Stationary energy storage system with safety devices

Abstract

Stationary energy storage device (10) comprising: a housing (1) with a base (2) made of a first material, wherein several battery cell modules (3) are arranged in the housing (1) and are electrically interconnected via busbars (4), each busbar (4) having at least one area made of a second material; wherein each battery cell module (3) is mounted in the housing (1) by means of at least one fastening element (5), each fastening element (5) having at least one area made of a third material; wherein at least one locking element (6) is additionally arranged between each battery cell module (3) and the housing (1); and wherein the first material, the second material and the third material each have a melting temperature which is below the melting temperature of the locking element (6).

Description

The present invention relates to a stationary energy store with fuse retaining means, by means of which the battery cell modules arranged in the energy store are additionally fastened to the housing of the energy store.In view of the ever increasing number of fully and partially electrically driven vehicles in road traffic, the corresponding charging possibilities are moving into the center. Since charging the traction battery of an electric vehicle takes more time than refueling a vehicle with an internal combustion engine, in principle a greater number of charging points is required in order to balance the time-related overhead. For this purpose, charging points can be distributed in the environment much more flexibly than classic fuel injectors, which can only be found at gas stations.Thus, for example, covered outer surfaces can be used to locate stationary energy stores therein. This is obviously possible in particular for covered outer surfaces for vehicles, such as carports and parking facilities at shopping houses, where parked electric vehicles can also be directly charged. In order to optimally utilize the area above the parking facility, the cell modules with the battery cells arranged therein can be positioned as compactly as possible with respect to one another.For example, CN 113650522 A discloses an intelligent battery exchange cabinet for electric vehicles, wherein a special extinguishing device is provided, which comprises a readily melting wax rod. Further, European patent EP 3 107 145 B1 discloses a fire extinguishing system for a vehicle battery, in which fire extinguishing packs comprising materials having different melting points are provided.KR1020100407A discloses a battery rack with fire prevention provisions, which includes a plurality of battery modules each having at least one secondary battery for storing and releasing energy, which are electrically connected to each other and stacked in a vertical direction with a lower surface inclined with respect to a horizontal surface, and a rack case in which the plurality of battery modules are accommodated and which includes an escape unit provided on a lower surface of the plurality of battery modules and to be opened by heat or pressure applied from the at least one battery module.DE 10 2020 204 402 B3 discloses a battery protection system for a motor vehicle, wherein the battery protection system has: a battery device having a battery housing, a protection device arranged on the battery housing having at least one protection body, wherein the at least one protection body is movable, wherein the protection body is arranged at least partially on a lower side of the battery housing in a normal position, and wherein the protection body is arranged at least partially on an upper side of the battery housing in a danger position, an activatable drive device which is configured to move the protection body from the normal position into the danger position when the drive device is activated.In the light of the above, the object of the present invention can be seen in configuring an energy store such that, in the event of a fault, for example a thermal runaway of a battery cell, the damage thereby arising at the energy store is minimized.This object is achieved by means of the subject matter of the independent claims. Further preferred embodiments are found in the dependent claims.According to the invention, a stationary energy store is provided, which has a housing with a base made of a first material, wherein a plurality of battery cell modules are arranged in the housing and are electrically connected to one another via busbars, wherein each busbar has at least one region having a second material. This region can function as a thermal predetermined breaking point. Each battery cell module is mounted in the housing by means of at least one fastening element, wherein each fastening element has at least one region made of a third material. This region can function as a thermal predetermined breaking point. Between each battery cell module and the housing, at least one securing means is additionally arranged. In this case, the first material, the second material and the third material each have a melting temperature which is below a melting temperature of the fuse retaining means.The stationary energy store is designed such that in the event of a fault in a cell module, in which a corresponding generation of heat occurs, the fastening elements, busbars and the base of the housing heat up or heat up excessively and thus lose mechanical strength. In addition to the selection of suitable materials with regard to their melting points, these components can additionally be designed such that they mechanically fail at a temperature which is above an operating temperature range to be assumed for the battery cell modules or the battery cells arranged therein, and for example melt or completely yield under the applied load. The battery cell module heated by the fault case can then in particular no longer be held in its original position by the fastening means and moves out of the original arrangement of the battery cell modules by gravity. In this case, the battery cell module can preferably move downward out of the battery cell module arrangement, as a result of which its distance from the adjacent battery cell modules is increased. As a result, the defective battery cell module cannot transfer its heat, or at least only to a reduced extent, to the adjacent battery cell modules, as a result of which these are protected from a fault situation.The function of the safety-retaining means is to prevent the defective battery cell module(s) that is no longer retained by its(s) fastening means from being completely released from the housing, that is to say to prevent the defective battery cell module from dropping onto a vehicle or other objects or even persons possibly parked beneath it. By contact of the faulty battery cell module with the base of the housing, the latter also loses its mechanical strength, so that the battery module can pass through the base and at least partially protrude from the housing. As a result, it can be cooled by the ambient air, which is usually cooler than the temperature of a thermally continuous battery cell module even at summer temperatures. Extinguishing by means of another extinguishing agent (e.g. extinguishing water) is also made possible in this way without the battery cell modules still located in the housing being adversely affected. The battery cell module affected by the fault can thus be quickly insulated from the remaining battery cell modules and the fault of the stationary energy store is easily visible from the outside by the battery cell module protruding outward from the bottom of the housing.The housing of the energy store according to the invention has a base which comprises or consists of a material having a low melting point, for example plastic or aluminum. The battery cell modules are mounted in the housing with fastening elements with at least regions with a likewise low melting point, e.g. plastic or aluminum. The busbars between the battery cell modules have or consist of at least one region with a material having a low melting point, e.g. aluminum. In contrast to these elements, each battery cell module is additionally secured in the battery housing by a securing holding means, for example a holding part, made of a material having a comparatively high melting point (e.g. steel).According to further embodiments of the stationary energy store, the battery cell modules can be fastened to the ceiling and / or to the side walls of the housing by means of the fastening elements.According to further embodiments of the stationary energy store, the region of the busbar comprising the second material can extend over the entire line cross section of the busbar. This maximizes the probability that, in the event of an excessive current flow, the affected busbar is completely cut through and, for example, melts.According to further embodiments of the stationary energy store, the busbars can be manufactured from the second material.According to further embodiments of the stationary energy store, the region of the fastening element comprising the third material can extend over the entire force-transmitting cross section of the fastening element. This measure also aims at the fastening means yielding mechanically over its entire force-transmitting cross section when excessively heated and not, for example, a thermally stable part of the fastening means counteracting this process.According to further embodiments of the stationary energy store, the fastening elements can be manufactured from the third material.According to further embodiments of the stationary energy store, the fuse retaining means can be designed such that they permit a predefined movement of each battery cell module relative to the housing in the event of the omission of the at least one fastening element belonging to the battery cell module. The omission of the fastening means can mean a loss of the mechanical strength. This therefore means the case in which the holding force which holds the corresponding battery cell module in its original position is no longer provided by the associated at least one fastening element, but the securing holding means has to apply the holding force in order to prevent the corresponding battery cell module from falling out of the housing.According to further embodiments of the stationary energy store, the predefined movement can be configured such that the distance between the moving battery cell module to all adjacent battery cell modules is increased. Furthermore, the predefined movement can be effected at least to such an extent that the battery cell module concerned comes into contact with the bottom of the housing.According to further embodiments of the stationary energy store, the fastening element can have a retaining cable or a spring.The present invention further comprises the use of materials in a base of a stationary energy store in which a plurality of battery cell modules are arranged, and in busbars by means of which the battery cell modules are electrically interconnected to one another, and in fastening elements by means of which the battery cell modules are mounted in the housing, which have a lower melting point than a material in fuse retaining means, at least one of which is arranged between each battery cell module and the housing, in order to bring about melting of the corresponding busbars and fastening elements in the event of a fault with heat development in an affected battery cell module and to let the affected battery cell module fall at least partially out of the arrangement of the battery cell modules in a manner controlled by the fuse retaining means through the base of the housing.It is understood that the features mentioned above and those still to be explained below can be used not only in the respectively specified combination, but also in other combinations or alone, without departing from the scope of the present invention.Further advantages and embodiments of the invention will become apparent from the description and the accompanying drawing. FIG. 1 shows an exemplary scenario for the use of the stationary energy store according to the invention. FIG. 2 is a cross-sectional view through the one exemplary stationary energy storage device according to the present invention. FIG. 3 illustrates a state of an exemplary stationary energy storage device according to the present invention in the event of a fault.FIG. 1 outlines an exemplary environment in which the present invention may be used. Thus, a covered outer surface 7, e.g. for a vehicle 8, offers space for a stationary energy storage device 10 according to the invention. In order to optimally utilize the area above the parking area, the battery cell modules are compactly combined in an energy store 10.Referring now to FIG. 2, there is shown a cross-sectional view through the one exemplary stationary energy storage device 10 in accordance with the present invention. This has a housing 1 with a base 2 made of a first material, wherein a plurality of battery cell modules 3 are arranged in the housing 1 and are electrically interconnected to one another via busbars 4. Each busbar 4 has at least one region comprising a second material. Each battery cell module 3 is mounted in the housing 1 by means of at least one fastening element 5, wherein each fastening element 5 has at least one region made of a third material. Between each battery cell module 3 and the housing 1 there is additionally arranged at least one securing means 6.As already described, the first material, the second material and the third material each have a melting temperature which is below a melting temperature of the fuse retaining means 6. As a result, a battery cell module 3 affected by a thermal fault can be released from the formation of the battery cell modules 3, since the heat emitted by the battery cell module fuses both the busbars 4 and the fastening means 5. As illustrated in FIG. 3, the fuse holding means 6 then takes over the function of the holding element and allows a movement of the relevant battery cell module 3 (middle battery cell module 3 in FIG. 3 ) downwards to the base 2 of the housing 1 and through it. In the final state, the battery cell module 3 affected by the fault event protrudes out of the housing 1, as a result of which a transfer of its waste heat to the adjacent battery cell modules 3 is prevented.

Claims

Stationary energy store (10), comprising: a housing (1) having a base (2) made of a first material, wherein a plurality of battery cell modules (3) are arranged in the housing (1) and are electrically connected to one another via busbars (4), wherein each busbar (4) has at least one region comprising a second material; wherein each battery cell module (3) is mounted in the housing (1) by means of at least one fastening element (5), wherein each fastening element (5) has at least one region made of a third material; wherein at least one fuse retaining means (6) is additionally arranged between each battery cell module (3) and the housing (1); and wherein the first material, the second material and the third material each have a melting temperature which is below a melting temperature of the fuse retaining means (6).Stationary energy store (10) according to Claim 1, wherein the battery cell modules (3) are fastened to the ceiling and / or to the side walls of the housing (1) by means of the fastening elements (5).Stationary energy store (10) according to Claim 1 or 2, wherein the region of the busbar (4) comprising the second material extends over the entire line cross section of the busbar (4).Stationary energy store (10) according to Claim 3, wherein the busbars (4) are manufactured from the second material.Stationary energy store (10) according to one of Claims 1 to 4, wherein the region of the fastening element (5) comprising the third material extends over the entire force-transmitting cross section of the fastening element (5).Stationary energy store (10) according to Claim 5, wherein the fastening elements (5) are manufactured from the third material.Stationary energy store (10) according to one of Claims 1 to 6, wherein the securing means (6) are designed such that they permit a predefined movement of each battery cell module (3) relative to the housing (1) if the at least one fastening element (5) belonging to the battery cell module (3) is omitted.Stationary energy store (10) according to claim 7, wherein the predefined movement is configured such that the distance between the moving battery cell module (3) to all adjacent battery cell modules (3) is increased.Stationary energy store (10) according to one of Claims 1 to 7, wherein the fastening element (5) has a retaining cable or a spring.Use of materials in a base (2) of a stationary energy store (10), in which a plurality of battery cell modules (3) are arranged, and in busbars (4), by means of which the battery cell modules (3) are electrically connected to one another, and in fastening elements (5), by means of which the battery cell modules (3) are mounted in the housing (1), which have a lower melting point than a material in fuse retaining means (6), at least one of which is arranged between each battery cell module (3) and the housing (1), in order to bring about melting of the corresponding busbars (4) and fastening elements (5) in the event of a fault with heat development in an affected battery cell module (3) and to let the affected battery cell module (31) fall at least partially out of the arrangement of the battery cell modules (3) in a manner controlled by the fuse retaining means (6) through the base (2) of the housing (1).

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