Method for producing a battery tray of a traction battery for a mobile work machine

Abstract

The invention relates to a method for producing a battery tray (1) of a traction battery (2), in particular a lithium-ion traction battery, for a mobile work machine, in particular an industrial truck, wherein the battery tray (1) is at least partially filled with a ballast filling (3), wherein the ballast filling (3) comprises a ballast material (3a) and a bonding substance (3b). The method comprises the steps of: providing the battery tray (1) and the ballast filling (3); filling the battery tray (1) with the ballast filling (3), wherein at least two filling steps (B1, B2, B3) are carried out, wherein, in each of the multiple filling steps (B1, B2, B3), the ballast material (3a) and the bonding substance (3b) are each filled sequentially into the battery tray (1), wherein first ballast material (3a) and subsequently bonding substance (3b) is filled into the battery tray (1); compressing the ballast filling (3); and setting the ballast filling (3) to form a laminate material.

Description

[0001] 24328 / P24029-DEa / KBS = EM-KBS007

[0002] February 13, 2025 - Geirhos

[0003] 1

[0004] Description

[0005] Method for manufacturing a battery tray for a traction battery for a mobile work machine

[0006] The invention relates to a method for manufacturing a battery trough for a traction battery, in particular a lithium-ion traction battery, for a mobile working machine, in particular a forklift truck, wherein the battery trough is at least partially filled with a ballast filling, the ballast filling comprising a ballast material and a composite material.

[0007] A mobile work machine powered by a battery-electric drive, in particular a battery-electric industrial truck, for example a battery-electric counterbalance forklift, has a traction battery to provide the electrical drive energy. The traction battery has a battery tray in which one or more battery modules are installed. In known battery-electric industrial trucks, the traction battery is usually designed to be replaceable, so that a discharged traction battery can be easily replaced with a charged one during operation of the industrial truck.

[0008] Electrically powered industrial trucks, such as counterbalance forklifts, have a lifting mast with a load-handling device, such as a fork, on the front axle. The stability of such trucks with a load is crucially determined by the vehicle's overall center of gravity, which in turn depends on the position of the counterweight, as well as the position and weight of the traction battery.

[0009] Conventional traction batteries are relatively heavy lead-acid batteries that contribute significantly to the counter-torque against a load in the industrial truck. To prevent unstable conditions and the risk of the truck tipping over, as well as during braking, the vehicle's weight and center of gravity are crucial. 24328 / P24029-DEa / KBS = EM-KBS007

[0010] February 13, 2025 - Geirhos

[0011] 2

[0012] Newer technologies now allow for the production and industrial use of batteries and accumulators that offer improved performance. These batteries can be described as high-performance batteries, characterized by a higher energy density relative to weight and / or volume compared to lead-acid batteries, and by the use of a different energy storage technology than a lead-acid reaction. Many high-performance batteries also feature the ability to deliver high power during discharge and / or charge at high power. The typical energy densities relative to weight and / or volume of a high-performance battery are higher than, and outside the range of, the corresponding parameters for lead-acid batteries, at least for one of these two values.

[0013] Lithium-ion batteries, which have achieved a level of reliability suitable for mass production, are increasingly being used on a larger scale than such high-performance batteries. They are characterized by high energy density, have only a low memory effect, and allow for high-power discharge and charging of the battery.

[0014] The use of such high-performance batteries is particularly advantageous in mobile machinery, for example industrial trucks, as traction batteries, because due to the high energy density in relation to the volume, a larger amount of electrical energy can be stored in the given installation space for the traction battery, thus increasing the range of a vehicle or the operating time of the industrial truck.

[0015] Battery-electric industrial trucks that use lithium-ion traction batteries as high-performance batteries, with lithium-ion battery modules installed in the battery tray, have the disadvantage that the lower weight of the lithium-ion traction battery compared to a lead-acid traction battery (with lead-acid battery modules installed in the battery tray) alters the center of gravity of the entire industrial truck, thus affecting its stability and load-bearing capacity. 24328 / P24029-DEa / KBS = EM-KBS007

[0016] February 13, 2025 - Geirhos

[0017] 3

[0018] Therefore, there is a need to align the weight of a lithium-ion traction battery with the weight of a lead-acid traction battery with the same external dimensions of the battery tray, so that a lead-acid traction battery can be replaced by a lithium-ion traction battery in the industrial truck without affecting the load-bearing capacity and stability of the industrial truck.

[0019] It is known from DE 102014 106644 B4 to attach a plate-shaped additional weight to the outside of the battery tray of a lithium-ion traction battery of a forklift truck using fasteners, in order to equalize the weight of the lithium-ion traction battery with that of a lead-acid traction battery with the same size battery tray. However, such a plate-shaped additional weight and the required fasteners result in a high degree of construction complexity.

[0020] To increase the weight of a lithium-ion traction battery for a mobile work machine, it is also possible to partially fill the battery tray with ballast. In the first process step of manufacturing the battery tray, a mixture of metal parts and a composite material is produced as ballast. This mixture is then poured into the battery tray in a second process step, where it hardens into a composite material. The battery tray has a double-walled structure with an outer and an inner wall, and the ballast is filled into the space between these two walls.

[0021] However, a disadvantage of this method is that the metal parts and the composite material must be premixed before the battery tray is filled with ballast. Furthermore, producing this mixture constitutes an additional process step prior to the second step of filling the battery tray, requiring extra processing time. Additionally, a mixing device, such as a mixing machine, is necessary to produce this mixture. Another disadvantage is that producing the mixture is highly time-consuming. 24328 / P24029-DEa / KBS = EM-KBS007

[0022] February 13, 2025 - Geirhos

[0023] 4

[0024] A significant amount of composite material is required. Furthermore, a disadvantage is that the battery tray with its double-walled construction incurs high manufacturing costs.

[0025] The present invention is based on the objective of providing a method for manufacturing a battery tray of the type mentioned at the outset, which is improved with regard to the aforementioned disadvantages.

[0026] This problem is solved according to the invention in a method for manufacturing a battery trough of a traction battery, in particular a lithium-ion traction battery, for a mobile working machine, in particular a forklift truck, wherein the battery trough is at least partially filled with a ballast filling, wherein the ballast filling comprises a ballast material and a composite material, by the following steps:

[0027] • Providing the battery tray and ballast filling;

[0028] • Filling the battery trough with the ballast filling, wherein at least two filling steps are carried out, wherein in each of the several filling steps the ballast material and the composite material are sequentially filled into the battery trough, wherein ballast material is filled into the battery trough first and then composite material;

[0029] • Compacting the ballast filling;

[0030] • Hardening of the ballast filling to form a composite material.

[0031] In the method according to the invention, the battery trough is filled in at least two filling steps. In each of the several filling steps, the ballast material and the composite material are filled sequentially, i.e., one after the other, into the battery trough, with ballast material being filled first and then the composite material in each of the several filling steps. The ballast filling is thus introduced into the battery trough in several layers, with ballast material being filled first and then the composite material in each layer.By producing the ballast filling in such several filling steps, a uniform wetting of the ballast material with the composite material can be achieved with a small amount of composite material applied to the ballast material filled into the battery trough in the associated filling step, which allows the ballast material to harden into the solid composite material 24328 / P24029-DEa / KBS = EM-KBS007.

[0032] February 13, 2025 - Geirhos

[0033] 5 ensures that the ballast filling is compacted after the battery trough has been filled with the ballast material, i.e., after the last filling step. This compaction ensures a reliable and uniform wetting of the ballast material with the composite material, thus guaranteeing the hardening of the ballast material into the solid composite material. A further advantage of the inventive method and the sequential filling of the battery trough with ballast material and composite material in several filling steps is that no prior mixing process is required to produce a mixture of metal parts and composite material, and no mixing device is needed to produce the mixture consisting of the metal parts and the composite material. Therefore, the acquisition, maintenance, and cleaning costs associated with a mixing device can also be avoided.

[0034] According to an advantageous embodiment of the invention, the same partial mass of the total mass of the ballast filling is added in each of the several filling steps. This allows for a simple and uniform build-up of the ballast filling, which has hardened into the composite material. For example, if the ballast filling of the battery trough is to have a total mass of 500 kg, then, in the case of, for example, five filling steps, a partial mass of 100 kg of ballast material and composite material can be added to the battery trough in each of the several filling steps.

[0035] According to an advantageous embodiment of the invention, a divisor of the total mass of the ballast filling is used as the partial mass. A divisor is a number by which a given number can be divided without a remainder. For example, if the ballast filling of the battery tray is to have a total mass of 500 kg (given number), the divisor of 100 kg of ballast material and composite material can be provided as the partial mass of each filling step, resulting in five filling steps with equal partial masses of ballast material and composite material to achieve the total mass of the ballast filling.

[0036] According to an advantageous embodiment of the invention, the battery trough has an outer shell with a bottom wall and a circumferential outer wall, wherein a flat surface of the ballast is created when the ballast is compacted, the flat surface extending to the circumferential outer wall. Thus, after the battery trough is filled with the ballast, the following occurs: 24328 / P24029-DEa / KBS = EM-KBS007

[0037] February 13, 2025 - Geirhos

[0038] 6

[0039] Compacting the ballast creates a flat, even surface that extends to the outer wall. This flat surface then hardens into a solid composite material. The flat surface of the ballast, and thus of the hardened composite material, extends to the outer wall, forming a continuous surface parallel to the bottom wall of the battery tray, with a base area equal to that of the bottom wall. On this flat surface of the ballast, and thus of the hardened composite material, one or more battery modules, such as lithium-ion battery modules, can be built and mounted during the manufacture of a traction battery without the need for a separate, additional load-bearing intermediate floor in the battery tray to cover the ballast.By producing a flat surface for the ballast filling in the inventive method, a battery trough can be used that consists only of the bottom wall and the surrounding outer wall, resulting in low manufacturing costs. Furthermore, in the inventive method, the ballast filling is designed as a ballast layer arranged on the bottom wall in the lower region of the battery trough. This leads to a low center of gravity for both the battery trough and the traction battery produced from it. Consequently, when a traction battery incorporating the inventive battery trough is installed in a mobile work machine, such as a forklift truck, the machine has a favorable center of gravity.

[0040] According to an advantageous embodiment of the invention, the flat surface of the cured composite material is used as a separating plane to a receiving space of the battery tray, into which at least one battery module, in particular a lithium-ion battery module, is installed. If the flat surface of the ballast filling, and thus of the cured composite material, forms the separating plane to the receiving space of the battery tray, into which at least one battery module, in particular a lithium-ion battery module, is installed during the manufacture of the traction battery, the at least one battery module can be mounted directly on the flat surface of the cured composite material without having to provide a separate and additional load-bearing intermediate floor on the battery tray to cover the ballast filling from above. 24328 / P24029-DEa / KBS = EM-KBS007

[0041] February 13, 2025 - Geirhos

[0042] 7

[0043] According to an advantageous embodiment of the invention, the battery trough filled with ballast is vibrated to compact the ballast. For the vibrating process, the ballast in the battery trough can be agitated using a vibrating bottle. Preferably, the battery trough containing the ballast is vibrated using a vibrating plate on which the battery trough rests. Furthermore, vibrating the battery trough filled with ballast easily creates a flat surface for the ballast.

[0044] According to an advantageous embodiment of the invention, the composite material comprises 99.5–95% by weight of ballast material and 0.5–5% by weight of composite material. Preferably, the composite material comprises 99–97% by weight of ballast material and 1–3% by weight of composite material. Particularly preferably, the composite material comprises 98.5–97.5% by weight of ballast material and 1.5–2.5% by weight of composite material. It has been shown that with these percentages of composite material, sufficient wetting of the ballast material is achieved in the process according to the invention, which hardens into a solid composite material after filling the battery trough and compacting the ballast.

[0045] According to an advantageous embodiment of the invention, a resin, in particular a polymer resin, is used as the composite material. Suitable resins include common types such as epoxy resin or polyester resin, which can be in the form of a one-component or multi-component resin. Preferably, the resin is in a liquid state so that, when applied to the previously filled ballast material in the associated filling step, it can fill the voids between the ballast material and thus achieve uniform wetting of the ballast material with the composite material, ensuring that the ballast material hardens into the solid composite material.

[0046] According to an advantageous embodiment of the invention, metal parts and / or slag are filled into the battery trough as ballast material. Preferably, scrap metal, steel scrap, or iron scrap is used as the metal parts, which can be crushed to a desired size before being filled into the battery trough. Alternatively or additionally, slag from the steel industry can be used as ballast material. 24328 / P24029-DEa / KBS = EM-KBS007

[0047] February 13, 2025 - Geirhos

[0048] 8. In particular, slag from iron or steel production, so-called blast furnace slag or steelworks slag, can be used, which may be in the form of slag material reduced to a desired size, especially fine-grained granules. By appropriately selecting the size of the metal parts and / or the reduced slag material, a flat surface of the ballast filling can be easily achieved by compaction, for example, by vibrating the ballast filling in the battery trough. After the ballast filling has hardened into the composite material, the metal parts and / or the reduced slag material are bound in the hardened composite, so that one or more battery modules can be built and mounted directly onto the flat surface of the hardened ballast filling.

[0049] The invention further relates to a lithium-ion traction battery for a mobile work machine, in particular a forklift truck, using a battery trough manufactured according to the invention, wherein at least one lithium-ion battery module is installed in the battery trough provided with the hardened ballast filling, wherein in particular there is no intermediate floor, in particular an intermediate sheet, in the battery trough between the flat surface of the hardened ballast filling and the at least one lithium-ion battery module.

[0050] The invention offers a number of advantages.

[0051] The method according to the invention enables a simplified filling process of the battery trough with the ballast filling, since the ballast material and the composite material do not need to be premixed before filling the battery trough, resulting in a simple filling process of the battery trough with the ballast filling, which is reduced in terms of process costs and process time by eliminating a prior mixing process of the ballast material and the composite material in a mixing device.

[0052] In the battery tray according to the invention, no intermediate floor, in particular an intermediate sheet, is required above the ballast filling to cover it and create a flat mounting surface for the at least one battery module. This results in a low material requirement for the battery tray, as it consists only of the bottom wall and the 24328 / P24029-DEa / KBS = EM-KBS007

[0053] February 13, 2025 - Geirhos

[0054] The battery trough consists of 9 surrounding outer walls. The elimination of the intermediate floor above the ballast filling results in a simplified trough geometry, leading to cost savings in terms of manufacturing costs, especially when the battery trough is made from welded sheets, as no welds are required for an intermediate floor.

[0055] In the battery trough according to the invention, the ballast filling, which is formed above the bottom wall with a uniform thickness, results in a low center of gravity and a uniform weight distribution of the battery trough provided with the ballast filling.

[0056] Further advantages and details of the invention are explained in more detail with reference to the exemplary embodiment shown in the schematic figures. Here,

[0057] Figure 1 shows a battery tray produced according to the inventive method in a sectional view and

[0058] Figure 2 shows a block diagram of the method according to the invention.

[0059] Figure 1 shows a battery tray 1 for a traction battery 2, for example a lithium-ion traction battery, for a mobile work machine, in particular a forklift truck, produced according to the method of the invention. The battery tray 1 is at least partially filled with ballast 3 to increase its weight.

[0060] The battery tray 1 is shown in a longitudinal section in Figure 1.

[0061] The battery tray 1 has an outer shell 4, which in the illustrated embodiment consists of a bottom wall 5, having a rectangular base, and a surrounding outer wall 6. The outer wall 6 comprises a left outer wall 6a, a right outer wall 6b, and a front wall located at the front in the plane of the drawing, which is not shown in detail in Figure 1. 24328 / P24029-DEa / KBS = EM-KBS007 13.02.2025 - Geirhos

[0062] 10 and a rear wall located in the plane of the drawing, which is not shown in detail in Figure 1.

[0063] The bottom wall 5 and the outer wall 6 are preferably formed from sheets, in particular steel sheets, which are welded to the battery trough 1.

[0064] The ballast filling 3 comprises a ballast material 3a and a composite material 3b, which are poured from above into the upwardly open battery trough 1.

[0065] In the battery trough 1 according to the invention, the space above the bottom wall 5 and within the outer wall 6 forms a cuboid filling chamber, which is partially filled with the ballast 3. The filling chamber is completely open at the top, i.e., at the upper edge of the outer wall 6, with the inner surfaces of the outer wall 6 forming a rectangular filling opening whose area corresponds to the base area of ​​the bottom wall 5. The battery trough 1 is thus provided with a filling chamber that is completely open at the top. The ballast 3 is poured into the filling chamber through the filling opening and falls onto the bottom wall 5.

[0066] In the battery trough 1 according to the invention, the filling of the battery trough 1 with the ballast material 3 is carried out in at least two filling steps B1, B2, B3. In each of the several filling steps, ballast material 3a and composite material 3b are sequentially filled into the battery trough 1, wherein in each of the several filling steps B1, B2, B3, ballast material 3a is filled into the battery trough 1 first and then composite material 3b.

[0067] In the illustrated embodiment, the ballast filling 3 is carried out in three filling steps B1, B2, B3.

[0068] The finished ballast filling 3 forms a ballast layer resting on the bottom wall 6 with a thickness D required for the desired weight increase.

[0069] In the illustrated embodiment, the finished ballast filling 3 has a flat and therefore level surface 8. The base area of ​​the flat surface 8 of the finished ballast filling 3 corresponds to the base area of ​​the bottom wall 5. The flat surface 8 extends to the surrounding outer wall 6, i.e., to the left outer wall 6a, 24328 / P24029-DEa / KBS = EM-KBS007

[0070] February 13, 2025 - Geirhos

[0071] 11 to the right outer wall 6b, to the front wall and to the rear wall. The flat surface 8 is preferably arranged as a continuous surface parallel to the bottom wall 5.

[0072] The flat surface 8 defines a separation plane to a receiving space 9 of the battery trough 1 formed above the ballast filling 3, into which at least one battery module 10, for example a lithium-ion battery module, can be installed.

[0073] In the traction battery 2 with the battery trough 1 according to the invention, the battery modules 10 are positioned and mounted directly and thus immediately, i.e. without an intermediate floor, for example an intermediate sheet, of the battery trough 1 on the flat surface 8 of the ballast filling 3 in the illustrated embodiment.

[0074] Figure 2 shows a block diagram of the inventive method for producing the battery trough 1 provided with the ballast filling 3.

[0075] In a first step S1, the battery trough 1 and the ballast filling 3 are provided, which includes the ballast material 3a and the composite material 3b.

[0076] The ballast material 3a of the ballast filling 3 is preferably formed from crushed metal parts. Metal scrap, specifically steel scrap or iron scrap, is preferably used as the metal parts and can be crushed to a desired size before being filled into the battery trough 1. Alternatively or additionally, slag from the steel industry, in particular slag from iron or steel production, so-called blast furnace slag or steelworks slag, can be used as ballast material 3a. This slag material can be in the form of slag material crushed to a desired size, especially fine-grained granules.

[0077] Composite material 3b preferably consists of a resin, in particular a synthetic resin. The resin is preferably in a liquid state. Suitable resins include common types such as epoxy resin or polyester resin, which can be in the form of a one-component or multi-component resin. 24328 / P24029-DEa / KBS = EM-KBS007 13.02.2025 - Geirhos

[0078] 12

[0079] In a subsequent second step S2, the battery trough 1 is filled with a desired amount of ballast material 3a and composite material 3b, and thus with a desired amount of ballast filling 3.

[0080] The ballast filling 3 is placed into the upwardly open filling space of the battery trough 1, which is formed by the bottom wall 5 and the outer wall 6.

[0081] In the second step S2 of filling the battery trough 1 with the ballast filling 3, a first filling step B1 and at least one further filling step B2 are carried out, and thus at least two filling steps B1 , B2 are carried out.

[0082] In each of the several filling steps B1, B2, the ballast material 3a and the composite material 3b are sequentially, i.e. one after the other, filled into the battery trough 1, with ballast material 3a being filled first and then composite material 3b into the battery trough 1.

[0083] The further filling step B2 is repeated – as shown in Figure 2 by the arrow P1 – until the ballast filling 3 has reached the desired total mass.

[0084] Following the second step S2, the ballast filling 3 is compacted in a subsequent third step S3.

[0085] In the third step S3, the battery trough 1, which is filled with ballast 3, is preferably vibrated. For this purpose, a vibrating table can be provided on which the battery trough 1 with the ballast 3 stands.

[0086] Compaction or vibration creates a bond between the ballast material 3a and the composite material 3b, resulting in uniform wetting of the ballast material 3a by the composite material 3b. Compaction or vibration also creates the flat surface 8 of the ballast filling 3.

[0087] In a subsequent fourth step S4, the ballast filling 3, consisting of ballast material 3a and composite material 3b, hardens to form a solid composite material. 24328 / P24029-DEa / KBS = EM-KBS007

[0088] February 13, 2025 - Geirhos

[0089] 13

[0090] During the curing process, a composite material continues to form between the ballast filling 3 and the battery tray 1.

[0091] In the battery trough 1 according to the invention, no intermediate floor, for example an intermediate sheet, of the battery trough 1 is required or provided above the flat surface 8 of the ballast filling 3, since after the ballast filling 3 has hardened, the composite material 3b, which is designed as a resin, binds the ballast material 3a, which is designed as metal parts and / or as crushed slag material.

[0092] After the ballast filling 3 has hardened into a solid composite material, the battery tray 1 can be used to manufacture a traction battery 2, for example, a lithium-ion traction battery, for a mobile work machine, in particular a forklift truck. In a fifth step S5, at least one battery module 10, for example, a lithium-ion battery module, is installed in the receiving space 9 of the battery tray 1, which is formed above the finished ballast filling 3. The battery modules 10 are positioned and mounted directly on the flat surface 8 of the ballast filling 3, i.e., without requiring an intermediate floor, for example, an intermediate plate, of the battery tray 1 that covers the ballast filling 3 from above.

[0093] The mass of the ballast filling 3 placed in the battery tray 2 is preferably selected such that the weight of the battery tray 1 according to the invention, which is provided with the ballast filling 3 and in which lithium-ion battery modules 10 are installed, is adapted and aligned with the weight of a lithium-ion traction battery having the same external dimensions of the battery tray 1 according to the invention, so that in a forklift truck a replacement of a lead-acid traction battery by a lithium-ion traction battery which is provided with the battery tray 1 according to the invention is made possible without impairing the load-bearing capacity and stability of the forklift truck.

[0094] The ballast filling 3, consisting of ballast material 3a and composite material 3b, thus represents a counterweight or additional weight of the battery tray 1 in order to support a lithium-ion battery formed with the battery tray 1 according to the invention. 24328 / P24029-DEa / KBS = EM-KBS007

[0095] February 13, 2025 - Geirhos

[0096] 14

[0097] To adjust the weight of the traction battery to that of a compression-acid traction battery with the same dimensions of the battery tray 1.

[0098] The invention is not limited to the illustrated embodiment. Alternatively, an intermediate floor, for example a

[0099] Intermediate plate, to be mounted in battery trough 1 to cover the ballast filling 3.

Claims

24328 / P24029-DEa / KBS = EM-KBS007 02 / 13 / 2025 - Geirhos 15 Patent claims 1. Method for manufacturing a battery tray (1) of a traction battery (2), in particular a lithium-ion traction battery, for a mobile working machine, in particular a forklift truck, wherein the battery tray (1) is at least partially filled with a ballast filling (3), wherein the ballast filling (3) comprises a ballast material (3a) and a composite material (3b), characterized by the steps: • Providing the battery tray (1) and ballast filling (3); • Filling the battery trough (1) with the ballast filling (3), wherein at least two filling steps (B1, B2, B3) are carried out, wherein in each of the several filling steps (B1, B2, B3) the ballast material (3a) and the composite material (3b) are sequentially filled into the battery trough (1), wherein first ballast material (3a) and then composite material (3b) are filled into the battery trough (1); • Compacting the ballast filling (3); • Curing of the ballast filling (3) to form a composite material.

2. Method according to claim 1, characterized in that in each of the several filling steps (B1, B2, B3) the same partial mass of the total mass of the ballast filling (3) is filled.

3. Method according to claim 2, characterized in that a divisor of the total mass of the ballast filling (3) is used as the partial mass.

4. Method according to one of claims 1 to 3, characterized in that the battery trough (2) has an outer shell (4) with a bottom wall (5) and a circumferential outer wall (6), wherein a flat surface (8) of the ballast filling (3) is produced when the ballast filling is compacted, the flat surface (8) extending to the circumferential outer wall (6).

5. Method according to claim 4, characterized in that the flat surface (8) of the cured composite material serves as a separating plane to a receiving space. 24328 / P24029-DEa / KBS = EM-KBS007 February 13, 2025 - Geirhos 16 (9) of the battery tray (1) is used, into which at least one battery module (10), in particular a lithium-ion battery module, is installed.

6. Method according to one of claims 1 to 5, characterized in that the battery trough (1) filled with the ballast filling (3) is shaken to compact the ballast filling (3).

7. Method according to any one of claims 1 to 6, characterized in that the composite material comprises 99.5 - 95 weight percent ballast material (3a) and 0.5 - 5 weight percent composite material (3b).

8. Method according to one of claims 1 to 7, characterized in that a resin, in particular a plastic resin, is used as the composite material (3b).

9. Method according to one of claims 1 to 8, characterized in that metal parts and / or slag are used as ballast material (3a).

10. Lithium-ion traction battery (2) for a mobile work machine, in particular a forklift truck, using a battery trough (1) manufactured according to one of claims 1 to 9, wherein at least one lithium-ion battery module (10) is installed in the battery trough (1) provided with the hardened ballast filling (3), wherein in particular there is no intermediate floor, in particular an intermediate sheet, in the battery trough (1) between the flat surface (8) of the hardened ballast filling (3) and the at least one lithium-ion battery module (10).

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