High-yield extraction of battery formation gases

Abstract

The present disclosure relates to degassing apparatus and degassing process schemes for high acquisition volume extraction of battery formation gases. An example method can include loading a battery into a sampling chamber of a degassing station and forming an opening in the battery to release formation gases. A first portion of the formation gases can be directed to a collection chamber of the degassing station while preventing the formation gases from being vented. After the first portion of the formation gases is directed to the collection chamber, a second portion of the formation gases can be vented until degassing is complete. The first portion of the formation gases can be diluted with a dilution fluid, and the diluted first portion of the formation gases can be directed to a battery quality control gas manifold configured to measure battery formation gas composition.

Description

Technical Field

[0001] This disclosure relates to battery manufacturing technology, specifically to the high-yield extraction of battery formation gases. Background Technology

[0002] Lithium-ion batteries are among the most commonly used energy storage technologies, with applications ranging from small portable electronic devices to large electric vehicle battery packs. Due to various desired energy storage characteristics, such as energy density, power density, maximum charge rate, internal leakage current, equivalent series resistance (ESR0), charge-discharge cycle durability, and high conductivity, lithium-ion batteries have become increasingly popular as a battery platform. Developing the capability to mass-produce high-efficiency next-generation lithium-ion batteries is crucial for the further development of portable electronic devices and the implementation of efficient electric vehicles.

[0003] In battery construction, a formation process is essential, and aside from raw material costs, it is the most expensive step in battery manufacturing. During formation, an interface grows on the battery surface to stabilize the electrolyte adjacent to the anode electrode (e.g., lithium-ion graphite). The electrolyte decomposes at the anode surface, leading to the formation of a solid electrolyte interphase (SEI) layer. The SEI layer acts as a protective layer to prevent further electrolyte decomposition and solvent co-intercalation into the graphite layer during subsequent cycles. Several gas evolution mechanisms exist in lithium-ion batteries, primarily originating from electrolyte reduction during the first cycle, simultaneously forming the SEI layer on the anode surface. Gases generated during SEI layer formation are degassed before the battery is sealed. Summary of the Invention

[0004] The technical method described herein provides high-yield extraction of battery formation gases for analysis. In one exemplary embodiment, a battery is loaded into a sampling chamber of a degassing station, and an opening is formed in the battery to release formation gases. A first portion of the formation gases can be directed to a collection chamber of the degassing station while preventing further venting. After the first portion of the formation gases has been delivered to the collection chamber, a second portion of the formation gases can be vented until degassing is complete. The first portion of the formation gases can be diluted with a dilution fluid, and the diluted first portion of the formation gases can be directed to a battery quality control gas manifold configured to measure the composition of the battery formation gases.

[0005] In some embodiments, guiding the first portion of the formation gas includes actuating a plurality of valves to form a path between the sampling chamber and the collection chamber. In some embodiments, the battery is recovered from the sampling chamber after the second portion of the formation gas is discharged.

[0006] In another exemplary embodiment, the dilution fluid includes air or an inert gas. In other embodiments, forming the opening includes activating an actuator to bring the piercing tool into contact with the battery.

[0007] In some embodiments, the expansion chamber is connected to the sampling chamber. In some embodiments, the expansion chamber includes a configurable volume.

[0008] In another embodiment, the ratio of the volume of the sampling chamber to the volume of the collection chamber is selected to achieve a predetermined capture volume of the formed gas. In some embodiments, the predetermined capture volume is 0.1 ml to 10 ml under normal temperature and pressure. In some embodiments, a first portion of the formed gas is diluted until a pressure setpoint is reached.

[0009] This disclosure includes aspects of a degassing system for providing high-yield extraction of battery formation gases. An exemplary system includes a sampling chamber configured to receive a battery. The sampling chamber may include an actuator operable to create an opening in the battery for releasing formation gases. The system may also include a collection chamber coupled to the sampling chamber and a battery quality control gas manifold coupled to the collection chamber. The battery quality control gas manifold may be configured to measure the composition of the battery formation gases. The system also includes a plurality of valves operable to direct a first portion of the formation gases to the collection chamber while preventing the formation gases from escaping. After directing the first portion of the formation gases to the collection chamber, the valves may also be operable to discharge a second portion of the formation gases.

[0010] In some embodiments, the system further includes a dilution fluid source connected to the collection chamber. In other embodiments, the dilution fluid includes air or an inert gas. In other embodiments, multiple valves are also operable to dilute the first portion of the formation gas with the dilution fluid. In some embodiments, multiple valves are also operable to direct the diluted first portion of the formation gas to a battery quality control gas manifold.

[0011] In some embodiments, an actuator operable to create an opening in the battery is coupled to a piercing tool that contacts the battery when the actuator is activated.

[0012] In some embodiments, the system further includes an expansion chamber coupled to the sampling chamber. The expansion chamber may include a configurable volume.

[0013] In some embodiments, the ratio of the volume of the sampling chamber to the volume of the collection chamber is selected to achieve a predetermined capture volume of the formed gas. In other embodiments, the predetermined capture volume is 1 ml at normal temperature and pressure. In other embodiments, the system includes a pressure sensor connected to the collection chamber. The pressure sensor can be configured to ensure that a first portion of the formed gas is diluted until a pressure setpoint is reached.

[0014] The above-described features and advantages, as well as other features and advantages, of this disclosure will become apparent from the following detailed description when taken in conjunction with the accompanying drawings. Attached Figure Description

[0015] Other features, advantages, and details appear only by way of example in the following detailed description, which refers to the accompanying drawings, wherein:

[0016] Figure 1 A degassing station according to one or more embodiments is shown, which is configured for high-yield extraction and analysis of battery-formed gases;

[0017] Figure 2A A block diagram of a degassing station according to one or more embodiments is shown, the degassing station being configured for high-yield extraction and analysis of battery-formed gases;

[0018] Figure 2B The following is illustrated after the processing operation according to one or more embodiments. Figure 2A A block diagram of the degassing station;

[0019] Figure 3A The following is illustrated after the processing operation according to one or more embodiments. Figure 2B A block diagram of the degassing station;

[0020] Figure 3B The following is illustrated after the processing operation according to one or more embodiments. Figure 3A A block diagram of the degassing station;

[0021] Figure 4A The following is illustrated after the processing operation according to one or more embodiments. Figure 3B A block diagram of the degassing station;

[0022] Figure 4B The following is illustrated after the processing operation according to one or more embodiments. Figure 4A A block diagram of the degassing station;

[0023] Figure 5A The following is illustrated after the processing operation according to one or more embodiments. Figure 4B A block diagram of the degassing station;

[0024] Figure 5B The following is illustrated after the processing operation according to one or more embodiments. Figure 5A A block diagram of the degassing station;

[0025] Figure 6 The relationship between the volume ratio of the captured gas to the degassing chamber and the collection chamber according to one or more embodiments is shown;

[0026] Figure 7AThe relationship between the degassing chamber volume, the collection chamber volume, and the gas concentration is shown according to one or more embodiments when the battery size is fixed.

[0027] Figure 7B The relationship between the degassing chamber volume, the collection chamber volume, and the gas concentration is shown according to one or more embodiments when the battery size is proportional to the degassing chamber volume.

[0028] Figure 8 It is a flowchart according to one or more embodiments. Detailed Implementation

[0029] The following description is exemplary in nature only and is not intended to limit this disclosure, its application, or use. It should be understood that in all the drawings, corresponding reference numerals denote the same or corresponding parts and features.

[0030] Developing scalable, high-efficiency next-generation lithium-ion battery manufacturing capabilities is crucial for the further development of portable electronic devices and the implementation of efficient electric vehicles. Battery manufacturing typically involves multiple steps, including electrode production, battery production, conditioning, and testing / validation. The first stage of battery manufacturing is the production of the positive and negative electrodes, including mixing, coating, drying, calendering, cutting, die-cutting, and tab welding. After completion, the electrodes are assembled into a battery and conditioned. The smallest unit of a lithium-ion battery consists of two electrodes, a separator, and an ion-conducting electrolyte that fills the electrode pores and the remaining space inside the battery.

[0031] Formation (also known as battery post-processing) is the final step in battery production, typically referring to the initial charge and discharge process. During formation, lithium ions are embedded in the graphite crystal structure on the anode side. The electrolyte decomposes at the anode surface, leading to the formation of a solid electrolyte interphase (SEI) layer, which creates an interface layer between the electrolyte and the electrode.

[0032] Following formation, the battery undergoes conditioning (sometimes referred to as post-treatment along with formation). This process typically involves degassing, during which gases released by electrolyte reduction are removed, accompanying the formation of the SEI layer on the electrode surfaces. During degassing, the battery pouch (pack) is punctured in a vacuum chamber to release the escaping gases. The battery is then sealed under vacuum.

[0033] After degassing and resealing, the battery can undergo various tests and quality verifications. These processes typically involve aging, where battery characteristics and performance are monitored over days or even weeks. Unfortunately, due to aging, battery degradation and other quality issues discovered during or after aging will inevitably be delayed from the actual manufacturing time.

[0034] Recently, advancements in battery quality control technology have shifted towards the analysis of battery formation gas composition to infer battery quality characteristics prior to the aging process. Unfortunately, current battery manufacturing processes are incompatible with methods for obtaining high quantities of these formation gases. Therefore, formation gas analysis is typically performed in batch processes on a subset (often very limited) of batteries on the production line and is not suitable for large-scale applications.

[0035] One or more embodiments address one or more of the aforementioned disadvantages by providing novel degassing apparatus and process methods for high-yield extraction of battery formation gases. Instead of venting the formation gases after battery degassing and resealing, embodiments of this disclosure improve the degassing apparatus by including a second chamber to capture the formation gases from the degassing chamber prior to venting. The formation gases can then be diluted, and the diluted gases can be sampled online using a battery quality control gas manifold.

[0036] The technical solutions described in this paper facilitate a series of improvements in battery technology. Firstly, the degassing equipment is modified to allow formation gases to be captured, pretreated, and delivered online to the quality control gas manifold, thereby enabling highly scalable battery quality control technology prior to aging. Early detection of battery quality issues saves time and resources. Advantageously, the degassing modifications according to one or more implementations require only minimal changes to existing manufacturing equipment and can be easily integrated into conventional production lines.

[0037] Other advantages are also possible. Battery grading before module assembly is greatly improved. For example, embodiments of this disclosure can be used to evaluate SEI formation gas composition and volume to reduce quality degradation. Reducing quality degradation frees up factory aging inventory space because batteries destined for disposal can be removed before aging, thereby reducing inventory holding time. For example, this can improve the production efficiency of next-generation high-capacity lithium-ion batteries.

[0038] Figure 1 A degassing station 100 according to one or more embodiments is shown, configured for high-yield extraction and analysis of battery-generated gases. (See also...) Figure 1 As shown, the degassing station 100 may include a vacuum pump 102 connected to a first valve (“V1”) 104 and an exhaust port 106. The vacuum pump 102 may include any suitable device for supplying a vacuum to the degassing station 100. As used herein, “vacuum” generally refers to conditions close to vacuum and does not require a complete vacuum (0 Torr), but rather allows a low vacuum (approximately 10 Torr). - 2 Torr) to ultra-high vacuum (approximately 10) -11 Torr).

[0039] Sampling chamber 108 is connected to ambient air source 110 (also referred to as chamber repressurization line) via a second valve (“V2”) 112. In some embodiments, sampling chamber 108 includes a pressure sensor 114 configured to measure the chamber pressure of sampling chamber 108. Sampling chamber 108 generally refers to a degassing chamber or degassing primary chamber in which a battery (not shown separately) is placed, punctured (sampled), and allowed to degas. In some embodiments, sampling chamber 108 includes a linear actuator (not shown separately) coupled to a needle, blade, or other tool capable of being activated to puncture the battery pouch; other puncture mechanisms are also within the scope of this disclosure. The output of sampling chamber 108 is controlled by a third valve (“V3”) 116.

[0040] The first valve (“V1”) 104 and the third valve (“V3”) 116 are connected to a common fourth valve (“V4”) 118, which in turn is connected to the expansion chamber 120. In some embodiments, the expansion chamber 120 includes a pressure sensor 122 configured to measure the chamber pressure of the expansion chamber 120. The sampling chamber 108 and the expansion chamber 120 may be collectively referred to as the degassing chamber (or primary chamber).

[0041] The function of expansion chamber 120 is to set the volume ratio of sampling chamber 108 to the rest of the system (i.e., degassing station 100). In this way, degassing station 100 can be flexibly matched to test conditions in the current production line, where the chamber volume of the manufacturing degasser (not shown separately) is known. In some embodiments, the volumes of sampling chamber 108 and / or expansion chamber 120 can be varied according to any desired volume ratio to match the manufacturing degasser chamber volume. For example, if the manufacturing degasser chamber volume is 30,000 ml and the desired volume ratio is 1:5, then sampling chamber 108 and expansion chamber 120 can be reduced to 1,000 ml and 5,000 ml, respectively. (Refer to...) Figure 6 The selection of the size and volume ratio of the collection chamber is discussed in more detail.

[0042] Sampling chamber 108 and expansion chamber 120 are connected to collection chamber 124 via a common fifth valve (“V5”) 126. In some embodiments, collection chamber 124 includes a pressure sensor 128 configured to measure the chamber pressure of collection chamber 124. As previously described, collection chamber 124 serves as a degassing secondary chamber configured to receive formation gases from degassing primary chambers (e.g., sampling chamber 108 and / or expansion chamber 120) before discharge.

[0043] In some embodiments, the volume of the collection chamber 124 is set to achieve a specific final capture volume of the formation gas for analysis. In some embodiments, the target capture volume is 0.1 ml to 10 ml of formation gas at ambient temperature and pressure, for example, 1 ml (Ambient temperature and pressure NTP is approximately 1 atmosphere at 20 degrees Celsius). (See reference...) Figure 6The dimensions of the collection chamber were discussed in more detail.

[0044] For ease of illustration and description, degassing station 100 is generally described relative to a single collection chamber 124; however, in some embodiments, one or more additional collection chambers (not shown separately) are connected to the output of valve 126 and a sixth valve (“V6”) 132. In some embodiments, dedicated input and output valves (not shown separately) can be used to control the input to each collection chamber. In this way, any number of collection chambers can be connected in parallel with degassing station 100, and other configurations are also within the scope of this disclosure.

[0045] In some embodiments, each collection chamber is constructed with different degassing volume specifications. For example, the first collection chamber may be a 1L chamber, while the second collection chamber may be constructed as 0.2L, 0.5L, 0.8L, 1.2L, 1.5L, 2L, etc. In this way, a range of collection chamber volumes can be used for degassing analysis. In some embodiments, based on the degassing conditions of this application (e.g., cell size and gas generation volume), the collection chamber is selected by guiding the formed gas to a specific chamber via a valve while isolating other chambers. In this way, a target capture volume can be achieved over a range of cell sizes and gas generation volumes without altering the degassing station 100.

[0046] The fifth valve (“V5”) 126 and the collection chamber 124 can be connected to a compressed air source 130 (also referred to as bottled air) via a sixth valve (“V6”) 132. The compressed air source 130 may include any suitable device for supplying compressed air to the degassing station 100. As used herein, “compressed air” generally refers to atmosphere at a pressure higher than one atmosphere, although ambient air is also within the scope of this invention. In some embodiments, the flow regulator 134 controls the flow rate of air from the compressed air source 130 through the sixth valve (“V6”) 132.

[0047] like Figure 1 As further shown, the output of collection chamber 124 is connected to a seventh valve (“V7”) 136, which serves as an input gate for battery quality control system 138. As shown, battery quality control system 138 includes a flow controller 140, a flow meter 142, a carrier gas source 144, and a battery quality control gas manifold 146 (gas manifold), configured and arranged as shown. In some embodiments, flow controller 148 controls the flow rate of air from carrier gas source 144.

[0048] Flow controller 140 may include any suitable device for flow control, such as a flow metering valve. Flow meter 142 may include any suitable device for measuring the flow rate from flow controller 140, such as a high-precision ultrasonic flow meter. Carrier gas source 144 may include any suitable device for supplying carrier gas to degassing station 100. As used herein, “carrier gas” generally refers to an inert gas (e.g., nitrogen or air) and may be pressurized (above 1 atm) or at atmospheric pressure (1 atm).

[0049] The battery quality control gas manifold 146 includes a device configured to analyze the composition of battery formation gases, and is not intended to be particularly limited. The battery quality control gas manifold 146 may include, for example, a gas chromatography (GC) sensor or a spectral-based system (e.g., mass spectrometry, infrared spectroscopy, laser absorption spectroscopy, etc.). In some embodiments, the battery quality control gas manifold 146 is calibrated to receive a specific capture volume of formation gas. As previously mentioned, in some embodiments, the target capture volume is 1 ml of formation gas at STP, although other calibration values ​​are possible. In some embodiments, the battery quality control gas manifold 146 is coupled to an exhaust port 106.

[0050] Figure 2A-5B The corresponding descriptions of the degassing station and degassing scheme ensure that 1 ml (or any desired target capture volume) of formation gas is delivered to the battery quality control gas manifold under NTP.

[0051] Figure 2A A block diagram of a degassing station 100 according to one or more embodiments is shown, the degassing station 100 being configured for high-yield extraction and analysis of battery-formed gases. Figure 2A The block diagram shown depicts Figure 1 The diagram shows a simplified block diagram of a portion of the degassing station 100 in its initial state (step 1), where battery 202 is loaded into sampling chamber 108 of the degassing chamber. In this initial state, all valves are closed (V1-V7 are closed) to isolate the various degassing devices.

[0052] In step 2 ( Figure 2BThe degassing chamber (e.g., sampling chamber 108 and expansion chamber 120) and collection chamber 124 (and any additional collection chambers, if present) are evacuated. In some embodiments of the invention, evacuation is a two-step process. In step 2A, valves 104, 116, 118, and 126 are opened (V1, V3, V4, and V5 are open), and sampling chamber 108 is evacuated to “slit pressure”. As used herein, “slit pressure” refers to a pressure low enough to remove any residual gas from sampling chamber 108 but not low enough to rupture the battery 202 bag, for example, 5 psi below atmospheric pressure. In step 2B, valve 116 is closed to isolate sampling chamber 108, and the remainder of degassing station 100 (e.g., expansion chamber 120 and collection chamber 124) reaches the final evacuation pressure (final vacuum pressure). During this state, expansion chamber 120 and collection chamber 124 are under vacuum due to exposure to vacuum pump 102. When isolated, battery 202 ruptures under burst pressure or is otherwise punctured (step 3) (to prevent the bag from rupturing / bursting due to excessive internal / external pressure difference). Once battery 202 ruptures, it disintegrates into gas, exits battery 202, and fills sampling chamber 108. In step 4, valves 104 and 126 close, and then valve 116 opens (V3 opens), allowing the gas to expand into expansion chamber 120. This results in an increase in pressure within expansion chamber 120. Steps 3 and 4 are not described separately.

[0053] In step 5 ( Figure 3A Valves 116, 118, and 126 are opened (V3, V4, and V5 are open), and sampling chamber 108, expansion chamber 120, and collection chamber 124 are allowed to reach equilibrium. During this stage, the gas expands into collection chamber 124 until equilibrium pressure is reached. After gas collection is complete, all valves are closed in step 6 (not shown separately) (V1-V7 are closed).

[0054] In step 7 ( Figure 3B Valves 104, 116, and 118 are opened (V1, V3, and V4 are open), and sampling chamber 108 and expansion chamber 120 are allowed to complete the degassing process. During this stage, the remaining formation gas is discharged via vacuum pump 102 through exhaust port 106. Notably, the formation gas in collection chamber 124 is isolated from vacuum pump 102 due to the closure of valve 126 (“V5”). In some embodiments, battery 202 is sealed after degassing. After degassing is complete, all valves (V1-V7 are closed) are closed in step 8 (not shown separately).

[0055] In step 9 ( Figure 4AValves 112, 116, and 118 are opened (V2, V3, and V4 are opened), and sampling chamber 108 and expansion chamber 120 are filled with air via ambient air source 110. In some embodiments, sampling chamber 108 and expansion chamber 120 reach normal pressure (1 atm), although other refill pressures are also possible.

[0056] In step 10 ( Figure 4B All valves are closed (V1-V7 are closed) and battery 202 is recycled. In some embodiments, battery 202 is completed using known processes (e.g., aging, initial cycling, etc.).

[0057] In step 11 ( Figure 5A When valve 132 opens (V6 opens), the formation gas in collection chamber 124 is diluted with air via compressed air source 130. In some embodiments, collection chamber 124 reaches a predetermined pressure setpoint, such as 1.25 atm, although other pressure setpoints are possible. Regarding... Figure 6 The calculation of the pressure setpoint for a given application is discussed in more detail. After dilution is complete, all valves (V1-V7 closed) are closed in step 12 (not shown separately).

[0058] In step 13 ( Figure 5B Valve 136 opens (V7 opens), and the diluted formation gas in collection chamber 124 can enter battery quality control system 138. In some embodiments, flow controller 140 and flow meter 142 precisely control the release of diluted formation gas. In some embodiments, carrier gas source 144 (particularly separate from compressed air source 130 to ensure isolation and prevent contamination) provides carrier gas (e.g., air, nitrogen, etc.) to deliver the diluted formation gas to battery quality control gas manifold 146.

[0059] Once delivered, the battery quality control gas manifold 146 can determine the diluted formation gas composition as described above. In some embodiments, the diluted formation gas composition is compared with a database of reference compositions or other records to infer the quality of the battery 202. A database can be established empirically or experimentally (or both) by recording the formation gas composition and final quality control results using conventional processes (i.e., after aging and / or cycling, etc.). In this way, the quality of the battery 202 can be inferred before the aging process is complete.

[0060] As mentioned earlier, the appropriate size (volume) of the collection chamber can be selected to achieve the predetermined capture volume of the formation gas. To reliably capture 1 ml of formation gas under STP, several input parameters are required: the volume of the degassing chamber (L), the size of the cell (Ah), the gas generation rate (ml / Ah) for a specific cell chemistry, and the relationship between the degassing chamber volume, the collection chamber volume, and the percentage of gas captured.

[0061] As an example only, consider a manufacturing specification that stipulates two 100 Ah batteries degassed in a 154 L degassed chamber to provide a gas generation of 6 ml / 5 Ah. Under these conditions, for each battery, at a concentration of 1.56 ml / L (240 ml / 154 L), the gas generation would be approximately 240 ml (200 Ah * 6 ml / 5 Ah). Further considering a 4 L degassed chamber volume (other sizes are also possible), the formation gas volume would be approximately 6.24 ml (1.56 * 4). Therefore, for a target capture of 1 ml of formation gas, we must achieve a gas capture rate of 16% (1 / 6.24). The 1 ml formation gas target is for illustrative purposes only; it should be understood that any capture volume can be targeted.

[0062] To achieve 16% gas capture, it is essential to understand the relationship between volumetric parameters (degassing chamber volume and collection chamber volume) and the gas capture percentage. Figure 6 The relationship between volumetric parameters and the percentage of gas captured is described. For example... Figure 6 As shown, the percentage of gas captured varies relative to the volume ratio (V1 / V2) of the degassing chamber volume (V1) to the collection chamber volume (V2). Based on observation, 16% gas capture corresponds to a volume ratio of approximately 5. Assuming the degassing chamber volume is 4 L (which is known for a given application and is not required to be limited to 4 L), the collection chamber volume should be 800 ml for 16% gas capture.

[0063] Once the collection chamber volume is determined, the predetermined pressure setpoint for sampling can be calculated (see [reference]). Figure 5A In some embodiments, the pressure setpoint is rigorously determined using, for example, computational fluid dynamics (CFD). In some embodiments, certain assumptions are made to simplify the calculations. Assumptions may include, for example, that the formation gas is an ideal gas of pure ethylene under isothermal conditions and has a negligible pipeline volume (i.e., the pipeline volume << the total volume of the degassing chamber and the collection chamber).

[0064] Under these assumptions, the molar load of the formation gas and the predetermined pressure setpoint for sampling can be determined through analysis. In the degassing chamber, 6 ml of ethylene gas collected for a 5 Ah cell under NTP represents 2.44 x 10⁻⁶ ppm. -4mol ethylene gas (n gas In the collection chamber, the molar equivalent (n) of 1 ml of ethylene gas under NTP. secondary The result is given by (PV2) / RT, which is 4.06 × 10 for this example. -5 mol, where P is the value from step 5 ( Figure 3A V2 is the equilibrium pressure of the degassing chamber and the collection chamber 124 in the degassing chamber, V2 is the volume of the collection chamber 124, R is the ideal gas constant, and T is the temperature expressed in Kelvin.

[0065] Oncen gas It is known that a predetermined pressure setpoint (P) can be determined for any desired dilution ratio (e.g., 1000:1v / v, 100:1v / v, 10:1v / v, etc.). SP According to formula P) SP = (n) gas + n air ) RT / V2. Assuming the required dilution ratio is 1000:1 (air:gas, v / v), P SP It is approximately 3.65 psig (1.25 atm absolute value).

[0066] The gas collection pressure can also be calculated. The pressure in the degassing chamber (P1) can be calculated using the ideal gas law (P1 = n). gas The pressure (RT / V1) is determined, and for this example, P1 = 151 Pa. The combined pressure (P3) in the degassing chamber and the collection chamber is given by P3 = (P1V1) / (V1+V2), and for this embodiment, P3 = 137.5 Pa.

[0067] According to one or more embodiments, in order to collect 1 ml of gas under NTP, Figure 7A The relationship between the degassing chamber volume (V1), the collection chamber volume (V2), and the gas concentration (ml / L) is shown when the battery size is constant (e.g., 100 Ah). According to observations, the collection chamber volume (V2) increases linearly with increasing degassing chamber volume (V1). Conversely, the gas concentration (V2) initially decreases rapidly with increasing degassing chamber volume (V1), then stabilizes slightly for larger degassing chamber volumes (e.g., above 100 L).

[0068] According to one or more embodiments, in order to collect 1 ml of gas under NTP, Figure 7BThe relationship between the degassing chamber volume (V1), the collection chamber volume (V2), and the gas concentration (ml / L) is shown when the battery size is proportional to the degassing chamber volume. By observation, the gas concentration 702 is constant over a wide range of degassing chamber volumes (V1) (e.g., approximately 1.5 ml / L). Conversely, the collection chamber volume (V2) decreases rapidly up to approximately 3 L, and then stabilizes slightly at larger degassing chamber volumes (e.g., above 10 L).

[0069] Now for reference Figure 8 According to one embodiment, a flowchart 800 is generally shown for providing high-yield extraction and analysis of battery formation gases. (Reference) Figure 1-7B Describe flowchart 800, and flowchart 800 may include Figure 8 Additional steps not shown. Although depicted in a specific order, Figure 8 The boxes depicted in the text can be rearranged, subdivided, and / or combined.

[0070] In block 802, the battery is loaded into the sampling chamber of the degassing station. In some embodiments, before loading a new battery (e.g., in...) Figure 2B and 3B In steps 2 and 7 shown), the degassing station (e.g., the degassing chamber, sampling chamber, and transfer line to the collection chamber) is emptied. At block 804, an opening is formed in the battery to release formation gases. In some embodiments, the opening is a slit created by piercing the battery. In some embodiments, forming the opening includes activating an actuator to bring a piercing tool into contact with the battery pouch.

[0071] In block 806, a first portion of the formation gas is directed to the collection chamber of the degassing station while preventing the formation gas from escaping. In some embodiments, directing the first portion of the formation gas includes actuating multiple valves to create a path between the sampling chamber and the collection chamber.

[0072] In block 808, after the first portion of the formed gas is directed to the collection chamber, a second portion of the formed gas is discharged. In some embodiments, after the second portion of the formed gas is discharged, the battery is recovered from the sampling chamber.

[0073] At block 810, a first portion of the formation gas is diluted with a dilution fluid. In some embodiments, the dilution fluid comprises air or an inert gas. At block 812, the diluted first portion of the formation gas is directed to a battery quality control gas manifold configured to measure the composition of the battery formation gas.

[0074] In some embodiments, the expansion chamber is connected to the sampling chamber. In other embodiments, the expansion chamber includes a configurable volume.

[0075] In some embodiments, the ratio of the volume of the sampling chamber to the volume of the collection chamber is selected to achieve a predetermined capture volume of the formed gas. In some embodiments, the predetermined capture volume is 0.1 ml to 10 ml under normal temperature and pressure. In some embodiments, the predetermined capture volume is 1 ml under normal temperature and pressure. In some embodiments, a first portion of the formed gas is diluted until a pressure setpoint is reached.

[0076] While the foregoing disclosure has been described with reference to exemplary embodiments, those skilled in the art will understand that various changes can be made without departing from its scope, and equivalents can replace its elements. Furthermore, many modifications can be made to adapt particular situations or materials to the teachings of this disclosure without departing from its essential scope. Therefore, it is intended that this disclosure be limited to the specific embodiments disclosed, but will include all embodiments falling within its scope.

Claims

1. A method for extracting gas from a battery, the method comprising: The battery is loaded into the sampling chamber of the degassing station; An expansion chamber is connected to a sampling chamber, the expansion chamber having a configurable volume; An opening is formed in the battery to release the gaseous material. The first part of the gas is guided to the collection chamber of the degassing station, while preventing the gas from being discharged. The volumes of the sampling chamber and the expansion chamber are variable; The ratio of the volume of the sampling chamber and the expansion chamber to the volume of the collection chamber is selected to achieve a predetermined capture volume for the gasification. After the first part, which has turned into gas, is guided to the collection chamber, the second part, which has turned into gas, is discharged. The first portion, diluted into a gas, is diluted with a diluent. and A first portion of the diluted formation gas is directed to a battery quality control gas manifold, which is configured to measure the composition of the battery formation gas.

2. The method according to claim 1, wherein, The first part of guiding the gasification includes activating multiple valves to create a path between the sampling chamber and the collection chamber.

3. The method according to claim 1, wherein, The diluting fluid includes air or an inert gas.

4. The method of claim 1, further comprising recovering the battery from the sampling chamber after venting the second portion of the formation gas.

5. The method according to claim 1, wherein, Creating an opening involves activating an actuator to bring the piercing tool into contact with the battery.

6. The method according to claim 1, wherein, The predetermined capture volume is 0.1 ml to 10 ml at room temperature and pressure.

7. The method according to claim 1, wherein, The first portion of the gas is diluted to the pressure set point.

Images