Agent for maintaining and recovering the function of lead storage battery and electrolyte using the same

Abstract: The present invention relates to an agent for maintaining and recovering the function of a lead storage battery, comprising as active ingredients a metal sulfate and at least one of an amino acid and a salt thereof, as well as an electrolyte for use in a lead storage battery comprising the above agent and a basal electrolyte. According to the present invention, there is provided a highly effective agent or electrolyte for maintaining the function of a lead storage battery over a long period and recovering the function of a lead storage battery whose storage capacity has been lowered.

Description: The present invention relates to an agent for maintaining the function of a lead storage battery over a long period, recovering the function of a lead storage battery whose storage capacity has been lowered and improving the efficiency of the storing of electrical charge therein, and an electrolyte comprising the agent. Amongst those methods for maintaining or recovering the function of a lead storage battery, there are known a method wherein water-soluble vitamins are added to the electrolyte (JP-A-52-72428 and JP-A-54-7134), a method wherein an organic acid, such as dicarboxylic acid or tricarboxylic acid, is added to the electrolyte (JP-A-53-10827), and a method wherein bis-β-ethylcarboxylate germanium sesquioxide is added to the electrolyte (JP-A-59-194367 and JP-A-63-19771). The present invention seeks to provide an agent suitable for maintaining and recovering the function of a lead storage battery, which agent is able to maintain the storage capacity and also to recover and improve the charging effect at the time of charging. The present invention also seeks to provide an electrolyte for a lead storage battery comprising the agent. The present invention accordingly provides an agent for maintaining and recovering the function of a lead storage battery, comprising as active ingredients a metal sulfate and at least one of an acidic amino acid and a salt thereof. The present invention further provides an electrolyte for use in a lead storage battery comprising the agent of the invention as defined above and a basal electrolyte. Examples of the metal sulfate include light metal sulfates such as sodium sulfate, magnesium sulfate, aluminium sulfate and the like, and heavy metal sulfates such as cobalt sulfate, barium sulfate, manganese sulfate, iron (II) sulfate, iron (III) sulfate and the like. The acidic amino acid may be glutamic acid, aspartic acid or the like. This acidic amino acid may be in the form of a metal salt, such as a sodium salt, potassium salt, magnesium salt, calcium salt, aluminium salt or the like. Also, the acidic amino acid may be in the L-form, the D-form or present as a mixture thereof. According to the present invention, the combining ratios of the metal sulfate and the acidic amino acid or salt thereof in the agent for maintaining and recovering the function of a lead storage battery are preferably from 5 to 95 parts by weight for the metal sulfate and from 5 to 95 parts by weight for the acidic amino acid or salt thereof. When the ratio of the metal sulfate is less than 5 parts by weight, it is difficult for the cathode plate of a lead storage battery to absorb the gas generated from the anode plate in the final stage of charging. On the other hand, when the ratio of the metal sulfate is more than 95 parts by weight, gas generation and absorption reactions in the anode and cathode plates take place less easily. More preferably, the combining ratio of the metal sulfate is from 10 to 60 parts by weight and the ratio of the acidic amino acid or salt thereof is from 40 to 90 parts by weight. The agent of the present invention as defined above may further comprise a metal carbonate to improve still further the maintenance and recovery function. Examples of the metal carbonates to be used for this purpose include alkali metal salts such as sodium carbonate and potassium hydrogencarbonate, and alkaline earth metal salts such as magnesium carbonate. The ratio of the metal carbonate to the acidic amino acid or salt thereof is usually from 0.1% to 80% by weight, preferably from 1% to 70% by weight. The agent of the present invention as defined above may further comprise a known agent for the maintenance and recovery of the function of lead storage batteries, such as vitamin C or citric acid. This can improve still more the effect of the agent of the invention. The agent of the present invention as defined above may be used in the form of a solid, a liquid or a semisolid. In the case of a solid, it is preferred that the agent be used in the form of a pulverulent body or granules. In the case of a liquid, it is preferred that the agent be used after being dissolved in a solvent such as dilute hydrochloric acid, dilute sulfuric acid or water. The specific gravity of the resulting solution is usually from 1.15 to 1.4. The resulting solution usually contains the metal sulfate and the acidic amino acid or salt thereof in a total amount of from 2% to 95% by weight, preferably from 5% to 80% by weight. The agent of the present invention may be added to a basal electrolyte before the basal electrolyte is put into the electrolytic cell of a lead storage battery. Alternatively, the agent may be added to a basal electrolyte after the basal electrolyte has been put into the electrolytic cell of a lead storage battery. The basal electrolyte as used herein means a conventional electrolyte comprising dilute sulfuric acid. With respect to the amount of the agent of the present invention to be added to the basal electrolyte, the total amount of metal sulfate and acidic amino acid or salt thereof is usually from 0.7% to 3% by weight based on the resulting electrolyte, preferably from 1% to 2% by weight. The specific gravity of the electrolyte after addition thereto of the agent is usually from 1.15 to 1.4, preferably from 1.25 to 1.35. The electrolyte of the present invention means an electrolyte containing a metal sulfate and at least one of an acidic amino acid and a salt thereof in a total amount of, typically, from 0.7% to 3% by weight, preferably from 1% to 2% by weight. The specific gravity of the electrolyte of the present invention is usually from 1.15 to 1.4, preferably from 1.25 to 1.35. The electrolyte of the present invention can be obtained by adding the agent of the present invention to the basal electrolyte to make a mixture and stirring the mixture. A lead storage battery whose function has been so lowered that it cannot supply sufficient electric power can recover its original function if the agent of the present invention is added to a basal electrolyte in the lead storage battery or if an electrolyte of the present invention is poured into an electrolytic cell of the lead storage battery. In addition, a storage battery whose function of supplying electric power is lowered immediately after charging can have its function improved by the addition of the agent to a basal electrolyte of the lead storage battery, so that it can supply electric power for a long time. In the accompanying drawings: Figure 1 is a graph showing the influence of various additives upon discharging effect of a lead storage battery. Addition of Agent 1 Addition of magnesium sulfate Addition of vitamin C Control (dilute sulfuric acid) and addition of citric acid Fig. 2 is a graph showing the influence of various additives upon discharging effect of a lead storage battery. Addition of Agent 2 Addition of aluminium sulfate Addition of L-glutamic acid Control (dilute sulfuric acid) and addition of magnesium carbonate Fig. 3 is a graph showing the influence of various additives upon charging effect of a lead storage battery. Addition of Agent 17 Addition of aluminium sulfate Addition of Agent 16 Addition of L-glutamic acid Control (dilute sulfuric acid) and addition of magnesium carbonate, oxalic acid or germanium oxide Fig. 4 is a graph showing the influence of various additives upon discharging effect of a lead storage battery. Addition of Agent 17 Addition of aluminium sulfate Addition of Agent 16 Addition of L-glutamic acid Control (dilute sulfuric acid) and addition of magnesium carbonate, oxalic acid or germanium oxide The present invention will be described in more detail in the following Examples. EXAMPLE 1 100 g of L-glutamic acid and 100 g of magnesium sulfate were ground and mixed homogeneously in a mortar, to thereby prepare 200 g of Agent 1. EXAMPLE 2 100 g of L-glutamic acid, 80 g of aluminium sulfate and 20 g of magnesium carbonate were ground and mixed homogeneously in a mortar, to thereby prepare 200 g of Agent 2. EXAMPLE 3 6 g of Agent 1 was dissolved in 100 ml of 2.3 weight percent dilute sulfuric acid to thereby obtain Agent 3. The specific gravity of Agent 3 was 1.26. EXAMPLE 4 8 g of Agent 2 was dissolved in 100 ml of 3.0 weight percent dilute sulfuric acid to thereby obtain Agent 4. The specific gravity of Agent 4 was 1.26. EXAMPLE 5 Agent 5 was obtained in the same manner as described in Example 1 except that L-aspartic acid was used instead of L-glutamic acid. EXAMPLE 6 Agent 6 was obtained in the same manner as described in Example 2 except that L-aspartic acid was used instead of L-glutamic acid. EXAMPLES 7-13 Agents 7-13 were obtained in the same manner as described in Example 1 except that sodium sulfate, aluminium sulfate, cobalt sulfate, barium sulfate, manganese sulfate, iron(II) sulfate and iron(III) sulfate were used, respectively, instead of magnesium sulfate. The relation of Example No., Agent No. and the metal salt of sulfuric acid used therein is shown below. Example No. Metal Sulfate Agent No. 7 Sodium sulfate 7 8 Aluminium sulfate 8 9 Cobalt sulfate 9 10 Barium sulfate 10 11 Manganese sulfate 11 12 Iron(II) sulfate 12 13 Iron(III) sulfate 13 EXAMPLES 14-15 Agents 14-15 were obtained in the same manner as described in Example 2 except that sodium sulfate and magnesium sulfate were used, respectively, instead of aluminium sulfate. EXAMPLE 16 100 g of L-glutamic acid, 70 g of aluminium sulfate, 20 g of magnesium carbonate, 9 g of oxalic acid and 1 g of germanium oxide were ground and mixed homogeneously in a mortar, to thereby prepare 200 g of Agent 16. EXAMPLE 17 160 g of L-glutamic acid, 25 g of aluminium sulfate, 5 g of magnesium carbonate, 9 g of oxalic acid and 1 g of germanium oxide were ground and mixed homogeneously in a mortar, to thereby prepare 200 g of Agent 17. TEST EXAMPLE 1 Addition to a Lead Storage Battery: 1 To the electrolyte of a used car battery of 6 V (Model 6Bx8-3B manufactured by Hitachi, Ltd., Japan), Agent 1, magnesium sulfate, citric acid or vitamin C was added in an amount of 10 g, respectively. (As a control, only dilute sulfuric acid was added to the electrolyte.) Then, each battery was charged with a charger (Model GS SP1-75-15A manufactured by Nippon Denchi Co., Ltd., Japan) at 6 V for 30 minutes, and discharged by lighting a tale lamp of 6 V 25 W. The battery was recharged with the charger at 6 V for 10 minutes, and then lighting experiment using a tale lamp of 6 V 25 W was conducted to examine the decrease in the voltage with the elapse of time under each of the conditions. The results are shown in Fig. 1. Fig. 1 shows that the best maintaining effect on voltage of the battery was obtained when Agent 1 was added. TEST EXAMPLE 2 Addition to a Lead Storage Battery: 2 To the electrolyte of a used car battery of 6 V (Model 6Bx8-3B manufactured by Hitachi, Ltd., Japan), Agent 2, aluminium sulfate, magnesium carbonate or L-glutamic acid was added in an amount of 10 g, respectively. (As a control, only dilute sulfuric acid was added to the electrolyte.) Then, each battery was charged with a charger (Model GS SP1-75-15A manufactured by Nippon Denchi Co., Ltd., Japan) at 6 V for 30 minutes, and discharged by lighting a tale lamp of 6 V 25 W. The battery was recharged with the charger at 6 V for 10 minutes, and then lighting experiment using a tale lamp of 6 V 25 W was conducted to examine the decrease in the voltage with the elapse of time under each of the conditions. The results are shown in Fig. 2. Fig. 2 shows that the best maintaining effect on voltage of the battery was obtained when Agent 2 was added. TEST EXAMPLE 3 Addition to a Lead Storage Battery: 3 To the electrolyte of a car battery of 12 V (Model 42B20R manufactured by Hitachi, Ltd., Japan), Agent 16, Agent 17, L-gultamic acid, aluminium sulfate, magnesium carbonate, oxalic acid or germanium oxide was added in an amount of 10 g, respectively. (As a control, only dilute sulfuric acid was added to the electrolyte.) Then, each battery was charged with a charger (Model PANB-24-15 manufactured by Hitachi, Ltd., Japan) at 12 V. The increase in the voltage with the elapse of time under each of the conditions was examined. The results are shown Fig. 3. Fig. 3 shows that the high recovering effect on voltage of the battery was obtained when Agent 16 or Agent 17, respectively, was added. TEST EXAMPLE 4 Addition to a Lead Storage Battery: 4 To the electrolyte of a car battery of 12 V (Model 42B20R manufactured by Hitachi, Ltd., Japan), Agent 16, Agent 17, L-glutamic acid, aluminium sulfate, magnesium carbonate, oxalic acid or germanium oxide was added in an amount of 10 g, respectively. (As a control, only dilute sulfuric acid was added to the electrolyte.) Then, each battery was charged with a charger (Model PANB-24-15 manufactured by Hitachi, Ltd., Japan) at 12 V for 30 minutes, and discharged by lighting a tale lamp of 12 V 50 W. The battery was recharged with the charger at 12 V for 10 minutes, and then lighting experiment using tale lamp of 12 V 50 W was conducted to examine the decrease in the voltage with the elapse of time under each of the conditions. The results are shown in Fig. 4. Fig 4 shows that the high maintaining effect on voltage of the battery was obtained when Agent 16 or Agent 17, respectively, was added. TEST EXAMPLE 5 A Lead Storage Battery for a Car 6 g of Agent 1 was added to each compartment of an electrolytic cell (containing 400 ml of electrolyte) of a lead storage battery (12 V 20-70 Ah) used in a car whose engine did not start well. The battery had been frequently charged since it ran down if the car was left undriven for one or two days. After the addition of Agent 1 and recharging, the start of the engine was improved and the engine of the car which had been left undriven for two days started. TEST EXAMPLE 6 A Lead Storage Battery for a Motorcycle A motorcycle become undrivable due to discharge of a lead storage battery (6 V 3-18 Ah) was used. In case of charging the lead storage battery in which no additive was supplemented, the engine of the motorcycle which had been left undriven did not start on the next day. By contrast, in case of charging the lead storage battery in which 3 g of Agent 1 was added to each compartment of the electrolytic cell, the engine of the motorcycle which had been left undriven for one week started. TEST EXAMPLE 7 A Lead Storage Battery for a Golf Cart 8 g of Agent 2, Agent 5 or Agent 6 was added to an electrolytic cell containing 600 ml of electrolyte of a lead storage battery (12 V) used in a golf cart (Model EB-65 manufactured by Furukawa Electric Co., Ltd., Japan). This golf cart driven by the battery was unable to go around a golf course even if the battery was charged everyday. After the addition of the above Agents and recharging, the golf cart which received any of the above Agents was able to go around the golf course. TEST EXAMPLE 8 A Lead Storage Battery for a Forklift A forklift (Model FG10 manufactured by Komatsu Ltd., Japan) become undrivable due to discharge of a lead storage battery (Model 48D26R manufactured by Hitachi, Ltd., Japan) was used. In case of charging the lead storage battery in which no additive was supplemented, the engine of the forklift which had been left undriven for five months started but the engine which had been left undriven for more than five months did not start. By contrast, in case of charging the lead storage battery in which 5 g of Agent 7 was added to each compartment of the electrolytic cell, the engine of the forklift which had been left undriven for eight months started.

Claims: An agent for maintaining and recovering the function of a lead storage battery, comprising as active ingredients a metal sulfate and at least one of an acidic amino acid and a salt thereof. An agent according to claim 1, wherein said metal sulfate is at least one salt selected from the group consisting of sodium sulfate, magnesium sulfate, aluminium sulfate, cobalt sulfate, barium sulfate, manganese sulfate, iron (II) sulfate and iron (III) sulfate. An agent according to claim 1 or 2, wherein said acidic amino acid is aspartic acid or glutamic acid. An agent according to any one of claims 1 to 3 further containing a metal carbonate. An agent according to claim 4, wherein said metal carbonate is magnesium carbonate. An electrolyte for use in a lead storage battery, comprising the agent according to any one of claims 1 to 5 and a basal electrolyte. An agent for maintaining and recovering the function of a lead storage battery, comprising as active ingredients a metal sulfate and at least one of an acidic amino acid and a salt thereof, provided that iron (II) sulfate and iron (III) sulfate are excluded as the metal sulfate. An agent for maintaining and recovering the function of a lead storage battery, comprising as active ingredients a metal sulfate selected from iron (II) sulfate and iron (III) sulfate, and at least one of an acidic amino acid and a salt thereof. An electrolyte for use in a lead storage battery, comprising the agent according to claim 7. An electrolyte for use in a lead storage battery, comprising the agent according to claim 8.

Inventors: KOMODA KATSUICHI, KOMODA, KATSUICHI
Applicants: K TEC CO LTD, KYOWA HAKKO KOGYO KK, K-TEC CO., LTD., KYOWA HAKKO KOGYO CO., LTD.
Application year: 1995
Main classification: H01M10
IPC codes: H01M10