JP2017033691A - On-vehicle battery pack, lithium ion replenishment device, and lithium ion replenishment method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an on-vehicle battery pack in which the battery capacity can be recovered by replenishing each lithium ion secondary battery with lithium ions, when lithium ions are lost from each lithium ion secondary battery and the battery capacity drops, while saving the space of each lithium ion secondary battery.SOLUTION: An on-vehicle battery pack 10 includes a plurality of lithium ion secondary batteries 20 mounted on an electric vehicle 1, a liquid supply port 26, and a drain port 27. The liquid supply port 26 is configured to be able to supply lithium ion replenishment liquid Sto the interior of the lithium ion secondary battery 20. The drain port 27 is configured to be able to drain the waste liquid S, produced when some lithium ions are lost from the lithium ion replenishment liquid S, to the outside of the lithium ion secondary battery 20.SELECTED DRAWING: Figure 2

Description

  The present invention relates to, for example, an in-vehicle battery pack that can replenish lithium ions, a lithium ion replenishing device that can replenish lithium ions in the in-vehicle battery pack, and a lithium ion replenishing method.

  Lithium ion secondary batteries have a high energy density among various secondary batteries, and are used as a power source for electric vehicles such as electric vehicles and hybrid vehicles. A lithium ion secondary battery operates without a chemical reaction by insertion and extraction of lithium ions as guest molecules with respect to a negative electrode active material and a positive electrode active material that are host molecules.

  However, when charging / discharging of the lithium ion secondary battery is repeated for a long time, metallic lithium is deposited on the surface of the negative electrode, and lithium ions that can move between the negative electrode active material and the positive electrode active material gradually decrease. When the lithium ions as charge carriers are reduced, the battery capacity of the lithium ion secondary battery is reduced and the travelable distance of the electric vehicle is shortened.

  Thus, as disclosed in Patent Document 1, there is a method for recovering the capacity of a lithium ion battery that calculates a reduction amount of lithium ions lost due to charge and discharge and replenishes a lithium ion secondary battery with an appropriate amount of lithium ions. Proposed.

Japanese Patent No. 5565600

  The capacity recovery method of a lithium ion battery of Patent Document 1 includes an electrode for replenishing lithium ions, and compares an initial charge / discharge characteristic of the lithium ion battery with a charge / discharge characteristic after use, to obtain an appropriate amount of lithium ion. Replenish from the lithium ion replenishment electrode.

  However, in the capacity recovery method of the lithium ion battery disclosed in Patent Document 1, a space for adding a lithium ion replenishment electrode as a third electrode inside the lithium ion secondary battery is required. Increase in size. Also, in the unlikely event that the initial charge / discharge characteristic data is lost, the amount of decrease in lithium ions cannot be calculated, and it may be impossible to know how much lithium ions should be replenished.

  Therefore, the present invention can recover the battery capacity by replenishing each lithium ion secondary battery with lithium ions when the lithium ion is lost from each lithium ion secondary battery and the battery capacity is reduced. Provided is an in-vehicle battery pack that can save space for a secondary battery.

  The in-vehicle battery pack of the present invention includes a plurality of lithium ion secondary batteries mounted on an electric vehicle, a liquid supply port provided in each of the lithium ion secondary batteries, and a drain provided in each of the lithium ion secondary batteries. And a mouth. The liquid supply port is configured to be able to supply the lithium ion replenisher into the lithium ion secondary battery. The drain port is configured to be able to discharge waste liquid from which lithium ions have been partially lost from the lithium ion replenisher to the outside of the lithium ion secondary battery.

  The in-vehicle battery pack further includes a plurality of liquid supply pipes, a plurality of liquid supply valves, a liquid supply collection pipe, a plurality of drainage pipes, a plurality of drainage valves, and a drainage collection pipe. Also good. The plurality of liquid supply pipes are connected to the liquid supply ports, respectively. The liquid supply valves are respectively attached to the liquid supply pipes, and open and close the liquid supply pipes. The liquid supply collecting pipe is connected to a plurality of liquid supply pipes. The plurality of drainage pipes are connected to the drainage ports, respectively. The drainage valves are respectively attached to the drainage pipes and open / close the drainage pipes. The drainage collecting pipe is connected to a plurality of drainage pipes.

  The lithium ion replenishing device of the present invention is a lithium ion replenishing device that replenishes the above-described on-vehicle battery pack with lithium ions, including a liquid supply tank, an upstream side pipe, a waste liquid tank, a downstream side pipe, and a downstream side sensor. And a control unit. The liquid supply tank stores a lithium ion replenisher. The upstream side pipe connects the liquid supply collecting pipe to the liquid supply tank. The downstream pipe connects the drainage collecting pipe to the waste tank. The waste liquid tank stores the waste liquid. The downstream sensor is attached to the drainage collecting pipe or the downstream pipe and monitors the waste liquid. The control unit controls the liquid supply valve and the liquid discharge valve based on information transmitted from the downstream sensor.

  Another lithium ion replenishing device of the present invention is a lithium ion replenishing device for replenishing lithium ion to the in-vehicle battery pack of the above-described embodiment, and includes a liquid supply tank, a waste liquid tank, an upstream pipe, and an upstream sensor. And a downstream pipe, a downstream sensor, and a control unit. The liquid supply tank stores the waste liquid and resupplies the waste liquid as a lithium ion replenisher. The upstream side pipe connects the liquid supply collecting pipe to the liquid supply tank. The upstream sensor is attached to the upstream pipe and monitors the lithium ion replenisher. The downstream side pipe connects the drainage collecting pipe to the liquid supply tank. The downstream sensor is attached to the downstream pipe and monitors waste liquid. The control unit controls the liquid supply valve and the drainage valve based on information transmitted from the upstream sensor and the downstream sensor.

  In these lithium ion replenishing devices, the control unit supplies the lithium ion replenisher to each lithium ion secondary battery with a time difference, and the downstream sensor passes through each lithium ion secondary battery by being discharged with the time difference. You may monitor individually the waste liquid of the state. You may further provide a deaeration pipe | tube and a vacuum valve. The deaeration pipe connects the upstream pipe to a vacuum source. The vacuum valve is attached to the deaeration pipe and opens and closes the deaeration pipe according to external control.

  In these lithium ion replenishing devices, an example of the lithium ion replenishing solution contains an aromatic compound having a lithium oxy group in the electrolytic solution. At this time, the downstream sensor quantifies the oxidant in a state in which the lithium ion is released from the lithium oxy group by the oxidation reaction at the positive electrode of the lithium ion secondary battery and the lithium oxy group is converted into an oxo group. The aromatic compound having a lithium oxy group is preferably a lithium salt of a reduced form corresponding to the aromatic compound having a ketonic carbonyl group. Preferred aromatic compounds having a ketonic carbonyl group include benzoquinone and its derivatives. About the aromatic compound which has these lithium oxy groups, a downstream sensor may quantify an oxidant by measuring the peak intensity of an absorption spectrum in an ultraviolet region.

  The lithium ion replenishment method for an in-vehicle lithium ion secondary battery according to the present invention includes a lithium ion replenisher containing an aromatic compound having a lithium oxy group in an electrolyte while charging the lithium ion secondary battery. Supply to the next battery. Oxidation reaction at the positive electrode of the lithium ion secondary battery releases lithium ions from the lithium oxy group to produce an oxidant in which the lithium oxy group is converted to an oxo group. While collecting the waste liquid discharged together with the lithium ion replenisher from the inside of the lithium ion secondary battery, the oxidant in the waste liquid is quantified. When the amount of oxidant in the waste liquid becomes a predetermined value or less, the supply of the lithium ion replenisher into the lithium ion secondary battery is stopped. When the amount of oxidant in the waste liquid becomes substantially zero, it is preferable to stop supplying the lithium ion replenisher into the lithium ion secondary battery.

  The lithium ion secondary battery replenishment method for another lithium ion secondary battery of the present invention is such that an electrolyte containing an aromatic compound having a lithium oxy group is placed inside and outside the lithium ion secondary battery while charging the lithium ion secondary battery. Circulate. Oxidation reaction at the positive electrode of the lithium ion secondary battery releases lithium ions from the lithium oxy group to produce an oxidized form in which the lithium oxy group is converted to an oxo group. The oxidant in the electrolyte flowing into the lithium ion secondary battery and the oxidant in the electrolyte flowing out from the lithium ion secondary battery are quantified. When the difference between the amount of oxidant flowing in and the amount of oxidant flowing out becomes a predetermined value or less, circulation of the electrolyte solution inside and outside the lithium ion secondary battery is stopped. When the difference between the amount of oxidant flowing in and the amount of oxidant flowing out becomes substantially zero, it is preferable to stop the circulation of the electrolyte solution inside and outside the lithium ion secondary battery.

  According to the present invention, when the lithium ion of each lithium ion secondary battery is lost and the battery capacity decreases, the lithium ion secondary battery can be replenished to restore the battery capacity, and each lithium ion secondary battery can be recovered. The next battery can be saved.

The schematic diagram which shows an example of an electric vehicle. The schematic diagram of the lithium ion replenishment apparatus of 1st Embodiment. The flowchart explaining the 1st method of replenishing lithium ion to a vehicle-mounted lithium ion secondary battery using the lithium ion replenishment apparatus shown by FIG. The flowchart explaining the 2nd method of replenishing lithium ion to a vehicle-mounted lithium ion secondary battery using the lithium ion replenishment apparatus shown by FIG. The schematic diagram of the lithium ion replenishment apparatus of 2nd Embodiment.

  First, an in-vehicle battery pack 10 of the present invention common to each embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic diagram illustrating an example of an electric vehicle 1. The electric vehicle 1 is equipped with an EV system 2. The electric vehicle 1 is an example of an electric vehicle.

  The EV system 2 includes, for example, a vehicle comprehensive control unit (EV-ECU) 3, a battery management unit (BMU) 4, an individual cell monitoring unit (CMU) 5, an in-vehicle charging unit (OBC) 6, and a motor control unit (MCU) 7. , An inverter (IPU) 8, a motor 9, an in-vehicle battery pack 10 and the like.

  The vehicle integrated control unit 3 controls the EV system 2. The battery management unit 4 manages the state of the in-vehicle battery pack 10 and transmits information to the vehicle integrated control unit 3. The individual cell monitoring unit 5 monitors the voltage, current, temperature, etc. of each lithium ion secondary battery 20 (LIB) of the in-vehicle battery pack 10 and transmits information to the battery management unit 4. The in-vehicle charging unit 6 controls the charging current from a household AC power source or a charging stand DC power source to charge the in-vehicle battery pack 10. The vehicle comprehensive control unit 3 and the battery management unit 4 are examples of a control unit. The in-vehicle charging unit 6 is an example of a charger.

  The motor control unit 7 controls the inverter 8 based on the control from the vehicle comprehensive control unit 3. The inverter 8 turns on / off a large current and exchanges electric power between the in-vehicle battery pack 10 and the motor 9. The motor 9 converts electric power into driving force and causes the electric vehicle 1 to travel.

  FIG. 2 is a schematic diagram showing an example of the in-vehicle battery pack 10 of the present invention and the lithium ion replenishment device 30 of the first embodiment. The in-vehicle battery pack 10 includes a plurality of lithium ion secondary batteries 20 generally called cells, a housing 12, a plurality of liquid supply pipes 14, a plurality of liquid supply valves 15, a liquid supply collecting pipe 16, and a plurality of liquid supply collection pipes 16. A drainage pipe 17, a plurality of drainage valves 18, a drainage collecting pipe 19, and the individual cell monitoring unit 5 are provided.

  In the example of FIG. 2, the first and second lithium ion secondary batteries 20 a and 20 b are shown as a representative of the plurality of lithium ion secondary batteries 20. In the actual vehicle battery pack 10, a large number of lithium ion secondary batteries 20 may be mounted. The lithium ion secondary battery 20 includes a power generation element 21 and an exterior material 25 that covers the power generation element 21.

  The power generation element 21 includes a positive electrode 21a, a negative electrode 21b, a separator 21c, a nonaqueous electrolytic solution 21d, and the like. The positive electrode 21a is composed of a positive electrode active material that is an oxidizing agent, a metal foil coated with a positive electrode active material, or the like. The negative electrode 21b is composed of a negative electrode active material that is a reducing agent, a metal foil coated with a negative electrode active material, or the like. The positive electrode 21a and the negative electrode 21b are wound through a separator 21c that prevents a short circuit between the positive electrode 21a and the negative electrode 21b, and are accommodated in an exterior material 25 filled with a nonaqueous electrolytic solution 21d.

  Examples of positive electrode active materials include layered rock salt type metal oxides such as lithium cobaltate and lithium nickelate, spinel type metal oxides such as lithium manganate, reverse spinel type metal oxides such as nickel lithium vanadate, and olivine Examples thereof include metal oxides that can occlude and release lithium, such as lithium iron phosphate, lithium manganese phosphate, lithium lithium phosphate, and oxo acid salt type metal oxides. In this embodiment, lithium cobaltate is used as the positive electrode active material.

  Examples of the negative electrode active material include graphite-based carbon materials, metal lithium, lithium alloys, metal oxides, metal sulfides, and the like. Examples of the graphite-based carbon material include graphite (graphite), graphitizable carbon (soft carbon), non-graphitizable carbon (hard carbon), and the like. In this embodiment, graphite is used as the negative electrode active material.

Examples of the nonaqueous electrolytic solution 21d include ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), diethyl carbonate (DEC), γ-butyrolactone, sulfolane, dimethyl sulfoxide, acetonitrile, dimethylformamide, dimethylacetamide, Examples include polar solvents such as 1,2-dimethoxyethane, 1,2-diethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, dioxolane, and methyl acetate. These polar solvents may be used as a mixture of two or more. A metal salt may be contained. As the metal salts, _{e.g., LiPF 6, LiPF 3 (C} 2 F 5) 3, LiBF 4, LiAsF 6, LiClO 4, LiSCN, LiI, LiCF 3 SO 3, LiCl, LiBr, lithium salts such as LiCF ₃ CO ₂ Can be mentioned. Two or more kinds of these metal salts may be mixed and used.

In the exterior member 25, a liquid supply port 26 for supplying the electrolytic solution containing the compound X into the lithium ion secondary battery 20 and the electrolytic solution containing the compound Y are discharged out of the lithium ion secondary battery 20. A drainage port 27 is provided. Hereinafter, in the present specification, the electrolytic solution containing the compound X flowing into the lithium ion secondary battery 20 through the liquid supply port 26 is transferred from the lithium ion replenisher S _in and the drain port 27 to the outside of the lithium ion secondary battery 20. The electrolytic solution containing the compound Y that has flowed _out is referred to as a waste liquid _Sout . _Examples of the electrolytic solution used for the lithium ion replenisher S _in and the waste liquid S _out include the same polar solvent as the non-aqueous electrolytic solution 21d of the power generation element 21.

  Compound X is, for example, an aromatic compound having a lithium oxy group (—O—Li), and is a compound that releases lithium ions from the lithium oxy group by an oxidation reaction at the positive electrode during charging. Compound Y is an oxidized form in which the lithium oxy group of compound X is converted to an oxo group (═O).

  Examples of the compound Y include aromatic compounds having a ketonic carbonyl group such as quinone compounds, polyquinone compounds, indigo and derivatives thereof, trioxoangulene and derivatives thereof. Examples of the quinone compound include benzoquinone such as dimethoxybenzoquinone and bis (trifluoromethyl) benzoquinone and derivatives thereof, anthraquinone and derivatives thereof, and the like. Examples of polyquinone compounds include polyacene compounds having four ketonic carbonyl groups, such as pentacentetron, octacentetron, indanthrone, indanthrene olive R, pyrantrone, violanthrone, and Japanese sren navy blue R, and more oxo groups Indanthrene Yellow 3RT, Indanthrene Khaki CG and the like. Examples of indigo and derivatives thereof include thioindigo, polycyclic aromatic compounds such as quinacridone and anthanthrone. Preferably, benzoquinone and its derivative are mentioned.

  Examples of compound X include lithium salts having the same π-electron structure as the reduced form corresponding to compound Y described above. The reduced form corresponding to compound Y refers to an aromatic compound of compound Y having a hydroxyl group instead of an oxo group.

  The housing 12 houses a plurality of lithium ion secondary batteries 20 therein. The plurality of liquid supply pipes 14 are connected to the liquid supply ports 26 of the respective lithium ion secondary batteries 20. The plurality of liquid supply valves E1 and E2 are attached to each liquid supply pipe 14, respectively. The liquid supply valves E1 and E2 can individually open and close the respective liquid supply pipes 14 according to the control of the vehicle comprehensive control unit 3 and the battery management unit. The liquid supply collecting pipe 16 is connected to each liquid supply pipe 14 so as to bundle a plurality of liquid supply pipes 14, and communicates with the inside and outside of the housing 12.

  The plurality of drain tubes 17 are connected to the drain ports 27 of the lithium ion secondary batteries 20, respectively. The plurality of drain valves F1 and F2 are attached to each drain pipe 17, respectively. The drain valves F <b> 1 and F <b> 2 can individually open and close each drain pipe 17 in accordance with the control of the vehicle integrated control unit 3 and the battery management unit 4. The drainage collecting pipe 19 is connected to each drainage pipe 17 so as to bundle a plurality of drainage pipes 17 and communicates with the inside and outside of the housing 12. Hereinafter, the liquid supply valves E1 and E2 and the drainage valves F1 and F2 may be collectively referred to as a supply / discharge valve.

[First Embodiment]
The lithium ion replenishment device 30 according to the first embodiment will be described. The lithium ion replenishing device 30 includes an in-vehicle unit 30a and a vehicle exterior 30b. The vehicle exterior 30b is installed in, for example, an automobile maintenance factory.

  The lithium ion replenishing device 30 includes a liquid supply tank 31, a waste liquid tank 32, an upstream pipe 34, a downstream pipe 36, pipe valves C and D, a downstream sensor 39, a control unit, and a deaeration pipe 35. , 37, vacuum valves A and B, and vacuum pumps P and Q. The control unit includes a vehicle comprehensive control unit 3 and a battery management unit 4. The vacuum pumps P and Q are an example of a vacuum source.

A supply tank 31, a lithium ion replenisher S _in is stored. The waste liquid tank 32 can store the waste liquid _Sout . In this embodiment, hydroxyquinone lithium salt is used as compound X, and benzoquinone is used as compound Y. The liquid supply tank 31 is preferably disposed at a higher position than the waste liquid tank 32.

  The upstream side pipe 34 connects the liquid supply collecting pipe 16 of the in-vehicle battery pack 10 to the liquid supply tank 31. The downstream pipe 36 connects the drainage collecting pipe 19 of the in-vehicle battery pack 10 to the waste liquid tank 32. Pipe valves C and D are provided in the upstream pipe 34 and the downstream pipe 36, respectively. The piping valves C and D can open and close the upstream piping 34 and the downstream piping 36, respectively, according to the control of the vehicle integrated control unit 3 and the battery management unit.

  The deaeration pipe 35 connects the upstream pipe 34 to the vacuum pump P. The deaeration pipe 37 connects the upstream pipe 36 to the vacuum pump Q. The deaeration pipes 35 and 37 are provided with vacuum valves A and B, respectively. The vacuum valves A and B can open and close the deaeration pipes 35 and 37 according to the control of the vehicle integrated control unit 3 and the battery management unit, respectively.

In the example of FIG. 2, the downstream sensor 39 is attached to the drainage collecting pipe 19 of the in-vehicle battery pack 10. That is, the downstream sensor 39 is included in the in-vehicle unit 30a. The downstream sensor 39 is, for example, an ultraviolet / visible spectrophotometer, and can measure the peak intensity of the absorption spectrum in the ultraviolet region for the compound Y contained in the waste liquid _Sout .

Below, the 1st and 2nd lithium ion replenishment method using the lithium ion replenishment apparatus 30 of this embodiment is demonstrated with reference to FIGS.
The first lithium ion replenishment method according to this embodiment will be described with reference to FIGS. In the first lithium ion replenishment method, first, the liquid supply collecting pipe 16 and the drainage collecting pipe 19 extending from the on-vehicle battery pack 10 of the electric vehicle 1 are connected to the upstream pipe 34 and the downstream side installed in an automobile maintenance factory or the like. Each is connected to the pipe 36 (see FIG. 2).

  The vacuum pumps P and Q are respectively operated (procedure 101). The vacuum valves A and B are opened, and the upstream side pipe 34 and the downstream side pipe 36 are deaerated (procedure 102). After removing moisture contained in the air in the upstream pipe 34 and the downstream pipe 36 by deaeration, the vacuum valves A and B are closed (step 103). The vacuum pumps P and Q are stopped (procedure 104).

The pipe valve C is opened, and the lithium ion replenisher S _in is supplied from the liquid supply tank 31 to the upstream pipe 34 and the liquid supply collecting pipe 16 (procedure 105). Further, the liquid supply valves E1 and E2 and the drainage valves F1 and F2 are opened (procedure 106). Thereby, the liquid supply tank 31 and the vehicle-mounted battery pack 10 communicate.

When the piping valve D is opened, the in-vehicle battery pack 10 and the waste liquid tank 32 communicate with each other, and the waste liquid Sout begins to be discharged _out of each lithium ion secondary battery 20 due to gravity (procedure 107). The downstream sensor 39 is turned ON (procedure 108), and each lithium ion secondary battery 20 is charged by the in-vehicle charging unit 6 (procedure 109).

Then, in each lithium ion secondary battery 20, the lithium ion is released from the lithium oxy group of the compound X _{in the} lithium ion replenisher S _in due to the oxidation reaction in the positive electrode 21 a, and the lithium oxy group from which the lithium ion is released is Conversion to an oxo group yields compound Y. The lithium ions released from the compound X are supplied to the negative electrode 21b, so that the lithium ions are replenished to each lithium ion secondary battery 20.

While the negative electrode 21b is short of lithium ions, the above reaction proceeds and compound X is converted to compound Y. The waste liquid Sout flowing _out from each lithium ion secondary battery 20 contains the compound Y. When the negative electrode 21b is filled with lithium ions, the above-described reaction is stopped, the compound Y is not generated, and the compound X is discharged.

The downstream sensor 39 monitors the compound Y and quantifies the compound Y contained in the waste liquid _Sout (procedure 110). When the amount of the compound Y in the waste liquid _Sout becomes substantially zero, it is determined that the above reaction has stopped. It can be determined that no more lithium ions can be replenished to the negative electrode 21b, that is, each lithium ion secondary battery 20 has been replenished with lithium ions. 0 is an example of a predetermined value.

When the amount of the compound Y in the waste liquid _Sout becomes substantially 0 (procedure 111), the control unit that has transmitted information from the downstream sensor 39 issues a trigger, and each valve C, D, E1, E2, F1, F2 Is closed (procedure 112).

It stops the supply of lithium ion replenisher S _in, the first lithium-ion replenishment method ends. If a predetermined value larger than 0 is set, the replenishment of lithium ions can be terminated before the lithium ions are completely satisfied.

Next, a second lithium ion replenishment method according to this embodiment will be described with reference to FIGS.
In the second lithium ion replenishment method, first, in the same manner as in the procedure of the first lithium ion replenishment method, the upstream side pipe 34 and the downstream side pipe 36 are deaerated (from step 201 to step 204), and the liquid supply valve E1. supplies lithium ions replenisher _{S in} to the upstream of the liquid supply collecting pipe 16 than E2 (Step 205).

Then, when supplying lithium ions replenisher S _in a lithium ion secondary battery 20, all the liquid supply valves E1, E2 and drain valves F1, F2 without opening simultaneously, the first lithium ion second-order Only the liquid supply valve E1 and the drainage valve F1 for operating the battery 20a are individually opened (procedure 206).

Further, the drainage collecting pipe 19 downstream of the drainage valves F1 and F2 is communicated with the wastewater tank 32 (procedure 207). When ON the downstream sensor 39 while charging the lithium ion secondary battery 20 by the vehicle-mounted charging unit 6 (Step 208 and Step 209), compounds for linking waste liquid S _out to the first lithium ion secondary battery 20a Y can be quantified (procedure 210).

If the amount of the compound Y tying has been in the waste liquid S _out to the first lithium ion secondary battery 20a is substantially 0 (Step 211), the control unit issues a trigger, the first lithium ion secondary battery The liquid supply valve E1 and the drainage valve F1 for operating 20a are closed (procedure 212).

Subsequently, a liquid supply valve En and a drain valve Fn that operate the next lithium ion secondary battery 20 (in this embodiment, a liquid supply valve E2 and a drain valve F2 that operate the second lithium ion secondary battery 20b). ) releases the (Step 213), individually to quantify the compound Y for linking waste liquid _{S out} in the following lithium-ion secondary battery 20 (Step 214).

If the amount of the compound Y tying has been in the waste liquid S _out in the following lithium-ion secondary battery 20 is substantially 0, the control unit issues a trigger to close the supply fluid valve En and drain valve Fn (Procedure 216) When there are three or more lithium ion secondary batteries 20, the procedure from Steps 213 to 215 is repeated, and the lithium ion secondary battery 20 is switched until the last one (Procedure 217).

The last (in this embodiment, the second lithium ion secondary battery 20b) lithium ion secondary battery 20 when the amount of the compound Y tying has been in the waste liquid S _out to become substantially 0 (Step 217), The control unit issues a trigger to stop charging (procedure 218) and close the piping valves C and D (procedure 219). Thus, the second lithium ion replenishment method is completed.

According to the on-vehicle battery pack 10 according to the present embodiment described above, the supply liquid collecting pipe 16 and the drainage collecting pipe 19 are connected to the upstream side pipe 34 and the downstream side pipe 36 of the lithium ion replenishing device 30, thereby The lithium ion replenisher S _in can be supplied to each lithium ion secondary battery 20 from the liquid port 26, and the waste liquid S _out can be discharged from the drain port 27. When lithium ions are lost from each lithium ion secondary battery 20 and the battery capacity of the in-vehicle battery pack 10 is reduced, the lithium ion secondary batteries 20 can be supplemented to restore the battery capacity.

  In addition, the in-vehicle battery pack 10 does not need to add a component serving as a lithium ion generation source in each lithium ion secondary battery 20. Therefore, each lithium ion secondary battery 20 can be saved in space.

According to the lithium ion replenishment system 30 of the present embodiment, for such vehicle battery pack 10 can supply lithium ion replenisher S _in each lithium ion secondary battery 20 while charging the in-vehicle charging unit 6. When lithium ions are lost from each lithium ion secondary battery 20 and the battery capacity of the in-vehicle battery pack 10 is reduced, the lithium ion secondary batteries 20 can be supplemented to restore the battery capacity.

Moreover, the lithium ion replenisher S _{in serving as} a lithium ion generation source is stored in the liquid supply tank 31 instead of each lithium ion secondary battery of the _in- vehicle battery pack 10. Therefore, each lithium ion secondary battery 20 can be saved in space. Furthermore, even without knowing the data of the initial charge-discharge characteristics of each lithium ion secondary batteries, by monitoring the compound Y in the effluent S _out on the downstream side sensor 39, replenishment of lithium ions was completed at any time Can be judged.

In this embodiment, compound X contained _in lithium ion replenisher Sin is a lithium salt of hydroxyquinone, and benzoquinone is produced as compound Y. The downstream sensor 39 is an ultraviolet / visible spectrophotometer, and can measure the peak intensity of the absorption spectrum in the ultraviolet region. Therefore, the compound Y can be quantified with high accuracy, and the timing at which replenishment of lithium ions is completed can be determined with high accuracy. In addition, the downstream sensor 39 can be made relatively small.

  According to the first lithium ion replenishing method using the lithium ion replenishing device 30 of the present embodiment, it is possible to replenish all the lithium ion secondary batteries 20 all at once. Therefore, lithium ion can be replenished to the vehicle-mounted battery pack 10 in the shortest time.

According to the second lithium ion replenishment method using the lithium ion replenishment device 30 of the present embodiment, replenishment of lithium ions individually with a time difference for each of the first and second lithium ion secondary batteries 20a and 20b. Can do. Because it can supply lithium ion replenisher S _in the amount necessary to 20 per lithium ion secondary battery, it is possible to replenish the lithium ion in-vehicle battery pack 10 by using the lithium ion replenisher S _in a minimum amount .

  Next, the lithium ion replenishment device 30 according to the second embodiment will be described. In addition, the structure which has the same or similar function as the structure of 1st Embodiment attaches | subjects the same code | symbol, considers description of 1st Embodiment corresponding, and abbreviate | omits description here. The configuration other than that described below is the same as that of the first embodiment.

[Second Embodiment]
The lithium ion replenishment device 30 of the second embodiment will be described with reference to FIG. Lithium-ion replenishment system 30 of the second embodiment is the downstream side pipe 36 of the waste liquid S _out flowing refluxed in supply tank 31 lithium ion replenisher resupplying points at each lithium ion secondary battery 20 as S _in However, this is different from the first embodiment.

  The lithium ion replenishing device 30 of the second embodiment is provided with an upstream sensor 38 and a liquid feed pump R, with the waste liquid tank 32 omitted. In the example of FIG. 5, the upstream sensor 38 and the downstream sensor 39 are attached to the upstream pipe 34 and the downstream pipe 36, respectively. The upstream sensor 38 is the same sensor as the downstream sensor 39, and is, for example, an ultraviolet / visible spectrophotometer.

  The compound Y flowing into each lithium ion secondary battery 20 is quantified by the upstream sensor 38, and the compound Y flowing out from each lithium ion secondary battery 20 is quantified by the downstream sensor 39. The liquid feed pump R is attached to the upstream pipe 34 or the downstream pipe 36 and operates when the pipe valves C and D are opened.

When the lithium ion replenisher S _in circulating 20 and out each of the lithium ion secondary battery while charging each lithium ion secondary battery 20 by the vehicle-mounted charging unit 6, while the lack of lithium ions in the negative electrode 21b Compound X Compound Converted to Y. During this time, the amount of compound Y flowing out from each lithium ion secondary battery 20 is greater than the amount of compound Y flowing into each lithium ion secondary battery 20.

  When the negative electrode 21b is filled with lithium ions, the reaction stops and the compound Y is not generated. Then, the difference between the amount of compound Y flowing into each lithium ion secondary battery 20 and the amount of compound Y flowing out from each lithium ion secondary battery 20 becomes substantially zero. 0 is an example of a predetermined value. By comparing the amount of the compound Y determined by the upstream sensor 38 and the downstream sensor 39, it is possible to determine the timing when the replenishment of lithium ions is completed.

According to the lithium ion replenishing device 30 of the second embodiment, lithium ion can be replenished to the in-vehicle battery pack 10 as in the first embodiment. Furthermore, can be reused waste _{S out} as a lithium-ion replenisher _{S in,} saving the use amount of the lithium ion replenisher _{S in.}

  Note that the present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine the component covering different embodiment suitably.

  For example, in the first embodiment, the downstream sensor can be attached to the downstream pipe. In this case, the downstream sensor is outside the vehicle, not the in-vehicle unit. Since a relatively large analytical instrument can be adopted outside the vehicle, various known analytical instruments such as a Raman spectrophotometer, a mass spectrometer, and a nuclear magnetic resonance apparatus can be selected. In the first embodiment, a liquid feed pump may be further provided. In the second lithium ion replenishment method using the first embodiment, not each single battery (cell) but individual batteries (module batteries) grouped with several single batteries Lithium ions may be replenished. The in-vehicle battery pack is composed of a plurality of assembled batteries.

  For example, in the second embodiment, either the upstream sensor or the downstream sensor may be omitted. In this case, a change with time in the amount of oxide is monitored by the other sensor. When the amount of oxide becomes substantially constant, it can be determined that the replenishment of lithium ions has been completed.

  For example, in each embodiment, the control unit may be provided outside the vehicle. The upstream and downstream degassing tubes may be merged into one. In this case, the joined deaeration pipes may be connected to one vacuum pump. The vacuum source may be a vacuum chamber previously deaerated with a vacuum pump or the like. In the in-vehicle battery pack used in each embodiment, the liquid supply valve and / or the drain valve may be omitted. In this case, an alternative valve is attached to the liquid supply collecting pipe or the drainage collecting pipe.

DESCRIPTION OF SYMBOLS 1 ... Electric vehicle (electric vehicle), 3 ... Vehicle comprehensive control unit (control part), 4 ... Battery management unit (control part), 10 ... In-vehicle battery pack, 14 ... Supply pipe, 15 ... Supply valve, 16 ... Liquid supply collecting pipe, 17 ... Drainage pipe, 18 ... Drainage valve, 19 ... Drainage collecting pipe, 20, 20a, 20b ... Lithium ion secondary battery, 21a ... Positive electrode, 21b ... Negative electrode, 26 ... Liquid supply port, 27 ... Drain port, 30 ... Lithium ion replenisher, 31 ... Liquid supply tank, 32 ... Waste liquid tank, 34 ... Upstream side piping, 36 ... Downstream side piping, 38 ... Upstream side sensor, 39 ... Downstream side sensor, E1, En, E2 ... supply fluid valve, F1, Fn, F2 ... drainage valve, S _{in ...} lithium ion replenisher, _{S out ...} waste, (lithium salt of a reduced form) X ... compound, Y ... compound (oxidant).

Claims (14)

A plurality of lithium ion secondary batteries mounted on an electric vehicle;
A liquid supply port provided in the lithium ion secondary battery for supplying a lithium ion replenisher into the lithium ion secondary battery;
A drain port provided in the lithium ion secondary battery, for discharging waste liquid from which a part of lithium ions has been lost from the lithium ion replenisher, to the outside of the lithium ion secondary battery;
In-vehicle battery pack with A plurality of liquid supply pipes respectively connected to the liquid supply ports;
A plurality of liquid supply valves respectively attached to the liquid supply pipe and opening and closing the liquid supply pipe;
A liquid supply collecting pipe connected to the plurality of liquid supply pipes;
A plurality of drainage pipes respectively connected to the drainage ports;
A plurality of drain valves each attached to the drain pipe and opening and closing the drain pipe;
A drainage collecting pipe connected to the plurality of drainage pipes;
The in-vehicle battery pack according to claim 1, further comprising: A lithium ion replenishment device for replenishing lithium ion to the in-vehicle battery pack according to claim 2,
A liquid supply tank in which the lithium ion replenisher is stored;
An upstream pipe connecting the liquid supply collecting pipe to the liquid supply tank;
A waste liquid tank for storing the waste liquid;
A downstream side pipe connecting the drainage collecting pipe to the waste liquid tank;
A downstream sensor attached to the drainage collecting pipe or the downstream pipe and monitoring the waste liquid;
A control unit that controls the liquid supply valve and the drainage valve based on information transmitted from the downstream sensor;
Lithium ion replenishment device with. A lithium ion replenishment device for replenishing lithium ion to the in-vehicle battery pack according to claim 2,
A liquid supply tank for storing the waste liquid and resupplying the waste liquid as the lithium ion replenisher;
An upstream pipe connecting the liquid supply collecting pipe to the liquid supply tank;
An upstream sensor attached to the upstream pipe for monitoring the lithium ion replenisher;
A downstream pipe connecting the drainage collecting pipe to the liquid supply tank;
A downstream sensor attached to the downstream pipe for monitoring the waste liquid;
A control unit for controlling the liquid supply valve and the drain valve based on information transmitted from the upstream sensor and the downstream sensor;
Lithium ion replenishment device with. The control unit supplies the lithium ion replenisher with a time difference to each of the lithium ion secondary batteries,
5. The lithium ion replenishing device according to claim 3, wherein the downstream sensor individually monitors the waste liquid in a state via each of the lithium ion secondary batteries by being discharged at a time difference. . A deaeration pipe connecting the upstream pipe to a vacuum source;
A vacuum valve attached to the degassing tube and opening and closing the degassing tube;
The lithium ion replenishing device according to claim 3, further comprising: The lithium ion replenisher contains an aromatic compound having a lithium oxy group in the electrolyte,
The downstream sensor quantifies an oxidant in a state in which lithium ions are released from the lithium oxy groups and converted into oxo groups by an oxidation reaction at a positive electrode of the lithium ion secondary battery. The lithium ion replenishment device according to any one of claims 3 to 6.   The lithium ion replenishing device according to claim 7, wherein the aromatic compound having a lithium oxy group is a lithium salt of a reductant corresponding to the aromatic compound having a ketonic carbonyl group.   9. The lithium ion replenishment apparatus according to claim 8, wherein the aromatic compound having a ketonic carbonyl group is benzoquinone or a derivative thereof.   10. The lithium ion replenishing device according to claim 7, wherein the downstream sensor quantifies the oxidant by measuring a peak intensity of an absorption spectrum in an ultraviolet region. A lithium ion replenishment method for a lithium ion secondary battery mounted on an electric vehicle,
While charging the lithium ion secondary battery, supplying a lithium ion replenisher containing an aromatic compound having a lithium oxy group in the electrolyte into the lithium ion secondary battery,
Producing an oxidant in which lithium ions are released from the lithium oxy groups by the oxidation reaction at the positive electrode of the lithium ion secondary battery and the lithium oxy groups are converted into oxo groups;
Quantifying the oxidant in the waste liquid while collecting the waste liquid discharged together with the lithium ion replenisher from the lithium ion secondary battery,
A lithium ion replenishment method comprising: stopping supply of the lithium ion replenisher into the lithium ion secondary battery when the amount of the oxidant in the waste liquid becomes a predetermined value or less. 12. The lithium according to claim 11, wherein the supply of the lithium ion replenisher into the lithium ion secondary battery is stopped when the amount of the oxidant in the waste liquid becomes substantially zero. Ion replenishment method. A lithium ion replenishment method for a lithium ion secondary battery mounted on an electric vehicle,
While charging the lithium ion secondary battery, circulating an electrolyte containing an aromatic compound having a lithium oxy group inside and outside the lithium ion secondary battery,
Producing an oxidant in which lithium ions are released from the lithium oxy groups by the oxidation reaction at the positive electrode of the lithium ion secondary battery and the lithium oxy groups are converted into oxo groups;
Quantifying the oxidant in the electrolyte flowing into the lithium ion secondary battery and the oxidant in the electrolyte flowing out from the lithium ion secondary battery;
Lithium ions characterized by stopping circulation of the electrolyte solution inside and outside the lithium ion secondary battery when the difference between the amount of the oxidant flowing in and the amount of the oxidant flowing out becomes a predetermined value or less. Replenishment method. When the difference between the amount of the oxidant flowing in and the amount of the oxidant flowing out becomes substantially zero, circulation of the electrolyte solution inside and outside the lithium ion secondary battery is stopped. The lithium ion replenishment method according to claim 13.

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