ELECTROCHEMICAL CELL COMPRISING A SHELL INCLUDING A FIRST PORTION COMPRISING A HEAT-SENSITIVE MATERIAL AND A SECOND PORTION COMPRISING A HEAT-RESISTANT MATERIAL

Abstract

The invention relates to an electrochemical cell (10) for a battery of an electric or hybrid motor vehicle, said electrochemical cell (10) having a prismatic shape, said electrochemical cell (10) comprising a shell (20), said electrochemical cell (10) being positioned in said shell (20), said shell (20) comprising two lateral faces positioned on either side of said electrochemical cell (10), each lateral face comprising a first portion (1) and a second portion (2), each second portion (2) comprising a positive electrode (3) or a negative electrode (4), characterized in that each first portion (1) comprises a first material capable of breaking in the event of thermal runaway of the electrochemical cell (10), each second portion (2) comprising a second material capable of resisting heat and / or pressure in the event of thermal runaway,said first portion (1) being configured to rupture in the event of overpressure of said electrochemical cell (10). Figure 2,

Description

Title of the invention: ELECTROCHEMICAL CELL COMPRISING A SHELL INCLUDING A FIRST PORTION COMPRISING A HEAT-SENSITIVE MATERIAL AND A SECOND PORTION COMPRISING A HEAT-RESISTANT MATERIAL

[0001] The invention relates to the field of electrochemical battery cells for electric or hybrid motor vehicles.

[0002] Prior art utility model CN218896778 is known, describing a battery housing comprising side plates connected in sequence. The side plates form a receiving cavity in which a battery cell is located. The battery cell contains a gas. Each side plate has a weakened area. Each weakened area has a flow guide and a flow guide channel open into the receiving cavity. The weakened areas rupture when the gas pressure is too high. However, a drawback remains. Rupture of the weakened areas risks damaging the battery cell electrodes because the latter have no protection.

[0003] The objective of the present invention is to remedy these drawbacks and to allow the degassing of an electrochemical cell while preserving its electrodes.

[0004] To achieve this objective, the invention proposes an electrochemical battery cell for an electric or hybrid motor vehicle, said electrochemical cell having a prismatic shape, said electrochemical cell comprising a shell, said electrochemical cell being positioned in said shell, said shell comprising two lateral faces positioned on either side of said electrochemical cell, each lateral face comprising a first portion and a second portion, each second portion comprising a positive electrode or a negative electrode, notable in that each first portion comprises a first material capable of breaking in the event of thermal runaway of the electrochemical cell, each second portion comprising a second material capable of resisting heat and / or pressure in the event of thermal runaway of the electrochemical cell,said first portion being configured to rupture in the event of overpressure of said electrochemical cell.

[0005] Thanks to the invention, in case of overpressure, the gas generated by the electrochemical cell is evacuated to avoid the deterioration of the surrounding electrochemical cells.

[0006] Preferably, the second portion has edges, the first portion having edges, the edges of the second portion having a length greater than the edges of the first portion.

[0007] In this way, when the thermal runaway of the electrochemical cell causes a fire to start, the risk of contact between the electrodes and the flames is reduced.

[0008] Advantageously, each second portion comprises an insulating material, said insulating material surrounding said positive electrode and / or said negative electrode.

[0009] In this way, the protection of the electrodes is reinforced in the event of overpressure of the electrochemical cell.

[0010] Advantageously, the first portion and the second portion form a rim.

[0011] The rim helps to guide the gas out of the electrochemical cell.

[0012] Advantageously, said electrochemical cell comprises a third portion, said first portion being positioned between said second portion and said third portion, said third portion comprising the second material.

[0013] The manufacture of an electrochemical cell comprising a third portion is easier.

[0014] Preferably, the first portion and the third portion form an additional rim.

[0015] The presence of an additional rim enhances the efficiency of guiding the gas outwards from the electrochemical cell.

[0016] Advantageously, said first material comprises plastic.

[0017] A first plastic portion facilitates breakage to allow degassing of the electrochemical cell.

[0018] Alternatively, said first material comprises aluminum, the second material comprising aluminum, said first portion having a first thickness, said second portion and / or said third portion having a second thickness, said first thickness being less than said second thickness.

[0019] The small thickness of the first portion compared to the thickness of the second portion facilitates the rupture of the first portion in case of overpressure and prevents the deterioration of the second portion when the pressure of the electrochemical cell increases.

[0020] The invention also relates to a battery for an electric or hybrid motor vehicle, remarkable in that said battery comprises a plurality of electrochemical cells as previously described.

[0021] Furthermore, the invention relates to an electric or hybrid motor vehicle comprising such a battery.

[0022] The invention will be further detailed by describing non-limiting embodiments, and based on the accompanying figures illustrating variants of the invention, in which: - [Fig.l] schematically illustrates a profile view of a shell comprising an electrochemical cell according to a first embodiment of the invention; - [Fig.2] schematically illustrates a front view of the hull including the electrochemical cell according to the first embodiment of the invention; - [Fig.3] schematically illustrates a profile view of the hull comprising the electrochemical cell according to a second embodiment of the invention; - [Fig.4] schematically illustrates a front view of the hull including the electrochemical cell according to the second embodiment of the invention.

[0023] A shell 20 comprising an electrochemical cell 10 according to a first embodiment of the invention is schematically illustrated in [Fig. 1] and [Fig. 2]. The electrochemical cell 10 has a prismatic shape. The electrochemical cell 10 is positioned in the shell 20. The shell 20 has two lateral faces. The lateral faces are positioned on either side of said electrochemical cell 10. Each lateral face has a first portion 1 and a second portion 2. The second portion 2 has a positive electrode 3 and / or a negative electrode 4 such that said electrochemical cell 10 has both a negative electrode 3 and a positive electrode 4. Preferably, each second portion 2 has an insulating material 8 positioned around said positive electrode 3 and / or said negative electrode 4.The first portion 1 of each lateral face comprises a first material capable of rupturing in the event of thermal runaway of the electrochemical cell 10. Indeed, in the event of an anomaly in the electrochemical cell 10, the pressure and temperature of said electrochemical cell 10 increase. This causes the first portion 1 to rupture, thus allowing the degassing of said electrochemical cell 10. The expulsion of the gas produced by the defective electrochemical cell 10 reduces the risk of damage to the surrounding electrochemical cells. The second portion 2 of each lateral face comprises a second material capable of resisting heat and / or pressure in the event of thermal runaway of the electrochemical cell 10. In the event of overpressure, the second portion 2 is not affected.Thus, the configuration of a battery containing a plurality of electrochemical cells is not affected because the electrochemical cell 10 deforms only at the lateral faces. This prevents disruption of the battery configuration, and consequently, the deterioration of the other non-defective electrochemical cells. Preferably, the first portion 1 and the... The second portion 2 forms a rim 5. Thus, during degassing, the gas produced by the defective electrochemical cell 10 is guided outwards from said electrochemical cell 10. Preferably, the first portion 1 and the second portion 2 each have edges. The edges of the second portion 2 are longer than the edges of the first portion 1. Thus, when thermal runaway degenerates into a fire, the positive electrode 3 and the negative electrode 4 are better protected because the edges of the second portion reduce the risk of the flames reaching the positive electrode 3 and the negative electrode 4.

[0024] The shell 20 comprising the electrochemical cell 10 according to a second embodiment of the invention is schematically illustrated in [Fig. 3] and [Fig. 4]. In the second embodiment, said electrochemical cell 10 comprises a third portion 6. The first portion 1 is positioned between the second portion 2 and the third portion 6. The third portion 6 comprises the second material capable of resisting heat and / or pressure in the event of thermal runaway of the electrochemical cell 10, so that said third portion 6 remains in place in the event of outgassing of said electrochemical cell 10. Preferably, the first portion 1 and the third portion 6 form an additional rim 7 which also allows, in the event of rupture of the first portion 1, the gas to be guided out of said electrochemical cell 10. Preferably, the third portion 6 comprises edges.The edges of the first part 1 are longer than the edges of the third part 6. As an example, the edges of the third part are the same length as the edges of the second part.

[0025] Preferably, the first material comprises plastic. Indeed, plastic has a relatively low melting point. Thus, the rupture of the first portion 1 occurs rapidly following deterioration, causing thermal runaway of the electrochemical cell 10 to allow for its rapid degassing. It is necessary to eliminate the overpressure quickly before it poses risks to the other electrochemical cells of the battery. Alternatively, the first and second materials comprise aluminum. In this case, the first portion 1 has a first thickness and the second portion 2 has a second thickness. The first thickness is less than the second thickness.The first portion 1 is thus less resistant to temperature and pressure compared to the second portion 2, so that when the electrochemical cell 10 malfunctions, the first portion 1 breaks while the second portion 2 remains intact. Furthermore, the first portion 1 can be pre-cut to facilitate its rupture in the event of thermal runaway of the electrochemical cell 10. In the second embodiment, . said third portion 6 presents the second thickness so as to avoid its rupture during the thermal runaway of the electrochemical cell 10.

[0026] Furthermore, the invention relates to a battery for an electric or hybrid motor vehicle comprising a plurality of electrochemical cells as previously described, as well as an electric or hybrid motor vehicle comprising such a battery.

Claims

Demands

1. An electrochemical cell (10) for a battery of an electric or hybrid motor vehicle, said electrochemical cell (10) having a prismatic shape, said electrochemical cell (10) comprising a shell (20), said electrochemical cell (10) being positioned in said shell (20), said shell (20) comprising two lateral faces positioned on either side of said electrochemical cell (10), each lateral face comprising a first portion (1) and a second portion (2), each second portion (2) comprising a positive electrode (3) or a negative electrode (4), characterized in that each first portion (1) comprises a first material capable of breaking in the event of thermal runaway of the electrochemical cell (10), each second portion (2) comprising a second material capable of resisting heat and / or pressure in the event of thermal runaway of the electrochemical cell (10),said first portion (1) being configured to rupture in the event of overpressure of said electrochemical cell (10).

2. Electrochemical cell (10) according to claim 1 characterized in that each second portion comprises an insulating material (8), said insulating material (8) surrounding said positive electrode (3) and / or said negative electrode (4).

3. Electrochemical cell (10) according to claim 1 or 2 characterized in that the second portion (2) has edges, said first portion (1) having edges, the edges of said second portion (2) having a length greater than the edges of said first portion (1).

4. Electrochemical cell (10) according to any one of claims 1 to 3 characterized in that the first portion (1) and the second portion (2) form a rim (5).

5. Electrochemical cell (10) according to any one of claims 1 to 4 characterized in that said electrochemical cell (10) comprises a third portion (6), said first portion (1) being positioned between said second portion (2) and said third portion (6), said third portion (6) comprising the second material.

6. Electrochemical cell (10) according to claim 5 characterized in that the first portion (1) and the third portion (6) form an additional rim (7).

7. Electrochemical cell (10) according to any one of claims 1 to 6 characterized in that said first material comprises plastic.

8. Electrochemical cell (10) according to any one of claims 1 to 6 characterized in that said first material comprises aluminum, the second material comprising aluminum, said first portion (1) having a first thickness, said second portion (2) having a second thickness, said first thickness being less than said second thickness.

9. Battery of an electric or hybrid motor vehicle, characterized in that said battery comprises a plurality of electrochemical cells (10) according to any one of claims 1 to Q

10. O. Electric or hybrid motor vehicle comprising a battery according to claim 9.

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