WO2025016528A1

WO2025016528A1 - Method of manufacturing a battery electrode assembly

Info

Publication number: WO2025016528A1
Application number: PCT/EP2023/069701
Authority: WO
Inventors: Minglong He; Gabriel SCHULER; Daniel Landmann; Pirmin Troendle
Original assignee: ABB Schweiz AG
Current assignee: ABB Schweiz AG
Priority date: 2023-07-14
Filing date: 2023-07-14
Publication date: 2025-01-23
Anticipated expiration: 2026-01-14

Abstract

A method of manufacturing a battery electrode assembly and a method for manufacturing a battery are described herein. The method of manufacturing the battery electrode assembly includes providing a continuous electrode workpiece; drying the continuous electrode workpiece by conveying a flow of a hydrophilic drying composition past the continuous electrode workpiece; partitioning the continuous electrode workpiece into a plurality of battery electrodes; and stacking or winding the plurality of battery electrodes and a plurality of separators.

Description

METHOD OF MANUFACTURING A BATTERY ELECTRODE ASSEMBLY

TECHNICAL FIELD

[0001] Embodiments of the present disclosure relate to a method of manufacturing a battery electrode assembly and a method for manufacturing a battery.

BACKGROUND

[0002] Currently, different plans have been announced in Europe to build more than 20 battery gigafactories in the coming years. In today’s battery manufacturing, electrode production has been realized in a continuous manner from battery material mixing to electrode slitting, winding or stacking, enclosing and formation.

[0003] Industrial battery cell manufacturing usually includes the following steps: slurry mixing, electrode coating, electrode slitting, electrode drying, electrode separation and electrode stacking, cell assembly (packaging), electrolyte filling, cell formation and end of line tests.

[0004] The most widely used method of drying the coated electrode material is based on a vacuum drying. However, a further continuous process to the end of cell production is disrupted by the vacuum drying step.

[0005] The vacuum drying step focuses on the removal of residual moisture remaining in the electrode material. Illustrative parameters and requirements for the vacuum drying step are: - Working pressure: at least 0.07 mbar and significantly below ambient pressure;

- Drying time: 12 to 30 hours per batch;

- Drying temperature: 60 °C to 150 °C (60 °C for polymer separator, typically >120 °C for electrodes);

Inert gas supply.

[0006] The vacuum drying process is time (up to 30 hours), energy (heating up to 150 °C), and factory volume/area consuming and therefore expensive.

[0007] There is a continuous demand for improved battery manufacturing methods. In particular, there is a need for methods which allow for manufacturing battery electrodes in a continuous manner while reducing costs of manufacture, in particular by reducing the required energy, the required time as well the required space for manufacturing battery electrodes.

SUMMARY

[0008] In light of the above, a method of manufacturing a battery electrode assembly according to independent claim 1 and a method for manufacturing a battery according to claim 15 is provided. Further aspects, advantages, and features are apparent from the dependent claims, the description, and the accompanying drawings.

[0009] According to an aspect of the present disclosure, a method of manufacturing a battery electrode assembly, in particular for a lithium-ion battery, is provided. The method includes a) providing a continuous electrode workpiece, and b) drying the continuous electrode workpiece by conveying a flow of a hydrophilic drying composition past the continuous electrode workpiece. The method further includes c) partitioning the continuous electrode workpiece into a plurality of battery electrodes; and d) stacking or winding the plurality of battery electrodes and a plurality of separators.

[0010] The electrode workpiece may also be referred to as electrode component or electrode material. The electrode workpiece may be regarded as a semi-finished component, which can be used to form the battery electrode in step c).

[0011 ] The term “continuous” electrode workpiece may be understood such that the electrode workpiece extends substantially along at least one dimension (e.g. along a length). In other dimensions, the electrode workpiece may not be substantially extended. The electrode workpiece may therefore be flat and/or have the form of s strip or band. A length of the continuous electrode workpiece may be in range of meters, for example between 1 m and several 100 m. The continuous electrode workpiece may be single- or doubleside coated and have a thickness in the sub-millimetre to millimetre range. A width of the electrode may be between 0.5 m and 3 m.

[0012] The methods disclosed herein allow for carrying out at least steps a) and b), but preferably all steps until partitioning of the electrode workpiece according to step c), in a continuous manner. The methods disclosed herein may allow for a flow production without interruption with the continuous electrode workpiece being in motion while being processed or otherwise treated. In particular, the drying according to step b) may be carried out by continuously conveying the continuous electrode workpiece through a drying assembly or apparatus. It is to be understood that the processing steps, such as the drying step b), may only affect a particular portion of the continuous electrode workpiece at a given point in time, i.e. the portion that is subjected to processing at that point in time.

[0013] The method disclosed herein allows for manufacturing battery electrodes in a continuous manner, thereby reducing the time, energy and factory volume/area consumed compared to prior art approaches, especially compared to vacuum drying based methods. Electrode assemblies and batteries may be produced faster and at lower costs compared to prior art methods by replacing the time-consuming and energy-intensive vacuum drying step. It enables continuous, safe, and cost-effective cell manufacturing.

[0014] Drying according to step b) and likewise other drying steps disclosed herein may also be referred to as extracting residual moisture, and preferably water, from the continuous electrode workpiece.

[0015] Drying according to step b) is carried out by conveying a flow of the hydrophilic drying composition past the continuous electrode workpiece, or in other words by exposing or rinsing the continuous electrode workpiece with a flow of the hydrophilic drying composition. Drying step b) allows for continuously wetting the electrode workpiece with the hydrophilic drying composition. The hydrophilic drying composition may enter pores in the electrode workpiece and dissolve and extract residual water from the electrode workpiece.

[0016] In one embodiment, the flow of the hydrophilic drying composition provided in drying step b) is a pressurised flow. This may allow for speeding up the drying step b).

[0017] Drying step b) may result in a trace water content in the electrode workpiece of around or below 100 ppm. Drying step b) allows for reducing the water content in the electrode workpiece to a level such the electrode workpiece can be used for manufacturing the battery electrode without the need for any further subsequent drying steps. In particular, the method of the present disclosure preferably does not comprise any further drying steps after step b).

[0018] The method of the present disclosure preferably does not include a vacuum drying step. Drying step b) is preferably is carried out essentially at ambient pressure. [0019] Additionally, or alternatively, drying step b) may be carried out without applying any current, e.g. no current is applied to the electrode workpiece. Drying step b) preferably does not include an electrolytic process, and e.g. does not include a counter electrode.

[0020] Additionally, or alternatively, the drying step b) may be carried out at a temperature of below 100°C. Illustratively, drying step b) may be carried out at approximately ambient temperature, e.g. between 15 °C and 30 °C. In another illustrative embodiment, drying step b) may be carried out at a temperature of at least 20°C, preferably at least 30°C or even at least 40 °C and/or at a temperature of below 80 °C, preferably below 60 °C, and more preferably of below 50 °C. For example, the hydrophilic drying composition may be heated and/or the electrode workpiece may be heated, e.g. by means of heated rollers. In one illustrative embodiment, drying step b) may be carried out at a temperature of between 40 °C and 80 °C. Carrying out step b) at an elevated temperature (above room temperature) may accelerate drying step b), e.g. by accelerating electrode wetting and extraction of water from the electrode workpiece.

[0021] Step c) may also be referred to as slitting the continuous electrode workpiece into a plurality of battery electrodes in some embodiments. In step c), the continuous (and dried) electrode workpiece may be partitioned such that the resulting electrodes are appropriately dimensioned to be directly used for preparing the electrode assembly in step d).

[0022] According to an embodiment, the hydrophilic drying composition includes one or more hygroscopic and/or polar solvent(s). The hydrophilic drying composition is preferably anhydrous. In a preferred embodiment, the hydrophilic drying composition includes one or more battery electrolyte solvent(s). Preferably, the one or more battery electrolyte solvent(s) is a lithium ion battery electrolyte solvent. Illustratively, the hydrophilic drying composition may consist of or essentially consist of the one or more battery electrolyte solvent(s). Alternatively, the hydrophilic drying composition used in the electrode drying bath may correspond to a liquid mixture to be included in an assembled battery. For example, the hydrophilic drying composition may further include other electrolyte co-solvents and/or a salt (e.g. LiPF₆).

[0023] The flow of the hydrophilic drying composition, and in particular the flow of the battery electrolyte solvent, may dissolve and extract residual water from the electrode workpiece. Concurrently, it is not necessary to dry the electrode workpiece from residual battery electrolyte solvent. The battery electrode solvent is typically not detrimental, but rather advantageous in the battery assembly or the fully assembled battery. After removing the electrode workpiece from the flow of the hydrophilic drying composition, the electrode workpiece may be left untreated (i.e. no rinsing out or otherwise removal of the hydrophilic drying composition). The hydrophilic drying composition may also be extracted or squeezed out of the continuous electrode workpiece, e.g. by means of rollers. Alternatively, if the particular battery electrolyte solvent is not desired as electrolyte solvent for the battery, an additional heating step may be carried out after step b) to remove excess hydrophilic drying composition.

[0024] The battery electrolyte solvent may be selected from the group consisting of ethylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, propylene carbonate, fluoroethylene carbonate, propylene carbonate and combinations thereof.

[0025] In one embodiment, the battery electrolyte solvent is ethylene carbonate (EC). Optionally, the hydrophilic drying composition may consist of or essentially consist of ethylene carbonate. For example, the ethylene carbonate may be the LP30 electrolyte produced by BASF. Drying step b) may be carried out at a temperature of at least 34 °C, preferably of at least 40 °C and/or at a temperature of no more than 80 °C, preferably no more than 60 °C, and more preferably no more than 50 °C. For example, heating means may be provided to heat the battery electrolyte solvent and/or the electrode workpiece may be heated, e.g. by means of heated rollers.

[0026] After drying step b), residual hydrophilic drying composition remaining on the electrode workpiece may be at least partially extracted or squeezed out of the continuous electrode workpiece, e.g. by means of rollers. The electrode workpiece may subsequently cool down to room temperature, and residual ethylene carbonate may become solid and remain in the pores of the electrode workpiece. In some embodiments, ethylene carbonate may be a major component of the battery. Advantageously, the residual ethylene carbonate need not be removed from the electrode workpiece after drying step b).

[0027] Moreover, conventional battery manufacturing methods include impregnating or wetting the battery electrode stack after arranging or packing the battery electrode stack in a cell housing. The impregnation or wetting time can range from minutes to hours for a lithium-ion battery electrolyte, depending on the specific battery design and manufacturing process. A conventional electrolyte filling step requires vacuum or pressure filling to help the electrolyte impregnation. Embodiments of the methods disclosed herein allow for improving the time efficiency for manufacturing the battery by omitting electrolyte impregnation. Drying step b) may already result in sufficient battery electrolyte solvent impregnation in the electrode pores. This advantage may be realised when using ethylene carbonate as battery electrolyte solvent, but also at least to a certain degree when using any of the other abovementioned battery electrolyte solvents.

[0028] In another embodiment, the battery electrolyte solvent is propylene carbonate (PC). Optionally, the hydrophilic drying composition may consist of or essentially consist of propylene carbonate (PC). Propylene carbonate (PC) has a rather high flash point of 132°C and a rather high autoignition temperature of 455°C, while being liquid at room temperature. Propylene carbonate (PC) as battery electrolyte solvent has the advantage that drying step b) may be carried out at room temperature without the need for providing any heating means in drying step b). The electrode workpiece may preferably be directly further processed according to steps c) and d), e.g. without having to cool down to room temperature. In some cases, the liquid electrolyte solvent (propylene carbonate) may not be desired for subsequent steps c) and d) (e.g. the stacking or winding step d)). An additional heating step may be carried out after step b) to remove excess hydrophilic drying composition, and optionally to recover the hydrophilic drying composition.

[0029] In other embodiments, the hydrophilic drying composition may include a mixture of several battery electrolyte solvents, such as ethylene carbonate (EC) and propylene carbonate (PC).

[0030] According to an embodiment, step b) further includes conveying the continuous electrode workpiece in an electrode drying bath. The electrode drying bath includes the hydrophilic drying composition. Step b) further includes conveying the hydrophilic drying composition through the electrode drying bath. The electrode drying bath may include a housing defining the bath. The housing may contain the hydrophilic drying composition.

[0031] Optionally, a plurality of electrode drying baths may be provided, such as a first and a second electrode drying bath, which may be arranged in sequence. Step b) may include conveying the continuous electrode workpiece in the first electrode drying bath, and then conveying the continuous electrode workpiece in the second electrode drying bath. Step b) may further include conveying or pumping a second hydrophilic drying composition through the second electrode drying bath. The second hydrophilic drying composition may preferably be different from the (first) hydrophilic drying composition. Further aspects described herein for the (first) electrode drying bath are correspondingly applicable for the second electrode drying. [0032] The electrode drying bath may include a first plurality of rollers to move or convey the electrode workpiece through the electrode bath. Step b) may further include conveying or moving the continuous electrode workpiece in the electrode drying bath by means of the first plurality of rollers. Additionally, the electrode drying bath may include a plurality of rollers for immersing or inserting the upstream portion of the continuous electrode workpiece into the electrode drying bath. The term upstream in this context refers to the movement of the electrode workpiece. Typically, the rollers may move or convey the electrode workpiece in an approximately sinusoidal manner.

[0033] Step b) may further include removing or lifting out a downstream portion of the continuous electrode workpiece from the electrode drying bath and/or extracting hydrophilic drying composition out of the downstream portion of the continuous electrode workpiece by means of a second plurality of rollers. The second plurality of rollers may squeeze out residual hydrophilic drying composition from the electrode workpiece. The step of extracting hydrophilic drying composition out of the continuous electrode workpiece may be carried out during or after removal of the downstream portion from the electrode drying bath.

[0034] The electrode drying bath may include an inlet for supplying the hydrophilic drying composition and an outlet for draining or discharging the hydrophilic drying composition. The inlet and the outlet may be formed in the housing of the electrode drying bath. The inlet may be arranged in a downstream portion or exit portion of the electrode drying bath, and/or the outlet may be arranged in an upstream portion or entry portion of the electrode drying bath.

[0035] The electrode drying bath may further include one or more pumps for conveying or pumping the hydrophilic drying composition past the electrodes. The one or more pumps may allow for providing a pressurised flow or rinsing of the hydrophilic drying composition in step b). This may allow for speeding up the drying step b).

[0036] After exiting through the outlet of the electrode drying bath, the hydrophilic drying composition may be disposed of. Alternatively, the hydrophilic drying composition may be reused by recirculating the hydrophilic drying composition through the electrode drying bath. The electrode drying bath may include a recirculation line for recirculating the hydrophilic drying composition. The recirculation line may be connected to the inlet and the outlet of the electrode drying bath.

[0037] After circulating the hydrophilic drying composition one or more times through the electrode drying bath, the water content in the hydrophilic drying composition may become too high to efficiently extract residual water from the electrode workpiece. The recirculation line may include a drying means, in particular a desiccant, for removing water from the hydrophilic drying composition. The recirculation line may include a container or a compartment having the drying means stored therein. For example, the drying means may be configured to remove water from the hydrophilic drying composition based on a chemical reaction or based on physical interaction (e.g. absorption), or alternatively based on thermal or thermo-chemical regeneration approaches. The drying means may remove a sufficient amount of water such that the hydrophilic drying composition can effectively continue to extract residual water from the electrode workpiece when being recirculated. The drying means may be replaced or regenerated on a regular basis. Additionally, or alternatively, the electrode drying bath may include the drying means.

[0038] The drying means may be a drying agent selected from the group consisting of a molecular sieve, silica gel, calcium hydride, a lithium metal and combinations thereof. Additionally, or alternatively, the drying means may include thermodynamic processing. [0039] The electrode workpiece provided in step a) is preferably an electrode workpiece for a lithium ion electrode assembly or a lithium ion battery. The electrode workpiece may correspond to an anode workpiece for forming an anode or to a cathode workpiece for forming a cathode.

[0040] The method of manufacturing the battery electrode assembly disclosed herein may be used to form a plurality of anodes and cathodes. Steps a) to c) of the method disclosed herein may be carried out separately for each of the continuous anode workpiece and a continuous cathode workpiece.

[0041] The method may include: a) Providing a continuous cathode workpiece and providing a continuous anode workpiece; b) Drying the continuous cathode workpiece by conveying a flow of a first hydrophilic drying composition past the continuous cathode workpiece; and drying the continuous anode workpiece by conveying a flow of a second hydrophilic drying composition past the continuous anode workpiece; c) Partitioning the continuous cathode workpiece into a plurality of battery cathodes; and partitioning the continuous anode workpiece into a plurality of battery anodes.

Steps a) to c) may be carried out according to any embodiment described herein. The first and second hydrophilic drying composition may be the same or may be different, e.g. different battery electrolyte solvents may be used.

[0042] The method may further include step d) stacking or winding the plurality of battery anodes, a plurality of separators, and the plurality of battery cathodes.

[0043] Step a) providing a continuous electrode workpiece may include one or more sub-steps as described in more detail below. [0044] Step a) may include a sub-step al) Providing a blank continuous electrode workpiece. In case the continuous electrode workpiece is a continuous cathode workpiece, the blank continuous cathode workpiece may be formed of aluminium (Al). In case the continuous electrode workpiece is a continuous anode workpiece, the blank continuous anode workpiece may be formed of copper (Cu) or aluminium (Al).

[0045] Step a) may include a sub-step a2) Manufacturing a slurry. Substep a2) may be carried out before, during or after sub-step al). The slurry may include an active component for forming the anode or cathode. In case the continuous electrode workpiece is a continuous cathode workpiece, the active component may be LiCoO₂. In case the continuous electrode workpiece is a continuous anode workpiece, the active component may be graphite. The slurry may further include one or more, preferably all, of a conductive additive (e.g. carbon black), a polymeric binder (e.g. PVDF), and a solvent (e.g. NMP, water).

[0046] Step a) may include a sub-step a3) Coating the blank continuous electrode workpiece with the slurry.

[0047] The method may further include a step e) Heating the continuous electrode workpiece. Heating step e) may be regarded as a second drying step, to reduce a water content of the continuous electrode workpiece and in particular to cure the coating. Step e) is preferably carried out before drying step b). Step e) may alternatively be regarded as part of step a), corresponding to a sub-step a4). Step e) is preferably carried out after step a), and in particular after sub-step a3). For example, the method may include a coating line for carrying out sub-step a3), and a furnace may be equipped with the coating line. Alternatively, the heating step e) may be carried out by means of infrared radiation or hot air blowing.

[0048] The method may further include a step f) Calendaring the continuous electrode workpiece. Step f) may be preferably carried out before step b) and/or after steps a) and e). Step f) may alternatively be regarded as part of step a), corresponding to a sub-step a5). Sub-step a5) may be carried out after sub-step a4). Alternatively, calendaring may be carried out several times in a step-wise manner. For example, step f) may be carried out before drying step b) and after drying step b).

[0049] According to an embodiment, the method includes step g) drying one or more separators by conveying a flow of a hydrophilic drying composition past the separators. Separators useful for assembling the battery electrode assembly disclosed herein are typically formed of a polymeric material and have a porous structure. The porous structure can adsorb moisture. Therefore, the separators may be dried before being used in step d) to reduce the residual water content in the separators. Step g) may be carried out by drying the one or more separators in the same electrode drying bath with the same hydrophilic drying composition as in drying step b). Alternatively, a separator drying bath may be provided and filled with a (third) hydrophilic drying composition. The third hydrophilic drying composition may be different than the (first) hydrophilic drying composition.

[0050] According to an embodiment, step b) further includes Monitoring a residual water content of the hydrophilic drying composition and/or the continuous electrode workpiece. Determining the water content of the hydrophilic drying composition may be indicative of the residual water content of the electrode workpiece. The monitoring is preferably a real time monitoring. Typically, the monitoring allows for providing information on the water content of one particular portion of the electrode workpiece (for example, other portions of the electrode workpiece may not be immersed in the electrode drying bath).

[0051] The monitoring may include recording, with one or more sensors, a signal associated with the residual water content of the electrode workpiece. For example, monitoring may be carried out based on Karl Fischer titration, and the sensor may be an automated Karl Fischer titrator. Alternatively, monitoring may be carried out based on a spectroscopy technique, e.g. based on absorption spectroscopy. The electrode drying bath may include a tube at the downstream portion or exit portion of the electrode drying bath. The tube may allow for extracting a test sample to be used for recording the signal with the one or more sensors. Alternatively, the electrode drying bath may include several tubes, e.g. a first tube at the upstream portion or entry portion of the electrode drying bath and a second tube at the downstream portion or exit portion of the electrode drying bath. Having several tubes may allow for monitoring progress in the drying of the electrode workpiece. Alternatively, the residual water content may be monitored in the recirculation line, for example upstream or downstream of the drying means or upstream or downstream of the compartment containing the drying means.

[0052] The monitoring may further include analysing, with a controller, the signal to determine the residual water content of the continuous electrode workpiece. The method may further include displaying the residual water content of the continuous electrode workpiece on a display device and/or transmitting the residual water content of the continuous electrode workpiece to an external control system for monitoring and controlling the drying step b).

[0053] The monitoring may further include comparing the residual water content of the continuous electrode workpiece with a predetermined threshold water content. If the residual water content is below the predetermined threshold water content, it may be concluded that the residual water content in the particular portion is sufficiently low to continue manufacturing the battery electrode assembly. The method may therefore proceed with step c).

[0054] If the residual water content is at or above a threshold water content, it may be concluded that the residual water content in the particular portion is too high to continue manufacturing the battery electrode assembly according to step c).

[0055] If the residual water content is at or above a threshold water content, the method may include repeating step b) until the water content is below the threshold water content. In one exemplary embodiment, the method includes repeatedly conveying the continuous electrode workpiece in the first electrode drying bath until the water content is below the threshold water content. In another exemplary embodiment, the method includes conveying the continuous electrode workpiece in a second electrode drying bath, and conveying a second hydrophilic drying composition through the second electrode drying bath. Preferably, the second hydrophilic drying composition is different from the (first) hydrophilic drying composition. The method may also include repeatedly conveying the continuous electrode workpiece in the first electrode drying bath and subsequently in the second electrode drying bath until the water content is below the threshold water content.

[0056] In another exemplary embodiment, if the residual water content is at or above a threshold water content, the particular portion of the electrode workpiece may be marked or labelled as not for use to form the electrode assembly. For example, after partitioning in step c), the particular portion having a water content at or above the threshold water content may be sorted out and not used for forming the electrode assembly in step d).

[0057] Step d) includes forming the battery electrode assembly. The battery electrode assembly may be directly used for forming a battery without the need to carry out further processing steps for the battery electrode assembly. Step d) may include forming a battery electrode stack by stacking the plurality of electrodes and a plurality of separators. The battery electrode stack may include several cathodes, anodes and separators (separator layers). As described further above, the method may be carried out to form a plurality of cathodes or a plurality of anodes, or may be carried out form both a plurality of cathodes and a plurality of anodes.

[0058] According to another aspect of the present disclosure, a method for manufacturing a battery, in particular a lithium-ion battery, is provided. The method includes A) Manufacturing the battery electrode assembly according to any embodiment disclosed herein; and B) Arranging the battery electrode assembly in a cell housing.

[0059] The method may further include step C) Filling the cell housing with a liquid mixture including a battery electrolyte solvent. The battery electrolyte solvent used in step C) may be the same solvent as used in step b) (of step A)). Alternatively, a different battery electrolyte solvent may be used in step C). Step C) may be carried out after step B). The liquid mixture may further include other electrolyte co-solvents and/or a salt (e.g. LiPF₆). Preparing the liquid mixture and filling the cell housing with the liquid mixture can be carried out within a few minutes, thereby substantially reducing the time required compared to prior art manufacturing methods, which require a timeconsuming vacuum or pressure filling for impregnating the electrodes with electrolytes.

[0060] Alternatively, if the electrode drying bath is already filled with the same battery electrolyte solvent desired for filling the cell housing, the electrode may already be fully wetted and step C) may also be omitted. Step C) may be partially omitted if only a certain salt is added to the battery electrolyte solvent. In this case, the method may include the step of wetting the plurality of separators before step c). The electrode assembly formed in step d) (of step A) may already include wetted electrodes and separators. The hydrophilic drying composition used in the electrode drying bath may correspond to the liquid mixture to be included in the assembled battery.

[0061] The method may further include finalising cell formation, such as closing off the battery cell housing and setting up all electrical connections. [0062] The method may further include carrying out end of line tests.

[0063] Those skilled in the art will recognise additional features and advantages upon reading the following detailed description, and upon viewing the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0064] The components in the Figures are not necessarily to scale, instead emphasis being placed upon illustrating the principles of the invention. Moreover, in the Figures, like reference signs designate corresponding parts. The accompanying drawings relate to embodiments of the disclosure and are described in the following:

Fig. 1 shows a schematic view of an electrode drying bath according to embodiments described herein;

Fig. 2 shows a schematic view of an electrode drying bath according to embodiments described herein;

Fig. 3 is a block diagram illustrating a method of manufacturing a battery electrode assembly according to embodiments described herein;

Fig. 4 is a block diagram illustrating a method of manufacturing a battery electrode assembly according to embodiments described herein;

Fig. 5 is a block diagram illustrating a method for manufacturing a battery according to embodiments described herein.

DETAILED DESCRIPTION OF EMBODIMENTS

[0065] Reference will now be made in detail to the various embodiments, one or more examples of which are illustrated in each figure. Each example is provided by way of explanation and is not meant as a limitation. For example, features illustrated or described as part of one embodiment can be used on or in conjunction with any other embodiment to yield yet a further embodiment. It is intended that the present disclosure includes such modifications and variations.

[0066] Within the following description of the drawings, the same reference numbers refer to the same or to similar components. Generally, only the differences with respect to the individual embodiments are described. Unless specified otherwise, the description of a part or aspect in one embodiment can apply to a corresponding part or aspect in another embodiment as well.

[0067] With exemplary reference to Fig. 1, an electrode drying bath 100 is described. The electrode drying bath 100 includes a housing defining a bath containing a hydrophilic drying composition.

[0068] The electrode drying bath 100 includes an inlet 103 for providing the hydrophilic drying composition and an outlet 104 for draining the hydrophilic drying composition. The electrode drying bath may further include one or more pumps (not shown) for conveying or pumping the hydrophilic drying composition through the electrode drying bath 100. The arrows indicate the direction of flow of the hydrophilic drying composition. The hydrophilic drying composition exiting via the outlet 104 may be disposed of or recovered and recycled for potential reuse at a later stage.

[0069] The electrode drying bath 100 further includes a first plurality of rollers 101A-101G for conveying or moving a continuous electrode workpiece 200 through the electrode drying bath 100. The first plurality of rollers 101 A-101G may be arranged in the electrode drying bath 100 such that the electrode workpiece 200 is moved in an approximately sinusoidal manner.

[0070] The electrode drying bath 100 further includes a second plurality of rollers 102A-102B. The second plurality of rollers 102A-102B may be provided to remove or lift out a downstream portion of the continuous electrode workpiece 200 from the electrode drying bath 100 and/or extract or squeeze out hydrophilic drying composition from the downstream portion of the continuous electrode workpiece 200.

[0071] With exemplary reference to Fig. 2, an electrode drying bath 300 according to another embodiment is described. Electrode drying bath 300 largely corresponds to the electrode drying bath 100 apart from specifically described differences. The electrode drying bath 300 includes a recirculation line 305 for recirculating the hydrophilic drying composition. The recirculation line 305 may be connected to the inlet 103 and the outlet 104 of the electrode drying bath 300.

[0072] The recirculation line 305 may include a drying means 306, in particular a desiccant, for removing water from the hydrophilic drying composition. The recirculation line 305 may include a container or a compartment having the drying means 306 stored therein. The drying means 306 may remove sufficient amount of water such that the hydrophilic drying composition can effectively continue to extract residual water from the electrode workpiece 200 when being recirculated. The drying means 306 may be replaced or regenerated on a regular basis. The drying means may also be configured to remove water from the hydrophilic drying composition by thermodynamic processing.

[0073] The electrode drying bath 300 may further include means 307 for monitoring a residual water content. For example, the means 307 may be an automated Karl Fischer titrator. In the example shown in Figure 1, means 307 is positioned at a downstream portion or exit portion of the electrode drying bath 300. Alternatively, the residual water content may be monitored in the recirculation line, for example upstream or downstream of the drying means 306. [0074] With reference to the block diagram in Fig. 3, a method 400 of manufacturing a battery electrode assembly, in particular for a lithium-ion battery according to embodiments described herein is provided. Method 400 includes steps 410-440: step 410 providing a continuous electrode workpiece (200); step 420 drying the continuous electrode workpiece by conveying a flow of a hydrophilic drying composition past the continuous electrode workpiece, step 430 separating the continuous electrode workpiece into a plurality of battery electrodes; and step 440 stacking or winding the plurality of battery electrodes and a plurality of separators.

[0075] With reference to the block diagram in Fig. 4, a method 500 of manufacturing a battery electrode assembly, in particular for a lithium-ion battery according to embodiments described herein is provided. Steps 420, 430 and 440 of method 500 correspond to steps 420, 430 and 440 of method 400. Furthermore, method 500 includes steps 511, 512 and 513 before step 420: step 511 providing a blank continuous electrode workpiece; step 512 manufacturing a slurry; and step 513 coating the blank continuous electrode workpiece with the slurry. Steps 511 and 512 are carried out before step 513. Step 511 may be executed before, during or after step 512.

[0076] Optionally, the method 500 may further include step 514 heating the continuous electrode workpiece. Step 514 is carried out after step 513 and before step 420.

[0077] Optionally, the method 500 may further include step 515 calendaring the continuous electrode workpiece. Step 515 may be preferably carried out after step 514. Step 515 may be carried out before or after step 420, preferably before step 420.

[0078] With reference to the block diagram in Fig. 5, a method 600 for manufacturing a battery, in particular a lithium-ion battery, according to embodiments described herein is provided. Method 600 includes manufacturing the battery electrode assembly according to method 400 or method 500 or any other method of manufacturing a battery electrode assembly disclosed herein.

[0079] Method 600 further includes step 610 arranging the battery electrode assembly in a cell housing.

[0080] Optionally, method 600 further includes step 620 filling the cell housing with a liquid mixture including a battery electrolyte solvent.

[0081] While the foregoing is directed to embodiments, other and further embodiments may be devised without departing from the basic scope, and the scope is determined by the claims that follow.

REFERENCE NUMERALS

100, 300 electrode drying bath

101A-101G first plurality of rollers

102A-102B second plurality of rollers

103 inlet

104 outlet

200 continuous electrode workpiece

305 recirculation line

306 drying means

307 means for monitoring a residual water content

Claims

1. Method (400, 500) of manufacturing a battery electrode assembly, in particular for a lithium-ion battery, the method comprising the following steps: a) Providing (410) a continuous electrode workpiece (200); b) Drying (420) the continuous electrode workpiece by conveying a flow of a hydrophilic drying composition past the continuous electrode workpiece; c) Partitioning (430) the continuous electrode workpiece into a plurality of battery electrodes; d) Stacking or winding (440) the plurality of battery electrodes and a plurality of separators.

2. The method of claim 1, wherein step b) further includes conveying the continuous electrode workpiece in an electrode drying bath (100), and conveying the hydrophilic drying composition through the electrode drying bath.

3. The method of claim 2, wherein step b) further includes conveying the continuous electrode workpiece in the electrode drying bath by means of a first plurality of rollers (101 A-101G).

4. The method of claim 2 or 3, wherein step b) further includes removing a downstream portion of the continuous electrode workpiece from the electrode drying bath and extracting hydrophilic drying composition out of the continuous electrode workpiece by means of a second plurality of rollers (102 A, 102B).

5. The method of any one of claims 2 to 4, wherein the electrode drying bath includes an inlet (103) for supplying the hydrophilic drying composition and an outlet (104) for discharging the hydrophilic drying composition.

6. The method of any one of claims 2 to 5, wherein the electrode drying bath includes a recirculation and recovery line (305) for recirculating the hydrophilic drying composition, preferably including the inlet and the outlet.

7. The method of any one of claims 2 to 6, wherein the recirculation line includes a drying means (306) for removing water from the hydrophilic drying composition.

8. The method of claim 7, wherein the drying means is a drying agent selected from the group consisting of a molecular sieve, silica gel, calcium hydride, a lithium metal and combinations thereof, and/or the drying means includes thermodynamic processing.

9. The method of any preceding claim, wherein the hydrophilic drying composition includes a battery electrolyte solvent.

10. The method of claim 9, wherein the battery electrolyte solvent is selected from the group consisting of ethylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, propylene carbonate, fluoroethylene carbonate, propylene carbonate and combinations thereof, preferably wherein the battery electrolyte solvent is ethylene carbonate and/or propylene carbonate.

11. The method of any preceding claim, wherein step b) further includes:

Monitoring a residual water content of the hydrophilic drying composition and/or the continuous electrode workpiece.

12. The method of claim 11, further including, if the residual water content is at or above a threshold water content, repeating step b) until the water content is below the threshold water content; wherein step b) further includes conveying the continuous electrode workpiece in a second electrode drying bath (100), and conveying a second hydrophilic drying composition through the second electrode drying bath, optionally wherein the second hydrophilic drying composition is different from the hydrophilic drying composition.

13. The method of any preceding claim, further comprising the step: e) Heating (514) the continuous electrode workpiece; wherein step e) is carried out after step a) and before step b).

14. The method of any preceding claim, further comprising the step: f) Calendaring (515) the continuous electrode workpiece; wherein step f) is preferably carried out before step b), and/or after step e).

15. Method (600) for manufacturing a battery, in particular a lithium-ion battery, including:

A) Manufacturing (400, 500) the battery electrode assembly according to any preceding claim;

B) Arranging (610) the battery electrode assembly in a cell housing.