JP3281057B2 - Rechargeable battery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a secondary battery,
Particularly, the present invention relates to a novel metal ion secondary battery in which a non-aqueous electrolyte is improved.

[0002]

2. Description of the Related Art Lithium secondary batteries are classified into two types according to differences in electrochemical reactions at the negative electrode.
One of them is to use lithium metal or its alloy for the negative electrode, the following two reactions on the surface of the lithium metal of the negative electrode during charge and discharge, (1) lithium ion loses charge and reacts as a metal, And (2) a battery in which a reaction is performed in which lithium metal obtains a charge and becomes an ion to be eluted. The other is to use carbon and other non-metals for the negative electrode, the following two reactions on the surface of the negative electrode during charge and discharge, (1) lithium ions penetrate into the negative electrode material in an ionic state (intercalation) And (2) a reaction in which intercalated ions are desorbed into the electrolyte solution again.

A secondary battery that performs the former reaction is called a lithium metal secondary battery, and a secondary battery that performs the latter reaction is called a lithium ion secondary battery. In addition, metals other than lithium, for example, alkali metals such as sodium and potassium, alkaline earth metals such as calcium and magnesium,
A similar secondary battery can be manufactured using aluminum, zinc, or another metal.

As described above, the form of the metal present in the battery system differs between the lithium metal secondary battery and the lithium ion secondary battery. In a lithium metal secondary battery, lithium metal or an alloy thereof is used for the negative electrode, and thus lithium metal always exists in the battery. Lithium metal in the battery may be in the form of lithium microcrystals that are necessarily generated on the electrodes by charging and discharging, in addition to the electrode plates that exist from the beginning.

[0005] The lithium electrode plate is active and reacts with air and water, so it is dangerous to come into contact with them and spontaneously ignites when heated in air. In addition, the lithium microcrystals are more active and highly reactive, and easily spontaneously ignite simply by contact with air. Therefore, when the safety valve of the battery is opened and the contents are discharged, or the battery is destroyed, and the lithium microcrystal is exposed to air, the lithium microcrystal spontaneously ignites, which is extremely dangerous.

For such a lithium metal secondary battery,
Since the lithium ion secondary battery uses carbon or other nonmetallic material for the negative electrode, the safety is higher than that of the lithium metal secondary battery because a dangerous lithium metal or the like or an alloy is not used for the negative electrode.

In the above lithium ion secondary battery,
Lithium present in the battery is usually all in a safe ionic state, not in a metallic state. Therefore, in the ideal state, the lithium ion secondary battery is a safer secondary battery than the lithium metal secondary battery, and even if the battery is destroyed and the contents of the battery are exposed to air, No ignition occurs.

In each of the secondary batteries, a non-aqueous electrolyte is used. The non-aqueous electrolyte can be commonly used for each of the secondary batteries. As the nonaqueous electrolyte, ethylene carbonate, propylene carbonate, high boiling point, high dielectric constant organic solvent such as γ-butyrolactone, and low boiling point, low viscosity organic solvent such as tetrahydrofuran, 2-methyltetrahydrofuran, dimethoxyethane, dioxolane Is used. The high-dielectric constant organic solvent has a high viscosity, and the low-viscosity organic solvent has a low dielectric constant.

The boiling points of the organic solvents are as follows: the former three high-dielectric-constant organic solvents are 248 ° C., 242 ° C., 206
° C, and the latter four low-viscosity organic solvents are 6
6 ° C, 78 ° C, 85 ° C, and 78 ° C. The flash points of these organic solvents are 152 ° C., 132 ° C. and 93 ° C. for the former three high dielectric constant organic solvents, respectively, and −14 ° C. and −11 ° C. for the latter four low viscosity organic solvents, respectively. , 0
° C and 1 ° C. Therefore, the former falls under the category of Class 4 Petroleums specified by the Fire Service Law, and the latter falls under the category of Class 4 Petroleums.

As described above, non-aqueous electrolytes such as the above-mentioned lithium ion secondary batteries are flammable and flammable. Therefore, it is housed inside the battery and there is no problem during normal use, but if it leaks out for any reason,
If there is a source of ignition, it burns easily and has the potential danger of fire.

Incidentally, in the above-mentioned ideal lithium ion secondary battery, lithium does not exist in a metallic state in principle. For example, the ideal state can be maintained by controlling an overcharge protection circuit or the like so that overcharge or the like does not occur. However, as soon as the above control is released and overcharging or the like is continued, lithium ions in the battery system change to a metallic state, and lithium microcrystals begin to be formed on the electrodes.

In an actual lithium ion secondary battery, the ideal state is not always maintained, and some cause (for example, failure of a control circuit, variation in control, variation in raw materials in battery manufacturing, Process variations), overcharging, overdischarging, or other electrochemical reactions may occur throughout the battery or locally, in which case lithium metal is formed on the electrodes and lithium microcrystals are formed. Form.

[0013] The lithium ion secondary battery in which the lithium microcrystals are formed has the same danger as the lithium metal secondary battery, and the safety valve of the battery is opened and the contents are discharged.
When the battery is destroyed or the metal microcrystals are exposed to air, the metal microcrystals first ignite, which in turn ignites the non-aqueous electrolyte, leading to fire.

As described above, the conventional lithium ion secondary battery is not a battery in which lithium is not essentially present in a metal state, but is a battery which is controlled by an external control circuit so that lithium does not exist in a metal state. And there is always the potential danger of lithium metal formation. Therefore, lithium metal microcrystals may be generated due to a failure of the control circuit or other causes, and there is a risk of ignition. The prior art could not solve this problem.

Further, it is difficult to sell the conventional lithium ion secondary battery alone by the above-mentioned reason, and it is always sold in a form combined with an external control circuit. This is because when sold as a single battery, the purchaser does not always charge with a charger with a dedicated control circuit, and there is a possibility that it will be charged by another charger without a control circuit by mistake. It is.

[0016]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a secondary battery capable of maintaining a state in which lithium or the like is not present in a metallic state at all as an essential characteristic of the battery itself, regardless of external control, that is, a lithium or the like. Does not produce metal microcrystals of
An object of the present invention is to provide a safe rechargeable battery having no danger of ignition.

Another object of the present invention is to provide a method in which the microcrystals of lithium or the like are not formed on the electrode by the self-control of the battery itself, regardless of the external control, and the amount of the metal such as lithium is small. It is intended to provide a secondary battery having a function of maintaining battery characteristics and a function of losing battery operation by interrupting conduction between a positive electrode and a negative electrode when a large amount of metal such as lithium is generated. .

[0018]

A secondary battery according to the present invention includes a positive electrode, a negative electrode, and a non-aqueous electrolyte, and uses a metal ion intercalation. The non-aqueous electrolyte contains a carbonaceous material to be absorbed and released as an active material, and the non-aqueous electrolyte contains a halogenated hydrocarbon which is converted into a non-metal by reacting with a metal generated from the metal ion. .

As the positive electrode, for example, a positive electrode containing a chalcogen compound as an active material is used. Examples of the chalcogen compound include manganese dioxide, lithium manganese composite oxide, lithium cobalt oxide, lithium nickel cobalt oxide, amorphous vanadium pentoxide containing lithium, titanium disulfide, molybdenum disulfide and the like. . In particular, lithium cobalt oxide is useful because the potential of the positive electrode can be increased and the battery voltage can be increased.

Examples of the carbonaceous substance contained in the negative electrode include coke, a sintered body of a synthetic resin, carbon fiber,
A pyrolysis gas phase carbon material, mesophase pitch-based carbonaceous material, mesocarbon microbeads, or the like can be used. As the carbonaceous substance, a substance in which lithium is stored in advance may be used.

The conversion of the metal to a non-metal means that when a metal element such as lithium existing in an ionic state in a battery forms a metal microcrystal by a chemical change from an initial ionic state, it reacts with a halogenated carbon. The metal produced by the action of hydrogen is returned to inorganic salts, organic acids, metal complexes, ions,
It means converting to a non-metallic state such as an organometallic compound.

The above-mentioned halogenated hydrocarbon means that one or more hydrogen atoms of the hydrocarbon are halogen atoms (I, B
r, Cl, F). Examples of such halogenated hydrocarbons include iodoethane, iodopropane (1-iodopropane, 2-iodopropane), and iodobutane (1-iodobutane, 2-iodobutane, 1-iodo-2-methylpropane, 2-iodo-).
Various substituted alkyl iodides such as 2-methylpropane), iodopentane (1-iodopentane and others), iodohexane (1-iodohexane and others), and iodooctane (1-iodooctane and others); 1,1-diiodoethane ,
1,2-diiodoethane, 1,1-diiodopropane,
1,2-diiodopropane, 1,3-diiodopropane, 1,1-diiodobutane, 1,4-diiodobutane, 1,5-diiodopentane, 1,6-diiodohexane, 1,8-diiodo Octane, 1-iodo-2-bromoethane, 1-iodo-3-bromopropane, 1-iodo-4-bromobutane, 1-iodo-5-bromopentane, 1-iodo-6-bromohexane, 1-iodo-
8-bromooctane, 1-iodo-2-chloroethane,
1-iodo-3-chloropropane, 1-iodo-4-chlorobutane, 1-iodo-5-chloropentane, 1-iodo-6-chlorohexane, 1-iodo-8-chlorooctane, 1-iodo-2-fluoroethane , 1-iodo-
3-fluoropropane, 1-iodo-4-fluorobutane,
1-iodo-5-fluoropentane, 1-iodo-6-fluorohexane, 1-iodo-8-fluorooctane, 1-
Iodo-polyfluoroethane, 1-iodo-polyfluoropropane, 1-iodo-polyfluorobutane, 1-iodo-
Polyfluoropentane, 1-iodo-polyfluorohexane, 1-iodo-polyfluorooctane, iodomethane,
Alkyl iodides such as diiodomethane, iodobromomethane, iodochloromethane and iodofluoromethane; alkylene iodides such as iodoethylene, iodopropene, iodobutene, iodopentene, iodohexene, iodooctene and iodobutadiene;
Bromoethane, bromopropane (1-bromopropane,
2-bromopropane), bromobutane (1-bromobutane, 2-bromobutane, 1-bromo-2-methylpropane, 2-bromo-2-methylpropane), bromopentane (1-bromopentane, etc.), bromohexane (1- Various substituents of alkyl bromides such as bromohexane and bromooctane (1-bromooctane and others); 1,2-dibromoethane, 1,3-dibromopropane, 1,4-dibromobutane, 1,5-dibromo Pentane, 1,6-dibromohexane, 1,8-dibromooctane, 1-bromo-
1-chloroethane, 1-bromo-2-chloroethane, 1
Alkyl bromides such as -bromo-1-chloropropane, 1-bromo-2-chloropropane, 1-bromo-3-chloropropane and the like; bromoethylene, bromopropene, bromobutene, bromopentene, bromohexene, bromooctene, bromobutadiene, dibromo Ethylene, dibromopropene, dibromobutene, dibromopentene, dibromohexene, dibromooctene, dibromobutadiene,
Alkylene bromide, alkylpolyene bromide, etc .; chloropropane (1-chloropropane, 2-chloropropane),
Chlorobutane (1-chlorobutane, 2-chlorobutane,
1-chloro-2-methylpropane, 2-chloro-2-methylpropane), chloropentane (1-chloropentane, etc.), chlorohexane (1-chlorohexane, etc.), chlorooctane (1-chlorooctane, etc.), etc. Alkyl chlorides such as 1,1-dichloropropane, 1,3-dichloropropane, and 1,4-dichlorobutane; alkylene chlorides such as dichloropropene, dichlorobutene and dichlorobutadiene; and alkylpolyene chlorides;
Iodocyclopropane, iodocyclobutane, iodocyclopentane, iodocyclohexane, iodotoluene, iodoxylene and the like; iodide cyclic compounds such as polyiodo compounds thereof; bromide cyclic compounds obtained by substituting iodine of the above iodide cyclic compound with bromine; There is a chlorinated cyclic compound in which iodine of an iodinated cyclic compound is substituted with chlorine.

Among the halogenated hydrocarbons, iodine-substituted compounds are most preferred, and iodine-substituted aliphatic hydrocarbons are particularly preferred. Next preferred halogenated hydrocarbons are
Bromine substituted compounds, followed by chlorine substituted compounds. The preferred order is the difference in the order of reactivity and the type of reaction between the halogenated hydrocarbon and metal microcrystals such as lithium generated in the battery, as described later. That is, an iodine-substituted aliphatic hydrocarbon is the most preferable because it has the highest reactivity and can perform a safe reaction.

In the halogenated hydrocarbon, part of carbon and / or part or all of hydrogen may be substituted by another functional group.

The halogenated hydrocarbon is preferably nonflammable. If it is nonflammable, even if these compounds are discharged to the outside of the battery, these compounds will not ignite or burn by an external ignition source.

The above-mentioned halogenated hydrocarbons may be used alone as the electrolyte, or may be used as a mixture of two or more kinds. In the case of mixing, a combination of the halogenated hydrocarbon alone may be used, but the halogenated hydrocarbon and a non-aqueous solvent used in an existing lithium secondary battery (for example, propylene carbonate, ethylene carbonate, γ-butyrolactone, dimethoxyethane) , Tetrahydrofuran)
May be combined. When it is combined with a non-aqueous solvent used in an existing lithium secondary battery, it is preferable to mix it in accordance with the amount of microcrystals of a metal such as lithium which produces the halogenated hydrocarbon.

Another secondary battery according to the present invention includes a positive electrode, a negative electrode, and a non-aqueous electrolyte, and uses a metal ion intercalation. The negative electrode stores and releases the metal ions. A carbonaceous material as an active material, and wherein the non-aqueous electrolyte solution contains a halogenated hydrocarbon which reacts with a metal generated from the metal ion to convert it to a non-metal and generate gas. It is.

The halogenated hydrocarbon includes, for example, iodoethane, iodopropane (1-iodopropane, 2-iodopropane) and iodobutane (1-iodobutane, 2-iodobutane, 1-iodo) among the above-mentioned halogenated hydrocarbons. -2-methylpropane, 2-iodo-
Those having one halogen group such as 2-methylpropane) can be used. Among such halogenated hydrocarbons, an iodine-substituted compound is most preferable, and an iodine-substituted aliphatic hydrocarbon is particularly preferable.

The function of reacting with the metal generated from the metal ion to convert it to a non-metal and the function of generating a gas include:
This may be achieved by one kind of halogenated hydrocarbon, or may be achieved by two or more kinds of halogenated hydrocarbons.

Still another secondary battery according to the present invention includes a positive electrode, a negative electrode, and a non-aqueous electrolyte, wherein the negative electrode stores and releases the metal ions. Wherein the non-aqueous electrolyte solution contains a halogenated hydrocarbon which reacts with a metal generated from the metal ion to convert it to a non-metal and generate a polymerizable substance. It is assumed that.

The halogenated hydrocarbon includes, for example, 1,1-diiodoethane, 1,2-diiodoethane, 1,1-diiodopropane, 1,2-diiodopropane, 1,3-Diiodobutane, 1,1-diiodobutane, 1,4-diiodobutane, 1,5-diiodopentane, 1,6-diiodohexane, 1,8-diiodooctane, 1-iodo-2-bromoethane , 1-iodo-3-bromopropane, 1-iodo-4-bromobutane and the like having two or more halogen groups can be used. Among such halogenated hydrocarbons, an iodine-substituted compound is most preferable, and an iodine-substituted aliphatic hydrocarbon is particularly preferable.

The function of converting to a non-metal by reacting with the metal generated from the metal ion and the function of forming a polymer may be achieved by one kind of halogenated hydrocarbon or two kinds of halogenated hydrocarbons. This may be achieved with the above halogenated hydrocarbons.

[0033] Still another secondary battery according to the present invention comprises a positive electrode, a negative electrode and a non-aqueous electrolyte, wherein the negative electrode stores and releases the metal ions. A non-aqueous electrolyte solution that reacts with a metal generated from the metal ion to convert it to an ionic non-metal, and that a metal is generated from the metal ion. A halogenated hydrocarbon having at least one function selected from a function of forming a barrier material that reacts with the metal to convert it into an ionic nonmetal and interrupts conduction between the positive electrode and the negative electrode. It is characterized by the following.

As the halogenated hydrocarbon, the above-mentioned halogenated hydrocarbon reacts with a metal formed from the metal ion to be converted into an ionic non-metal and has one halogen group. Alternatively, a compound having two or more halogen groups can be used. The former halogenated hydrocarbons generate gas as a barrier material, and the latter halogenated hydrocarbons generate polymers as barrier materials. The halogenated hydrocarbon used as the former halogenated hydrocarbon is most preferably an iodine-substituted compound, and particularly preferably an iodine-substituted aliphatic hydrocarbon. The halogenated hydrocarbon used as the latter halogenated hydrocarbon is most preferably an iodine-substituted compound.

The secondary battery according to the present invention allows a safety device to be attached to the container.

The safety device is provided so that the battery can self-control when the temperature rises above the normal operating temperature due to overcharging or other reasons, or when the internal pressure becomes extremely high. ing. Therefore, when the temperature of the battery exceeds the temperature considered to be dangerous or exceeds the internal pressure considered to be dangerous, the inside of the battery is opened and the function of the battery is lost. By operating such a safety device, the inside of the battery is opened and the electrolyte solution inside is discharged. Since the electrolyte is discharged, the internal pressure of the battery decreases, and the function of the battery is lost. Therefore, overcharging stops, and the temperature of the battery gradually decreases.

The safety device is constituted by a safety valve or other opening mechanism that operates when the temperature of the battery exceeds a temperature considered dangerous or exceeds an internal pressure considered dangerous. The value of the temperature considered to be dangerous or the value of the internal pressure considered to be dangerous may be arbitrarily determined by the battery designer in consideration of the specifications of the battery. In the case of a general lithium secondary battery, usually 80 to 200
° C., or often set in the range of 3~30kg / cm ^2.

It is preferable that the safety mechanism operates with high sensitivity to the set value. The accuracy of the safety mechanism is set within a range necessary to achieve the purpose of preventing danger of each secondary battery. Safety mechanisms that operate when the battery temperature exceeds a certain set value include, for example, a low melting metal that melts at a certain temperature, a metal that deforms at a certain temperature, and a thermoplastic resin whose strength decreases at a certain temperature. It can be realized by using a material whose physical properties, shape, and the like change with temperature and utilizing the change.

In a battery completely sealed by the safety mechanism, the contents are shielded from the outside until a certain temperature is reached, but when the temperature reaches that temperature, for example, the metal sealing the battery lid is removed. Melts and the lid is free. Then, the lid is removed by the pressure of the electrolyte vapor inside the battery, and the electrolyte is discharged in the form of gas and liquid.

A safety mechanism that operates when the battery pressure exceeds a certain set value includes, for example, a material such as a metal film designed to break at a certain pressure or a valve designed to release at a certain pressure. And can be realized by devising the structure.

In a battery completely sealed by the safety mechanism, the contents are isolated from the outside until a certain pressure is reached, but the electrolyte inside the battery expands due to boiling or the like, so that the internal pressure of the battery is reduced. When the pressure reaches the above pressure, the internal pressure breaks the lid made of, for example, a metal film that sealed the battery, and the electrolyte is discharged in the form of gas and liquid.

The safety mechanism may be a non-return type that does not return to its original state once it has been activated, or a return type that returns to its original state when the internal pressure decreases.

The above-described safety device may be combined with a safety mechanism for controlling a current flowing through the battery according to the temperature or pressure, in addition to the mechanism for discharging the nonflammable organic solvent. The safety mechanism, for example, to allow the electrode terminal (safety valve) that is in electrical contact with the positive electrode lead inside the battery to be able to operate at the set pressure, and when the internal pressure rises and reaches the set pressure, The electrode terminal is operated by the pressure to bring the electrode terminal into a non-contact state with the positive electrode lead to cut off the circuit. This combination makes it possible to more reliably prevent overcharging of the battery. In particular, when the above-described safety mechanism is attached to a secondary battery using an electrolyte containing an organic solvent of a type that generates a gas by reacting with a metal, the current is interrupted by the pressure of the gas generated in proportion to the amount of the generated metal. However, it is very preferable because the generation of metal can be stopped.

The safety mechanism for controlling the electric current includes a non-return type which does not return to its original state once it is operated, and a return type which returns to its original state when the internal pressure and the battery temperature decrease as described below.

The non-return type is a method in which the function of the battery is permanently stopped if the battery has fallen into a dangerous state even once. For example, when the overcharge protection circuit fails, the internal pressure of the battery is reduced. Rises and activates a non-recoverable safety device built into the battery, making the battery permanently unchargeable, preventing overcharging of the battery and putting the battery in a more dangerous state To block.

The return type is a method in which the function of the battery is temporarily stopped when the battery falls into a dangerous state. For example, when the overcharge protection circuit breaks down, the temperature of the battery rises. The internal pressure increases, activating a reset-type safety device built into the battery and temporarily preventing the battery from being charged, thereby preventing the battery from being overcharged and causing the battery to become more dangerous. Prevent becoming. When the battery temperature drops and the internal pressure decreases due to the stop of overcharging, the charging circuit returns and charging starts again.However, when the battery temperature rises and the internal pressure increases, the safety device operates again. , Temporarily make the battery unchargeable. By repeating this operation, the battery is prevented from going into a dangerous state such as an explosion.

The safety mechanism for controlling the current may be installed independently of the safety valve or may be installed in combination with the safety valve, and there is no limitation on what kind of mechanism is used.
For example, if the non-return type safety valve is used in a current circuit, the current is cut off simultaneously with the operation of the safety valve, so that the non-return type current control mechanism can also be used. Conversely, if a return-type safety valve is used in the current circuit, a return-type current control mechanism can be provided.

As the current control method, a method of discontinuous ON / OFF control at a certain pressure boundary, a method of continuously decreasing the current value in proportion to the pressure, and a method of combining these (for example, a certain constant Constant current value up to pressure,
Above that, a method of continuously decreasing the current value in proportion to the pressure, or conversely, a method of continuously decreasing the current value in proportion to the pressure up to a certain pressure and cutting off the current above that) Can be adopted.

The safety mechanism for controlling the current is particularly effective as a countermeasure when the protection circuit of the charger is broken and the battery is overcharged.

In particular, if a current control mechanism that operates at a set temperature at which the safety valve operates, and at a temperature and pressure lower than the set pressure is incorporated, the current control mechanism operates before the safety valve operates and the overcharge state of the battery is reduced. Can be stopped,
Battery safety measures become more reliable.

Further, in the secondary battery according to the present invention, abnormal reactions (particularly, decomposition of metal formed from metal ions, electrolytic solution, generation of gas, increase of internal pressure, generation of heat, generation of abnormal current, abnormal voltage) Is generated by a sensor, and a monitor system for monitoring the safety of the sensor is provided.

While the above-described safety device is installed inside the battery to limit the function of the battery to ensure its safety, the monitor system is mainly installed outside the battery and the safety device limits the battery function. Before any action is taken
This system protects the battery by detecting an abnormality in the battery and sending an alarm signal, or automatically controlling the entire necessary circuit including the battery.

When comparing the safety device with the monitor system, the battery incorporating the safety device allows the user to notice abnormality of the battery for the first time when the safety device is activated, whereas the monitor system uses the safety device. Battery malfunction can be detected before operation. For this reason, the monitor system is used especially when a large secondary battery is used or when the secondary battery is used for important equipment (for example, a power supply for vehicles such as electric vehicles, a home or industrial power storage system, and a control system such as a computer). When the battery and the equipment are incorporated in a backup power supply, the battery and the equipment can be protected.

The monitor system comprises means for detecting an abnormal reaction of the battery and means for processing the information.
Here, the abnormal reaction of the battery means all reactions that hinder the normal operation of the battery. Further, detecting the abnormal reaction means detecting the abnormal reaction itself or a phenomenon caused by the abnormal reaction.

The abnormal reaction detecting means detects an abnormal reaction starting inside the battery as early as possible before the safety device operates, and sends a signal to the information processing means. The information processing means performs a desired safety measure in response to the signal. The safety measures include (1) informing the user of the battery status, (2)
And automatically controlling the entire necessary circuit including the battery to protect the battery. In some cases, only one of the safety measures need be performed.

The information processing means may be of any type, from an advanced type using a computer having a judgment function to a simple type only performing simple transmission. It is desirable that the content of the information processing be selected according to each system in which the battery is used. As a method of notifying the user of the state of the battery, a method of displaying a message on a display image, a method of transmitting light or sound waves including sound, or other methods can be adopted. Using these methods, an abnormal reaction occurred in the battery, the details of the abnormal reaction, the details of the safety measures that were automatically performed, the state of the battery after the measures, and the specific measures to be taken by the user Etc. are communicated as necessary.

The simple information processing and the advanced information processing will be specifically exemplified below, but the present invention is not limited to these examples.

As an example of the above-mentioned simple information processing, it is displayed on the display that there is some abnormality in the battery.
Informing the user of the occurrence of an abnormality by, for example, turning on an alarm lamp on a monitoring panel or generating a sound such as a buzzer to warn the user.

As an example of the above-mentioned advanced information processing, the state of the battery is constantly monitored from various aspects using various sensors, and the information obtained from them is integrated to diagnose the state of the battery with a computer. If an abnormality is found in the battery, the state of the abnormality is determined by a method such as inference and the cause is determined. After the cause is determined, the optimal countermeasures are selected and executed. Monitor the situation that occurs as a result of implementing the countermeasures, and take the following countermeasures as necessary. The progress and results are displayed to the user on a display screen, a monitor panel,
Communicate through voice, etc.

For example, when a metal such as lithium is generated by overcharging, an internal pressure rise signal due to a gas produced by a reaction with a halogenated hydrocarbon, a temperature rise signal due to reaction heat, a voltage abnormality signal of a battery electrode, a charging current Comprehensively judges the abnormal signal of the battery and the signal indicating the abnormality of the charging circuit outside the battery, infers that the battery is in an overcharged state due to the failure of the charging circuit, and immediately stops charging. The above process and results are transmitted to the user.

The above-described secondary battery according to the present invention comprises a positive electrode, a negative electrode, and a non-aqueous electrolyte. In the secondary battery utilizing intercalation of metal ions, the negative electrode absorbs and releases the metal ions. The nonaqueous electrolytic solution contains a halogenated hydrocarbon which is converted into a nonmetal by reacting with the metal generated from the metal ion. The halogenated hydrocarbon reacts with lithium metal microcrystals generated in the battery to convert a metal such as lithium into a nonmetal compound, so that all of the metal microcrystals can be converted into a safe compound. As a result, a state in which lithium or the like does not exist in a metallic state in the secondary battery can be maintained.

A typical example of the above reaction is a reaction between lithium metal microcrystals and an iodine-substituted aliphatic hydrocarbon. For example, highly reactive alkyl iodide causes a Wurtz reaction represented by the following formula (1) to produce a safe lithium salt (lithium iodide) that does not cause ignition.

2C ₂ H ₅ I + 2Li → C ₄ H ₁₀ + 2LiI (1) As described above, the non-aqueous electrolyte containing a halogenated hydrocarbon is capable of safely igniting lithium metal microcrystals generated in the battery without ignition. It can be converted into a compound to maintain a safe state of the battery.

In the reaction between lithium metal microcrystals and another halogenated hydrocarbon, the following halogen substitution reaction occurs in addition to the Wurtz reaction depending on the conditions, and an organic lithium compound is produced as an intermediate. For example, tert-butyl bromide produces tert-butyllithium as shown in the following formula (2).

(CH ₃ ) ₃ CBr + 2Li → (CH ₃ ) ₃ CLi + LiBr (2) The produced tert-butyl lithium has a high activity and immediately reacts with another electrolytic solution or the like.

For example, when the electrolytic solution is tetrahydrofuran, a reaction represented by the following formula (3) occurs to change to a safe lithium compound (C ₂ H ₃ OLi) which does not ignite.

(CH ₃ ) ₃ CLi + C ₄ H ₈ O → C ₂ H ₄ + C ₄ H ₁₀ + C ₂ H ₃ OLi (3) When, for example, the electrolytic solution is ethylene carbonate, the following formula (4) is used. The reaction shown in (1) occurs, and the reaction is similarly changed to a safe lithium compound that does not ignite.

2 (CH ₃ ) ₃ CLi + (CH ₂ O) ₂ CO → (CH ₃ ) ₃ CCOC (CH ₃ ) ₃ + (CH ₂ OLi) ₂ (4) Further, for example, triphenyl boron is added to the electrolytic solution. If dissolved in advance, the reaction represented by the following formula (5) occurs immediately, and the compound is converted into a safe lithium salt.

(CH ₃ ) ₃ CLi + (C ₆ H ₅ ) ₃ B → [(CH ₃ ) ₃ C (C ₆ H ₅ ) ₃ B] Li (5) As described above, an organolithium compound is used as an intermediate substance. Also, the lithium metal microcrystals generated in the battery can be changed to a safe compound having no ignitability by the method of passing through.

When comparing the above equations (1) to (5),
It is safest to use iodide as the halogenated hydrocarbon, since iodide does not produce an organolithium compound having a risk of ignition in addition to the rapid reaction.

When a bromide, chlorinated compound or fluorinated compound is used as a halogenated hydrocarbon, an organolithium compound having a risk of ignition is produced as an intermediate product, which further reacts to lose the risk of ignition. The safety of the secondary battery can be ensured by using these. Of these three halogenated hydrocarbons, bromide reacts fastest with metals such as lithium generated from metal ions, and is therefore preferred next to iodide. Then chlorinated,
The order is fluorinated.

In a secondary battery using a metal ion such as sodium or potassium which is more active than lithium, the reaction between these metal microcrystals and the halogenated hydrocarbon rapidly proceeds through the Wurtz reaction regardless of the type of substituted halogen. Occur.
In these cases, a safe salt (NaCl,
NaBr, NaI, KCl,...).

In a secondary battery using a metal ion other than an alkali metal, such as calcium, magnesium, aluminum, or zinc, the metal generated from the metal ion and the halogenated hydrocarbon are represented by the following formulas (6), (7), The reaction shown in (8) occurs.

2RX + 2M → RR + 2MX (6) RX + 2M → RM + MX (7) RX + M → RMX (8) where RX is a halogenated hydrocarbon, X is a halogen, and M is a metal generated from a metal ion. Represent.

Among the reactions of the above formulas (6) to (8), the reaction of the formula (6) is a Wurtz type reaction. The reaction of formula (7) is of the type that produces the aforementioned organometallic compounds. In these metals, as in the case of lithium described above, the metals are converted into safe nonmetals.

The reaction of the above formula (8) is a type of reaction that produces a so-called Grignard reagent. For example, when iodoethane reacts with metallic magnesium generated from magnesium ions, a product that does not spontaneously ignite even when exposed to air is generated as shown in the following equation (9).

C ₂ H ₅ I + Mg → C ₂ H ₅ MgI (9) Further, the above-mentioned product reacts with iodoethane as shown in the following formula (10) to change into a safe magnesium salt.

C ₂ H ₅ I + C ₂ H ₅ MgI → C ₄ H ₁₀ + MgI ₂ (10) The same applies to other metal elements.

As described above, the electrolytic solution containing the halogenated hydrocarbon immediately reacts with the lithium metal microcrystals generated in the secondary battery to change into a safe compound. Also,
The halogenated hydrocarbon not only reacts with a metal such as lithium generated from a metal ion but also reacts almost quantitatively and quickly to convert the metal to a nonmetal. Therefore, lithium or the like does not exist in a metal state in a lithium ion secondary battery using the electrolytic solution, and a metal such as lithium can always be kept in an ionic state.
Therefore, the secondary battery according to the present invention is not ignitable,
It is safe.

On the other hand, the conventional electrolytic solution hardly reacts with metals such as lithium, and even if slightly reacted, the reaction speed is slow, and only a small part of the metal surface reacts. Therefore, the point that most of the metal generated from the metal ion remains as it is is clearly different from the electrolytic solution of the present invention, that is, since the metal such as lithium generated from the metal ion is active, strictly speaking Reacts with most electrolytes in contact. However, the conventional reaction between the electrolytic solution and the metal such as lithium occurs only on the surface of the metal such as lithium and stops without proceeding inside. For example, it is known that propylene carbonate, ethylene carbonate, γ-butyrolactone, dimethoxyethane, tetrahydrofuran and other electrolytic solutions react with lithium metal on the surface. However, these reactions are not quantitative bulk reactions, but only surface reactions. As a result of the reaction, a protective film is formed on the surface of the metallic lithium, and further reaction stops. Therefore, a metal such as lithium generated from a metal ion remains as lithium as it is. In addition, since the reaction rate is low, formation of metallic lithium cannot be prevented in these reactions.

Therefore, when the lithium ion secondary battery using the above-mentioned electrolytic solution is overcharged, metallic lithium is continuously generated on the electrode, and the amount of generated lithium is increased, which is dangerous. Even if overcharging is stopped halfway, the amount of generated metallic lithium does not decrease and remains as metallic lithium as it is, so that the dangerous state continues.

Since the secondary battery of the present invention has a built-in mechanism for converting the generated microcrystals of metal such as lithium into a safe compound, the state where no metal such as lithium exists in the battery system is always maintained. It can be clearly distinguished from conventional secondary batteries.

The secondary battery according to the present invention exerts its function and effect even more when it is combined with a safety device for opening the inside of the battery and a safety device such as a mechanism for controlling the current flowing inside the battery.

When a safety device that opens at a specified temperature or a specified pressure is mounted on a conventional lithium ion secondary battery, a flammable and flammable electrolyte is discharged from the safety valve, and the generated metal microcrystals such as lithium are discharged. There is a danger that the electrolyte and the battery will burn because they ignite on contact with air. For this reason,
The conventional lithium secondary battery with a safety valve could prevent the explosion but could not prevent the combustion.

On the other hand, when the safety device is mounted on the secondary battery of the present invention, it is possible to prevent the explosion and, of course, the combustion and fire because of the absence of metal microcrystals such as lithium. Play.

The operation and effect when the mechanism for controlling the current and the electrolyte contained in the secondary battery of the present invention are combined will be described below.

In the case of a battery in which a current control mechanism is combined with a conventional electrolytic solution, although there is an effect of preventing the battery from exploding due to overcharging, formation of a metal such as lithium cannot be prevented. That is, when a non-return type current control mechanism is used, the generation of a metal such as lithium is stopped when the current control mechanism is activated due to overcharging, but the metal such as lithium generated up to that time remains unchanged. Remains.

On the other hand, when a return-type current control mechanism is used, the overcharge state continues intermittently, so that the generation of metal such as lithium continues intermittently, and the amount of generation gradually increases.

In these batteries, the generated metal such as lithium remains in the batteries as they are. Therefore, when the contents of the battery come into contact with air due to the opening or breakage of the safety device, there is a risk that a metal such as lithium generated from metal ions may ignite.

On the other hand, when the above-mentioned electrolyte containing a halogenated hydrocarbon is used in combination, the generated metal such as lithium is immediately converted into a safe compound by the halogenated hydrocarbon. Not only when a control mechanism is used, but also when a return-type current control mechanism is used, the inside of the battery is always free of metals such as lithium, and the contents of the battery are safe even if they come into contact with air. is there.

A comparison between the case where the electrolytic solution of the present invention and the current control mechanism are used without being combined and the case where the current control mechanism is combined is quite advantageous. The advantage is that the amount of metal such as lithium is limited by the current control mechanism. For this reason, the burden of the halogenated hydrocarbon is reduced, which is effective not only for the reaction to proceed completely, but also for reducing the blending amount of the halogenated hydrocarbon.

Further, as described above, since there is no danger even when the safety device is activated, the basic concept of the battery safety device can be changed, and the utilization of the safety device which has been conventionally restricted is greatly increased. Can be extended to In other words, in the past, there was a risk that the battery would burn when the safety valve was activated.Therefore, the operation of the safety valve was limited to the utmost limit, and if further danger or explosion could not be avoided, it was activated just before it occurred. Was designed to be. In other words, it was a kind of explosive mitigation device.

In the present invention, since there is no danger of fire even when the safety device is activated, the safety device can be actively utilized not only as a mere explosion mitigation device but also as a device for broadly preventing danger. It is possible. For example, when the charge protection circuit breaks down and the battery becomes overcharged, the battery safety valve is opened using the heat generated by overcharge or the accompanying increase in the internal pressure of the battery to stop the function of the battery. This can stop overcharging and prevent the battery from becoming dangerous.

That is, it is separated from the explosive mitigation device,
It can be used as a simple overheat prevention device or overpressure prevention device incorporated in the battery.

As described above, the secondary battery of the present invention utilizes the safety valve to charge the battery even if the protection circuit for charging has failed or the user has accidentally charged the battery with a charger without the protection circuit. Even in this case, danger can be prevented. That is, the battery can be separated from the explosive power mitigation device and used as a mere device for preventing overheating and a device for preventing overheating incorporated in the battery.

In particular, when a secondary battery provided with an electrolytic solution containing a halogenated hydrocarbon that generates gas is combined with a current control mechanism, the current is cut off without opening the safety valve, and a dangerous state is reached. Therefore, the degree of safety can be further improved, which is preferable. The above method has an excellent feature that other methods do not directly detect the generated metal and generate gas in proportion to the amount of generated metal. The safety device can be activated.

Also, by utilizing the safety device,
Even if the charge protection circuit breaks down, or if the user accidentally charges with a charger without a protection circuit, danger can be prevented.

Conventional lithium ion secondary batteries are dangerous if a user accidentally charges them with a charger without a protection circuit, and are generally manufactured and sold in such a form as to prevent such a situation. It was a target. That is, the battery is manufactured and sold in a form that cannot be separated from the dedicated charger, or is manufactured and sold in a form that cannot be taken out by a general user by being incorporated into the device. On the other hand, the manufacture and sale of a single battery involves risks. On the other hand, since the lithium ion secondary battery of the present invention is safe, it is possible to manufacture and sell the battery alone.

Further, the secondary battery according to the present invention can convert a metal such as lithium generated from a metal ion into a nonmetal by the halogenated hydrocarbon contained in the electrolytic solution, thereby inhibiting the intercalation of the metal ion. The formation of metal on the electrode can be prevented, and good characteristics can be maintained.

That is, if a metal such as lithium generated from metal ions is formed on the electrode and a protective film is formed on the electrode surface and is stably present, the intercalation of the metal ions is hindered. Deteriorate electrode characteristics. Further, the deposited metal is difficult to be re-ionized, so that it is difficult to remove the metal. Furthermore, the amount of metal ions for the production of the metal is reduced. Thus, the deposition of metal deteriorates the characteristics of the secondary battery.

On the other hand, in the present invention, as described above, a metal such as lithium generated from metal ions by the halogenated hydrocarbon contained in the electrolytic solution can be converted into a nonmetal, and thus the metal formed on the electrode can be converted. Is deposited and coating of the electrode can be prevented beforehand. Therefore, good characteristics can be maintained without inhibiting metal ion intercalation.

Another secondary battery according to the present invention includes a positive electrode, a negative electrode, and a non-aqueous electrolyte, and uses a metal ion intercalation. The non-aqueous electrolytic solution contains a halogenated hydrocarbon which reacts with a metal generated from the metal ion to convert to a non-metal and generates a gas while containing a carbonaceous substance to be released as an active material. ing. The halogenated hydrocarbon reacts with lithium metal microcrystals generated in the battery to convert a metal such as lithium into a nonmetal compound, so that all of the metal microcrystals can be changed to a safe compound. As a result, a state in which lithium or the like does not exist in a metallic state in the secondary battery can be maintained.

The halogenated hydrocarbon reacts with the metal generated from the metal ion to generate a gas.
For example, when iodoethane is used as the halogenated hydrocarbon, the reaction shown in the above-described formula (1) occurs with lithium generated from lithium ions to generate lithium iodide and generate butane as a gas.

As described above, (a) maintaining a state in which lithium or the like does not exist in a metallic state, and (b) generating gas in the battery system to reduce lithium or the like generated from metal ions such as lithium ions. The following two functions are exhibited according to the amount of metal.

That is, generation of metallic lithium and reaction with the halogenated hydrocarbon do not cause ignition, can be converted into a safe nonmetal, and prevent metal deposition on the electrode which inhibits intercalation of metal ions. be able to. The gas generated simultaneously with the generation of the non-metal correlates with the generation amount of the metal lithium. When the amount of the metal lithium is small, the gas generation amount is naturally small. Since such a small amount of gas dissolves in the electrolyte, it does not generate bubbles,
Does not adversely affect battery characteristics. Therefore, the characteristics of the battery can be prevented by preventing the metal deposition on the electrode that inhibits the intercalation of the metal ions, and by preventing the gas generated by the reaction between the metal and the halogenated hydrocarbon from affecting the battery. Is maintained.

In particular, when the non-metal is an ionic non-metal such as lithium iodide changed in the above formula (1), lithium ion dissociated into lithium ion and iodine ion and regenerated is Since it functions as an electrolyte, a function of maintaining battery characteristics in a better state can be realized.

On the other hand, when the production amount of the metal lithium increases, the halogenated hydrocarbon continues the reaction stoichiometrically corresponding to the production amount, and generates a large amount of gas.
At this time, the amount of gas generated exceeds the solubility in the electrolyte,
The gas will be present in the battery system in gaseous state.
The gas covers the electrode surface and the separator surface, and enters between the electrode and the separator. As a result, the gas acts as a barrier material that blocks conduction between the positive electrode and the negative electrode, thereby suppressing a current flowing between the positive electrode and the negative electrode. Therefore, a second function of stopping the mechanism for generating metal lithium from lithium ions, that is, a function of reducing battery characteristics is performed.

Further, if the secondary battery is provided with a safety device that operates at the internal pressure, the internal pressure can be increased by the large amount of gas. This enhances the second function, which activates the safety device and completely shuts off the mechanism for generating lithium metal from lithium ions by improving the interruption of the current circuit inside the battery.

As described above, the two functions are developed according to the amount of metal generated from metal ions in the battery system. In other words, the first function operates at a stage where the amount of the metal generated is small, and the second function is automatically realized when the amount of the metal that has been continuously generated increases.

The two functions protect the battery and the system related to the battery. Specifically, the first function is to prevent the temporary deterioration of characteristics due to the metal generated from metal ions to maintain the battery characteristics, and to reduce the metal generated inside the battery to a safe non-metal state (or ion state). (Non-metallic state) to ensure safety. The second function is to protect the battery from explosion or fire and to protect against dangers such as fire that the system may have suffered due to loss of battery operation.

As described above, according to another secondary battery according to the present invention, lithium or the like does not exist in a metallic state at all or does not exist due to self-control of the battery itself, regardless of external control. There is no danger of ignition due to no generation of crystals, and when the amount of metal such as lithium is small, a first function of preventing temporary deterioration of characteristics due to the generated metal and maintaining battery characteristics; If the amount of generated metal is large, the second function of interrupting the conduction between the positive electrode and the negative electrode, and in some cases, losing the battery operation itself with a safety device and deteriorating the battery characteristics is provided. Can be realized.

Further, another secondary battery according to the present invention includes a positive electrode, a negative electrode, and a non-aqueous electrolyte, and uses a metal ion intercalation. A structure including a carbonaceous substance to be released as an active material, and a non-aqueous electrolyte solution containing a halogenated hydrocarbon which reacts with a metal generated from the metal ion to be converted to a non-metal and generates a polymerizable substance. It has become. The halogenated hydrocarbon reacts with lithium metal microcrystals generated in the battery to convert a metal such as lithium into a nonmetal compound, so that all of the metal microcrystals can be changed to a safe compound. As a result, a state in which lithium or the like does not exist in a metallic state in the secondary battery can be maintained.

The halogenated hydrocarbon reacts with the metal generated from the metal ion to generate a polymerizable substance. For example, when 1,2-diiodoethane is used as the halogenated hydrocarbon, lithium generated from lithium ions reacts with the above-described formula (11) to produce lithium iodide and to form 1,4-diiodobutane. Is produced as a polymerizable substance.

2C ₂ H ₄ I ₂ + 2Li → C ₄ H ₈ I ₂ + 2LiI (11) When the generation of lithium continues, the 1,4-diiodobutane further reacts and the molecular weight increases.

As described above, (a) maintaining a state in which lithium or the like does not exist in a metallic state, and (b) generating a polymerizable substance in a secondary battery, thereby generating lithium or other metal ions. The following two functions are exhibited according to the amount of metal such as lithium.

That is, generation of metallic lithium and reaction with the halogenated hydrocarbon do not cause ignition, can be converted into a safe nonmetal, and prevent metal deposition on the electrode which inhibits intercalation of metal ions. be able to. The molecular weight of the polymerizable substance produced together with the non-metal correlates with the production amount of the metallic lithium. When the metallic lithium content is small, the molecular weight of the polymerizable substance is naturally small. Such a low molecular weight polymerizable substance dissolves in the electrolytic solution and does not adversely affect the characteristics of the battery. Therefore, the battery can be prevented from being deposited on the electrode that inhibits the intercalation of the metal ions, and the polymerizable substance generated by the reaction between the metal and the halogenated hydrocarbon does not adversely affect the battery. The first function of maintaining the characteristics of the above is performed.

In particular, when the non-metal is, for example, the compound represented by the formula (11)
In the case of ionic non-metals such as lithium iodide changed in the above, lithium ions dissociated into lithium ions and iodine ions and act as electrolytes to maintain battery characteristics in a better state Function can be realized.

On the other hand, when the production amount of the metallic lithium increases, the halogenated hydrocarbon continues to react stoichiometrically in accordance with the produced amount, thereby producing a high molecular weight polymerizable substance. The high molecular weight polymerizable substance separates due to low solubility in the electrolyte, and the polymerizable substance covers the electrode surface and the separator surface as an oligomer or a polymer, and enters between the electrode and the separator. As a result, the oligomer or polymer acts as a barrier material that blocks conduction between the positive electrode and the negative electrode, thereby suppressing a current flowing between the positive electrode and the negative electrode. Therefore, a second function of stopping the mechanism for generating metal lithium from lithium ions, that is, a function of reducing battery characteristics is performed.

As described above, according to still another secondary battery according to the present invention, lithium or the like does not exist at all in a metal state due to self-control of the battery itself, or does not depend on external control. A first function of preventing the generation of microcrystals and the danger of ignition, and, when the generation amount of a metal such as lithium is small, preventing temporary deterioration of the characteristics due to the generated metal and maintaining the battery characteristics; When a large amount of metal such as lithium is generated, the battery has a second function of interrupting conduction between the positive electrode and the negative electrode to lower battery characteristics, and can achieve high added value.

[0120]

Embodiments of the present invention will be described below in detail.

Example 1 Lithium-containing cobalt dioxide (LiCoO ₂ ) for the positive electrode, carbon for the negative electrode, polyethylene porous film for the separator, 40 vol% of propylene carbonate, 40 vol% of tetrahydrofuran and 20 vol% of nonflammable iodoethane for the electrolytic solution And a lithium ion secondary battery having a capacity of 1000 mAh using lithium hexafluorophosphate (LiPF ₆ ) as an electrolyte.

Comparative Example 1 A cylindrical lithium ion secondary battery was manufactured in the same manner as in Example 1, except that 20% by volume of tetrahydrofuran was used instead of iodoethane for the electrolytic solution.

The batteries of Example 1 and Comparative Example 1 were replaced with 2C
After overcharging with the current of A for 1 hour, the contents of the battery were taken out.

As a result, in the secondary battery of Example 1, the generated lithium metal reacted with iodoethane.
There was no lithium metal generated and it was safe to touch air. On the other hand, in the secondary battery of Comparative Example 1, microcrystals of lithium metal were generated, which ignited upon contact with air.
Further, tetrahydrofuran was ignited and transferred to propylene carbonate, and the entire battery was burned.

Further, the batteries of Example 1 and Comparative Example 1 were overcharged at a current of 0.1 CA for 50 hours.
The contents of the battery were removed.

As a result, in the secondary battery of Example 1, since the generated lithium metal reacted with iodoethane, no lithium metal was generated, and it was safe to touch air. On the other hand, in the secondary battery of Comparative Example 1, microcrystals of lithium metal were generated, which ignited upon contact with air. Further, tetrahydrofuran was ignited and transferred to propylene carbonate, and the entire battery was burned.

Example 2 Lithium-containing cobalt dioxide as a positive electrode, carbon as a negative electrode, a porous film of polypropylene as a separator, 70% by volume of propylene carbonate and iodoethane 3 as an electrolytic solution.
Lithium perchlorate (LiC)
A safety valve which was opened by the action of pressure was attached to a cylindrical lithium ion secondary battery having a capacity of 1000 mAh using 10 ₄ ).

The safety valve is normally in a state as shown in FIG. 1 (a). That is, 1 in the figure is a battery container. The conductive plates 2 and 3 are disposed above the container 1 with the insulating plate 4 interposed therebetween.
A hole 5 is opened at the center of the insulating plate 3 and the insulating plate 4.
The hat-shaped electrode terminal 6 is attached to the upper conductive plate 2. The positive electrode lead 7 is connected to the lower conductive plate 3. A metal spring 8 is arranged in the hole 5;
A safety valve 9 made of aluminum is attached to the spring 8. The safety valve 9 has a function of shutting off the contents of the battery from the outside air. However, when the internal pressure of the battery is increased due to an abnormality in the battery, the safety valve 9 is 5 kg / cm ²
It is set so that it is detached and opened when it receives the above pressure. The box-shaped insulating member 10 whose lower part is opened is attached inside the electrode terminal 6. Air hole 11
Are opened above the electrode terminal 6 and the insulating member 10. The upper conductive plate 2, the insulating plate 4, and the electrode terminals 6 are held in the container 1. In such a structure, in the current circuit in the battery, the positive electrode lead 7 and the lower conductive plate 3 are electrically connected, and the conductive plate 3 is connected to the upper portion by a metal spring 8 attached to the safety valve 9. Electrically connected to the conductive plate 2,
Further, the conductive plate 2 is connected to the electrode terminal 6. Therefore, the safety valve 8 constitutes a current circuit connecting the positive electrode lead 7 and the electrode terminal 6.

FIG. 1B shows the opened state. When the safety valve 9 also serving as the current circuit is opened, the current flowing in the battery is shut off.

An overcharge test was performed by passing a current of 5 CA through the secondary battery of Example 2.

As a result, when the temperature inside the battery rose to 100 ° C. or more due to the heat generated by overcharging, iodoethane was vaporized, the pressure inside the battery increased, the safety valve was opened, and the electrolyte was discharged. At this time, the electrodes were exposed and contacted with air, but the metallic lithium reacted with iodoethane and was converted to non-metallic lithium iodide, so that no metallic lithium was produced, and thus, no ignition occurred even when touched with air. .

Comparative Example 2 A secondary battery was manufactured in the same manner as in Example 2 except that an electrolyte containing only propylene carbonate containing no iodoethane was used, and a 5C overcharge test was performed.

As a result, the temperature inside the battery exceeded 100 ° C. due to heat generated by overcharging, but the safety valve did not operate,
The safety valve was opened with an explosion when it exceeded.
This caused a hot electrolyte to squirt. At this time, the electrode was exposed and came into contact with air, and reacted with metallic lithium generated on the electrode to ignite. The fire ignited the electrolyte and the battery burned.

Comparative Example 3 A secondary battery was manufactured in the same manner as in Example 2 except that an electrolytic solution using the same volume of tetrahydrofuran instead of iodoethane was used, and a 5C overcharge test was performed.

As a result, when the temperature inside the battery rose to 100 ° C. or higher due to the heat generated by overcharging, tetrahydrofuran was vaporized, the pressure inside the battery was increased, the safety valve was opened, and the electrolyte was discharged. At this time, the electrode was exposed and came into contact with air, and reacted with metallic lithium generated on the electrode to ignite. The fire ignited the electrolyte and the battery burned.

Example 3 A porous film of lithium-cobalt dioxide for the positive electrode, carbon for the negative electrode, polypropylene for the separator, 50 vol% of γ-butyrolactone, 30 vol% of ethylene carbonate and 20 vol% of iodoethane as the electrolytic solution,
Capacity 1 using lithium hexafluorophosphate as electrolyte
A safety valve that was opened by the action of pressure was attached to a 2,000 mAh cylindrical lithium ion secondary battery.

The safety valve is normally in a state as shown in FIG. 2 (a). That is, in the current circuit in the battery, the positive electrode lead 7 and the lower conductive plate 3 are electrically connected, and the conductive plate 3 is connected to the upper conductive plate 2 by a box-shaped aluminum safety valve 9 whose lower part is opened. The conductive plate 2 is electrically connected, and the conductive plate 2 is connected to an electrode terminal 6. Therefore, the safety valve 9 forms a current circuit connecting the positive electrode lead 7 and the electrode terminal 6. The safety valve 9 has a role of shutting off the contents of the battery from the outside air. However, when the internal pressure of the battery increases due to an abnormality in the battery, the safety valve 9 comes off when receiving a pressure of 10 kg / cm ² or more. It is set to be opened.

FIG. 2B shows the opened state. When the safety valve 10 also serving as the current circuit is opened, the current flowing in the battery is cut off.

After the overcharge test was performed on the secondary battery of Example 3 at a current of 0.5 CA for 10 hours, the secondary battery was placed on a hot plate and the temperature was gradually increased.

As a result, when the temperature rose to 100 ° C. or higher, iodoethane was vaporized, the pressure inside the battery increased, the safety valve was opened, and the electrolyte was discharged. At this time, the electrode was exposed and contacted with air. However, lithium metal reacted with iodoethane and was converted to a nonmetal of lithium iodide, and no metal lithium was present.

Comparative Example 4 A secondary battery was prepared in the same manner as in Example 3 except that iodoethane was not used as the electrolytic solution and a mixed solution of γ-butyrolactone and 50% by volume of ethylene carbonate was used. After performing the overcharge test for 10 hours, a hot plate heating test was performed.

As a result, even when the battery temperature exceeded 100 ° C., the safety valve did not operate, and at 200 ° C., the safety valve was activated with an explosion. This caused a hot electrolyte to squirt. At this time, the electrode was exposed and came into contact with air, and reacted with metallic lithium generated on the electrode to ignite. The fire ignited the electrolyte and the battery burned.

Comparative Example 5 Instead of iodoethane, the same volume of 1,2-
A secondary battery was manufactured in the same manner as in Example 3 except that an electrolytic solution using dimethoxyethane was used. After performing a 0.5C overcharge test for 10 hours, a hot plate heating test was performed.

As a result, when the temperature of the battery rose to 150 ° C. or higher, 1,2-dimethoxyethane was vaporized, the pressure inside the battery was increased, the safety valve was opened, and the electrolyte was discharged. At this time, the electrode was exposed and came into contact with air, and reacted with metallic lithium generated on the electrode to ignite. The fire ignited the electrolyte and the battery burned.

Example 4 Lithium-containing cobalt dioxide for the positive electrode, carbon for the negative electrode, a porous film of polyethylene for the separator, a mixed solution of 30% by volume of propylene carbonate, 50% by volume of tetrahydrofuran and 20% by volume of 1-iodopropane as the electrolytic solution, The above-described safety valve shown in FIG. 2 was attached to a rectangular lithium ion secondary battery having a capacity of 900 mAh using lithium hexafluorophosphate as an electrolyte.

An overcharge test was performed by passing a current of 5 CA through the secondary battery of Example 4.

As a result, when the temperature of the battery rose to 120 ° C. or higher due to the heat generated by overcharging, 1-iodopropane vaporized, the pressure inside the battery increased, the safety valve opened, and the electrolyte was discharged. At this time, the electrode was exposed and came into contact with air, but metallic lithium reacted with 1-iodopropane and was converted to nonmetallic lithium iodide, and there was no metallic lithium. Did not.

Example 5 A porous film of lithium-cobalt dioxide for the positive electrode, carbon for the negative electrode, polypropylene for the separator, 40% by volume of propylene carbonate, 50% by volume of 1,2-dimethoxyethane and 10% by volume of 1-iodobutane as the electrolytic solution The above-mentioned safety valve shown in FIG. 1 was attached to a square lithium ion secondary battery having a capacity of 900 mAh and using lithium hexafluorophosphate as an electrolyte.

An overcharge test was performed by applying a current of 3 CA to the secondary battery of Example 5, and the internal temperature of the battery was raised to 100 ° C. or more due to the heat generated by the overcharge.

As a result, 1,2-dimethoxyethane was vaporized, the pressure inside the battery was increased, the safety valve was opened, and the electrolyte was discharged. At this time, the electrodes were exposed and contacted with air. However, metal lithium reacted with 1,2-dimethoxyethane and was converted to non-metallic lithium iodide, and no metal lithium was present. Also did not ignite.

Comparative Example 6 1-Iodobutane was replaced with 10% by volume of the same volume of 1,2.
-A secondary battery similar to that of Example 5 was prepared using dimethoxyethane except that an electrolyte of 40% by volume of propylene carbonate and 60% by volume of 1,2-dimethoxyethane was used, and a 3C overcharge test was performed. .

As a result, when the temperature inside the battery rises to 100 ° C. or more due to the heat generated by overcharging, 1,2-dimethoxyethane evaporates, the pressure inside the battery increases, the safety valve opens, and the electrolyte is discharged. Was done. At this time, the electrode was exposed and came into contact with air, and reacted with metallic lithium generated on the electrode to ignite. The fire ignited the electrolyte and the battery burned.

Example 6 A porous film of lithium-cobalt dioxide was used for the positive electrode, carbon was used for the negative electrode, polypropylene was used for the separator, 60% by volume of propylene carbonate and iodoethane 4 were used for the electrolytic solution.
A safety device capable of controlling the current flowing through the battery by the action of pressure was mounted on a 1000-mAh cylindrical lithium-ion secondary battery using a mixed solution of 0% by volume and lithium hexafluorophosphate as an electrolyte.

The safety device is normally in a state as shown in FIG. In other words, reference numeral 12 in the figure denotes a cylindrical body that is provided upright around the hole 13 of the electrode terminal 6. The lid 14 is mounted on the cylindrical body 12 via a ring-shaped low melting point metal plate 15. The low melting point metal plate 15 includes:
When the temperature of the battery becomes 150 ° C. or higher, the battery is melted and opened. The insulating plate 17 having the holes 16
It is attached to the lower surface of the electrode terminal 6. The slider 18 is arranged in the hole 13 of the electrode terminal 6.
One end of the coil spring 19 is attached to the slider 18, and the other end is attached to the lid 14. The slider 18 is urged toward the insulating plate 17 by the coil spring 19 and has a weight of 5 kg /
It is set to move against the urging force when receiving a pressure of ² cm ² or more. The positive electrode lead 7 is in contact with the slider 18. In such a structure, the positive electrode lead 7 is electrically connected to the slider 18 and the electrode terminal 6.

An overcharge test was performed by applying a current of 3 CA to the secondary battery of Example 6, and the internal temperature of the battery was raised to 100 ° C. or higher due to overcharged heat.

As a result, iodoethane was vaporized and the pressure inside the battery increased, and as shown in FIG. 3B, the slider 18 was moved toward the lid 14 to cut off the charging current. Therefore, generation of metallic lithium due to overcharging was stopped.

Further, the already formed metallic lithium was reacted with iodoethane to be converted into nonmetallic safe lithium iodide.

Example 7 Lithium-containing cobalt dioxide for the positive electrode, carbon for the negative electrode, a porous film of polypropylene for the separator, 40 vol% of propylene carbonate, 40 vol% of diethyl carbonate and 1-iodo-3-chloropropane 2 for the electrolytic solution.
The above-described safety device shown in FIG. 3 was attached to a cylindrical lithium ion secondary battery having a capacity of 1000 mAh and using a mixed solution of 0% by volume and lithium hexafluorophosphate as an electrolyte.

An overcharge test was performed by applying a current of 3 CA to the secondary battery of Example 7, and the internal temperature of the battery was raised to 140 ° C. or more due to the heat generated by the overcharge.

As a result, 1-iodo-3-chloropropane vaporized, the pressure inside the battery increased, and the charging current was cut off as shown in FIG. 3B. Therefore, generation of metallic lithium due to overcharging was stopped.

In addition, the already formed lithium metal was reacted with 1-iodo-3-chloropropane to be converted into a nonmetallic safe lithium iodide.

Example 8 A mixture of lithium-cobalt dioxide for the positive electrode, carbon for the negative electrode, a porous film of polypropylene for the separator, 40% by volume of propylene carbonate, 40% by volume of tetrahydrofuran, and 20% by volume of tert-butyl bromide for the electrolytic solution. A safety valve that opened when a pressure of 10 kg / cm ² or more was received was attached to a cylindrical lithium ion secondary battery having a capacity of 1000 mAh using lithium hexafluorophosphate as an electrolyte.

The safety valve is normally in a state as shown in FIG. 4 (a). That is, a hole 5 is opened in the conductive plate 2 and the insulating plate 4 that are overlapped with each other, and a movable valve (safety valve) 20 is attached to the conductive plate 2 side so as to close the hole 5. The movable valve 20 has a structure in which aluminum and plastic located on the lower surface side are laminated. The positive electrode lead 7 is attached to the insulating plate 4 and is electrically connected to the lower surface of the movable valve (safety valve) 20. In such a structure, the movable valve (safety valve) 20 is set so as to move upward due to an increase in internal pressure, and when receiving a pressure of 3 kg / cm ² or more, as shown in FIG. And the electrical connection between the positive electrode lead 7 and the movable valve 20, that is, the conductive plate 2 is cut off.

An overcharge test in which a current of 0.1 CA was applied to the secondary battery of Example 7 for 50 hours was performed.

As a result, as overcharging progressed, lithium metal microcrystals began to be generated, but the lithium metal microcrystals generated by the reaction with tert-butyl bromide became tert-butyl.
Changed to butyllithium. This tert-butyllithium immediately reacted with tetrahydrafuran and turned into a safe, non-ignitable alcoholate.

After the test, the contents of the battery were taken out, but it was safe because there was no lithium metal microcrystal.

Example 9 A mixture of lithium-containing cobalt dioxide (LiCoO ₂ ) for the positive electrode, carbon for the negative electrode, a polyethylene porous film for the separator, 50% by volume of propylene carbonate, 30% by volume of tetrahydrofuran and 20% by volume of iodoethane for the electrolytic solution. A 1000 mAh cylindrical lithium ion secondary battery using lithium hexafluorophosphate (LiPF ₆ ) as an electrolyte was manufactured.

The secondary battery 10 of the ninth embodiment charged to 100%
An overcharge test was performed by further passing a current of 3 CA to each of the test pieces. Five of the rechargeable batteries are 10
After stopping for 5 minutes, the remaining 5 secondary batteries continued for 10 hours.

When the discharge characteristics of the five stopped secondary batteries were measured immediately after the stop, the discharge characteristics were found to be reduced by 20%. However, when the discharge characteristics were examined again after being left for 2 hours, the values returned to the original values.

On the other hand, as for the five continuous secondary batteries, the inside was filled with gas and the internal resistance increased, so that the overcharge current was limited and no dangerous state was reached.

After the experiment was completed, the contents of all the secondary batteries were taken out into the air. However, since the metallic lithium generated from lithium ions was converted into lithium salt (lithium iodide), only one battery ignited. None were found.

A secondary battery was fabricated in the same manner as in Example 9, except that 1,3-diiodopropane was used instead of iodoethane. The same overcharge test result as in Example 9 was obtained for this secondary battery.

Example 10 A lithium-containing cobalt dioxide film was used for the positive electrode, carbon was used for the negative electrode, a polyethylene porous film was used for the separator, a mixture of 60% by volume of propylene carbonate, 20% by volume of ethylene carbonate and 20% by volume of iodoethane was used as the electrolyte. A cylindrical lithium ion secondary battery having a capacity of 1000 mAh using lithium perchlorate (LiClO ₄ ) was equipped with the safety device shown in FIG. 4 which was opened when a pressure of 10 kg / cm ² or more was received.

Rechargeable Battery 1 of Example 10 Charged to 100%
An overcharge test was performed by further passing a current of 3 CA to 0 pieces. Five of the rechargeable batteries are 1
Stop for 0 minutes and leave the remaining 5 rechargeable batteries at 100
Continued for hours.

When the discharge characteristics of the five stopped secondary batteries were measured immediately after the stop, they were found to be 20% lower. However, when the discharge characteristics were examined again after being left for 2 hours, the values returned to the original values.

On the other hand, for the five continuous secondary batteries, the safety device was activated by the pressure of the gas generated in the process of overcharging, and the current flowing through the batteries was cut off.
The overcharge current stopped flowing halfway and did not lead to a dangerous state.

After the experiment was completed, the contents of all the secondary batteries were taken out into the air. However, since the lithium metal produced from lithium ions was converted into lithium salt (lithium iodide), only one battery ignited. None were found.

Example 11 Lithium-containing cobalt dioxide (LiCoO ₂ ) for the positive electrode, carbon for the negative electrode, polyethylene porous film for the separator, propylene carbonate 30% by volume, tetrahydrofuran 50% by volume and nonflammable iodoethane 20% by volume for the electrolytic solution The above-described safety device shown in FIG. 3 was attached to a cylindrical lithium ion secondary battery having a capacity of 1000 mAh and using lithium hexafluorophosphate (LiPF ₆ ) as an electrolyte and an electrolyte.

The secondary battery of Example 11 was charged at a current of 0.1 CA while maintaining the temperature at 50 ° C. or lower.

As a result, lithium metal microcrystals began to be generated as overcharging progressed, but the lithium metal microcrystals were gradually reacted with iodoethane to generate safe inorganic salts. At this time, since the butane gas was generated as a reaction product and the pressure inside the battery was gradually increased, the slider 18 was moved as shown in FIG. 3B to interrupt the charging current. For this reason, generation of metallic lithium was stopped by overcharging.

After the test, the contents of the battery were removed, but were safe because no lithium metal microcrystals were present.

Example 12 A porous film of lithium-containing cobalt dioxide for the positive electrode, carbon for the negative electrode, polyethylene for the separator, a mixture of 60% by volume of propylene carbonate, 20% by volume of ethylene carbonate and 20% by volume of iodoethane as the electrolytic solution, and A cylindrical lithium ion secondary battery having a capacity of 1000 mAh using lithium perchlorate (LiClO ₄ ) was equipped with the safety device shown in FIG. 4 which was opened when a pressure of 10 kg / cm ² or more was received.

As in Example 11, the secondary battery of Example 12 was overcharged at a current of 0.1 CA while maintaining the temperature at 50 ° C. or lower.

As a result, lithium metal microcrystals began to be generated as overcharging progressed, but the lithium metal microcrystals thus formed reacted with iodoethane and gradually changed to safe inorganic salts. At this time, since butane gas was generated as a reaction product and the pressure inside the battery was gradually increased, the movable valve 20 was moved as shown in FIG.
For this reason, generation of metallic lithium was stopped by overcharging.

After the test, the contents of the battery were removed, but were safe because no lithium metal microcrystals were present.

Comparative Example 7 A secondary battery was produced in the same manner as in Example 12, except that an electrolytic solution using the same volume of dimethoxyethane instead of iodoethane was used. Overcharging was performed while maintaining the temperature at 50 ° C. or lower.

In the case of Comparative Example 7, the generated lithium metal microcrystals were hardly consumed and continued to be generated, and a large amount of lithium metal microcrystals were generated on the electrode, which was dangerous. Moreover, the charging was continued without interrupting the charging current.

After the test, the contents of the battery were taken out, but the lithium metal microcrystals were present and they ignited upon contact with air.

Example 13 An overcharge test was performed by passing a current of 5 CA through the secondary battery of Example 12.

As a result, as in the case of Example 12, lithium metal microcrystals began to be generated with the progress of overcharging. However, the lithium metal microcrystals were generated by reacting with iodoethane and gradually became safe inorganic salt. Changed to At this time, since butane gas was generated as a reaction product and the pressure inside the battery was gradually increased, the movable valve 20 was moved as shown in FIG. For this reason, generation of metallic lithium was stopped by overcharging.

Although the temperature inside the battery rose due to the heat generated by the overcharging, the temperature gradually decreased and returned to room temperature due to the interruption of the charging current. Moving the movable valve 20,
Since the charge current was interrupted by the pressure of butane gas, the charge current remained interrupted even when the battery returned to room temperature.

Thus, a non-return type safety device was realized.

After the test, the contents of the battery were removed, but were safe due to the absence of lithium metal microcrystals.

Comparative Example 8 An overcharge test was performed by passing a current of 5 CA through the secondary battery of Comparative Example 7.

As a result, when the temperature inside the battery rises to 100 ° C. or more due to the heat generated by overcharging, dimethoxyethane is naturalized and the pressure inside the battery rises, and the movable valve 20 is moved as shown in FIG. The charging current was shut off. For this reason, generation of metallic lithium was stopped by overcharging.

Although the temperature gradually decreased due to the interruption of the charging current, tetrahydrofuran was again liquefied, and the internal pressure of the battery was lowered.
The value of “0” returns to its original state, and the positive electrode lead 7 and the movable valve 20 are electrically connected again.

Therefore, the overcharging of 5CA was restarted and the generation of lithium metal was started, and continued until the temperature inside the battery rose to 100 ° C. or more due to the heat generated by the overcharging again.

With the secondary battery of Comparative Example 8, a non-return type safety device could not be realized, and the above process was repeated and continued. Since the generation of metallic lithium continued intermittently each time the above process was repeated, the amount of metallic lithium generated on the electrode continued to increase, and became dangerous.

After the test, when the content of the battery was taken out, it was ignited by contact with air due to the presence of lithium metal microcrystals.

Comparative Example 9 A secondary battery was produced in the same manner as in Example 12, except that an electrolyte solution containing no iodoethane and containing 60% by volume of propylene carbonate and 40% by volume of ethylene carbonate was used. Overcharging was performed at a current of 1 CA while maintaining the temperature at 50 ° C. or lower.

As a result, the temperature inside the battery exceeded 100 ° C. due to the heat generated by overcharging, but the movable valve 20 did not operate as shown in FIG. The amount of metallic lithium produced continued to increase and became dangerous.

After the test, the contents of the battery were taken out and fired by contact with air due to the presence of lithium metal microcrystals.

Example 14 A mixture of lithium-containing cobalt dioxide for the positive electrode, carbon for the negative electrode, a porous film of polypropylene for the separator, 40 vol% of propylene carbonate, 40 vol% of tetrahydrofuran, and 20 vol% of tert-butyl bromide for the electrolytic solution. The above-described safety valve shown in FIG. 1 was attached to a cylindrical lithium ion secondary battery having a capacity of 1000 mAh using lithium hexafluorophosphate as an electrolyte.

The secondary battery of Example 14 was overcharged at a current of 0.1 CA while maintaining the temperature at 50 ° C. or lower.

As a result, lithium metal microcrystals began to be generated as overcharging proceeded, but the lithium metal microcrystals generated by the reaction with tert-butyl bromide changed to tert-butyllithium. This tert-butyllithium immediately reacted with tetrahydrofuran to generate ethane gas and 2-methylpropane in addition to the lithium salt. Since the pressure inside the battery was gradually increased by these gases, the safety valve 9 was opened to shut off the charging current as shown in FIG. For this reason, generation of metallic lithium was stopped by overcharging.

After the test, the contents of the battery were removed, but were safe because no lithium metal microcrystals were present.

Example 15 A mixture of lithium-cobalt dioxide (LiCoO ₂ ) for the positive electrode, carbon for the negative electrode, a polyethylene porous film for the separator, 30 vol% of propylene carbonate, 50 vol% of tetrahydrofuran and 20 vol% of iodoethane for the electrolytic solution. , in large lithium ion secondary battery having a capacity 2kWh for mounting on an electric vehicle using lithium hexafluorophosphate (LiPF ₆₎ in the electrolyte, as well as attaching the safety device illustrated in FIG. 3 mentioned above, it detects the abnormal reaction A monitor system for monitoring was added.

As shown in FIG. 5, the monitor system includes a pressure sensor 22 for measuring the internal pressure of the battery 21, a temperature sensor 23 for measuring the internal temperature of the battery 21, the pressure sensor 22 and the temperature sensor 23. A control unit 25 for controlling a circuit (for example, a charging circuit or the like) related to the battery 21 in accordance with an instruction from the computer 24;
And a warning device (not shown). Although not shown, information on the electrode voltage, the current flowing through the battery, and the temperature of the battery is constantly input to the computer 24.

The circuit for each battery is controlled, for example, by a computer to control the charging voltage, the charging current, the charging time, etc., so as to always be in an appropriate state. However, if an abnormality is found in a certain battery, Automatically protects the battery by disconnecting it from the circuit. In addition, a spare battery is incorporated in the circuit instead of the abnormal battery, and the entire battery configuration is maintained.

For example, when the internal pressure of the battery after the temperature correction rises to 1.2 times the initial value, the temperature, the electrode voltage, the current flowing through the battery, and the like are determined in consideration of the rising speed. The computer 24 performs the judgment.

The progress and the result of the treatment are transmitted to the user through the display 26 and the alarm device.

In the fifteenth embodiment provided with the above-described monitor system, the abnormality is determined at an extremely early stage, and the battery is protected. Therefore, the determined battery can still be used sufficiently, and the cause needs to be determined after investigating the cause. After making some adjustments, it could be used again.

Example 16 Lithium-containing cobalt dioxide (LiCoO ₂ ) for the positive electrode, carbon for the negative electrode, a polyethylene porous film for the separator, 40 vol% of propylene carbonate, 50 vol% of dimethoxyethane and 10 vol% of iodoethane for the electrolytic solution A large-sized lithium ion secondary battery having a capacity of 2 kWh used in a home power storage system for storing surplus power using lithium hexafluorophosphate (LiPF ₆ ) for the mixed solution and the electrolyte is shown in FIG. 3 described above. A safety device was installed, and a monitor system for detecting abnormal reactions was installed.

The monitor system is the same as that of FIG. 5 described above. However, not only is the battery replaced when an abnormal reaction is detected, but also the power supply system can be switched to a household commercial power supply. Has become.

Example 17 Lithium-containing cobalt dioxide (LiCoO ₂ ) for the positive electrode, carbon for the negative electrode, a polyethylene porous film for the separator, a mixed solution of 90% by volume of propylene carbonate and 10% by volume of iodoethane for the electrolytic solution, and hexafluoro for the electrolyte Capacity 10A using lithium phosphate (LiPF ₆ )
The safety device shown in FIG. 3 described above was mounted on the prismatic lithium ion secondary battery of h, and a monitor system for detecting an abnormal reaction was provided. The battery is used as a power source for a personal computer.

The monitor system is a simple one comprising a pressure sensor and an information processing section. When the output from the pressure sensor becomes 1.3 times the initial pressure, the display screen shows “abnormal battery internal pressure”, Therefore, a message recommending “switch and use commercial power” is displayed.

[0217] The user can take appropriate measures by seeing this.

[0218]

As described above, according to the present invention, regardless of external control, the essential characteristic of the battery itself is a state in which lithium or the like does not exist in a metal state at all, that is, a metal microcrystal such as lithium. It is possible to provide a safe secondary battery that is not generated and has no risk of ignition or fire. Further, according to the present invention, the state in which lithium or the like does not exist in a metallic state at all is maintained by the self-control of the battery itself without any external control, that is, there is no risk of ignition because metal microcrystals such as lithium are not generated. In addition, when the amount of metal such as lithium is small, the function of maintaining the battery characteristics is maintained. When the amount of metal such as lithium is large, conduction between the positive electrode and the negative electrode is interrupted, and the battery operation is lost. And a secondary battery having a function.

[Brief description of the drawings]

FIG. 1 is a partial schematic sectional view showing a safety device attached to a battery of the present invention.

FIG. 2 is a partial schematic cross-sectional view showing a safety device attached to the battery of the present invention.

FIG. 3 is a partial schematic cross-sectional view showing a safety device attached to the battery of the present invention.

FIG. 4 is a partial schematic cross-sectional view showing a safety device attached to the battery of the present invention.

FIG. 5 is a schematic diagram showing a battery safety monitoring system according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Battery container, 2, 3 ... Conductive plate, 5 ... Hole, 6 ... Electrode terminal, 7 ... Positive electrode lead, 8 ... Metal spring, 9 ... Safety valve, 11
... air holes, 15 ... low melting point metal plate, 18 ... slider, 19
... Coil spring, 20 ... Slider, 21 ... Battery, 2
2 ... pressure sensor, 23 ... temperature sensor, 24 ... computer, 26 ... display.

Claims (4)

(57) [Claims] 1. A secondary battery comprising a positive electrode, a negative electrode, and a non-aqueous electrolytic solution and utilizing intercalation of metal ions, wherein the negative electrode contains a carbonaceous material that absorbs and releases the metal ions as an active material. And the non-aqueous electrolyte contains a halogenated hydrocarbon which reacts with a metal generated from the metal ion to convert the metal ion into a non-metal. 2. A secondary battery comprising a positive electrode, a negative electrode, and a non-aqueous electrolyte, and utilizing intercalation of metal ions, wherein the negative electrode contains a carbonaceous material that absorbs and releases the metal ions as an active material. And the non-aqueous electrolyte contains a halogenated hydrocarbon which reacts with a metal generated from the metal ion to convert it to a non-metal and generate gas. 3. A secondary battery comprising a positive electrode, a negative electrode, and a non-aqueous electrolyte, and utilizing intercalation of metal ions, wherein the negative electrode contains a carbonaceous material that absorbs and releases the metal ions as an active material. And the non-aqueous electrolyte contains a halogenated hydrocarbon which reacts with a metal generated from the metal ion to convert to a non-metal and generate a polymerizable substance. 4. A secondary battery comprising a positive electrode, a negative electrode, and a non-aqueous electrolyte and utilizing intercalation of metal ions, wherein the negative electrode contains a carbonaceous material that absorbs and releases the metal ions as an active material. And the non-aqueous electrolyte has a function of reacting with a metal generated from the metal ion to convert it to an ionic non-metal, and a function of reacting with the metal when the metal is generated from the metal ion to form an ionic non-metal. A secondary battery comprising a halogenated hydrocarbon having at least one function selected from a function of converting into a nonmetal and a function of generating a barrier material that blocks conduction between the positive electrode and the negative electrode.