Method for dismantling batteries, involving deep discharging and energy recovery

Abstract

Disclosed is a method for dismantling (1) batteries comprising at least one module of electrical storage cells, the method comprising: - a step of providing (3) at least one undamaged battery at the end of its life; and - a step of deep-discharging (40) the undamaged battery, during which step the energy from the discharge is recovered by an energy recovery unit.

Description

Description Title of the invention: Method for dismantling batteries with deep discharge and energy recovery.

[0001] The invention relates to the field of battery recycling, and in particular to the field of battery dismantling.

[0002] The market for electric and hybrid vehicles has been growing steadily since the early 2000s. By 2030, players in the Waste from Electrical and Electronic Equipment (WEEE) sector will have to process a significant volume of Li-ion batteries from electric vehicles.

[0003] An electric vehicle battery is composed of the following elements: Cover: Protects and insulates the electronic component from the external environment. It is attached to the housing. Module: The modules are composed of cells. The quantity and design of the modules and cells depend on the expected energy and power of the vehicle. The modules can be built in series or parallel. Bus bar: Electrical cable that connects the modules to each other and to the contactor, also known as a bus bar or busbar according to their English name. Cooling system: Allows the internal temperature of the battery to be regulated. Indeed, during the charging and discharging processes, the modules and cells generate heat through the Joule effect, which can affect the battery's efficiency and increase the risk of flammability. BMS (Battery Management System): System that monitors cell temperature and voltage.

[0004] A known solution for recycling li-ion batteries is to directly crush the battery module.

[0005] However, such a solution is not fully satisfactory because it does not take into account the specific characteristics and condition of each battery, and does not satisfactorily address the safety issues related to battery dismantling.

[0006] There is therefore a need for a battery dismantling process and facility that addresses these issues.

[0007] For this purpose, a method is proposed for dismantling batteries comprising at least one module of electric accumulator cells, the method comprising:

[0008] - a step of supplying at least one undamaged end-of-life battery; and

[0009] - a step of deep discharging said undamaged battery during which the energy from the discharge is recovered by an energy recovery device.

[0010] Advantageously, the supply step also includes the supply of damaged end-of-life batteries, the supply step including a sub-step of diagnosing the end-of-life batteries to determine whether they are damaged or not.

[0011] Advantageously, each battery comprises a case containing said at least one module, and the undamaged end-of-life batteries are subjected to steps prior to said deep discharge step, comprising:

[0012] - A preparation step for unscrewing the case and decontaminating the battery; and

[0013] - A step of unscrewing the battery case.

[0014] Advantageously, the method comprises, after the deep discharge step, the steps of:

[0015] - Removal of electronic components; and

[0016] - Extraction of modules.

[0017] Advantageously, the supply step also includes the supply of damaged batteries and production scrap, said method comprising a set of manual dismantling steps for these damaged batteries and production scrap, comprising:

[0018] - A discharge step in a saline solution; and

[0019] - A step of manual dismantling of the battery including at least the recovery of battery modules or production scrap.

[0020] Advantageously, said extracted modules are subjected to a grinding step.

[0021] The invention also relates to a battery dismantling installation comprising at least one module of electric accumulator cells, comprising:

[0022] - means of supplying at least one undamaged end-of-life battery; and

[0023] - a deep discharge unit of said undamaged battery during which the energy from the discharge is recovered by an energy recovery member.

[0024] In particular, the batteries comprise a housing containing said at least one module.

[0025] The installation comprising a semi-automated dismantling unit for undamaged batteries, comprising the deep discharge unit and comprising upstream of the deep discharge unit:

[0026] - A battery preparation and decontamination charging station;

[0027] - A station for unscrewing battery boxes;

[0028] And downstream of the deep discharge unit:

[0029] - An electronic component removal station; and

[0030] - A battery module extraction station.

[0031] Advantageously, the installation comprises means for supplying damaged batteries, damaged end-of-life batteries, and production scrap, the installation comprising a manual dismantling unit for damaged batteries, damaged end-of-life batteries, and production scrap comprising:

[0032] - A unit for discharging batteries and waste into a saline solution; and

[0033] - A unit for manual dismantling of said batteries and scrap, including at least the recovery of battery modules and scrap.

[0034] Advantageously, the installation comprises a crushing unit for crushing the modules extracted and / or recovered from said batteries and / or scrap.

[0035] Other features and advantages of the invention will emerge from reading the description given below of a particular embodiment of the invention, given for informational purposes but not as a limitation, with reference to the appended drawings in which:

[0036] [Fig. 1] is a schematic representation of the method according to one embodiment of the invention;

[0037] [Fig. 2] is a schematic representation of a battery dismantling installation according to the invention. Dismantling process

[0038] The dismantling method according to the invention 1 aims to enable the extraction of electric battery modules in order to supply them to the crushing process, and the recovery of eight material streams: electronic components, ferrous metals, non-ferrous metals, polypropylene (PP) and polyethylene (PE), cables, Busbars, PP-PAGF, which is a composite of polypropylene (PP) reinforced with aligned glass fibers (PAGF - Polypropylene Aligned Glass Fiber), and non-ferrous metals associated with polymers.

[0039] With reference to Figure 1, the process 1 firstly comprises an unpacking step 2 or a supply step 3 of the batteries to be dismantled and the production waste also called “scraps”, corresponding to the cells, modules and packs deemed non-compliant by the manufacturers.

[0040] During this unpacking step 2 or supply step 3, or possibly before this unpacking / supply step, the damaged batteries, scrap and end-of-life batteries are separated.

[0041] During this unpacking or supply step, a diagnostic sub-step 3' is carried out, during which it is determined whether the end-of-life battery is damaged or not damaged.

[0042] Then the dismantling process comprises two sets of steps 10 and 20, forming two distinct treatment flows, each corresponding to treatment steps of different battery flows.

[0043] The first set of steps 10, called manual dismantling steps 10, is intended to deal with damaged batteries, for example batteries from accident vehicles, or end-of-life batteries diagnosed as damaged as well as scrap.

[0044] In this set of manual dismantling steps 10, a saline discharge step 11 of the batteries is first carried out.

[0045] Saline discharge 11 is a discharge method in which the battery, and therefore the modules, are immersed in a saline solution, which slowly and safely discharges the battery. However, the energy from such a discharge is generally lost.

[0046] Then, once the saline discharge is complete, the battery is manually dismantled 12 and the modules are extracted.

[0047] The second set of steps 20 is called the semi-automated dismantling set of steps, and deals with undamaged end-of-life batteries.

[0048] During the set of semi-automated dismantling steps 20, the battery is loaded 21 onto a treatment unit, and the external parts of the battery are dismantled and the battery is decontaminated.

[0049] We then proceed to unscrew 30 of the casing.

[0050] A deep discharge step 40 of the battery is then implemented, during which the energy contained in the battery is fully recovered.

[0051] Such a discharge procedure requires taking into account several imperatives, described below.

[0052] This deep discharge step, in the context of this process, makes it possible to address several issues, and in particular the risks linked to EV Li-ion batteries (risk of explosion, fire, electrical).

[0053] In particular, deep discharge of batteries is carried out mainly for safety reasons when handling the batteries but also to reduce the energy level as much as possible before the crushing stage. Indeed, the capacity of a crusher is approximately 4 tonnes per hour, which corresponds to approximately 13 batteries or 465 kWh.

[0054] In this context, the invention implements a system for discharging Li-ion batteries making it possible to: reduce the risks linked to the discharge process; optimize the quantity of battery treated; reduce the error rate.

[0055] According to the invention, the discharging process is capable of discharging different types of batteries from their current voltage to 0V and 0A.

[0056] The discharge system is capable of processing between 15,000 tonnes and 30,000 tonnes of batteries per year, which represents a daily productivity of between 230 and 440 batteries per day.

[0057]

[0058] Safety Considerations

[0059] Electrical risk

[0060] In today's market, electric vehicle (EV) batteries contain a large amount of energy (with an average energy of 25 kWh and a power of 65 kW, up to maximum values ​​of 93 kWh of energy and 560 kW of power) and can operate on average at 340 V (and up to 800 V for high-voltage batteries). Even if the batteries are discharged and short-circuited, the battery voltage must be checked and handled with specific equipment. The main risks identified are electric shock, which can cause burns and serious injuries, but also thermal runaway.

[0061] Risk of fire and explosion

[0062] First- to third-generation Li-ion batteries contain a highly flammable liquid electrolyte under pressure. Under these conditions, thermal runaway can occur above 60°C.

[0063] Other risks

[0064] To prevent these risks, the following safety measures are applied: control and regulate the internal temperature; space the batteries from each other (to reduce the risk of fire); space the batteries from other equipment; implement a detection and extinguishing system. General description of the process

[0065] The discharge process includes the following steps: Step 1: Identify the battery (database and software development suitable for the discharge system should be advised by the supplier). Step 2: Opening the upper housing, this part of the process will be incorporated into the automated dismantling process (out of scope). Step 3: Battery Safety Check: - Disconnection of the BMS (supplier advice is required) - Battery polarity check (the objective is to identify the battery poles and connect the corresponding poles to the discharge equipment) - Voltage control (equipment proposal is requested) - Measurement of the initial energy inside the battery Step 4: Connecting the battery to the discharge system The supplier must indicate the solution for connecting the batteries to the discharge system: cables, plug, etc. Step 5: Battery Discharge. The supplier must provide a discharge system capable of handling high battery variability. Step 6: The battery is short-circuited to avoid the hysteresis effect. The short-circuit is performed by extending the discharge after the battery voltage reaches zero, until the current within the battery is zero. Description of the discharge system

[0066] The discharge system must be able to perform a deep discharge (0V, OA) of 30 batteries / hour.

[0067] Main functions: The discharge system is capable of discharging a battery down to 0V in less than an hour. The discharge equipment supports batteries with different discharge parameters. The discharge system measures different parameters: 1(A), V(V), C (Ah), P (kW), T(C°) The discharge system performs a second life diagnosis, based on the battery's state of charge (SOC) and state of health (SOH). The discharge system creates and stores a discharge sequence. The discharge system is capable of discharging a battery with or without access to the BMS The discharge system is controlled by a centralized supervision and data backup system. The discharge system recovers energy from the battery on a specific network to provide energy to the recycling plant The discharge system has a recovery rate of over 90%. The power factor is greater than 0.93.

[0068] Safety device The discharge equipment is protected against reverse polarity The discharge equipment has reverse polarity measurement The discharge equipment is equipped with a power contactor to activate / deactivate the connection between the battery and the discharge system. The discharge equipment is equipped with a fire detection system The discharge equipment is equipped with a fire protection system The discharge equipment is equipped with high current protection The discharge equipment is equipped with a temperature control system The discharge equipment preferably complies with the IP2X standard The supply voltage is for example 400V AC. Battery discharge facility

[0069] The installation is suitable for batteries of all sizes and types.

[0070] It includes discharge equipment and a discharge facility with the following characteristics: Rack or discharge platform with safety system to prevent ignition Control system with sensors and thermal camera Cables and cable support Electrical cabinet of the discharge equipment Centralized monitoring system The security system is controlled by a central system

[0071] Main functions: The discharge system makes it easy to connect the discharge system. The discharge system can hold up to 30 batteries. The discharge system has wiring and connections suitable for all battery types and high currents. Ensures a safe discharge process.

[0072] Design constraints: The discharge facility handles batteries weighing between 41 kg and 750 kg and with dimensions between (590 x 260 mm and 2830 x 772 mm).

[0073] In the main embodiment of the invention, the deep discharge is carried out so as to recover in an energy recovery unit, the energy contained in the battery. According to the invention, the deep discharge method 40 allows a discharge rate close to 100%, preferably between 90% and 100%.

[0074] Once the deep discharge has been carried out, the electronic components 50 are removed and then a step 60 of extracting the modules is carried out.

[0075] Then all the recovered modules, resulting from the set of semi-automatic dismantling steps 20 and manual dismantling 10, are subjected to a crushing step 31. Dismantling facility

[0076] With reference to Figure 2, the invention also relates to a dismantling installation implementing a method 1 according to the invention.

[0077] The 100 installation is here subdivided into several processing units.

[0078] The installation 100 firstly comprises an unpacking unit 101 in which the batteries are received.

[0079] The batteries received are end-of-life batteries, damaged batteries, for example from accident vehicles, and scrap.

[0080] In this unpacking unit 101, an unpacking and diagnostic station ST 10 for end-of-life batteries is installed.

[0081] This ST10 diagnostic station allows you to test batteries to determine if they are damaged or not damaged.

[0082] In fact, end-of-life batteries diagnosed as damaged will then be reintegrated into the group of damaged and scrap batteries.

[0083] This ST 10 station is a semi-automated station. It allows the unpacking of batteries from their transport crates as well as the analysis of the electrical and physical condition of the battery.

[0084] The ST 10 station has the following systems: an EV, PHEV and HEV battery handling system allowing the batteries to be removed from their transport crate; a system for vacuuming the vermiculite or clay balls present in the crate; a battery identification system, for example implementing an automatic recognition module, such as deep convolutional machine learning modules, or any other type of module known under the general term of artificial intelligence, or a scanner associated with a Human-Machine Interface, known as HMI, containing the image banks of the different models as well as the associated technical specifications; a diagnostic system analyzing the following parameters: Voltage (V), Current (I), Capacity (Ah), the state of charge abbreviated SOC (from the English State Of Charge, measured in %), and the state of health of the battery, generally abbreviated SOH (from the English State Of Health, generally measured in %).

[0085] Undamaged end-of-life batteries are then processed by a semi-automated dismantling unit 120.

[0086] This 120 semi-automated dismantling unit includes the following stations:

[0087] A battery preparation station for ST20 unscrewing

[0088] The ST20 station is a manual station for preparing batteries for unscrewing and for their decontamination. This station allows the battery to be paired with its transport system, such as a trolley or an automated guided vehicle, generally called by its English abbreviation AGV.

[0089] The ST20 station has the following systems: 1. a coolant suction system associated with a storage system; 2. a modular battery hanging system, in order to adapt to the diversity of battery shapes and dimensions (Maximum dimension - 2830mm X 1772mm), associated with an RFID type traceability system allowing to identify the battery along the line, and to trace the operations carried out on it; 3. a standard dismantling station composed of: 4. a workbench with storage spaces for tools in its lower part; 5. storage boxes of different formats which can contain the following fractions: electronic components, ferrous, non-ferrous, plastics; 6. A battery identification system with HMI + scanner or RFID system.

[0090] An ST30 unscrewing station

[0091] The ST30 station is a robotic unscrewing station. It is composed of the following elements: 1. Two unscrewing robots 2. An RFID recognition system 3. A camera allowing recognition of fixing locations 4. A screw-out system with socket changer 5. A system for hanging different types of sockets

[0092] An ST40 deep discharge station

[0093] A programmable ST40 deep discharge station with a universal connection system. The ST40 station is a programmable semi-automated discharge system. Each battery, once connected, will discharge according to the specifications of the battery model as well as the measurements taken at the ST 10 station.

[0094] This station includes the following elements: 1. A robotic gripping system that has a dual function: Removal of the upper casing Removing the battery from the stacker crane's moving platform 2. A stacker crane system connected to a discharge system with energy recovery on the installation. Each location of the stacker crane is identified by a number possibly associated with a barcode or a QR code and is associated with a bidirectional discharge power supply. 3. A connection system will allow connection to all types of battery poles, positive and negative. 4. Immersion tanks in case of fire

[0095] An ST50 station for removing electrical components

[0096] The ST50 station is a manual station composed of the following elements: 1. A coolant suction system associated with a storage system. 2. A module handling system. 3. A standard dismantling station composed of: - A workbench with storage spaces for tools in its lower part; - Storage boxes of different formats that can contain the following fractions: electronic components, ferrous, non-ferrous, plastics; - A battery identification system with HMI associated with scanner or RFID system.

[0097] An ST60 module extraction station

[0098] The ST60 station is automated and includes: 1. A robotic unscrewing station comprising a robot, an unscrewing tool with socket change, a camera with a fastening system identification system; 2. A station with a gripping robot capable of handling modules up to 2m long and weighing up to 25kg.

[0099] Damaged batteries (end of life or not) and scrap are processed by a manual dismantling unit 110.

[0100] This 110 manual dismantling unit includes the following stations: - A chemical discharge unit SU comprising a discharge tank, here a tank of approximately 12m3 (2mx3mx2m), although these dimensions are given as a non-limiting example. These tanks are continuously filled with a saline solution, here salt water (NaCl + water). This salt water mixture is produced by an electrolyser. The wastewater is then collected and treated so that it can be redistributed to the electrolyser for water reuse. - A 2mx3m battery handling support - A handling bridge allowing the removal and removal of batteries from the immersion tanks. - A drying system with a storage capacity of 20 batteries.

[0101] The batteries are removed from the drying system using the handling bridge.

[0102] The manual dismantling unit 110 further comprises, in addition to the saline discharge unit S 11 , the following elements:

[0103] - A coolant suction system associated with a storage system.

[0104] - An identification and traceability system composed of a scanner and an HMI.

[0105] - A battery and module handling system.

[0106] - A standard dismantling station consisting of: a. A workbench with storage spaces for tools in its lower part b. Storage boxes of different formats that can contain the following fractions: electronic components, ferrous, non-ferrous, plastics c. A battery identification system with HMI + scanner or RFID system

[0107] Finally, once the modules have been discharged and extracted from the batteries and / or scrap, they are sent to a crushing unit 130.

Claims

Claims

1. Method for dismantling (1) batteries comprising at least one module of electric accumulator cells, the method comprising: - a step of supplying (3) by means of supplying at least one undamaged end-of-life battery; and - a step of deep discharging (40) said undamaged battery by a deep discharging unit, during which the energy from the discharge is recovered by an energy recovery member.

2. Method according to claim 1, characterized in that the supplying step (3) also comprises the supply of damaged end-of-life batteries, the supplying step (3) comprising a sub-step (3') of diagnosing the end-of-life batteries making it possible to determine whether they are damaged or not damaged.

3. Method according to claim 2, each battery comprising a case containing said at least one module, characterized in that the undamaged end-of-life batteries are subjected to steps prior to said deep discharge step, comprising: - A preparation step for unscrewing the case and decontaminating the battery; and - A step of unscrewing (30) the battery case.

4. Method according to claim 2 or 3, characterized in that it comprises after the deep discharge step (40) steps of: - Removal (50) of electronic components; and - Extraction of modules (60).

5. A method according to any one of claims 1 to 4, characterized in that the supplying step (3) also comprises the supply of damaged batteries and production scrap, said method comprising a set of manual dismantling steps (10) for these damaged batteries and production scrap, comprising: - A discharge step (11) in a saline solution; and - A step of manual dismantling (12) of the battery comprising at least the recovery of the battery modules or production scrap.

6. Method according to claim 4 or claims 4 and 5, characterized in that said extracted modules are subjected to a grinding step (31).

7. Battery dismantling installation (100) comprising at least one module of electric accumulator cells, comprising: - means of supplying at least one undamaged end-of-life battery; and - a deep discharge unit (ST40) of said undamaged battery during which the energy from the discharge is recovered by an energy recovery member.

8. Installation according to claim 7, the batteries comprising a housing containing said at least one module, the installation being characterized in that it comprises a semi-automated dismantling unit (120) for the undamaged batteries, comprising the deep discharge unit (ST40) and comprising upstream of the deep discharge unit (ST40): - A station (ST20) for charging, preparing and decontaminating the battery; - A station (ST30) for unscrewing battery boxes; And downstream of the deep discharge unit (ST40): - An electronic component removal station (ST50); and - A battery module extraction station (ST60).

9. Installation according to claim 7 or 8, characterized in that it comprises means for supplying damaged batteries, damaged end-of-life batteries, and production scrap, the installation comprising a manual dismantling unit (110) for damaged batteries, damaged end-of-life batteries, and production scrap including: - A discharge unit (SI 1) for batteries and waste in a saline solution; and - A unit for manual dismantling of said batteries and scrap, including at least the recovery of battery modules and scrap.

10. Installation according to any one of claims 8 or 9, characterized in that it comprises a crushing unit (31) for crushing the modules extracted and / or recovered from said batteries and / or scrap.

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