FLAT MATERIAL, SANDWICH MATERIAL, ELECTROCHEMICAL STORAGE UNIT, AND METHOD FOR PRODUCING A FLAT MATERIAL

Abstract

The aim of the invention is to provide a flat material that is as stable as possible and can be produced as easily as possible. According to the invention, this is achieved in that the flat material comprises a thermoplastic polymer matrix material in which a fiber material is received, wherein the fiber material comprises fibers or is made of fibers that are arranged at least approximately parallel to one another, and the proportion of the fiber material to the flat material equals approximately 75 wt. % or more, based on the total mass of the flat material.

Claims

1. A flat material, in particular for use in sandwich materials in vehicles and/or electrochemical storage units, wherein the flat material comprises a thermoplastic polymer matrix material in which a fiber material is received, wherein the fiber material comprises fibers or is made of fibers that are arranged at least approximately parallel to one another, and the proportion of the fiber material to the flat material equals approximately 75 wt. % or more, based on a total mass of the flat material.

2. The flat material according to claim 1, wherein the thermoplastic polymer matrix material is made of a thermoplastic polymer material that has a melt flow index of approximately 400 (g/10 min) or more, in particular of approximately 700 (g/10 min) or more, in particular of approximately 1200 (g/10 min) or more.

3. The flat material according to claim 1, wherein the thermoplastic polymer matrix material and/or a thermoplastic polymer material from which the thermoplastic polymer matrix material is made is a polyolefin material, in particular a polypropylene material.

4. The flat material according to claim 1, wherein a proportion of the fiber material in the flat material is approximately 78 wt. % or more, in particular approximately 80 wt. % or more, based on the total mass of the flat material, and/or wherein a modulus of elasticity of the flat material is in a range of approximately 41 GPa to approximately 50 GPa, in particular in a range of approximately 44 GPa to approximately 47 GPa.

5. The flat material according to claim 1, wherein the fiber material comprises glass fibers or is made of glass fibers.

6. The flat material according to claim 1, wherein the fiber material is a continuous fiber material.

7. The flat material according to claim 1, wherein the flat material is made of the fiber material pre-impregnated with a polymer material, which is in particular a thermoplastic polymer material, wherein the fiber material is in particular completely impregnated with the polymer material.

8. A sandwich material, in particular for use as a load-bearing element in a vehicle and/or in a receiving element of an electrochemical storage unit, wherein the sandwich material has a first layer element, a second layer element and an intermediate layer arranged between the first layer element and the second layer element, and the first layer element and/or the second layer element comprises a flat material according to claim 1 or is formed therefrom.

9. An electrochemical storage unit, comprising one or more electrochemical cells and a receiving element for receiving and/or fastening the one or more electrochemical cells, wherein the receiving element comprises a flat material according to claim 1.

10. A method for producing a flat material, in particular a flat material according to claim 1, wherein the method comprises the following: impregnating a fiber material that comprises fibers or is made of fibers that are arranged at least approximately parallel to one another with a thermoplastic polymer material, wherein a proportion of the fiber material to a resulting flat material is approximately 75 wt. % or more, based on a total mass of the flat material.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0113] FIG. 1 is a schematic representation of a sequence of an embodiment of a method for producing a flat material;

[0114] FIG. 2 is a schematic sectional view of an embodiment of a sandwich material comprising a first layer element, a second layer element and an intermediate layer arranged between the first layer element and the second layer element, the first layer element and/or the second layer element being made from the flat material from FIG. 1;

[0115] FIG. 3 is a schematic sectional view of an electrochemical storage unit comprising a receiving element, the receiving element comprising a flat material; and

[0116] FIG. 4 is a diagram of temperature curves over time in different ranges during a fire test.

[0117] The same or functionally equivalent elements are provided with the same reference signs in all figures.

DETAILED DESCRIPTION OF THE DRAWINGS

[0118] In FIG. 1 a sequence of an embodiment of a method for producing a flat material designated as a whole with 100 is shown schematically.

[0119] The flat material 100 is preferably a material whose extent in two spatial directions is greater by a factor of 50 or more, in particular by a factor of 100 or more, for example by a factor of 1000 or more, than the extent of the flat material 100 in the third spatial direction.

[0120] A thermoplastic polymer material 102 is preferably provided that forms a thermoplastic polymer matrix material 104 in the flat material 100 in particular.

[0121] As an alternative to a thermoplastic polymer material 102, it can be provided that the polymer material 102 is a thermosetting polymer material or an elastomeric polymer material.

[0122] Alternatively, a thermoplastic elastomeric polymer material or a thermosetting elastomeric polymer material or a thermoplastic thermosetting polymer material can be used as the polymer material 102.

[0123] The thermoplastic polymer matrix material 104 preferably serves as a matrix system in which a fiber material 106 is received.

[0124] It can be favorable if the fiber material 106 is integrated into the thermoplastic polymer material 102 and/or is embedded in the thermoplastic polymer material 102.

[0125] Preferably, the fiber material 106 is integrated into the thermoplastic polymer matrix material 104 and/or embedded in the thermoplastic polymer matrix material 104.

[0126] It can be advantageous if the thermoplastic polymer material 102 wets fibers, in particular all fibers, of the fiber material 106 and/or adheres to the fibers, in particular all fibers, of the fiber material 106.

[0127] It can be provided that the thermoplastic polymer material 102 is chemically and/or physically identical to the thermoplastic polymer matrix material 104.

[0128] Alternatively, it can be provided that the thermoplastic polymer material 102 reacts chemically, for example during a curing reaction, for example in a crosslinking reaction.

[0129] The thermoplastic polymer material 102 preferably comprises a polyolefin material, such as a polypropylene material, or is formed from a polyolefin material, such as a polypropylene material.

[0130] It can be favorable if the thermoplastic polymer material 102 comprises a curing agent and/or a reaction accelerator. These preferably serve to optimize and/or accelerate the curing reaction.

[0131] The thermoplastic polymer material 102 preferably has a melt flow index of approximately 400 (g/10 min) or more.

[0132] It can be favorable if the thermoplastic polymer material 102 has a melt flow index of approximately 700 (g/10 min) or more.

[0133] Preferably, the thermoplastic polymer material 102 has a melt flow index of approximately 1200 (g/10 min) or more.

[0134] With such high melt flow indices, the thermoplastic polymer material 102 preferably has a sufficiently low viscosity to wet the fiber material 106, in particular completely.

[0135] The melt flow index is preferably determined according to DIN EN ISO 1133. The DIN EN ISO 1133 standard is a standard for determining the melt flow index of thermoplastics.

[0136] For example, the melt flow index is determined using a capillary rheometer.

[0137] The determination of the melt flow index is preferably carried out at a test temperature of approximately 190° C. and a bearing load of approximately 5 kg.

[0138] It can be advantageous if a polypropylene material, for example polypropylene, having one of the aforementioned melt flow indices is used as the thermoplastic polymer material 102.

[0139] It can be favorable if the fiber material 106 is impregnated with the polymer material 102.

[0140] For example, so-called “prepregs” are produced.

[0141] In the case of the prepregs, the thermoplastic polymer material 102 is preferably cured and/or crosslinked in a curing reaction before and/or during assembly. The curing reaction preferably takes place at an elevated pressure and/or an elevated temperature.

[0142] Alternatively, the fiber material 106 impregnated with the thermoplastic polymer material 102 can also be used directly as the flat material 100 without a curing reaction.

[0143] A continuous fiber material is preferably used as the fiber material 106, in which continuous fiber material approximately 90% of the fibers or more have a length of approximately 50 mm or more, preferably approximately 1000 mm or more.

[0144] Preferably, approximately 95% of the fibers of the fiber material 106 or more have a length of approximately 50 mm or more, in particular approximately 1000 mm or more.

[0145] For example, approximately 98% of the fibers of the fiber material 106 or more have a length of approximately 50 mm or more, in particular approximately 1000 mm or more.

[0146] By using a continuous fiber material, the thermoplastic polymer material 102 is preferably used exclusively to fix the fiber material 106.

[0147] A fiber material 106 is preferably used that comprises fibers or is made of fibers that are arranged at least approximately parallel to one another.

[0148] Approximately 90% of the fibers of the fiber material 106 or more, in particular approximately 95% of the fibers of the fiber material 106 or more, for example approximately 98% of the fibers of the fiber material 106 or more, are preferably arranged at least approximately parallel to one another.

[0149] It can be advantageous if the fibers of the fiber material 106 in the flat material 100 are arranged at least approximately parallel to a main extension plane of the flat material 100.

[0150] The flat material 100 can preferably be wound up, in particular in the form of a single layer. The flat material 100 can preferably be wound up with a thickness in a range from approximately 0.1 mm to approximately 0.6 mm.

[0151] The thickness of the flat material 100 is preferably defined perpendicular to the main extension plane thereof, in particular in an unwound state.

[0152] It can be favorable if the flat material 10 is a band material 108 and/or a tape material 110.

[0153] A thickness of the flat material 100 perpendicular to the main extension plane thereof is preferably approximately 5 mm or less, in particular approximately 4 mm or less, for example approximately 3 mm or less.

[0154] The thickness of the flat material 100 perpendicular to the main extension plane thereof is preferably approximately 0.5 mm or more, in particular approximately 1 mm or more, for example approximately 1.2 mm or more.

[0155] A proportion of the fiber material 106 to the flat material 100 is preferably approximately 70 wt. % or more, in particular approximately 75 wt. % or more, for example approximately 78 wt. % or more, based on a total mass of the flat material 100.

[0156] It can be favorable if the proportion of the fiber material 106 to the flat material 100 is approximately 90 wt. % or less, in particular approximately 85 wt. % or less, for example approximately 80 wt. % or less, based on the total mass of flat material 100.

[0157] It can be advantageous if the proportion of the fiber material 106 to the flat material 100, based on a total volume of flat material 100, is approximately 50 vol. % or more, in particular approximately 55 vol. % or more, for example approximately 58 vol. % or more.

[0158] In particular, the proportion of the fiber material 106 to the flat material 100, based on the total volume of the flat material 100, is approximately 70 vol. % or less, in particular approximately 65 vol. % or less, for example approximately 62 vol. % or less.

[0159] Due in particular to the high proportion of the fiber material 106 to the flat material 100, a modulus of elasticity of the flat material 100 is preferably approximately 35 GPa or more, in particular approximately 36 GPa or more.

[0160] The modulus of elasticity of the flat material 100 is in particular approximately 46 GPa or less, in particular approximately 45 GPa or less.

[0161] The modulus of elasticity of the flat material 100 is preferably determined at approximately 20° C. and/or in the direction of the fibers.

[0162] It can be advantageous if the fiber material 106 comprises glass fibers or is made of glass fibers.

[0163] By using the fiber material 106 in the flat material 100, forces acting on the flat material 100 can be redirected in particular from the fibers of the fiber material 106 into the thermoplastic polymer matrix material 104 or vice versa.

[0164] In particular, the adhesion of the thermoplastic polymer material 102 or of the thermoplastic polymer matrix material 104 to the fiber material 106 is optimized.

[0165] The flat material 100 preferably forms a stabilization and/or protective material.

[0166] As can be seen in particular in FIG. 2, the flat material 100 is preferably used in a sandwich material 112.

[0167] The sandwich material 112 preferably comprises a first layer element 114 and a second layer element 116.

[0168] The first layer element 114 preferably comprises a flat material 100 or is made of a flat material 100.

[0169] It can be favorable if the second layer element 116 comprises a flat material 100 or is made of a flat material 100.

[0170] The thickness of the first layer element 114 and/or the second layer element 116 preferably corresponds to a thickness described in connection with the flat material 100.

[0171] An intermediate layer 118 is preferably arranged between the first layer element 114 and the second layer element 116. The intermediate layer 118 is preferably integrally connected to the first layer element 114 and the second layer element 116.

[0172] The intermediate layer 118 is made of a metallic material, for example, or comprises a metallic material.

[0173] Preferably, the intermediate layer 118 comprises or is made of a fiber-reinforced polymer material as an alternative to a metallic material. A fiber content of the intermediate layer 118 is preferably lower than the fiber content of the flat material 100.

[0174] A polymer material that is compatible, similar or identical to the polymer matrix material 104 of the flat material 100 is preferably used as the polymer material.

[0175] In this way, recyclability can be given.

[0176] For example, short fibers are used for the intermediate layer 118. The short fibers preferably have an average length of approximately 40 mm to approximately 100 mm.

[0177] In embodiments in which the intermediate layer 118 is reinforced with short fibers, the intermediate layer 118 is produced, for example, in an injection molding process.

[0178] Additionally or alternatively, the polymer material 102 of the intermediate layer 118 comprises long fibers. The long fibers preferably have an average length of approximately 100 mm or more and/or approximately 999 mm or less.

[0179] In embodiments in which the intermediate layer 118 is reinforced with long fibers, the intermediate layer 118 is preferably formed using a compression molding process, such as a DLFT (direct long fiber thermoplastic) compression molding process.

[0180] Alternatively, the intermediate layer 118 can comprise or be made of a glass mat reinforced thermoplastic (GMT).

[0181] The sandwich material 112 is preferably used in vehicles, for example in load-bearing elements of a vehicle, and/or in electrochemical storage units 120.

[0182] The vehicle in which the sandwich material 112 is used is, for example, an electric vehicle and/or a gas vehicle and/or a fuel cell vehicle.

[0183] The sandwich material 112 preferably forms a bulletproof protective plate.

[0184] Because a flat material 100 having the described properties is used in the first layer element 114 and/or the second layer element 116, the first layer element 114 and/or the second layer element 116 can be made thicker than layer elements made of aluminum while the weight remains the same. This is due in particular to the lower density of the flat material 100 compared to aluminum.

[0185] The sandwich material 112 preferably has an increased structural rigidity compared to sandwich structures having layer elements made of aluminum, in particular due to a higher moment of resistance to bending.

[0186] An electrochemical storage unit 120 is shown schematically in FIG. 3.

[0187] The electrochemical storage unit 120 is a battery module and/or an accumulator module, for example.

[0188] An electrochemical storage unit 120 preferably comprises one or more—in this case a plurality of—electrochemical cells 122. The electrochemical cells 122 are preferably received by a receiving element 124 of the electrochemical storage unit 120.

[0189] The receiving element 124 preferably serves to attach and/or stabilize the electrochemical cells 122.

[0190] The electrochemical cells 122 are preferably lithium-ion batteries and/or lithium-ion accumulators.

[0191] For example, the receiving element 124 forms a frame for the electrochemical cells 122 and/or a housing.

[0192] It can be advantageous if the receiving element 124 comprises four sidewalls 126 that surround the electrochemical cells 122 laterally and/or on four sides.

[0193] Openings formed by the sidewalls 126 are preferably closed, in particular in a fluid-tight manner, by a cover element 128 of the receiving element 124 on a side facing the connection elements of the electrochemical cells 122 and by a bottom wall 130 of the receiving element 124 on an opposite side.

[0194] It can be advantageous if the cover element 128 comprises a flat material 100 or is made of a flat material 100.

[0195] Additionally or alternatively, one or more sidewalls 126 of the receiving element 124 comprise a flat material 100 or are formed from a flat material 100.

[0196] Additionally or alternatively, the bottom wall 130 of the receiving element 124 comprises a flat material 100 or is formed from a flat material 100.

[0197] It can be provided that the flat material 100 is integrated into a sandwich material 112. In this case, reference is made to the description in connection with FIG. 2.

[0198] The flat material 100 preferably has high fire resistance.

[0199] Preferably, the flat material 100 does not have burn through in conjunction with structural failure in a fire test, such as an ECE180 fire test.

[0200] A temperature on an inner side of the flat material 100 is preferably not critical to underlying assemblies.

[0201] In the ECE180 fire test, a mixed accident of an internal combustion engine vehicle and/or a battery electric car and/or a plug-in hybrid vehicle and/or a hydrogen-powered vehicle is preferably simulated. In this case, fuel usually leaks and catches fire.

[0202] In the fire test, a fire pan is preferably filled with a fuel, for example premium-grade gasoline, and allowed to burn for approximately 60 seconds until a defined and/or constant flame temperature of approximately 700° C. to approximately 800° C. is reached.

[0203] A defined evacuation time of 130 seconds, during which the occupants of a vehicle can be rescued, is preferably established in the fire test.

[0204] After the flame temperature is set, the fire pan moves under a test plate and remains there for approximately 70 seconds.

[0205] A stone grate then moves in to form a chimney effect and remains under and/or near the test plate for a further 60 seconds.

[0206] A test plate is preferably installed as the bottom wall of a receiving element in the fire test. A battery box can be simulated in this way.

[0207] A frame of the receiving element is made of aluminum for the fire test, while a cover element is made of gypsum.

[0208] The test plate is preferably made of a sandwich material 112, the first layer element 114 and the second layer element 116 of which are made of a flat material 100.

[0209] The flat material 100 is made of a polypropylene material, for example, in which a fiber material 106 having a proportion of approximately 80 wt. %, based on the total mass of the flat material 100, is received. The fiber material 106 is preferably made of glass fibers.

[0210] A thickness of the first layer element 114 and of the second layer element 116 perpendicular to their respective main extension plane is preferably approximately 1.5 mm in each case.

[0211] In particular, the test plate for the fire test has dimensions of approximately 695 mm×approximately 695 mm.

[0212] FIG. 3 shows a temporal temperature profile of different regions.

[0213] The temperature in ° C. over the time tin seconds is plotted on the x-axis.

[0214] A temporal profile of the temperature of an inner side of the test plate facing an interior space of the receiving element and arranged away from the flames is shown as graph C (dash-dot line).

[0215] Graphs A (dashed line) and B (dotted line) show a temporal profile of the temperatures of the regions made of aluminum. From graphs A and B, it can be seen that the regions made of aluminum heat up to temperatures in excess of 350° C.

[0216] Graph C shows that the temperature on the inner side of the test plate also increases to a maximum of 99° C. after approximately 130 seconds.

[0217] In the fire test carried out, there is in particular only a loss of mass of approximately 14 g or less of the test plate made of the sandwich material 112.

[0218] This means in particular that the flat material 100 offers adequate protection and/or is stable even in the event of a fire.

[0219] Due to the high proportion of fiber material 106 to the flat material 100, preferably no and/or little oxygen can penetrate into deeper layers of the outer layer element, as a result of which the test plate has increased stability in particular.

[0220] The flat material 100 preferably has increased impact properties.