allowing PVA to adsorb onto the particle surface. This adsorption creates a polymeric coating layer on the silica particle surface, generating a strong steric hindrance effect that prevents cross-linking between fumed silica particles. Through the synergistic effect of electrostatic repulsion and steric hindrance of SDBS and PVA, the fumed silica particles maintain long-term stability in the electrolyte. This extends the gel time of the silica electrolyte, maintaining its stability for a longer period, equivalent to extending the storage time of the prepared colloidal sulfuric acid electrolyte, while also facilitating production.

[0015] The flooded parking battery prepared by adding fumed silica dispersion, polyvinyl alcohol and sodium dodecylbenzenesulfonate to the electrolyte of this invention showed that the low voltage 100% DoD deep cycle capacity plateau was increased from (53±3)% Cn to (63±3)% Cn, which is an improvement of (6-10)% compared with the previous method, thus extending the parking time of the flooded parking battery; and the number of cycles was increased by 19%-31%. Attached Figure Description

[0016] Figure 1 This is a comparison curve of the 100% DoD cycle life capacity platform of battery #1 and battery #4 of this invention;

[0017] Figure 2 This is a comparison curve of the 100% DoD cycle life capacity platform of battery #2 and battery #4 of this invention;

[0018] Figure 3 This is a comparison curve of the 100% DoD cycle life capacity platform of the No. 3 and No. 4 batteries of this invention. Detailed Implementation

[0019] The following is a further description of the embodiments of the present invention:

[0020] A battery electrolyte comprises the following components in the following weight ratios: (26.0–30.0) wt% sulfuric acid (H₂SO₄), (0.08–0.13) wt% anhydrous sodium sulfate, (2.0–3.0) wt% fumed silica dispersion, (0.04–0.15) wt% polyvinyl alcohol, 0.05 wt% sodium dodecylbenzenesulfonate, and the remainder being distilled water. The sum of the percentages of all components is 100%, wherein the content of pure SiO₂ in the fumed silica dispersion is 13%–20%.

[0021] Adding a certain proportion of fumed silica dispersion, polyvinyl alcohol, and sodium dodecylbenzenesulfonate to the sulfuric acid electrolyte of a storage battery can reduce the crystallization rate of the polymer system, allowing it to remain in an amorphous phase for a longer period. The granular silica between the positive and negative plates maintains the consistency of the electrolyte in the battery and allows oxygen cavitation. Silica particles can absorb moisture from the liquid electrolyte, reducing interfacial reactions and significantly reducing the risk of dry-water failure in the battery. Experimental studies have shown that adding fumed silica dispersion, polyvinyl alcohol, and sodium dodecylbenzenesulfonate to the electrolyte can improve low-voltage charging efficiency, thereby increasing the cycle capacity plateau.

[0022] A storage battery includes a battery casing, and a sulfuric acid electrolyte is contained inside the battery casing. A positive electrode group and a negative electrode group are immersed in the sulfuric acid electrolyte, and the sulfuric acid electrolyte is the storage battery electrolyte described in the above technical solution.

[0023] In one embodiment, the battery casing includes a battery case, a battery cover, and a vent cover. The positive electrode group, the negative electrode group, and the sulfuric acid electrolyte are disposed in the battery case. The battery case and the battery cover are sealed together by heat sealing. The vent cover and the battery cover are connected by heat sealing. The vent cover is provided with a venting device for venting the battery. The positive electrode group is formed by welding a positive electrode plate, a terminal post, an intermediate post, and a positive busbar. The negative electrode group is formed by welding a negative electrode plate, a terminal post, an intermediate post, and a negative busbar.

[0024] In one embodiment, the density of the sulfuric acid electrolyte is 1.200 g / cm³. 3 ~1.240g / cm 3 .

[0025] In one embodiment, after the sulfuric acid electrolyte is poured into the battery casing and the battery assembly is completed, battery formation is performed, and the battery is charged with a capacity of 4.8-5.6Cn.

[0026] The positive and negative electrode groups undergo a chemical reaction in the sulfuric acid electrolyte to form a chemical energy storage power source. During discharge, lead dioxide in the positive electrode and spongy lead in the negative electrode react with sulfuric acid in the electrolyte to gradually transform into lead sulfate, while the sulfuric acid concentration gradually decreases. During charging, the lead sulfate in the positive and negative electrodes is converted into lead dioxide and spongy lead, respectively, while releasing sulfuric acid components from the active materials, causing the sulfuric acid concentration to gradually increase. The chemical reactions occurring within the lead-acid battery are as follows:

[0027]

[0028] A method for improving the power platform of a storage battery involves adding (2.0–3.0) wt% fumed silica dispersion, (0.04–0.15) wt% polyvinyl alcohol, and 0.05 wt% sodium dodecylbenzenesulfonate to the sulfuric acid electrolyte of the storage battery.

[0029] 1. Battery preparation and filling with sulfuric acid electrolyte

[0030] Four sets of assembled 12V 200Ah lead-acid batteries for flooded parking vehicles were randomly selected and numbered as 1#, 2#, 3# and 4#. Battery 1# was filled with the sulfuric acid electrolyte described in Example 1, battery 2# was filled with the sulfuric acid electrolyte described in Example 2, battery 3# was filled with the sulfuric acid electrolyte described in Example 3, and battery 4# was filled with the sulfuric acid electrolyte described in the comparative example. Then, battery formation was performed on batteries 1#, 2#, 3# and 4#.

[0031] Example 1

[0032] The sulfuric acid electrolyte used for battery formation consists of: 26.0 wt% sulfuric acid (H₂SO₄), 0.1 wt% anhydrous sodium sulfate, 2.0 wt% fumed silica dispersion, 0.04 wt% polyvinyl alcohol, 0.05 wt% sodium dodecylbenzenesulfonate, and distilled water. The total amount of each substance added is 100%, and the electrolyte density is 1.200 g / cm³. 3 (25℃) sulfuric acid electrolyte.

[0033] Example 2

[0034] The sulfuric acid electrolyte used for battery formation consists of: 27.8 wt% sulfuric acid (H₂SO₄), 0.1 wt% anhydrous sodium sulfate, 2.9 wt% fumed silica dispersion, 0.10 wt% polyvinyl alcohol, 0.05 wt% sodium dodecylbenzenesulfonate, and distilled water. The total amount of each substance added is 100%, and the density of the prepared electrolyte is 1.210 g / cm³. 3 (25℃) sulfuric acid electrolyte.

[0035] Example 3

[0036] The sulfuric acid electrolyte used in battery formation consists of: 31.0 wt% sulfuric acid (H₂SO₄), 0.1 wt% anhydrous sodium sulfate, 2.5 wt% fumed silica, 0.15 wt% polyvinyl alcohol, 0.05 wt% sodium dodecylbenzenesulfonate, and distilled water. The total amount of each substance added is 100%, and the electrolyte density is 1.240 g / cm³. 3 (25℃) sulfuric acid electrolyte.

[0037] Comparative Example

[0038] The sulfuric acid electrolyte used in battery formation consists of: 28.5 wt% sulfuric acid (H₂SO₄), 0.1 wt% anhydrous sodium sulfate, and the remainder being distilled water. The total amount of each substance added is 100%, and the electrolyte density is 1.210 g / cm³. 3 (25℃) sulfuric acid electrolyte.

[0039] 2. Battery formation

[0040] After assembly, the sulfuric acid battery undergoes battery formation, and the battery is charged to a capacity of 4.8-5.6Cn to bring it to a fully charged state.

[0041] Battery #1 was charged to a capacity of 4.8Cn to obtain a 12V 200Ah lead-acid battery.

[0042] Battery #2 was charged with 5.0Cn to obtain a 12V 200Ah lead-acid battery.

[0043] Battery #3 was charged to a capacity of 5.6Cn to obtain a 12V 200Ah lead-acid battery.

[0044] Battery #4 was charged to a capacity of 5.0Cn to obtain a 12V 200Ah lead-acid battery.

[0045] 3. 100% DoD Cycle Life Test

[0046] Fully charged batteries #1, #2, #3, and #4 were placed in an ambient temperature of (40±2)℃ for at least 8 hours, and then subjected to a 100% cycle life test according to the following steps:

[0047] a) Discharge the battery at 25.0A until the terminal voltage reaches 10.50V;

[0048] b) Charge for 6 hours at (14.00±0.05)V and a current limit of 70A;

[0049] c) Charge at 80.0A for 2.5 minutes;

[0050] d) The above steps a) to c) constitute one complete test cycle. Repeat steps a) to c) until the battery's discharge capacity drops below 0.5C during the cycle discharge. 20 The experiment was terminated at that time.

[0051] 4. Test Results

[0052] The capacity plateaus of batteries #1 through #3 during 100% DoD cycling were compared with the capacity plateau of battery #4 during 100% DoD cycling.

[0053] like Figures 1 to 3 As shown, the capacity plateau of battery #1 during the 100% DoD cycle is 60.7%, with 281 cycles; the capacity plateau of battery #2 during the 100% DoD cycle is 64.2%, with 311 cycles; the capacity plateau of battery #3 during the 100% DoD cycle is 63.2%, with 301 cycles; and the capacity plateau of battery #4 during the 100% DoD cycle is 54.2%, with 236 cycles.

[0054] The capacity plateau of batteries #1 to #3 during the 100% DoD cycle is significantly higher than that of battery #4 during the 100% DoD cycle. The capacity plateau of the batteries prepared according to the technical solution of this invention reaches 64%Cn during the 100% DoD cycle, which is an increase of 6% to 10%, and the number of 100% cycles is increased by 19% to 31%.

[0055] This embodiment is merely an illustration of the concept and implementation of the present invention and is not intended to limit it. Under the concept of the present invention, technical solutions without substantial changes are still within the scope of protection.

Claims

1. A battery electrolyte, characterized in that, It includes the following components in the following weight ratios: (26.0–30.0) wt% sulfuric acid (H₂SO₄), (0.08–0.13) wt% anhydrous sodium sulfate, (2.0–3.0) wt% fumed silica dispersion, (0.04–0.15) wt% polyvinyl alcohol, 0.05 wt% sodium dodecylbenzenesulfonate, and the remainder being distilled water. The sum of the percentages of all components is 100%.

2. The battery electrolyte as described in claim 1, characterized in that, The content of pure SiO2 in the fumed silica dispersion is 13% to 20%.

3. A storage battery, comprising a battery casing, wherein a sulfuric acid electrolyte is contained within the battery casing, and a positive electrode group and a negative electrode group are immersed in the sulfuric acid electrolyte, characterized in that, The sulfuric acid electrolyte is the battery electrolyte according to any one of claims 1 to 2.

4. The storage battery as described in claim 3, characterized in that, The density of the sulfuric acid electrolyte is 1.200 g / cm³. 3 ~1.240g / cm 3 .

5. The storage battery as described in claim 4, characterized in that, After the sulfuric acid electrolyte is poured into the battery casing and the battery is assembled, battery formation is carried out, and the battery is charged with a capacity of 4.8-5.6Cn.

6. A method for improving the power platform of a storage battery, characterized in that, Add (2.0–3.0) wt% fumed silica dispersion, (0.04–0.15) wt% polyvinyl alcohol, and 0.05 wt% sodium dodecylbenzenesulfonate to the sulfuric acid electrolyte of a lead-acid battery.

Images