SOLID ELECTROLYTE AND FORMATION OF LEAD BATTERY USING IT

Solid Electrolyte and Formation of Lead Battery Using It

Description

Field of the Invention

The present invention relates to a solid electrolyte and a formation charge of lead batteries for power, energy storage and starting up.

Background of the Invention

The atmosphere pollution phenomena to be caused by deflation of gas and acid fog generating in manufacturing process of lead battery, especially formation process inflict serious damages to human bodies and natural environment.

There have been a lot of methods relating to reducing gas deflation generating during use of lead battery.

US patent No. 4,317,872 discloses a lead battery utilizing a gel electrolyte containing silica particles.

Another method of gelling electrolyte is disclosed in US patent No. 4,465,748 where liquid electrolyte is immobilized when it is absorbed and retained in a very absorbent glass fiber.

International Patent Publication WO 03/067684 provides a novel- method of gelling electrolyte by filtration action of absorbent separators.

These relate to methods using plates which passed formation process, but not formation methods.

It has become an important problem to improve formation process and formation method.

The present invention provides a solid electrolyte to be used for formation of lead battery and formation method of lead battery using it in order to solve above problem.

The invention is aimed at decreasing pollution phenomena and reducing formation time by introducing solid electrolyte into formation process of lead battery.

Summary of the Invention

The present invention provides a novel solid electrolyte which can be used in both plate formation process and lead battery.

The present invention provides manufacturing method of solid electrolyte.

The invention makes it possible to save labor and time to be wasted for changing electrolyte or drying pole plates after finishing formation charge.

According to the present invention, gas deflation to be generated during formation process is decreased, self-discharge becomes less and time for formation charge is reduced.

Solid electrolyte of the present invention contains 75~86wt% of calcium sulfate, 9~12wt% of sulfuric acid and 5~16wt% of stabilizer.

The stabilizer of solid electrolyte described in the present invention consists of more than two metals, metallic oxides and metallic salts.

The solid electrolyte of the present invention is used as not only in formation process, but also as it was after formation process.

Lead batteries using solid electrolyte of the present invention are not limited in respect of size and shape.

At present, the formation method of battery plate that is mostly used in the prior art is step-by-step method. According to the present invention, both single formation and bundle formation of lead batteries using electrolyte of the present invention are possible. Formation process is done for 12~14hours with current intensity equal to 1/12-1/14 of the lead battery capacity and current intensity regulation is not necessary during formation charge (Figure 1, Figure 2).

As it is distinct through the figures, both 2V single formation and 12V bundle formation using solid electrolyte of the present invention generate gas much less than formation of normal lead acid battery since formation voltages (2.2-2.3 V, 13V) are lower than gas generating- voltages (2.6V, 13.5V) and formation times are short.

Electrolyte used for formation charge can be used as it was, and changed. The formation charge process of the lead battery according to the present invention makes it possible to provide high productivity and save electricity, labor and time since unformed plates are used as they were after being dried and thus there is no need to take them out, wash, dry or save them after charge.

The invention will be described in more detail with reference to the following examples:

Example 1

CaSO4-2H2O 75 wt% AI2O3 5.2 wt%

Na2CO3 10.7 wt% Ge 0.02 wt%

H2SO4

Solid electrolyte is produced according to the following steps;

mixing aluminum oxide, calcium sulfate and germanium in order with sulfuric acid; heating the mixture at temperature of 70^°C~80°C forl 5-20min; adding sodium carbonate in the mixture and heating it at temperature of 110^oC~120°C for 10~20min; and cooling the mixture to temperature of 15°C~35°C

Example 2

CaSO4 · 2H2O 78 wt% MgSO4 6.7 wt%

SrSO4 3.5 wt% Na2SO4 « 10H2O 1.35 wt%

H2SO4

Solid electrolyte is produced according to the following steps;

mixing strontium sulfate, calcium sulfate and magnesium sulfate in order with sulfuric acid; heating the mixture at temperature of 70°C~75^oC for 20~30min; adding sodium sulfate in the mixture and heating it at temperature of 90^eC~115^°C for 15~25min; and cooling the mixture to temperature of 15"C~35⁰C Example 3

CaSO4 « 2H2O 82 wt% Ti2(SO4) 3 3.5 wt%

ZnSO4 1.2 wt% CoSO4 * 7H20 2.3 wt%

BeSO4 « 4H2O 1.4 wt% H2SO4

Solid electrolyte is produced according to the following steps;

mixing zinc sulfate, calcium sulfate, beryllium sulfate and titan sulfate in order with sulfuric acid; heating the mixture at temperature of 80°C~90°C for 20-25min; adding cobalt sulfate in the mixture and heating it at temperature of 120°C~125°C for 10-15min; and cooling the mixture to temperature of 15°C~35°C Example 4

CaSO4 · 2H2O 86 wt% Al2 (SO4)3 · H2O 2.4wt%

CdSO4 · 4H2O 0.4 wt% Na2SO4 · I OH2O 2.2 wt%

H2SO4

Solid electrolyte is produced according to the following steps;

mixing sodium sulfate, aluminum sulfate and calcium sulfate in order with sulfuric acid; heating the mixture at temperature of 80^oC~110^°C for 15~20min; adding cadmium sulfate in the mixture and heating it at temperature of 125^oC~130^eC for 10~15min; and cooling the mixture to temperature of 15°C~35^°C

According to the invention, a cycle charge time of lead battery after completing formation process is 60~80min (Figure 3).

12V-lead battery using solid electrolyte of the invention is allowed to be discharged to low voltage of 4.5-5V. Though it is discharged to low voltage, the battery capacity is still capable of being regenerated.

Self-discharge rates per a month of lead batteries using above mentioned examples of solid electrolyte of the invention are 0.8-1% at 60°C of temperature and 80% of relative humidity (Table 1).

Table 1 Lead battery using solid electrolyte of the invention has advantages of high capacity, short charge time and allowance of complete discharge, etc. It is more advantageous that the lead battery using solid electrolyte of the invention can be sealed since complete charge voltage for the solid electrolyte of the invention is lower than gas deflation voltage of the same.

While the invention has been described with particular examples to certain embodiments of the invention, it will be understood that changes and modifications may be made by those skilled in the art within the scope and spirit of the present invention as defined in the following claims.