PRISMATIC SECONDARY BATTERY CELL AND METHOD FOR PRODUCING A SECONDARY BATTERY CELL

Abstract

A secondary battery cell comprises a battery cell casing, an electrolyte, and an electrode assembly. The electrode assembly includes a cathode with a cathode region, an anode, a separator (i) with an anode-facing side and a cathode-facing side, (ii) with a bonding region on the cathode-facing side and entirely outside the cathode region, and (iii) designed to physically separate the cathode and the anode, and an adhesive strip applied exclusively to the cathode-facing side of the separator. The cathode is either partially or completely enclosed by the separator. The adhesive strip is located entirely within the bonding region. Two segments of the adhesive strip on opposite sides of the cathode are bonded together.

Description

INTRODUCTION

[0001] The present invention relates to a secondary battery cell and a method for manufacturing a prismatic secondary battery cell.

[0002] For general background information, reference is made in advance to the publications DE 10 2016 218 496 A1, DE 10 2019 216 043 A1 and DE 10 2021 200 586 A1.

[0003] Lithium-ion battery cells describe a class of rechargeable battery cells in which lithium ions move between a negative electrode (i.e., anode) and a positive electrode (i.e., cathode). Liquid and polymeric electrolytes can facilitate the movement of lithium ions between the anode and the cathode. Lithium-ion battery cells are becoming increasingly popular for applications in the automotive and aerospace industries due to their increasing energy storage density and ability to undergo successive charge and discharge cycles.

[0004] Accordingly, experts are continuing their research and development efforts in the field of prismatic secondary battery cell designs to improve energy storage density. SUMMARY

[0005] According to the invention, a secondary battery cell is presented which is characterized by the features of claim 1.

[0006] The secondary battery cell comprises a battery cell casing, an electrolyte arranged within the battery cell casing, and an electrode assembly arranged within the battery cell casing. The electrode assembly comprises a cathode with a cathode region, an anode, a separator (i) with a side facing the anode and a side facing the cathode, (ii) with a bonding region on the side facing the cathode and entirely outside the cathode region, and (iii) designed to physically separate the cathode and the anode, and an adhesive strip applied exclusively to the side of the separator facing the cathode. The cathode is either partially or completely enclosed by the separator. The adhesive strip is located entirely within the bonding region. Two segments of the adhesive strip on opposite sides of the cathode are bonded together.

[0007] In one or more embodiments of the secondary battery cell, the separator is in direct physical contact with the anode and the cathode.

[0008] In one or more embodiments of the secondary battery cell, the battery cell housing is a prismatic metal casing. A pair of electrical terminals is arranged in a common plane along one side of the prismatic metal casing. The pair of electrical terminals has a terminal height. The casing height of the prismatic metal casing is between approximately 100 mm and approximately 110 mm, excluding the terminal height of the pair of electrical terminals. The casing width of the prismatic metal casing is between approximately 250 mm and approximately 300 mm.

[0009] In one or more embodiments of the secondary battery cell, the ratio between the cathode height of the cathode and the housing height of the prismatic metal housing is greater than 0.874 to 1.

[0010] In one or more embodiments of the secondary battery cell, the cathode, the anode, and the separator are arranged in a Z-shaped folded stack. A plurality of tabs is (i) connected to the cathode and the anode and (ii) arranged in a plane parallel to a position of the pair of electrical terminals.

[0011] In one or more embodiments of the secondary battery cell, the secondary battery cell has a nominal voltage between approximately 3.63 volts and approximately 3.66 volts, while the energy is measured between a maximum and a minimum voltage of the secondary battery cell. The cathode has a specific air capacity load between approximately 4.95 milliampere-hours per square centimeter and approximately 5.4 milliampere-hours per square centimeter. The specific capacity of the cathode active material is at least approximately 195 milliampere-hours per gram, measured at a rate of 1 / 10 Celsius at 25 degrees Celsius. The thickness of the cathode current collector is between approximately 10 micrometers and approximately 14 micrometers. The anode active material comprises graphite and silicon dioxide. The weight fraction of silicon dioxide in the anode is less than 6 percent.

[0012] In one or more embodiments of the secondary battery cell, the cathode and the anode contain a plurality of carbon nanotubes. The plurality of carbon nanotubes does not exceed at least (i) 0.2 percent by weight for the anode and (ii) 1.2 percent by weight for the cathode.

[0013] In one or more embodiments of the secondary battery cell, the secondary battery cell has a nominal voltage between approximately 3.67 volts and approximately 3.71 volts, while the energy is measured between a maximum and a minimum voltage of the secondary battery cell. A cathode has a specific air capacitance load between approximately 4.95 milliampere-hours per square centimeter and approximately 5.4 milliampere-hours per square centimeter. The specific capacitance of the cathode material is at least approximately 195 milliampere-hours per gram, measured at a rate of 1 / 10 Celsius at 25 degrees Celsius. The anode active material is graphite.

[0014] In one or more embodiments of the secondary battery cell, the electrode arrangement contains between at least 70 and at most 85 layers of the cathode.

[0015] In one or more embodiments of the secondary battery cell, the binding area width of the binding area in the separator is less than approximately 2 millimeters.

[0016] According to the invention, a method for manufacturing a secondary battery cell is further presented, which is characterized by the features of claim 10.

[0017] The method comprises applying an adhesive strip exclusively to one cathode-facing side of a separator. The separator (i) has an anode-facing side and a cathode-facing side, (ii) has a bonding region on the cathode-facing side that is entirely outside the cathode region of a plurality of cathodes, and (iii) is designed to physically separate the plurality of cathodes and a plurality of anodes. The plurality of cathodes is either partially or completely enclosed by the separator. The adhesive strip is entirely within the bonding region. The method further comprises placing the separator on a base plate, placing a first anode of the plurality of anodes on the separator, folding the separator over the first anode, and placing a first cathode of the plurality of cathodes on the separator opposite the first anode.Folding the separator over the first cathode, applying force to the separator in the bonding area to join two segments of the adhesive strip on opposite sides of the first cathode, placing a second anode or the plurality of anodes on the separator opposite the first cathode, folding the separator over the second anode, placing a second cathode or the plurality of cathodes on the separator opposite the second anode, applying force to the separator in the bonding area to join two additional segments of the adhesive strip on opposite sides of the second cathode, wrapping the plurality of cathodes and the plurality of anodes with the separator to form an electrode assembly, arranging the electrode assembly in a battery cell housing, and arranging an electrolyte in the battery cell housing.

[0018] In one or more embodiments of the method, the separator is in direct physical contact with the plurality of anodes and the plurality of cathodes.

[0019] In one or more embodiments of the method, the plurality of cathodes, the plurality of anodes and the separator are arranged in a Z-shaped folded stack.

[0020] In one or more embodiments of the method, the battery cell housing is a prismatic metal housing.

[0021] In one or more embodiments, the method comprises attaching a pair of electrical terminals in a common plane along one side of the prismatic metal housing. The pair of electrical terminals has a terminal height.

[0022] In one or more embodiments, the method comprises connecting the plurality of cathodes and the plurality of anodes to the pair of electrical terminals.

[0023] In one or more embodiments of the method, the housing height of the prismatic metal housing is between approximately 100 millimeters and approximately 110 millimeters, excluding the height of the pair of electrical terminals. The housing width of the prismatic metal housing is between approximately 250 millimeters and approximately 300 millimeters.

[0024] In one or more embodiments of the method, the ratio between the cathode height of the plurality of cathodes and the housing height of the prismatic metal housing is greater than 0.874 to 1.

[0025] In one or more embodiments of the method, the electrode arrangement contains between at least 70 and at most 85 layers of the plurality of cathodes.

[0026] A vehicle is provided here. The vehicle includes a battery pack with a plurality of secondary battery cells. At least one of the secondary battery cells comprises a battery cell casing, an electrolyte arranged within the battery cell casing, and an electrode assembly arranged within the battery cell casing. The electrode assembly comprises a cathode with a cathode region, an anode, a separator (i) with a side facing the anode and a side facing the cathode, (ii) with a bonding region on the side facing the cathode and entirely outside the cathode region, and (iii) designed to physically separate the cathode and the anode, and an adhesive strip applied exclusively to the side of the separator facing the cathode. The cathode is either partially or completely enclosed by the separator. The adhesive strip is located entirely within the bonding region.Two segments of the adhesive strip on opposite sides of the cathode are connected to each other.

[0027] The above-mentioned features and advantages, as well as other features and advantages of the present invention, are readily apparent from the following detailed description of the best ways of carrying out the invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a schematic plan diagram that illustrates the context of a system. Fig. Figure 2 is a schematic cross-sectional diagram of a prismatic secondary battery cell according to one or more exemplary embodiments. Fig. Figure 3 is a schematic cross-sectional diagram of a sequence of cathode conversion during manufacturing according to one or more exemplary embodiments. Fig.Figure 4 is a schematic perspective diagram of a process for assembling a secondary battery cell according to one or more exemplary embodiments. Fig. Figure 5 is a schematic cross-sectional diagram of a processing method according to one or more exemplary embodiments. Fig. Figure 6 is a schematic side view diagram of an electrode arrangement according to one or more exemplary embodiments. Fig. Figure 7 is another schematic side view diagram of the electrode arrangement according to one or more exemplary embodiments. Fig. Figure 8 is a schematic perspective diagram of an unfolded electrode arrangement according to one or more exemplary embodiments. Fig. Figure 9 is a flowchart of a process for manufacturing a secondary battery cell according to one or more exemplary embodiments. DETAILED DESCRIPTION

[0028] Embodiments of the invention generally provide a prismatic secondary battery cell with an increased energy density compared to existing prismatic battery cells. A battery cell arrangement within the prismatic secondary battery cell increases the electrode size within a protective (e.g., metallic) prismatic housing. The increased electrode size can be achieved by reducing the overhang dimension of a separator between adjacent electrodes. An adhesive layer at the overhang positions of the separator in composite electrodes, followed by a bonding process of the layers formed by the separator after completion of the electrode arrangement process, generally enables the reduction of the separator overhang in the battery electrode arrangement.The bonded layers of the separator generally improve resistance to short circuits due to plating and bridging across the separator if the separator is folded or torn due to problems in the manufacturing process.

[0029] With reference to Fig.Figure 1 shows a schematic diagram illustrating the context of a system. The system can implement a vehicle 60. The vehicle 60 generally comprises a battery pack 70, a wiring harness 90, a controller 92, and a motor 94. The battery pack 70 can include a positive battery pack terminal 76 and a negative battery pack terminal 78. For illustrative purposes, the front of the vehicle 60 can be oriented in the positive X direction. A right side of the vehicle 60 (viewed from above) can be oriented in the positive Y direction. The positive Y direction can be perpendicular to the positive X direction.

[0030] Vehicle 60 can include, among other things, mobile objects such as a passenger car, a truck, an autonomous vehicle, a gas-powered vehicle, an electric vehicle, a hybrid vehicle, a motorcycle, a boat, an agricultural vehicle, a train, and / or an aircraft. In some embodiments, Vehicle 60 can include stationary objects such as billboards, kiosks, and / or marquees. Other Vehicle 60 types can also be implemented to meet the design criteria of a particular application.

[0031] The battery pack 70 can implement a high-voltage battery pack designed for storing electrical energy. The battery pack 70 is generally capable of receiving electrical power from the controller 92 and supplying electrical power to the controller 92. The battery pack 70 can comprise multiple battery modules connected electrically in series and / or parallel between the positive battery pack terminal 76 and the negative battery pack terminal 78. In various embodiments, the battery pack 70 can provide an electrical potential of approximately 400 to 800 volts DC (direct current) between the positive battery pack terminal 76 and the negative battery pack terminal 78. Other battery voltages can be implemented to meet the design requirements of a specific application.The positive battery pack terminal 76 and the negative battery pack terminal 78 can be physically and electrically connected to the wiring harness 90.

[0032] The wiring harness 90 can implement an electrical wiring harness. The wiring harness 90 is generally capable of transmitting electrical power between the controller 92 and the battery pack 70. In a charging mode, the wiring harness 90 can transfer electrical power from the controller 92 to the battery pack 70. In a discharging mode, electrical power can flow along the wiring harness 90 from the battery pack 70 to the controller 92.

[0033] The controller 92 can implement battery control. The controller 92 is generally operable to transfer electrical power to the battery pack 70 in charging mode. The controller 92 can draw electrical power from the battery pack 70 in discharging mode. The electrical power received from the battery pack 70 can be used to drive the motor 94 and / or other consumers within the vehicle 60.

[0034] The motor 94 can incorporate an electric motor. The motor 94 is generally capable of providing rotation and torque to the drive wheels of the vehicle 60. The electrical power consumed by the motor 94 can be supplied by the battery pack 70 and / or an AC generator of the vehicle 60 under the control of the controller 92.

[0035] With reference to Fig.Figure 2 shows a schematic cross-sectional diagram of an exemplary implementation of a prismatic secondary battery cell 100 according to one or more exemplary embodiments. Several prismatic secondary battery cells 100 can be located in the battery pack 70 to receive electrical power, store electrical energy, and supply electrical power to the vehicle 60. In various embodiments, the prismatic secondary battery cell 100 comprises a battery cell housing 110, several (e.g., two) electrical terminals 112a-112b, and an electrode assembly 114. The electrode assembly 114 generally comprises one or more cathodes 120, one or more anodes 130, a separator 140, and an adhesive strip 150.

[0036] The battery cell housing 110 incorporates a sealed enclosure. The battery cell housing 110 is arranged to accommodate the cathodes 120, the anodes 130, the separator 140, and the adhesive strip 150. In various embodiments, the battery cell housing 110 can be a prismatic metal housing 110a. The housing height of the battery cell housing 110 / prismatic metal housing 110a can be between approximately 100 millimeters (mm) and approximately 110 mm (e.g., 103 mm), excluding the connection height of the pair of electrical terminals 112a-112b. The housing width of the battery cell housing 110 / prismatic metal housing 110a is between approximately 250 mm and approximately 300 mm (e.g., 260 mm). The housing width of the battery cell housing 110 / prismatic metal housing 110a is between approximately 25 mm and approximately 36 mm.

[0037] The electrical terminals 112a-112b implement a pair of battery terminals. The electrical terminals 112a-112b can be operated as a positive terminal and a negative terminal. The electrical terminals 112a-112b are arranged in a common plane 116 along a side 118 (e.g., a top surface, as shown in the figure) of the battery cell housing 110. The pair of electrical terminals 112a-112b has a terminal height 119.

[0038] The electrode assembly 114 implements a logical arrangement of the cathodes 120, the anodes 130, the separator 140, and the adhesive strip 150. The electrode assembly 114 generally provides a mechanical support for the cathodes 120, the anodes 130, the separator 140, and the adhesive strip 150. The electrode assembly 114 is operable to contain an electrolyte 160. The electrode assembly 114 can contain between a minimum of 70 and a maximum of 85 layers of cathodes and a similar number of anodes.

[0039] In various embodiments, the electrode arrangement 114 can be formed wholly or partially by the battery cell housing 110.

[0040] The cathodes 120 implement parts of electrochemical cells. During the discharge of the prismatic secondary battery cell 100, ions can migrate from the anodes 130 to the cathodes 120. The cathodes 120 have a generally rectangular shape that defines a cathode area.

[0041] The anodes 130 implement opposite parts of the electrochemical cells. During the charging process of the prismatic secondary battery cell 100, ions can migrate from the cathodes 120 to the anodes 130. The anodes 130 have a generally rectangular shape that defines an anode area. The anode area may be distinct from or identical to the cathode area.

[0042] Separator 140 incorporates an ion-permeable membrane. It is designed to physically separate the cathodes 120 and the anodes 130. Separator 140 is operable to conduct ions during charging and discharging and, optionally, to conduct molecules of the electrolyte 160 (e.g., a liquid electrolyte). In various embodiments, separator 140 has an anode-facing side that faces the anodes 130 and a cathode-facing side that faces the cathodes 120. A binding region is defined exclusively on the cathode-facing side of separator 140. This binding region lies entirely outside the cathode region, while separator 140 is aligned with the cathodes 120 and the anodes 130. The bonding area is generally an area where the separator 140 overhangs the cathode material and / or the anode material.

[0043] The adhesive strip 150 incorporates a layer or coating on one side of the separator 140. The adhesive strip 150 has an adhesive mixture that enables bonding to the separator 140 and to itself. In various embodiments, the adhesive strip 150 can be a continuous strip, a discontinuous strip, or a combination thereof.

[0044] The electrolyte 160 incorporates an electrical conductor in which the current is transported between the cathodes 120 and the anodes 130 by the movement of ions. In various embodiments, the electrolyte 160 is a liquid electrolyte.

[0045] In various embodiments, the prismatic secondary battery cell 100 has a nominal voltage between approximately 3.63 volts and approximately 3.66 volts, while the energy is measured between a maximum voltage and a minimum voltage of the prismatic secondary battery cell 100. The cathodes 120 have a specific air capacity load of approximately 4.95 milliampere-hours per square centimeter (mAh / cm²). 2 ) and approximately 5.4 mAh / cm² 2The specific capacity of the cathode active material in the cathodes 120 is at least approximately 195 milliampere-hours per gram (mAh / g), measured at 1 / 10 Celsius at 25 degrees Celsius. The anode active material of the anodes 130 comprises graphite and silicon oxide. The weight fraction of silicon oxide in the anodes 130 is generally less than 6 percent. The area-specific capacity refers to the amount of charge that can be stored per unit area of ​​the electrode. The specific capacity refers to the amount of charge that can be stored per unit mass of the electrode.

[0046] In some embodiments, the prismatic secondary battery cell 100 has a nominal voltage between approximately 3.67 volts and approximately 3.71 volts, while the energy is measured between a maximum and a minimum voltage of the prismatic secondary battery cell 100. The cathode electrode has a specific air capacity load that is between approximately 4.95 milliampere-hours per square centimeter and approximately 5.4 mAh / cm². 2 The specific capacity of the cathode material in the cathodes 120 is at least approximately 195 mAh / g, measured at a rate of 1 / 10 Celsius at 25 degrees Celsius. The anode active material of the anodes 130 can be graphite.

[0047] In other embodiments, the cathodes 120 and / or the anodes 130 may contain a plurality of carbon nanotubes. The carbon nanotubes do not exceed at least (i) 0.2 percent by weight for the anodes 130 and (ii) 1.2 percent by weight for the cathodes 120.

[0048] With reference to Fig.Figure 3 is a schematic cross-sectional diagram of an exemplary sequence of cathode conversion during fabrication according to one or more exemplary embodiments. The cathode 120 is illustrated as cathode 120a before fabrication. A cathode 120b is illustrated after fabrication, wherein the cathode 120b is partially enclosed by the separator 140. A cathode 120c is illustrated after fabrication, wherein the cathode 120c is completely enclosed by the separator 140. The cathodes 120, 120a, and 120b generally comprise a current collector 180 and several (e.g., two) blocks of cathode material 182.

[0049] The current collector 180 incorporates a conductive metal film (or plate). The current collector 180 is designed to transfer electrons between a positive electrical terminal 112a of the prismatic secondary battery cell 100 and the cathode materials 182. The current collector 180 is positioned between the two cathode materials 182, in direct physical contact with them, and is in direct electrical contact with them. The thickness of the current collector 180 at the cathode 120 is between approximately 10 micrometers and approximately 14 micrometers.

[0050] The cathode material 182 incorporates an active cathode material. The cathode material 182 is operable to undergo intercalation and deintercalation while acting as the positive pole of the electrode arrangement 114.

[0051] Before the manufacture (or assembly) of the prismatic secondary battery cell 100, the separator 140 can be aligned parallel to the current collector 180 of the cathode 120a. The two segments 152 of the adhesive strip 150 are physically separated from each other and from the current collector 180. The two segments 152 are attached to the side 142 of the separator 140 facing the cathode.

[0052] After the prismatic secondary battery cell 100 has been manufactured, the separator 140 can be bent (or curved) towards the current collector 180 of the cathode 120b in various embodiments. The two segments 152 of the adhesive strip 150 physically touch and adhere to each other and to the current collector 180. At the opposite end of the cathode 120b, the ends of the separator 140 remain apart, so that the cathode 120b is partially enclosed by the separator 140.

[0053] After the prismatic secondary battery cell 100 has been manufactured, in other embodiments the separator 140 can be bent (or curved) towards the current collector 180 of the cathode 120c. The two segments 152 of the adhesive strip 150 physically touch and adhere to each other and to the current collector 180. At the opposite end of the cathode 120c, the ends of the separator 140 are pressed together so that the cathode 120c is completely enclosed by the separator 140.

[0054] The anodes 130 have, with a few differences, the same general structure as the cathodes 120. Instead of the cathode material 182 on each side of the current collector 180, the anodes 130 can have an anode material on each side of the current collector 180. The current collector 180 of an anode 130 is operable to transfer electrons between a negative electrical terminal 112b of the prismatic secondary battery cell 100 and the anode materials. Furthermore, the adhesive strip 150 is omitted on the side 144 of the separator 140 facing the anode.

[0055] With reference to Fig.Figure 4 shows a schematic perspective diagram of an exemplary process 200 for assembling a prismatic secondary battery cell 100 according to one or more exemplary embodiments. The process 200 generally consists of nesting the cathodes 120 and the anodes 130 together in layers and folding the separator 140 between the layers. The nesting can be a Z-shaped folded stacking technique 202. One or more pneumatic guns 204 or similar devices can be used to apply a pneumatic or mechanical force that compresses an edge of the separator 140 to bond the adhesive strip 150 to itself and enclose the cathodes 120 and the anodes 130.

[0056] With reference to Fig.Figure 5 shows a schematic cross-sectional diagram of an exemplary processing method 220 with a cathode 120 according to one or more exemplary embodiments. The method (or process) 220 generally comprises steps 222 to 226, as illustrated. The sequence of steps is shown as a representative example. Other step sequences can also be implemented to meet the criteria of a particular application.

[0057] In step 222, a first force 232 can be applied to one side (e.g., the top, as illustrated) of the separator 140 at a first segment 152a of the adhesive strip 150. The first force 232 generally bends the separator 140 such that the first segment 152a of the adhesive strip 150 is connected to the current collector 180.

[0058] In step 224, the first force 232 is released, and a second force 234 can be applied to the opposite side (e.g., a bottom side as illustrated) of the separator 140 on a second segment 152b of the adhesive strip 150. The second force 234 generally bends the separator 140 such that the second segment 152b of the adhesive strip 150 connects to the current collector 180 and to the first segment 152a. In step 226, the second force 234 is released. The resulting cathode 120b (see Fig. 3) can be partially enclosed. In different embodiments, the forces 232 and 234 can be applied in a different order or simultaneously.

[0059] With reference to Fig.Figure 6 shows a schematic side view diagram of an exemplary electrode arrangement 114 according to one or more exemplary embodiments. The electrode arrangement 114 may comprise a pair of tabs 240a-240b. A binding area 242 in the separator 140 is generally aligned along a tab side 244 of the electrode arrangement 114. The tab side 244 is the same side that contains the pair of tabs 240a-240b. In various embodiments, the tabs 240a-240b are formed from the current collectors 180 ( Fig. 5) formed by the cathodes 120 and the anodes 130. The lugs 240a from the cathodes 120 can be connected by a first busbar. The lugs 240b from the anodes 130 can be connected by a second busbar.

[0060] With reference to Fig. 7 with cross-references to Fig.Figure 5 shows a further schematic side view diagram of the exemplary electrode arrangement 114 according to one or more exemplary embodiments. A mechanical force 236 (e.g., the first force 232 and / or the second force 234 in Fig. 5) can be applied to the separator 140 in the area for bonding 242. The mechanical force 236 generally causes the segments 152a and 152b of the adhesive strip 150 to bond to each other and to the current collector 180.

[0061] With reference to Fig.Figure 8 shows a schematic perspective diagram of an exemplary unfolded electrode arrangement 114 according to one or more exemplary embodiments. The electrode arrangement 114 illustrates several (e.g., two) cathodes 120 and several (e.g., two) anodes 130 connected to the separator 140. The cathodes 120 occupy the cathode region 122. The anodes 130 occupy the anode region 132. The separator 140 includes a bonding region 146 on the side 142 facing the cathode. The cathode-facing side 142 is opposite the anode-facing side 144. The bonding region 146 may be located entirely outside the cathode region 122. The bonding region width of the bonding region 146 in the separator 140 may be less than approximately 2 millimeters.

[0062] The adhesive strip 150 is attached to the separator 140 in the bonding area 146. The adhesive strip 150 can be divided into segments 152a-152e, with each cathode 120 having two adjacent segments 152a-152e assigned to it. While the separator 140 is folded and the segments 152a-152e are connected to each other, segment 152e can be attached to segment 152d, segment 152c can be attached to segment 152b, and so on. In various embodiments, the segments 152a-152e can be continuous (e.g., as illustrated by segment 152a) or dotted (e.g., as illustrated by segment 152e). If the dotted (or non-continuous) segments 152a-152e are connected, the cathode 120 can be considered as partially enclosed.

[0063] With reference to Fig.Figure 9 shows a flowchart of an exemplary method 260 for manufacturing a prismatic secondary battery cell 100 according to one or more exemplary embodiments. Method 260 can be carried out using existing battery cell manufacturing equipment. Method 260 comprises steps 262 to xxx, as illustrated. The sequence of steps is shown as a representative example. Other step sequences can also be implemented to meet the criteria of a particular application.

[0064] In step 262, the adhesive strip 150 is applied to the separator 140. In step 264, the separator 140 is placed on a base plate. An anode 130 can be placed on the separator 140 in step 266.

[0065] In step 268, the separator is folded over the anode 130. In step 270, a cathode is placed on the separator 140 opposite the anode 130. In step 272, the separator 140 is folded over the cathode 120. In step 274, a force is applied to the separator 140 in the bonding area 146 to join two segments 152 of the adhesive strip 150 on opposite sides of the cathode 120.

[0066] In step 276, another anode can be placed on the separator 140 opposite the existing cathode 120. In step 278, the separator 140 is folded again to cover the previously placed anode 130. In step 280, another cathode 120 is placed on the separator 140 opposite the last placed anode 130. In the bonding area 146, further force is applied to the separator 140 to bond two additional segments 152 of the adhesive strip 150 together on opposite sides of the cathode 120 in step 282.

[0067] If additional cathodes 120 and anodes 130 are to be included, steps 266 to 282 can be repeated in step 284. The cathodes 120 and the anodes 130 can be wrapped with the separator 140 to form an electrode assembly 114 in step 286. In step 288, the electrode assembly is arranged (or placed) in a battery cell housing 110.

[0068] In step 290, the tabs are connected to the busbars. In step 292, the busbars are connected to the electrical terminals 112a-112b. In step 294, an electrolyte 160 is introduced into the battery cell housing 110. The battery cell housing 110 can be sealed in step 296 to complete the manufacture of the prismatic secondary battery cell 100.

[0069] A study of prismatic cell design was conducted to determine cell properties for various exemplary embodiments (e.g., Examples 1-4) relative to the designs of control cells. The properties are the same for each example and the corresponding control cell design, except for the "fresh energy" property, the cathode dimensions, and the anode dimensions. The dimensions of the secondary battery cell are approximately 260 mm length x 103 mm height x 30.9 mm width. The properties are provided in Table I as follows: Table I Characteristic Example 1 Example 2 Example 3 Example 4 Fresh energy (Wh) 560 560 560 560 Controlled fresh energy 556,91 556,91 556,91 556,91 Nominal voltage (V) 3,68 3,64 3,64 3,64 Specific discharge capacity (mAh / g) 217,0 225,7 225,7 225,7 Specific capacity (mAh / g) 360,1 420,4 420,4 420,4 Active material %(+) / (-) 97,55 / 97,44 97 / 95,2 97 / 95,2 97 / 95,2 Area-specific capacity (mAh / cm²) 2 ) 5,461 5,442 5,414 5,002 N / P 1,065 1,08 1,08 1,08 Current collector (+) / (-) 12 / 8 12 / 8 12 / 8 12 / 8 Cathode dimensions H x W (cm) 9,1 x 25,14 9,18 x25,14 9,1 x 25,14 9,1 x 25,14 Control cathode dimensions HxW (cm) 9,05 x25,14 9,13 x25,14 9,05 x25,14 9,05 x25,14 Anode dimensions (cm) 9,3 x 25,54 9,38 x25,59 9,3 x 25,54 9,3 x 25,54 Control anode dimensions HxW (cm) 9,25 x25,54 9,33 x25,59 9,25 x25,54 9,25 x25,54 Separator thickness (mm) 13 13 13 13 Separator height 9,5 9,58 9,5 9,5 Number of cathodes 64 73 74 80

[0070] The composition of the cathode active material (CAM) for the various exemplary embodiments and the associated control cell designs in the study were: Example 1: LiNi 89 Co6Mn5O2 Example 2: LiNi 86,6 Co5Mn 6,6 Al 1,8 Al 1,3 O2 Example 3: LiNi 86,6 Co5Mn 6,6 Al 1,8 Al 1,3 O2 Example 4: LiNi 86,6 Co5Mn 6,6 Al 1,8 Al 1,3 O2

[0071] According to the cathode dimensions in Table I, the ratio between the cathode height (e.g. 91 mm) and the case height (e.g. 103 mm) is greater than 0.874 to 1.

[0072] In various embodiments, the roles of the cathodes 120 and the anodes 130 can be reversed. For example, the adhesive strip 150 in the bonding area can only be applied to the side of the separator 140 facing the anode.

[0073] Embodiments of the invention generally provide a technique for achieving a high-energy secondary lithium-ion battery cell by maximizing electrode dimensions without increasing cell resistance. The maximum electrode dimension can be achieved with minimal separator overhang by applying an adhesive during the electrode assembly process and subsequently performing a bonding step. In existing designs, a pressure- or thermally activated bonding layer is applied to the entire surface of the separator to improve the robustness of the electrode assembly process, but the resulting adhesive-coated separator exhibits higher resistance to ion movement compared to an untreated separator.In various embodiments, the adhesive is applied to a position limited to the separator overhang, allowing the design and manufacturing process to ensure robustness of the electrode assembly process with increased energy density without increasing the resistance of the battery cell. In particular, the resistance can be lower than in existing cell designs. The adhesive is applied to the separator overhang area during the electrode stacking process, as the separator is peeled from a separator roll in the electrode assembly equipment.

[0074] Increasing the electrode size allows for higher volumetric energy densities. The larger electrode (e.g., cathode) can reduce the number of electrodes required. By reducing separator overhang through the use of separator bonding, the volumetric energy density can be increased from approximately 673 watt-hours per liter (Wh / L) to 677 Wh / L, and the energy content can also increase from 556.9 watt-hours (Wh) to 560 Wh. The gravimetric energy density of the cell generally increases from 283.16 watt-hours per kilogram (Wh / kg) to 283.45 Wh / kg. The higher energy (Wh) and volumetric energy density (Wh / L) of the cell generally improves the vehicle's range and can contribute to a reduction in battery pack size.

Claims

[1] Secondary battery cell (100), comprising: a battery cell housing (110); an electrolyte (160) arranged in the battery cell housing (110); and an electrode arrangement (114) which is arranged in the battery cell housing (110), the electrode arrangement (114) comprising: a cathode (120) with a cathode area (122); an anode (130); a separator (140) (i) having one side facing the anode (130) and one side facing the cathode (120), (ii) having a bonding area (146) on the side facing the cathode (120) and completely outside the cathode area (122), and (iii) designed to physically separate the cathode (120) and the anode (130); and an adhesive strip (150) which is attached exclusively to the side of the separator (140) facing the cathode, wherein: the cathode (120) is either partially enclosed or completely enclosed by the separator (140); the adhesive strip (150) is located entirely within the bonding area (146); and two segments (152) of the adhesive strip (150) are connected to each other on opposite sides of the cathode (120). [2] Secondary battery cell (100) according to claim 1, wherein: the separator (140) is in direct physical contact with the anode (130) and the cathode (120). [3] Secondary battery cell (100) according to claim 1, wherein: the battery cell housing (110) is a prismatic metal housing; a pair of electrical terminals (112a-112b) are arranged in a common plane along one side of the prismatic metal housing; the pair of electrical terminals (112a-112b) has a terminal height; a housing height of the prismatic metal housing between 100 millimeters and 110 millimeters, excluding the connection height of the pair of electrical terminals (112a-112b); and The case width of the prismatic metal case is between 250 millimeters and 300 millimeters. [4] Secondary battery cell (100) according to claim 3, wherein: the ratio between the cathode height of the cathode (120) and the case height of the prismatic metal case is greater than 0.874 to 1. [5] Secondary battery cell (100) according to claim 4, wherein: the cathode (120), the anode (130) and the separator (140) are arranged in a Z-shaped folded stack; and a plurality of tabs (240a-240b) (i) is connected to the cathode (120) and the anode (130) and (ii) is arranged in a plane parallel to a position of the pair of electrical terminals (112a-112b). [6] Secondary battery cell (100) according to claim 5, wherein: the secondary battery cell (100) has a nominal voltage between 3.63 volts and 3.66 volts, while the energy is measured between a maximum voltage and a minimum voltage of the secondary battery cell (100); the cathode (120) has a specific air capacity load between 4.95 milliampere-hours per square centimeter and 5.4 milliampere-hours per square centimeter; a specific capacity of the cathode active material in the cathode (120) is at least 195 milliampere-hours per gram, measured at a rate of 1 / 10 Celsius at 25 degrees Celsius; a current collector thickness of the cathode (120) is between 10 micrometers and 14 micrometers; an anode active material of the anode (130) comprising graphite and silicon oxide; and the weight fraction of silicon oxide in the anode (130) is less than 6 percent. [7] Secondary battery cell (100) according to claim 6, wherein: the cathode (120) and the anode (130) contain a multitude of carbon nanotubes; and the number of carbon nanotubes does not exceed at least one of (i) 0.2 weight percent for the anode (130) and (ii) 1.2 weight percent for the cathode (120). [8] Secondary battery cell (100) according to claim 5, wherein: The secondary battery cell (100) has a nominal voltage between 3.67 volts and 3.71 volts, while the energy is measured between a maximum voltage and a minimum voltage of the secondary battery cell (100); a cathode (120) has a specific air capacity load between 4.95 milliampere-hours per square centimeter and 5.4 milliampere-hours per square centimeter; a specific capacity of a cathode material in the cathode (120) is at least 195 milliampere-hours per gram, measured at a rate of 1 / 10 Celsius at 25 degrees Celsius; and an anode active material of the anode (130) is graphite. [9] Secondary battery cell (100) according to claim 1, wherein: the binding area width of the binding area (146) in the separator (140) is less than 2 millimeters. [10] Method for manufacturing a secondary battery cell (100), comprising: Applying an adhesive strip (150) exclusively to one side of a separator (140) facing the cathode (120), wherein: the separator (140) (i) has a side facing the anode (130) and a side facing the cathode (120), (ii) has a bonding area (146) on the side facing the cathode (120) which is entirely outside a cathode area (122) of a plurality of cathodes (120), and (iii) is designed to physically separate the plurality of cathodes (120) and a plurality of anodes (130); the plurality of cathodes (120) is either partially or completely enclosed by the separator (140); and the adhesive strip (150) is completely within the bonding area (146); Placing the separator (140) on a base plate; Placing a first anode (130) of the plurality of anodes (130) on the separator (140); Folding of the separator (140) over the first anode (130); Placing a first cathode (120) of the plurality of cathodes (120) on the separator (140) opposite the first anode (130); Folding of the separator (140) over the first cathode (120); Applying a force to the separator (140) in the bonding area (146) to join two segments (152) of the adhesive strip (150) on opposite sides of the first cathode (120) together; Placing a second anode (130) of the plurality of anodes (130) on the separator (140) opposite the first cathode (120); Folding of the separator (140) over the second anode (130); Placing a second cathode (120) of the plurality of cathodes on the separator (140) opposite the second anode (130); Applying force to the separator (140) in the bonding area (146) to join two additional segments (152) of the adhesive strip (150) together on opposite sides of the second cathode (120); Wrapping the plurality of cathodes (120) and the plurality of anodes (130) with the separator (140) to form an electrode arrangement (114); Arranging the electrode assembly (114) in a battery cell housing (110); and Arranging an electrolyte (160) in the battery cell housing (110).

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