KR102066912B1 - Battery System with Improved Charge-Discharge Function and Mobile Device Comprising the Same - Google Patents

Abstract

The present invention includes a first battery pack including a plurality of first secondary batteries capable of charging and discharging, and directly connected to a device to supply power; And a second battery pack detachably connected to the first battery pack and including at least one second secondary battery, wherein the second battery pack is electrically connected to the first battery pack. The present invention provides a battery system comprising charging first secondary batteries or supplying power to a device via a first battery pack.

Description

Battery System with Improved Charge-Discharge Function and Mobile Device Comprising the Same}

The present invention relates to a battery system having an improved charging function and a mobile device including the same.

A mobile device is a portable electronic device that is portable and has one or more functions for making voice and video calls, inputting / outputting information, and storing data.

As the functions of the mobile devices are diversified, they are equipped with complex functions such as taking pictures or videos, playing music files or video files, playing games, receiving broadcasts, wireless Internet, and the like. ) Is implemented. Mobile devices implemented in the form of such multimedia devices have various new approaches in terms of hardware or software to implement complex functions, and power systems capable of higher capacity and high output are able to satisfy the mobile devices. It is required.

As such, the mobile device uses a high-capacity battery pack as a power source so that the mobile device can be carried for a long time and the complex functions can be implemented.

In addition, the recent mobile device is a high power consumption as the complex data processing and multi-tasking is common, in order to use the mobile device for a long time, not only a high-capacity battery pack, but also to charge the battery pack or drive the mobile device with external power There is also a need for an environment.

However, when the battery pack is discharged in an environment in which an external power supply is not possible, the use of the mobile device may be greatly restricted, and some mobile devices may assist the mobile device for a long time even in the absence of an external power source. Alternative power supply methods and systems using battery packs are being applied.

The battery system using the secondary battery pack is a form of charging the battery pack with the secondary battery pack or driving the mobile device with the power of the secondary battery pack, and the secondary battery pack supplements the available capacity of the existing battery pack, The actual use time can be greatly increased.

On the other hand, the battery pack means that the secondary batteries, which are chargeable and dischargeable units are packaged appropriately for the device, and the packaging includes various control circuits for driving, controlling or monitoring the secondary battery.

Here, the charging circuit, one of the control circuits, mainly controls the charging and discharging of the secondary battery, and the other control circuit, the protection circuit, cuts off the circuit during the overcharge or overdischarge of the secondary battery, thereby extending the life of the secondary battery and It plays a role of ensuring stable operation, and a unit in which such circuits are aggregated or a unit that performs overall management of a battery pack is sometimes called a battery management unit (BMU) in a broad sense. When charging and discharging, it may further play a role of managing stable current flow.

As such, the secondary batteries are reliably discharged by the battery management unit included in the battery pack to provide power to the mobile device and to be charged with external power. As described above, the auxiliary battery pack is connected to the battery pack. When used as an alternative power supply for a mobile device, the circuits included in the battery pack battery management unit of the battery pack and the battery pack unit of the secondary battery pack are operated and mixed individually, causing a profound error in charging and discharging.

Although the auxiliary battery pack is typically connected to the battery pack, the battery management unit of the battery pack does not recognize the state of charge, so the charging by the auxiliary battery pack is not performed.

In addition, when an external power source is connected, the battery management unit of the battery pack recognizes the state of charge and charges from the power of the external power source, whereas the battery management unit of the auxiliary battery pack maintains a discharge state, so that the battery pack is overcharged. Or the secondary battery pack may fail to be charged.

In order to improve these errors and user convenience, a separate control system for controlling battery management units of the battery pack and the auxiliary battery pack is required separately, and a complicated algorithm such as the operation priority of the battery management units is provided through the control system. Since this must be accompanied, it is not only difficult to implement a stable battery system, but also for this reason, the design of the battery system is difficult and the manufacturing cost is increased.

Therefore, there is a very high need for a battery system in which the charging and discharging functions are stabilized while allowing the long-term use of the mobile device.

The present invention aims to solve the problems of the prior art as described above and the technical problems that have been requested from the past.

Specifically, an object of the present invention is, firstly, in a battery system consisting of a first battery pack for supplying power to a device and a second battery pack which is an alternative power source, the first battery only with a battery management unit included in the first battery pack. By simultaneously controlling the charge and discharge of the pack and the second battery pack, to provide a battery system that can fundamentally prevent the occurrence of charge and discharge errors, and secondly, while charging the first battery pack and the second battery pack at the same time at high speed It is to provide a technology that can be charged.

A battery system according to the present invention for achieving this object is a battery system for supplying power to the device,

A first battery pack including a plurality of first secondary batteries capable of charging and discharging, and directly connected to the device to supply power; And

A second battery pack detachably connected to the first battery pack and including at least one second secondary battery;

Including,

When the second battery pack is electrically connected to the first battery pack, the second battery pack may charge the first secondary batteries or supply power to the device via the first battery pack.

Therefore, the battery system according to the present invention can charge the first secondary batteries of the first battery pack by connecting the second battery pack to the first battery pack in a capacity state where the first battery pack is not desired or in a completely discharged state. In some cases, since the device can be driven by the power of the second battery pack, the driving time of the device can be significantly extended.

It should also be noted that the second battery pack in the battery system of the present invention supplies power to the device via the first battery pack. Specifically, in the battery system, when the voltage of the first secondary batteries is relatively lower than that of the second secondary battery when the second battery pack passes through the first battery pack, some power of the second battery pack may be reduced. While charging them, the remaining power can be supplied to the device, where the first battery pack also supplies the charged power to the device.

On the contrary, if the voltage of the first secondary batteries is relatively higher than that of the second secondary battery, the second battery pack may supply power to the device together with the first battery pack without charging the first secondary batteries.

That is, when the first battery pack and the second battery pack are connected, the total capacity of the battery system is equal to the capacity of the first battery pack (or the capacity of the first secondary batteries connected in series) and the capacity of the second battery pack (or the first connected in series). The capacity of secondary batteries).

For reference, in the present invention, the first battery pack and the second battery pack are concepts including at least one selected from a rechargeable battery capable of charging and discharging, other circuits, a pack case and a housing accommodating them, and providing and charging actual power. The discharge is performed in the secondary battery.

Such a charging and discharging function may be achieved by the battery management unit, and in the battery system of the present invention, the battery management unit may have a structure included in the first battery pack.

Specifically, the first battery pack further includes a battery management unit for controlling the discharge of the first secondary batteries for the device and the charging of the first secondary batteries from a power source external to the battery system,

When the second battery pack is electrically connected to the first battery pack, the discharge of the second secondary battery for the device and the charging of the second secondary battery from an external power source may be controlled by the battery management unit.

That is, the battery system of the present invention includes a battery management unit only in the first battery pack, when the second battery pack is connected to the first battery pack, the first battery pack and the second battery pack of the battery management unit It is configured to share a function, and in detail, the battery management unit controls charging and discharging of the first battery pack, while charging and discharging the first battery pack and the second battery pack when the second battery pack is connected to the first battery pack. Can be controlled at the same time.

This structure does not cause fatal errors caused when the battery management units included in different battery packs collide with each other or operate individually, and the second battery pack is powered by external power when the second battery pack is connected to the first battery pack. It also has the advantage of being able to charge.

The first battery pack and the second battery pack have a structure electrically connected to the battery management unit with two or more first secondary batteries connected in series. When the first battery pack and the second battery pack are interconnected, Secondary batteries and second secondary batteries may be electrically connected in parallel.

Here, the second battery pack may be connected in parallel with the secondary batteries of the first battery pack and electrically connected to the battery management unit of the first battery pack.

In this regard, in the present invention, the first secondary batteries in the first battery pack include a charging function from an external power source, a discharge function to a device, and a charging function from a second battery pack.

In the second battery pack, the second secondary batteries include a charging function from an external power source, a discharge function to a device, and a discharge function to the first secondary batteries.

That is, in the battery system of the present invention, the function of charging the first secondary batteries from the second secondary batteries may be directly performed without passing through the battery management unit, and the remaining charge / discharge functions are controlled from the battery management unit. Can be.

The second battery pack may have its second secondary batteries electrically connected to the first secondary batteries and the battery management unit, and the second secondary battery may be connected to the device via the battery management unit. That is, in the battery system of the present invention, the discharge of the second battery pack to the device can be controlled by the battery management unit of the first battery pack.

The voltage of the first battery pack has a voltage of more than 8V to 20V, the second battery pack may have a voltage of 100% to 300% of the voltage of the first battery pack, the capacity of the second battery pack is 1 may be 100% to 300% of the capacity of the battery pack.

The battery management unit of the present invention controls the current and the voltage of the charge and discharge of the first secondary batteries included in the first battery pack, and when the second battery pack is connected to the first battery pack, It can be configured to further control the current and voltage of the charge and discharge.

To this end, the battery management unit may further include a charging circuit for transmitting current to the first secondary batteries and the second secondary battery to charge them while the battery system is connected to an external power source.

Such a charging circuit may include, for example, a charge-field effect transistor (C-FET) and a discharge-field effect transistor (D-FET) capable of controlling charging and discharging.

Specifically, the battery management unit includes a charge-field effect transistor (C-FET) and a discharge-field effect transistor (D-FET) for controlling the first battery pack, and the battery management unit turns on the C-FET ( In the ON state, charging of the first secondary batteries may be performed, and when the D-FET is controlled in the ON state, the discharge of the first secondary batteries may be performed.

In addition, the battery management unit recognizes this connection when the second battery pack is connected, and configures a current circuit such that the C-FET and D-FET and the second secondary batteries of the second battery pack are electrically connected, and in this state. In this case, when the battery management unit controls the C-FET to the ON state, the first secondary batteries and the second secondary batteries are charged together, and when the D-FET is controlled to the ON state, the first secondary battery And the second secondary batteries may be discharged together.

In addition, the potential value is measured across the circuit of each of the FETs, and by using the difference in the potential value, the battery management unit may determine the charging voltage and the charging current for the first secondary batteries and the second secondary batteries. .

Here, the charging and discharging, as described above, means a concept other than charging from the second secondary batteries of the second battery pack to the first secondary batteries, that is, charging and discharging the external power supply and the device.

In the battery system, when the first battery pack and the second battery pack are connected to each other, the first secondary batteries and the second secondary battery form an electrically parallel connection structure, and the charging circuit includes first and second secondary batteries connected in parallel. 2 Secondary batteries can be charged at the same time.

The battery system of the present invention has a basic state in which a first battery pack and a device are connected, a first battery pack state in which a first battery pack and an external power source are connected, and a first battery pack and a second battery pack are connected to a device. And a state of charge of the first and second battery packs in which the first battery pack and the second battery pack are connected to an external power source.

The battery management unit may be programmed with charge and discharge current and voltage of the first battery pack in the basic state and the state of charge of the first battery pack. Therefore, in the above state, the first battery pack can be charged and discharged with the programmed current and voltage.

Alternatively, in the modified state and the state of charge of the first and second battery packs, the battery management unit may variably change the programmed current and voltage, and thus another input to the battery management unit to change the current and voltage. The value can be programmed.

That is, the battery management unit may charge and discharge the first battery pack and / or the second battery pack with a predetermined charge and discharge current and voltage according to the electrical connection state of the battery packs.

In this regard, the charging circuit may amplify the charging current when the first battery pack and the second battery pack are interconnected to increase the total charging capacity of the battery system.

The structure, when the battery management unit recognizes the connection of the second battery pack and the external power supply, performs a process of turning on the C-FET ON, the C-FET according to the connection of the second battery pack The change of the potential value is detected, and based on this, the battery management unit may determine the amplification of the current, and charge the first battery pack and the second battery pack with a preset current and voltage.

As described above, since the charging current may be variably amplified in some cases, the battery system of the present invention does not increase the charging time required for buffering the battery pack even when the first battery pack and the second battery pack are connected.

In contrast, when the first battery pack and the second battery pack are separated from each other, the battery system may charge only the first secondary batteries, and the charging circuit may include the first battery pack and the second battery. If the packs are separated from each other and the total charge capacity of the battery system is reduced, the charge current can be reduced.

In the above structure, when the battery management unit recognizes the detachment of the second battery pack and the connection of the external power source, the battery management unit performs a process of turning on the C-FET, and the C-FET detaches the second battery pack. Detects the amount of change in the potential value, and based on this, the battery management unit may determine a decrease in current and charge only the first battery pack with a preset current and voltage.

That is, while the battery management unit of the present invention is operated under the charge / discharge conditions for the first battery pack that is basically set, when the second battery pack is connected, the charging current is variably changed so as to connect the battery packs (first battery). The charging time can be kept constant regardless of the pack, the external power source, and the first battery pack and the second battery pack and the external power source.

The battery system may further include a protection circuit configured to sense an overcurrent and an overvoltage state of the first secondary batteries and to block current flow in the state, wherein the second battery pack is connected to the first battery pack. By the protection circuit of the battery system, detection of overcurrent and overvoltage conditions and blocking of current flow of the second secondary battery may be ensured.

The battery system according to the present invention also includes a special configuration as described in detail below so that the first battery pack and the second battery pack can be correctly recognized and disconnected from each other, and are not limited according to the present invention below. Through specific embodiments, this will be described in detail.

In one specific example, a plurality of connectors are formed in the first battery pack, and at least one of the connectors may be an interconnect connector that interconnects the second battery pack and the battery management unit.

The interconnect connector,

A first connection connector to which the negative terminals of the battery management unit and the first secondary batteries connected in series are interconnected;

A second connection connector having a positive terminal connected to the battery management unit and the first secondary batteries connected in series; And

An identification connector for identifying a connection state of the second battery pack;

It may include.

The first connecting connector may be further connected to the negative terminal of the second battery pack, and the second connecting connector may be further connected to the positive terminal of the second battery pack. In addition, these connection connectors may be connected to the positive terminal and the negative terminal of the first battery pack, respectively. Therefore, when the first connection connector and the second connection connector are connected to the second battery pack, the secondary batteries of the first battery pack and the second battery pack may be connected in parallel to each other.

An identification pin is formed on the second battery pack to be electrically connected to the identification connector. When the identification connector and the identification pin are electrically connected to the battery management unit, the second battery pack is connected to the first battery pack. If it is recognized as being connected to, and the identification connector and the identification pin is electrically shorted, it can be recognized that the second battery pack is not connected to the first battery pack.

The identification pin is formed with a specific resistance of 110% to 150% of the resistance of the positive terminal or the negative terminal of the second battery pack, the battery management unit is connected to the identification connector and the identification pin electrically, Recognizing that it is the second battery pack, it is possible to allow the charging or discharging of the second battery pack.

Here, the battery management unit amplifies the charging current of the battery system using an external power source in the state of recognizing that the second battery pack is mounted, or decreases the charging current in the state of recognizing that the second battery pack is not installed. Can kill.

Therefore, the battery system of the present invention, through the above structure, the battery management unit accurately recognizes the electrical connection state of the first battery pack and the second battery pack, so that the conditions of the current or voltage according to the charging and discharging without occurrence of an error It can be adjusted precisely.

On the other hand, the first battery pack may further include a cover configured to surround the connectors and the opening and closing device for manually operating the opening and closing of the cover.

Therefore, the battery system according to the present invention may be closed by an opening and closing device so that the connectors of the first battery pack are not exposed to the outside when the connection of the second battery pack is unnecessary, thereby preventing the connector from being damaged, and the second battery On the contrary, when the pack needs to be connected, the switch may be opened to be connected to the second battery pack through the connector of the first battery pack.

The present invention also provides a device including the battery system as a power source.

Specifically, the device,

A first form in which the first battery pack and the second battery pack are separated; And

It includes a second form that the first battery pack and the second battery pack is connected,

In the first aspect, the first battery pack may be driven by the power of the first battery pack, and when the first battery pack is switched to an undesired power state or a completely discharged state, the first battery pack may be converted to the second form to be used as the power of the second battery pack. Charges one battery pack, or is driven through the power of the second battery pack via the first battery pack.

Accordingly, the device according to the present invention can extend the driving time of the device by connecting the second battery pack to the first battery pack in a capacity state where the first battery pack is not desired or in a fully discharged state.

In one specific example, the device has a structure in which the first battery pack is built inside the interconnection connectors of the first battery pack are exposed to the outside, and the device is formed at the exposed portions of the interconnection connectors. A mounting port to which the second battery pack can be mounted is formed, and the second battery pack can be electrically connected to the first battery pack and the device while being mounted to the mounting port so as to be detachable.

In another specific example, the device has a structure in which the first battery pack is detachably mounted on the outside thereof, and the second battery pack is mounted on an outer surface of the first battery pack in which the interconnecting connectors are formed. The mounting port may be formed, and the second battery pack may be connected to the first battery pack and the device while being mounted to the mounting port so as to be detachable.

The device may be a portable mobile device.

Such a mobile device may be, for example, a tablet PC, a notebook computer, a smart phone, a leaflet device, but is not limited thereto.

On the other hand, the secondary battery in the present invention is not particularly limited, but as a specific example, lithium ion (Li-ion) secondary battery, lithium polymer (Li-Li) having advantages such as high energy density, discharge voltage, output stability, etc. -polymer secondary battery, or a lithium secondary battery such as a lithium-ion polymer (Li-ion polymer) secondary battery.

In general, a lithium secondary battery is composed of a positive electrode, a negative electrode, a separator, and a lithium salt-containing nonaqueous electrolyte.

The positive electrode is manufactured by, for example, applying a mixture of a positive electrode active material, a conductive material, and a binder on a positive electrode current collector and / or an extension current collector, and then drying the composition, and optionally adding a filler to the mixture. do.

The positive electrode current collector and / or the extension current collector is generally made to a thickness of 3 to 500 micrometers. The positive electrode current collector and the extension current collector are not particularly limited as long as they have high conductivity without causing chemical change in the battery. For example, stainless steel, aluminum, nickel, titanium, calcined carbon, or aluminum Surface treated with carbon, nickel, titanium, silver or the like on the surface of the stainless steel may be used. The positive electrode current collector and the extension current collector may form fine irregularities on the surface thereof to increase adhesion of the positive electrode active material, and may be in various forms such as a film, a sheet, a foil, a net, a porous body, a foam, and a nonwoven fabric.

The positive electrode active material may be a layered compound such as lithium cobalt oxide (LiCoO ₂ ), lithium nickel oxide (LiNiO ₂ ), or a compound substituted with one or more transition metals; Lithium manganese oxides such as Li _{1 + x} Mn _2-x O ₄ (where x is 0 to 0.33), LiMnO ₃ , LiMn ₂ O ₃ , LiMnO _2, and the like; Lithium copper oxide (Li ₂ CuO ₂ ); Vanadium oxides such as LiV ₃ O ₈ , LiFe ₃ O ₄ , V ₂ O ₅ , Cu ₂ V ₂ O ₇ and the like; Ni-site type lithium nickel oxide represented by the formula LiNi _1-x M _x O ₂ , wherein M = Co, Mn, Al, Cu, Fe, Mg, B, or Ga, and x = 0.01 to 0.3; Formula LiMn _2-x M _x O ₂ (wherein M = Co, Ni, Fe, Cr, Zn or Ta and x = 0.01 to 0.1) or Li ₂ Mn ₃ MO ₈ (wherein M = Fe, Co, Lithium manganese composite oxide represented by Ni, Cu or Zn); LiMn ₂ O _{4 in} which a part of Li in the formula is substituted with alkaline earth metal ions; Disulfide compounds; Fe ₂ (MoO ₄ ) ₃ and the like, but are not limited to these.

The conductive material is typically added in an amount of 1 to 30 wt% based on the total weight of the mixture including the positive electrode active material. Such a conductive material is not particularly limited as long as it has conductivity without causing chemical change in the battery, and examples thereof include graphite such as natural graphite and artificial graphite; Carbon blacks such as carbon black, acetylene black, Ketjen black, channel black, furnace black, lamp black, and summer black; Conductive fibers such as carbon fibers and metal fibers; Metal powders such as carbon fluoride powder, aluminum powder and nickel powder; Conductive whiskeys such as zinc oxide and potassium titanate; Conductive metal oxides such as titanium oxide; Conductive materials such as polyphenylene derivatives and the like can be used.

The binder is a component that assists the bonding of the active material and the conductive material to the current collector, and is generally added in an amount of 1 to 30 wt% based on the total weight of the mixture including the positive electrode active material. Examples of such binders include polyvinylidene fluoride, polyvinyl alcohol, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene , Polypropylene, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene butylene rubber, fluorine rubber, various copolymers and the like.

The filler is optionally used as a component for inhibiting expansion of the positive electrode, and is not particularly limited as long as it is a fibrous material without causing chemical change in the battery. Examples of the filler include olefinic polymers such as polyethylene and polypropylene; Fibrous materials, such as glass fiber and carbon fiber, are used.

The negative electrode is manufactured by coating and drying a negative electrode active material on a negative electrode current collector and / or an extension current collector, and optionally, the components as described above may be further included if necessary.

The negative electrode current collector and / or the extension current collector is generally made to a thickness of 3 to 500 micrometers. Such a negative electrode current collector and / or an extension current collector is not particularly limited as long as it has conductivity without causing chemical change in the battery. For example, copper, stainless steel, aluminum, nickel, titanium, calcined carbon, Surface treated with carbon, nickel, titanium, silver, or the like on the surface of copper or stainless steel, aluminum-cadmium alloy, and the like can be used. In addition, like the positive electrode current collector, fine concavities and convexities may be formed on the surface to enhance the bonding strength of the negative electrode active material, and may be used in various forms such as a film, a sheet, a foil, a net, a porous body, a foam, and a nonwoven fabric.

As said negative electrode active material, For example, carbon, such as hardly graphitized carbon and graphite type carbon; Li _x Fe ₂ O ₃ (0 ≦ _x ≦ 1), Li _x WO ₂ (0 ≦ _x ≦ 1), Sn _x Me _1-x Me ' _y O _z (Me: Mn, Fe, Pb, Ge; Me' Metal complex oxides such as Al, B, P, Si, Group 1, Group 2, Group 3 elements of the periodic table, halogen, 0 <x ≦ 1; 1 ≦ y ≦ 3; 1 ≦ z ≦ 8); Lithium metal; Lithium alloys; Silicon-based alloys; Tin-based alloys; SnO, SnO ₂ , PbO, PbO ₂ , Pb ₂ O ₃ , Pb ₃ O ₄ , Sb ₂ O ₃ , Sb ₂ O ₄ , Sb ₂ O ₅ , GeO, GeO ₂ , Bi ₂ O ₃ , Bi ₂ O ₄ , and metal oxides such as Bi ₂ O ₅ ; Conductive polymers such as polyacetylene; Li-Co-Ni-based materials and the like can be used.

The separator is interposed between the anode and the cathode, and an insulating thin film having high ion permeability and mechanical strength is used. The pore diameter of the separator is generally from 0.01 to 10 micrometers, the thickness is generally from 5 to 300 micrometers. As such a separator, for example, olefin polymers such as chemical resistance and hydrophobic polypropylene; Sheets or non-woven fabrics made of glass fibers or polyethylene are used. When a solid electrolyte such as a polymer is used as the electrolyte, the solid electrolyte may also serve as a separator.

The electrolyte may be a lithium salt-containing non-aqueous electrolyte, and consists of a non-aqueous electrolyte and a lithium salt. As the nonaqueous electrolyte, nonaqueous organic solvents, organic solid electrolytes, inorganic solid electrolytes, and the like are used, but not limited thereto.

Examples of the non-aqueous organic solvent include N-methyl-2-pyrrolidinone, propylene carbonate, ethylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, and gamma Butyl lactone, 1,2-dimethoxy ethane, tetrahydroxy franc, 2-methyl tetrahydrofuran, dimethylsulfoxide, 1,3-dioxorone, formamide, dimethylformamide, dioxorone , Acetonitrile, nitromethane, methyl formate, methyl acetate, phosphate triester, trimethoxy methane, dioxorone derivatives, sulfolane, methyl sulfolane, 1,3-dimethyl-2-imidazolidinone, propylene carbo Aprotic organic solvents such as nate derivatives, tetrahydrofuran derivatives, ethers, methyl pyroionate and ethyl propionate can be used.

Examples of the organic solid electrolyte include polyethylene derivatives, polyethylene oxide derivatives, polypropylene oxide derivatives, phosphate ester polymers, polyedgetion lysine, polyester sulfides, polyvinyl alcohols, polyvinylidene fluorides, Polymers containing ionic dissociating groups and the like can be used.

Examples of the inorganic solid electrolyte include Li ₃ N, LiI, Li ₅ NI ₂ , Li ₃ N-LiI-LiOH, LiSiO ₄ , LiSiO ₄ -LiI-LiOH, Li ₂ SiS ₃ , Li ₄ SiO ₄ , Nitrides, halides, sulfates and the like of Li, such as Li ₄ SiO ₄ -LiI-LiOH, Li ₃ PO ₄ -Li ₂ S-SiS ₂ , and the like, may be used.

The lithium salt is a good material to be dissolved in the non-aqueous electrolyte, for example, LiCl, LiBr, LiI, LiClO ₄ , LiBF ₄ , LiB ₁₀ Cl ₁₀ , LiPF ₆ , LiCF ₃ SO ₃ , LiCF ₃ CO ₂ , LiAsF _{6, LiSbF 6, LiAlCl 4,} CH 3 SO 3 Li, CF 3 SO 3 Li, (CF 3 SO 2) 2 NLi, chloroborane lithium, lower aliphatic carboxylic acid lithium, lithium tetraphenyl borate and imide have.

In addition, for the purpose of improving charge / discharge characteristics, flame retardancy, etc., for example, pyridine, triethyl phosphite, triethanolamine, cyclic ether, ethylene diamine, n-glyme, hexaphosphate triamide, Nitrobenzene derivatives, sulfur, quinone imine dyes, N-substituted oxazolidinones, N, N-substituted imidazolidines, ethylene glycol dialkyl ethers, ammonium salts, pyrroles, 2-methoxy ethanol, aluminum trichloride and the like may be added. have. In some cases, in order to impart nonflammability, halogen-containing solvents such as carbon tetrachloride and ethylene trifluoride may be further included, and carbon dioxide gas may be further included to improve high temperature storage characteristics, and FEC (Fluoro-Ethylene) may be further included. Carbonate), PRS (Propene sultone) may be further included.

In one specific example, lithium salts such as LiPF ₆ , LiClO ₄ , LiBF ₄ , LiN (SO ₂ CF ₃ ) _2, and the like, may be prepared by cyclic carbonate of EC or PC, which is a highly dielectric solvent, and DEC, DMC, or EMC, which are low viscosity solvents. Lithium salt-containing non-aqueous electrolyte can be prepared by adding to a mixed solvent of linear carbonate.

As described above, the battery system according to the present invention provides the following advantages.

First, the battery system may charge the first secondary batteries of the first battery pack by connecting the second battery pack to the first battery pack in an undesired capacity state or in a fully discharged state. Therefore, since the device can be driven by the power of the second battery pack, the driving time of the device can be significantly extended.

Second, when the battery system includes a battery management unit only in the first battery pack, and the second battery pack is connected to the first battery pack, the first battery pack and the second battery pack share the functions of the battery management unit. In detail, the battery management unit controls charging and discharging of the first battery pack, and simultaneously controls charging and discharging of the first battery pack and the second battery pack when the second battery pack is connected to the first battery pack. can do.

This structure does not cause fatal errors caused when the battery management units included in different battery packs collide with each other or operate individually, and the second battery pack is powered by external power when the second battery pack is connected to the first battery pack. It also has the advantage of being able to charge.

Third, the battery management unit of the present invention is operated under the charging and discharging conditions for the first battery pack which is basically set, and when the second battery pack is connected, the charging current is changed variably regardless of the connection state of the battery packs, The charging time can be kept constant.

Fourth, the battery system of the present invention, through the identification connector of the battery management unit and the identification pin of the second battery pack, the battery management unit accurately recognizes the electrical connection state of the first battery pack and the second battery pack to generate an error. Without this, it is possible to precisely adjust the conditions of current or voltage according to charge and discharge.

1 and 2 are discharge circuit diagrams of a battery system 100 according to the present invention;
3 is a schematic view of the first battery pack 110 and the second battery pack 120;
4 and 5 are charging circuit diagrams of the battery system 100 according to the present invention.
6 is a circuit diagram of a battery system according to another embodiment of the present invention.

Hereinafter, although described with reference to the drawings according to an embodiment of the present invention, this is for easier understanding of the present invention, the scope of the present invention is not limited thereto.

1 and 2 illustrate a discharge circuit diagram of the battery system 100 according to the present invention, and FIG. 3 shows a schematic diagram of the first battery pack 110 and the second battery pack 120.

Referring to these drawings together, the battery system 100 includes a first battery pack and a second battery pack 120.

The first battery pack 110 includes four first secondary batteries 112 and a battery management unit 114 capable of charging and discharging. The first secondary batteries 112 are electrically connected in series with each other and electrically connected to the battery management unit 114.

The battery management unit 114 includes a field effect transistor (FET) 118 capable of controlling charging and discharging and a protection circuit (not shown) that can cut off current in an abnormal state, and the current in the FET 118 It includes a control unit 116 that can control the flow.

The controller 116 may be programmed with a charge and discharge current and voltage for the first battery pack 110 or the first battery pack 110 and the second battery pack 120 is connected.

That is, the controller 116 of the battery management unit 114 charges the first battery pack 110 and / or the second battery pack 120 with a predetermined charge / discharge current and voltage according to the electrical connection state of the battery packs. And discharge.

The first battery pack 110 includes a first connection connector 130 in which the negative electrode terminals of the battery management unit 114 and the first battery pack 110 are interconnected; A second connection connector 132 having a positive terminal connected to the battery management unit 114 and the first battery pack 110; And an identification connector 134 for identifying a connection state of the second battery pack 120.

The first battery pack 110 also includes a cover 142 that is configured to surround the connectors, and an opening and closing device 140 that can manually manipulate the opening and closing of the cover 142.

Such a structure seals the connectors so that the connectors are not exposed to the outside while the cover 142 moves upward when the switch 140 is operated, and the cover 142 moves downward when the cover 140 is released. Are exposed to the outside.

The second battery pack 120 includes four second secondary batteries 122 capable of charging and discharging, and the second secondary batteries 122 are electrically connected in series with each other.

The second battery pack 120 is provided with an identification pin 128 for electrically connecting the negative terminal 126 and the positive terminal 124 and the identification connector 134 of the first battery pack 110. It is.

The battery system 100 has a structure in which the second battery pack 120 is detachably connected to the first battery pack 110, and specifically, the second secondary batteries 122 of the second battery pack 120 are provided. ) Is connected in parallel with the secondary batteries of the first battery pack 110, and is electrically connected to the battery management unit 114 of the first battery pack 110.

That is, when the first battery pack 110 and the second battery pack 120 are connected, the total capacity of the battery system 100 is the sum of the capacity of the first battery pack 110 and the capacity of the second battery pack 120. That is, the total capacity of the first secondary batteries 112 and the second secondary batteries 122 connected in parallel.

This structure is such that when the voltage of the first secondary batteries 112 is lower than that of the second secondary battery in a state where the second battery pack 120 is connected to the first battery pack 110, the second battery pack ( Some of the power of 120 charges the first secondary batteries 112 connected in parallel, while the remaining power is supplied to the device 10. In addition, if the first battery pack 110 is not completely discharged, the first battery pack 110 is charged from the second battery pack 120 and supplies some power to the device 10.

As described above, when the battery system 100 of the present invention includes a battery management unit 114 only in the first battery pack 110, the second battery pack 120 is connected to the first battery pack 110. In addition, the first battery pack 110 and the second battery pack 120 is configured to share the function of the battery management unit 114, in detail, the battery management unit 114 is the first battery pack 110 When the second battery pack 120 is connected to the first battery pack 110, the discharge of the first battery pack 110 and the second battery pack 120 may be simultaneously controlled.

Such discharge control may be accomplished by the FET 118 of the battery management unit 114.

The potential value is measured across the circuit of each of the FETs 118, and the controller 116 of the battery management unit 114 uses the first secondary cells 112 and the second secondary battery by using the difference in the potential values. The discharge voltage and discharge current for the field 122 are determined and transmitted to the device 10.

The control unit 116 of the battery management unit 114 includes a protection circuit for detecting an overcurrent and an overvoltage state of the first secondary batteries 112, and the protection circuit includes a current in an abnormal state of the first secondary batteries 112. Shut off the flow. In addition, in a state in which the second battery pack 120 is connected to the first battery pack 110, the protection circuit detects an overcurrent and an overvoltage state of the second secondary batteries 122 and detects an overcurrent state of the second secondary batteries 122. Shut off current flow in abnormal conditions.

That is, when the second battery pack 120 is connected to the first battery pack 110, the battery management unit 114 simultaneously performs abnormal states of the first secondary batteries 112 and the second secondary batteries 122. Can sense and respond.

The battery system 100 according to the present invention may also supply power to the device 10 with only the first battery pack 110 in a state in which the second battery pack 120 is separated as shown in FIG. 2.

In the above structure, the controller 116 recognizes that the first battery pack 110 and the second battery pack 120 are separated from each other, and the FET 118 changes the potential value according to the separation of the second battery pack 120. The controller 116 of the battery management unit 114 discharges the first battery pack 110.

Meanwhile, when the first battery pack 110 and the second battery pack 120 are connected to each other so that the identification connector 134 and the identification pin 128 are connected to each other, the battery management unit 114 may include the second battery pack 120. When it is recognized that the first battery pack 110 is connected, and the identification connector 134 and the identification pin 128 are electrically shorted, the second battery pack 120 is recognized as not connected to the first battery pack 110. can do.

The identification pin 128 has a resistance higher than that of the positive terminal or the negative terminal of the second battery pack 120, and the battery management unit 114 has the identification connector 134 and the identification pin 128 electrically connected to each other. When connected to, it is recognized that the second battery pack 120 through the resistance of the identification pin 128, it is possible to allow the discharge of the second battery pack 120.

Meanwhile, FIGS. 4 and 5 show a charging circuit diagram of the battery system 100 according to the present invention.

Referring to these drawings, the battery system 100 is connected to the secondary batteries 122 of the second battery pack 120 and the secondary batteries of the first battery pack 110 and at the same time, the first battery It is electrically connected to the battery management unit 114 of the pack 110.

In this state, when the external power source 20 is connected to the battery system 100, the power of the external power source 20 is transferred to the first secondary batteries 112 and the second secondary batteries via the battery management unit 114. 122).

That is, the battery management unit 114 may include the first secondary batteries 112 and the first secondary batteries 112 included in the first battery pack 110 while the second battery pack 120 is connected to the first battery pack 110. It is configured to control the charging of the second secondary batteries 122 of the second battery pack 120.

This structure prevents fatal errors that occur when the battery management units 114 included in different battery packs collide with each other or operate individually, and the second battery pack 120 is connected to the first battery pack 110. If the state has an advantage that the second battery pack 120 can be charged by the external power source 20.

Such charge control may be accomplished by the FET 118 of the battery management unit 114.

The potential value is measured across the circuit of each of the FETs 118, and the controller 116 of the battery management unit 114 uses the first secondary cells 112 and the second secondary battery by using the difference in the potential values. The charging voltage and the charging current for the fields 122 are determined and transmitted to the first secondary batteries 112 and the second secondary batteries 122.

In such a structure, since the first secondary batteries 112 and the second secondary batteries 122 form an electrically parallel connection structure, the battery management unit 114 may be formed of the first secondary batteries 112 and the first secondary batteries 112 connected in parallel. 2 Secondary batteries can be charged at the same time.

Here, the battery system 100 of the present invention, as shown in Figure 2, the basic state that the first battery pack 110 and the device 10 is connected, as shown in Figure 5 the first battery pack 110 and the external power source ( Charge state of the first battery pack 110 is connected to 20, as shown in Figure 1, the modified state in which the first battery pack 110 and the second battery pack 120 is connected to the device 10 and FIG. As described above, the first battery pack 110 and the second battery pack 120 include a state of charge of the first and second battery packs connected to the external power source 20.

The battery management unit 114 is programmed with a charge and discharge current and voltage of the first battery pack 110 in a basic state and a charged state of the first battery pack 110. The first battery pack 110 may be charged and discharged. For reference, such programming is performed in the controller 116.

Alternatively, the battery management unit 114 may variably change the programmed current and voltage in the charge and discharge states of the first and second battery packs as shown in FIGS. 2 and 4. As such, another input value may be programmed into the battery management unit 114 to change the current and the voltage.

That is, the battery management unit 114 charges the first battery pack 110 and / or the second battery pack 120 while changing a condition to predetermined charge / discharge current and voltage values according to the electrical connection state of the battery packs. And discharge.

In this regard, referring to the drawing, when the first battery pack 110 and the second battery pack 120 are interconnected to increase the total charge capacity of the battery system 100, the battery management unit 114 may increase the charging current. Can be amplified.

Specifically, when the battery management unit 114 recognizes the connection between the second battery pack 120 and the external power source 20, the FET 118 changes the amount of potential value change according to the connection of the second battery pack 120. The controller 116 may determine the amplification of the current and charge the first battery pack 110 and the second battery pack 120 with a preset amplified current and voltage.

As described above, the battery system 100 of the present invention may have a variable amplification of the charging current according to the connection state of the first battery pack 110 and the second battery pack 120. Even when the second battery pack 120 is connected, the charging time required for buffering them does not increase.

Unlike this, as shown in FIG. 5, when the first battery pack 110 and the second battery pack 120 are separated from each other, the battery management unit 114 charges only the first secondary batteries 112. In this case, the battery management unit 114 may reduce the charging current when the first battery pack 110 and the second battery pack 120 are separated from each other and the total charge capacity of the battery system 100 is reduced.

That is, when the battery management unit 114 recognizes the detachment of the second battery pack 120 and the connection of the external power source 20, the FET 118 changes the potential value according to the detachment of the second battery pack 120. The controller 116 may determine a decrease in current, and charge the first battery pack 110 under a preset reduced current and voltage.

As a result, while the battery management unit 114 of the present invention is operated under the charge / discharge condition for the first battery pack 110 which is basically set, when the second battery pack 120 is connected, the condition is variably changed. By changing, the charging time can be kept constant regardless of the connection state of the battery packs.

In addition, in connection with such a structure, the battery system 100 of the present invention, through the connection recognition of the identification connector 134 of the battery management unit 114 and the identification pin 128 of the second battery pack 120, the battery The management unit 114 accurately recognizes the electrical connection state between the first battery pack 110 and the second battery pack 120 to precisely adjust the conditions of the current or the voltage according to charging and discharging without generating an error.

On the other hand, Figure 6 is a circuit diagram of a battery system according to another embodiment of the present invention.

The battery system 200 shown in FIG. 6 has the same structure as that of the first battery pack 110 and the first battery pack 110 and the second battery pack 120 shown in FIGS. 1 to 5. .

However, the second battery pack 220 shown in FIG. 6 includes a FET 224 which is a separate charging circuit. This structure is a structure in which only the second battery pack 220 can be charged by the external power source 30 while the second battery pack 220 is separated into the first battery pack 210. However, the FET 224 of the second battery pack 220 is not a structure that is electrically connected to the first battery pack 210, such as a controller such as the battery management unit 214 of the first battery pack 210. Since the main IC is not included, the current and voltage control and the abnormal state of the second battery pack 220 cannot be performed.

The structure of the second battery pack 220 is to perform charging independently only in a situation in which it is not easy to be connected to the first battery pack 210, and the second battery pack 220 is connected to the first battery pack 210. When connected, the electrical connection between the second secondary batteries 222 and the FET 224 is released, and the second secondary batteries 222 manage the first secondary batteries 212 and the battery management of the first battery pack 210. It may be connected to the unit to perform the charge and discharge function as shown in FIGS.

As an application of the above embodiment, when moved to the first secondary batteries of the first battery pack 210 by the power of the second battery pack 220, the second battery pack 220 of the first battery pack 210 Even after releasing the coupling, the first battery pack 210 can be driven for a relatively extended time, thereby forming user convenience and simultaneously connecting only the second battery pack 220 to an external power source to perform charging. The utilization of the battery system may be further increased, such as connection to the first battery pack 210 may be repeated.

Although described with reference to the drawings according to an embodiment of the present invention, those of ordinary skill in the art will be able to perform various applications and modifications within the scope of the present invention based on the above contents.

Claims (23)

A battery system for powering a device,
A first battery pack including a plurality of first secondary batteries capable of charging and discharging, and directly connected to the device to supply power; And
A second battery pack detachably connected to the first battery pack and including at least one second secondary battery;
Including;
The first battery pack and the second battery pack have a structure electrically connected to the battery management unit with two or more first secondary batteries connected in series, and when the first battery pack and the second battery pack are interconnected with each other, Secondary batteries and second secondary batteries are electrically connected in parallel,
The first battery pack is configured to include a battery management unit (Battery Management Unit) for controlling the discharge of the first secondary batteries for the device and the charge of the first secondary batteries from a power source external to the battery system,
The battery management unit,
The battery management unit is configured to include a charging circuit for transmitting current to charge the first secondary batteries and the second secondary battery in a state connected to the external power source, the battery management unit
When only the first battery pack is charged, the first battery pack is charged by receiving a first charging current from an external power source.
When charging the first battery pack and the second battery pack at the same time, by receiving a second charging current greater than the first charging current from an external power source to charge the first battery pack and the second battery pack at the same time,
The second battery pack is
When electrically connected to and discharged from the first battery pack, the first secondary batteries are charged or power is supplied to the device via the first battery pack.
The second battery pack is a battery system, characterized in that when the charge is electrically connected to the first battery pack, the charging current is applied from the second charging current greater than the first charging current from the battery management unit.
According to claim 1,
When the second battery pack is electrically connected to the first battery pack, the battery management unit controls the discharge of the second secondary battery for the device and the charging of the second secondary battery from an external power source. Battery system.
The battery pack of claim 2, wherein the second battery pack is configured such that its second secondary batteries are electrically connected to the first secondary batteries and the battery management unit, and the second secondary battery is connected to the device via the battery management unit. Characterized by a battery system. delete The battery system according to claim 2, wherein the first battery pack has a voltage of 8V or more and 20V, and the second battery pack has a voltage of 100% to 300% of the voltage of the first battery pack. The method of claim 2, wherein the battery management unit controls the current and voltage of the charge and discharge of the first secondary batteries included in the first battery pack, and when the second battery pack is connected to the first battery pack, A battery system, characterized by further controlling the current and voltage of the charge and discharge of the secondary battery. The battery pack of claim 2, wherein the battery system includes a protection circuit configured to sense an overcurrent and an overvoltage state of the first secondary batteries and to block current flow in the state, wherein the second battery pack is connected to the first battery pack. The battery system, characterized in that the detection of the over-current and over-voltage state and blocking the current flow of the second secondary battery by the protection circuit of the battery system. delete delete delete delete delete The battery system according to claim 2, wherein the first battery pack has a plurality of connectors, and at least one of the connectors is an interconnect connector for interconnecting the second battery pack and the battery management unit. The method of claim 13, wherein the interconnect connector,
A first connection connector to which the negative terminals of the battery management unit and the first secondary batteries connected in series are interconnected;
A second connection connector having a positive terminal connected to the battery management unit and the first secondary batteries connected in series; And
An identification connector for identifying a connection state of the second battery pack;
Battery system comprising a. 15. The battery system according to claim 14, wherein the first connection connector is connected to the negative terminal of the second battery pack, and the second connection connector is connected to the positive terminal of the second battery pack. 15. The method of claim 14, wherein the second battery pack is formed with an identification pin (Identification Pin) to be electrically connected to the identification connector, the battery management unit is a second battery when the identification connector and the identification pin is electrically connected Recognizing that the pack is connected to the first battery pack, if the identification connector and the identification pin is electrically shorted, the battery system, characterized in that the second battery pack is recognized as not connected to the first battery pack. The method of claim 16, wherein the identification pin is formed with a specific resistance of 110% to 150% of the resistance of the positive terminal or the negative terminal of the second battery pack, and the battery management unit is electrically connected to the identification connector and the identification pin And recognizing that the second battery pack is through the intrinsic resistance, and allowing the charging or discharging of the second battery pack. The battery management unit of claim 17, wherein the battery management unit amplifies the charging current of the battery system using an external power source while recognizing that the second battery pack is installed, or recognizes that the second battery pack is not installed. A battery system, characterized by reducing charging current. The battery system according to claim 13, wherein the first battery pack further comprises a cover configured to surround the connectors and an opening and closing device capable of manually operating the opening and closing of the cover. A device comprising the battery system of any one of claims 1 to 3, 5 to 7, and 13 to 19 as a power source,
A first form in which the first battery pack and the second battery pack are separated; or
The first battery pack and the second battery pack is driven in any one of the second form connected,
The first aspect is,
The device is driven by the power of the first battery pack,
The second aspect is
Device for charging the first battery pack with the power of the second battery pack, or the device is driven through the power of the second battery pack via the first battery pack.
21. The device of claim 20, wherein the device has a structure in which the first battery pack is embedded inside the interconnection connectors of the first battery pack and is exposed to the outside. 2 is a mounting port for mounting the battery pack is formed, the second battery pack is a device which is electrically connected to the first battery pack and the device while being mounted to the mounting port to be removable. 21. The device of claim 20, wherein the device has a structure in which a first battery pack is detachably mounted on an outer side thereof, and a second battery pack is mounted on an outer surface of the first battery pack in which interconnect connectors are formed. The mounting port is formed, the second battery pack is a device, characterized in that connected to the first battery pack and the device while being mounted to the mounting port to be removable. 21. The device of claim 20, wherein the device is a portable mobile device.

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