DE102013208135B4 - Battery with overcharge protection - Google Patents

Abstract

Battery (1), comprising- a battery cell (10) and- a hard-shell battery cell housing (20) with an interior (21) for accommodating the battery cell (10), the battery cell (10) having at least one current conductor which is equipped with a fuse (11 ) is provided for interrupting a short-circuit current, an insulation means (30) for electrically insulating the battery cell (10) from the hard-shell battery cell housing (20) being provided between the battery cell (10) and an inner wall of the hard-shell battery cell housing (20) delimiting the interior (21). is, and wherein the battery (1) comprises an arc extinguishing agent (12) for extinguishing an arc, the arc extinguishing agent (12) having an inner layer (12a) and an outer layer (12b), the outer layer (12b) of the arc extinguishing agent ( 12) the inner layer (12) of the arc extinguishing agent (12) is coated, the inner layer (12a) of the arc extinguishing agent (12) being made of a melamine-based material and the outer layer (12b) being made of a silicone rubber.

Description

State of the art

Various tests are carried out on lithium-ion battery cells for approval for transport and use in motor vehicles. Among other things, so-called abuse tests are carried out, which assess the behavior of the cells under extreme situations.

In order to mitigate the consequences of some abuse tests, mechanisms are known which interrupt the flow of current into the cell in extreme situations.

The publication US 2011/0183192 A1 describes a hard-shell battery cell housing with an oxide layer formed thereon and a colored sealing layer formed on the oxide layer.

The publication US 3,166,656 A describes a fuse cartridge with an extinguishing agent core which comprises a binder selected from the group consisting of melamine resins, silicone resins, calcium sulfate and mixtures thereof.

The US 2011 / 0 244 280 A1 shows a secondary battery with a fuse.

The JP H10-3 901 A shows a high temperature secondary battery.

The EP 2 793 291 A2 shows a rechargeable battery module.

The US 4,251,699 A shows an arc extinguishing agent with dicyandiamide.

The US 2011 / 0 244 286 A1 discloses an electrochemical cell with an electrically insulating housing.

The EP 1 162 640 A1 describes an extinguishing agent for quenching arcs.

Disclosure of the invention

The subject of the invention is a battery which comprises a battery cell and a hard-shell battery cell housing with an interior for accommodating the battery cell. The battery cell has at least one current arrester, which is provided with a fuse for interrupting a short-circuit current. An insulation means for electrically isolating the battery cell from the hard-shell battery cell housing is provided between the battery cell and an inner wall of the hard-shell battery cell housing that delimits the interior space. In addition, the battery includes (at least) an arc extinguishing agent for extinguishing an arc.

In addition, the invention relates to a battery cell fuse suitable for such a battery and to a hard-shell battery cell housing suitable for such a battery.

By means of the battery according to the invention, the battery fuse according to the invention and the hard-shell battery cell housing according to the invention, a battery cell can advantageously be better protected in extreme situations. The fuse can significantly reduce the risk of a short circuit. The insulating agent and the arc extinguishing agent can also significantly reduce the risk of arcs within the housing. This can be achieved in particular by the insulation means electrically insulating the battery cell from the inner wall of the hard-shell battery cell housing delimiting the interior space and in this way preventing the formation of arcs between the battery cell, for example the anode and/or the cathode or the cell coil (jelly roll). on the one hand and the housing on the other hand hindered or even prevented. However, if an arc occurs in an extremely extreme situation, it can be extinguished by the arc extinguishing agent. Overall, not only the reject rate when approving the battery, but also the safety of the battery in other extreme situations can be significantly improved. Such batteries can be used particularly advantageously in large battery systems in which a large number of battery cells are interconnected, in particular to achieve high voltages, for example 400 V, since they - for example even at high voltage differences - still cause arcing and an associated rise in temperature can suppress or even prevent and thereby increase security.

The arc extinguishing agent can in particular comprise a melamine-based material and/or a silicone rubber. Both material classes have a high level of stability compared to the high temperatures that arise when arcs are formed and have good arc extinguishing properties, which can extinguish an arc that is formed, for example by melting and/or expanding.

Melamine-based materials also offer the advantage that when they decompose at high temperatures, they form non-ionizable gases that can have very good arc extinguishing properties.

In the context of an embodiment not according to the invention, the arc extinguishing agent comprises a melamine-based material. In particular, the arc extinguishing agent can comprise a melamine-based polymer.

With silicone rubbers, however, the mechanical strength and robustness can advantageously be adjusted very well.

As part of a further embodiment not according to the invention, the arc extinguishing agent comprises a silicone rubber. In this way, good arc extinguishing and good material properties can advantageously be achieved on the one hand.

According to the invention, the arc extinguishing agent has an inner layer and an outer layer. The outer layer of the arc extinguishing agent covers the inner layer of the arc extinguishing agent. The inner layer of the arc extinguishing agent is made of a melamine-based material, in particular polymer. The outer layer of the arc extinguishing agent is made of a silicone rubber. In this way, the very good arc extinguishing properties of melamine-based materials can be advantageously combined with the very easily adjustable mechanical strength and robustness of silicone rubbers. The fact that the outer layer is made of silicone rubber and is therefore elastic can also advantageously ensure that arc-extinguishing gas created from melamine-based material is held at the point where the arc is generated and can therefore develop its arc-extinguishing effect even better.

In another embodiment not according to the invention, the arc extinguishing agent is a melamine resin-silicone rubber copolymer or a melamine resin-silicone rubber polymer blend. The advantages of both classes of materials can be advantageously combined in one material.

In principle, the battery can have both one arc extinguishing agent and several arc extinguishing agents.

In one embodiment, the fuse is equipped with an arc extinguishing agent for extinguishing an arc. In this way, in the event of the fuse tripping, the formation of an arc between the ends of the tripped fuse can advantageously be prevented.

The arc extinguishing means of the fuse can be designed, for example, as described above. For example, the fuse can be encased, in particular completely, with the arc extinguishing agent. For example, the inner layer of the arc extinguishing agent can be applied, in particular directly, to the fuse.

The current arrester equipped with the fuse can be made of aluminum, for example, and/or the cathode current arrester of the battery cell.

The fuse can be made, for example, from aluminum and/or the material of the current arrester equipped with it.

The insulating means in the form of a type of internal insulation can advantageously reduce or even prevent the formation of arcs between the battery cell, in particular the anode or the cell coil.

In the context of a further embodiment, the insulation means comprises an insulation layer made of an electrically insulating material formed on the inner wall of the hard-shell battery cell housing. The insulation layer formed on the inner wall of the hard-shell battery cell housing can in particular be an oxide layer, for example anodized, produced by anodic oxidation or a powder coating.

For example, the insulation layer can be produced by anodizing or anodizing, i.e. oxidizing, the hard-shell battery cell housing, in particular a housing base body of the hard-shell battery cell housing, for example made of aluminum. The anodizing or anodizing of the hard-shell battery cell housing can be carried out, for example, in aqueous electrolytes. Depending on the reaction conditions, the electrolyte used or the additives, the resulting oxide layer, for example aluminum oxide layer, is porous (Porous Oxides) or non-porous or dense (Barrier Oxides). The hardness of the oxide layer, for example aluminum oxide layer, can also be controlled via the reaction conditions.

However, it is also possible to provide the inner wall or inside of the hard-shell battery cell housing, in particular a housing base body of the hard-shell battery cell housing, with a powder coating. During powder coating, the hard-shell battery cell housing, in particular a housing base body of the hard-shell battery cell housing, can in particular be electrostatically charged and, for example coated with an epoxy and/or polyester resin.

The insulation layer formed on the inner wall of the hard-shell battery cell housing can in particular have a layer thickness in a range of ≥ 1 µm to ≤ 100 µm.

It is also possible to provide two or more insulation layers. For example, an oxide layer, for example aluminum oxide layer, which is formed by anodizing or anodizing the surface of the hard-shell battery cell housing, can be additionally powder-coated. In this way, pores and/or defects in the oxide layer can advantageously be closed, in particular completely, with the powder coating and the electrical insulation can thus be improved by the insulating agent.

In the context of a further embodiment, the insulation means additionally comprises a further insulation layer made of an electrically insulating material, which is applied to the insulation layer formed on the inner wall of the hard-shell battery cell housing. The insulation layer formed on the inner wall of the hard-shell battery cell housing can be an oxide layer, for example anodized, in particular produced by anodic oxidation. The further insulation layer can be a powder coating.

The further insulation layer can in particular also have a layer thickness in a range of ≥ 1 µm to ≤ 100 µm.

As part of another, alternative or additional embodiment, the insulation means comprises an insert made of an electrically insulating material that can be inserted into the interior of the hard-shell battery cell housing. The insert can be made of a plastic, for example.

Alternatively or in addition to equipping the fuse with an arc extinguishing agent, in a further embodiment the insulation means is equipped with an arc extinguishing agent for extinguishing an arc. Advantageously, even if an arc can be formed between the battery cell and the hard-shell battery cell housing despite the electrically insulating properties of the insulating agent, the formation of the arc can be hindered or prevented by the arc extinguishing agent of the insulating agent.

The arc extinguishing means of the insulation means can also be designed as described above. The arc extinguishing agent of the insulation agent can be applied, for example, to an insulation layer or the insert. For example, the inner layer of the arc extinguishing agent of the insulation agent can be applied, in particular directly, to an insulation layer or the insert.

As part of a further embodiment, the hard-shell battery cell housing has an electrically conductive membrane and an electrically conductive contact element. The membrane can be electrically conductively connected or connectable to one pole, in particular the positive pole, of the hard-shell battery cell housing and the contact element to the other pole, in particular the negative pole, of the hard-shell battery cell housing.

In a starting position, the membrane can in particular be arranged at a distance from the contact element. For example, in the initial position, the membrane can be curved towards the interior of the hard-shell battery cell housing. In a triggered position, the membrane can in particular contact the contact element. For example, the membrane can be curved outwards. If the membrane is curved, the transition from the starting position to the triggered position can be brought about, for example, by an increase in pressure in the interior of the hard-shell battery cell housing.

A current conductor of the battery cell can in particular be connected or connectable in an electrically conductive manner to one pole of the hard-shell battery cell housing. In addition, this current conductor of the battery cell can be connected or connectable in an electrically conductive manner, in particular to the membrane. The other current conductor of the battery cell can in particular be electrically conductively connected or connectable to the other pole of the hard-shell battery cell housing. In addition, the other current conductor of the battery cell can be connected or connectable in an electrically conductive manner, in particular to the contact element.

The current conductor of the battery cell provided with the fuse can be connected or connectable in an electrically conductive manner, in particular via the fuse, to the pole of the hard-shell battery cell housing.

In a special embodiment, the current arrester provided with the fuse is the cathode current arrester of the battery cell. The cathode current arrester can be connected or connectable in an electrically conductive manner, in particular via the fuse, to the positive pole of the hard-shell battery cell housing. In particular, the Cathode current arrester can also be electrically conductively connected or connectable to the membrane. The other current arrester can in particular be the anode current arrester of the battery cell. The anode current arrester can in particular be connected or connectable in an electrically conductive manner to the negative pole of the hard-shell battery cell housing. In particular, the anode current arrester can also be electrically conductively connected or connectable to the contact element.

The battery cell can in particular be a wound cell and/or a lithium-ion cell.

In a further embodiment, the battery cell is a lithium-ion wound cell.

The hard-shell battery cell housing (cell can) can essentially be made of aluminum, for example apart from electrical contacts such as the poles and electrical insulators. In particular, the hard-shell battery cell housing can have a housing base body made of aluminum that forms the interior. In addition, the hard-shell battery cell housing can, for example, have a cover made of aluminum, in particular closing the interior.

With regard to further technical features and advantages of the battery according to the invention, reference is hereby made explicitly to the explanations in connection with the battery cell fuse according to the invention and the hard-shell battery cell housing according to the invention as well as to the figures and the description of the figures.

Another object is a battery cell fuse, which comprises a melamine-based layer made of a melamine-based material, in particular a melamine-based polymer, and a silicone rubber layer made of a silicone rubber, the melamine-based layer being applied, in particular directly, to the fuse and wherein the silicone rubber layer covers the melamine-based layer. The fuse can be made of aluminum, for example.

With regard to further technical features and advantages of the battery cell fuse according to the invention, reference is hereby explicitly made to the explanations in connection with the battery according to the invention and the hard-shell battery cell housing according to the invention as well as to the figures and the description of the figures.

The invention further relates to a hard-shell battery cell housing with an interior for accommodating a battery cell and an inner wall delimiting the interior, an oxide layer being formed on the inner wall of the hard-shell battery cell housing, with a coating, in particular a powder coating, made of an electrically insulating material and / or or an arc extinguishing material is applied.

The oxide layer can in particular be produced by anodic oxidation. For example, the oxide layer can be an oxide layer produced or anodized using an anodizing process.

The coating, in particular the powder coating, can comprise, for example, a melamine-based material, in particular a melamine-based polymer, and/or a silicone rubber as the arc-extinguishing material.

For example, the coating, in particular the powder coating, may comprise an inner/lower layer and an outer/upper layer, the inner layer being formed from a melamine-based material and the outer layer from a silicone rubber.

Alternatively or additionally, the coating, in particular the powder coating, can also comprise a melamine resin-silicone rubber copolymer or a melamine resin-silicone rubber polymer blend.

With regard to further technical features and advantages of the hard-shell battery cell housing according to the invention, reference is hereby made explicitly to the explanations in connection with the battery according to the invention and the battery cell fuse according to the invention as well as to the figures and the description of the figures.

drawings

• 1 einen schematischen Querschnitt durch eine Ausführungsform einer erfindungsgemäßen Batterie in einer Ausgangsstellung;
• 2 die in 1 gezeigte Batterie in einer ausgelösten Stellung;
• 3a eine schematische Seitenansicht einer Ausführungsform einer erfindungsgemäßen Batteriezellensicherung;
• 3b eine schematische, perspektivische Ansicht der in 3a gezeigten Batteriezellensicherung;
• 3c einen stark schematisierten Querschnitt durch die in 3a und 3b gezeigte Batteriezellensicherung;
• 4 eine chemische Strukturformel eines Melamin-basierten Polymers; und
• 5 eine chemische Strukturformel eines Silikonkautschuks.

Further advantages and advantageous refinements of the objects according to the invention are illustrated by the drawings and explained in the following description. It should be noted that the drawings are only descriptive and are not intended to limit the invention in any way. Show it

• 1 a schematic cross section through an embodiment of a battery according to the invention in a starting position;
• 2 in the 1 battery shown in a tripped position;
• 3a a schematic side view of an embodiment of a battery cell fuse according to the invention;
• 3b a schematic, perspective view of the in 3a battery cell fuse shown;
• 3c a highly schematized cross section through the in 3a and 3b battery cell fuse shown;
• 4 a chemical structural formula of a melamine-based polymer; and
• 5 a chemical structural formula of a silicone rubber.

1 shows a battery 1, which includes a hard-shell battery cell housing 20 with an interior 21 for accommodating a battery cell 10 and a battery cell 10 arranged in the interior 21. The battery cell 10 can be, for example, a lithium-ion wound cell, a so-called jelly roll.

1 indicates that the battery cell 10 has two current arresters, one of which is provided with a fuse 11 for interrupting a short-circuit current. This current arrester is electrically connected to a pole 24 of the hard-shell battery cell housing 20 via the fuse 11. The other current collector is electrically connected to the other pole 25 of the hard-shell battery cell housing 20, which is electrically insulated by an insulating element 26 with respect to a metallic housing base body of the hard-shell battery cell housing 20, for example made of aluminum, which forms the interior 21.

The current arrester provided with the fuse 11 can in particular be the cathode current arrester of the battery cell 10 and electrically conductively connected to the positive pole 24 of the hard-shell battery cell housing 20. Accordingly, the other current collector can be the anode current collector of the battery cell 10 and electrically conductively connected to the negative pole 25 of the hard-shell battery cell housing 20.

1 shows that the hard-shell battery cell housing 20 further has an electrically conductive membrane 22, which in the starting position shown, i.e. a fault-free state, is curved inwards or towards the interior 21 of the hard-shell battery cell housing 20 and is arranged at a distance from an electrically conductive contact element 23.

Via the hard-shell battery cell housing 20, in particular its housing base body, the membrane 22 is electrically conductively connected to the positive pole 24 of the hard-shell battery cell housing 20 and to the current arrester (cathode current arrester) of the battery cell 10, which is equipped with the fuse 11. The contact element 23 is electrically conductively connected to the negative pole 25 of the hard-shell battery cell housing 20 and to the other current collector (anode current collector) of the battery cell 10. Through the insulation element 26, the contact element 23 is electrically insulated from the housing base body of the hard-shell battery cell housing 20 and thus the membrane 23 and the positive pole 24 of the hard-shell battery cell housing 20 as well as the fuse 11 and the cathode current arrester of the battery cell 10.

1 shows that between the battery cell 10 and an inner wall of the hard-shell battery cell housing 20 delimiting the interior 21, in particular of its housing base body, an insulating means 30 for electrically insulating the battery cell 10 from the hard-shell battery cell housing 20 is provided, which comprises an insulating layer made of an electrically insulating material , which is formed on the inner wall of the hard-shell battery cell housing 20. This can in particular be a layer system made up of two insulation layers (not shown), which, in addition to the insulation layer formed on the inner wall of the hard-shell battery cell housing 20, comprises a further insulation layer made of an electrically insulating material, which is on the inner wall of the hard-shell battery cell housing 20 trained insulation layer is applied. The insulation layer formed on the inner wall of the hard-shell battery cell housing 20 can in particular be an oxide layer and the further insulation layer can be a powder coating.

1 further indicates that the fuse 11 is equipped, for example encased, with an arc extinguishing agent 12 for extinguishing an arc. The arc extinguishing agent 12 can in particular comprise a melamine-based polymer and/or a silicone rubber. In addition to the fuse 11, the insulation means 30 can also be equipped with an arc extinguishing means for extinguishing an arc (not shown).

2 shows the in 1 Battery shown in the initial position in a triggered position.

2 illustrates that in the triggered position the membrane 22 is curved outwards and contacts the contact element 23. The arching or outward pushing of the membrane 22 from the starting position into the out Released position can be caused in particular by increased pressure in the cell 10 and thus in the interior of the hard-shell battery cell housing 20. Such a device formed by the membrane 22 and the contact element 23 can also be referred to as an OSD (Overcharge Safety Device) or CID (Current Interruptive Device).

Because the membrane 22 contacts the contact element 23 in the triggered position, the membrane 22 is connected to the negative pole 25 in an electrically conductive manner. The contact element 23 preferably has a lower electrical resistance than the battery cell 10 or its chemically active parts (jelly roll). The arrows in 2 illustrate that this can cause a current applied to the poles 24, 25, for example charging current, to no longer flow through the cell 10, but through the hard-shell battery cell housing 20, in particular its housing base body.

The different arrows in 2 illustrate that, however, at the same time a short circuit occurs across the cell 10, which without the fuse 11 would flow from the cell 10 through the hard-shell battery cell housing 20, in particular its housing base body, over the membrane 22 and could destroy it, which, however, would occur if the fuse 11 was triggered can advantageously be avoided. In addition to overcharging the cell 10, the cell fuse 11 can also be triggered by an external short circuit, that is, by a conductive connection between the positive pole 24 and negative pole 25 with a very low resistance.

The 3a and 3b show an embodiment of a battery cell fuse 11 according to the invention, which is provided with an arc extinguishing agent 12 and can also be referred to as ARSD (English: Arc Remocal Safety Device). Such a fuse 11 provided with an arc extinguishing agent 12 can advantageously prevent the formation of an arc at the ends of the triggered cell fuse 11, at least in the event that the fuse 11 is triggered. Such a fuse 11, 12 can be attached, for example, to the cathode current collector of a battery cell 10 and melted with the arc extinguishing agent 12. When the fuse 11 is triggered, the arc extinguishing agent 12 can then melt, expand and/or gas and thus extinguish the resulting arc and thereby prevent or at least reduce an increase in temperature.

3c illustrates that the arc extinguishing agent 12 has an inner layer 12a and an outer layer 12b, the outer layer 12b of the arc extinguishing agent 12 encasing the inner layer 12a of the arc extinguishing agent 12. The inner layer 12a of the arc extinguishing agent 12 can in particular be made of a melamine-based material and the outer layer 12b can be made of a silicone rubber. 3c shows that the inner layer 12a of the arc extinguishing agent 12 is applied directly to the fuse 11.

4 shows a chemical structural formula of a melamine-based polymer, which can be produced by polymerizing melamine with formaldehyde and can be used as an arc-extinguishing agent, in particular for forming the arc-extinguishing agent 12.

5 shows a chemical structural formula of a silicone rubber, which can also be used as an arc-extinguishing agent, in particular for forming the arc-extinguishing agent 12.

Claims (11)

Battery (1), comprising - a battery cell (10) and - a hard-shell battery cell housing (20) with an interior (21) for accommodating the battery cell (10), wherein the battery cell (10) has at least one current collector which is provided with a fuse (11) for interrupting a short-circuit current, wherein an insulation means (30) for electrically isolating the battery cell (10) from the hard-shell battery cell housing (20) is provided between the battery cell (10) and an inner wall of the hard-shell battery cell housing (20) delimiting the interior (21), and wherein the battery (1) comprises an arc extinguishing means (12) for extinguishing an arc, wherein the arc extinguishing agent (12) has an inner layer (12a) and an outer layer (12b), the outer layer (12b) of the arc extinguishing agent (12) encasing the inner layer (12) of the arc extinguishing agent (12), the inner layer (12a) of the arc extinguishing agent (12) is made of a melamine-based material and the outer layer (12b) is made of a silicone rubber. Battery after Claim 1 , wherein the fuse (12) is equipped with an arc extinguishing means (12) for extinguishing an arc. Battery after one of the Claims 1 or 2 , wherein the insulation means (30) is on the inner wall of the hard-shell battery cell housing (20) formed insulation layer made of an electrically insulating material, wherein the insulation layer formed on the inner wall of the hard-shell battery cell housing (20) is an oxide layer or a powder coating. Battery after Claim 3 , wherein the insulation means (30) additionally comprises a further insulation layer made of an electrically insulating material, which is applied to the insulation layer formed on the inner wall of the hard-shell battery cell housing (20), wherein the insulation layer formed on the inner wall of the hard-shell battery cell housing (20) has an oxide layer and the further insulation layer is a powder coating. Battery after one of the Claims 1 until 4 , wherein the insulation means (30) comprises an insert made of an electrically insulating material that can be inserted into the interior (21) of the hard-shell battery cell housing (20). Battery after one of the Claims 1 until 5 , wherein the insulation means (30) is equipped with an arc extinguishing agent for extinguishing an arc, the arc extinguishing agent being applied to an insulation layer or the insert. Battery after one of the Claims 1 until 6 , wherein the hard-shell battery cell housing (20) has an electrically conductive membrane (22) and an electrically conductive contact element (23), the membrane (22) being connected to one pole (24) of the hard-shell battery cell housing (20) and the contact element (23) to the other Pole (25) of the hard-shell battery cell housing (20) is electrically conductively connected or connectable, the membrane (22) being spaced apart from the contact element (23) in a starting position and the membrane (22) contacting the contact element (23) in a triggered position , the current conductor of the battery cell (10) provided with the fuse (11) being connected via the fuse (11) to one pole (24) of the hard-shell battery cell housing (20) and the other current conductor of the battery cell (10) to the other pole (25) of the Hard-shell battery cell housing (20) is electrically conductively connected or connectable. Battery after one of the Claims 1 until 7 , wherein the current arrester provided with the fuse (11) is the cathode current arrester of the battery cell (10) and is electrically conductively connected or connectable via the fuse (11) to the positive pole (24) of the hard-shell battery cell housing (20). Battery after one of the Claims 1 until 8th , wherein the battery cell (10) is a lithium-ion wound cell. Battery cell fuse (11), in particular for a battery according to one of the Claims 1 until 9 , comprising a melamine-based layer (12a) made of a melamine-based material and a silicone rubber layer (12b) made of a silicone rubber, wherein the melamine-based layer (12a) is applied to the fuse (11) and wherein the silicone rubber layer (12b) the melamine-based layer (12a) is coated. Hard-shell battery cell housing (20) for a battery according to one of Claims 1 until 9 with an interior (21) for accommodating a battery cell (10) and an inner wall delimiting the interior (21), an oxide layer being formed on the inner wall of the hard-shell battery cell housing (20), with a powder coating made of an electrically insulating material and on the oxide layer /or an arc extinguishing material is applied.

Images