CN209217069U - Secondary cell and battery modules - Google Patents

Abstract

The utility model relates to a kind of secondary cell and battery modules.Secondary cell includes: shell, and including bottom plate and the side plate being connected with bottom plate, the opening that bottom plate and side plate form receiving hole and be connected with receiving hole, opening and bottom plate should be arranged along the axially opposing of receiving hole, and the thickness of bottom plate is greater than the thickness of side plate；Cap assembly is tightly connected with side plate with lid make and break mouth；Electrode assembly, it is set in receiving hole, electrode assembly includes more than two electrode units, electrode unit is formed by the first pole piece, the second pole piece and membrane winding, and there is wide face and leptoprosopy, more than two electrode units are along axially stacked, and the wide face setting corresponding with bottom plate of each electrode unit, and the leptoprosopy of each electrode unit is towards side plate.Swell increment of the secondary cell of the utility model embodiment on thickness direction is smaller or without swell increment, thus it is lower to the stiffness and strength requirement of external fixator when forming battery modules in groups, be conducive to improve energy density.

Description

Secondary cell and battery modules

Technical field

The utility model relates to battery technology fields, more particularly to a kind of secondary cell and battery modules.

Background technique

With the development of technology, secondary cell will be used wider and wider, and is related to producing or live.Secondary cell is also referred to as dynamic Power battery is rechargeable battery.Secondary cell is widely used.The secondary cell of low capacity can be used for small-sized electric car , the secondary cell of high capacity can be used for Large Electric vehicle, such as hybrid vehicle or electric car.Secondary cell is in groups In use, needing each secondary cell serial or parallel connection using busbar connector.Usually busbar connector and secondary cell is positive and negative Pole is welded to connect.Battery modules include multiple secondary cells and the connector for fixing multiple secondary cells.

Secondary cell mainly includes shell, electrode assembly, afflux component and cap assembly.Wherein, electrode assembly be by Anode pole piece, cathode pole piece and isolation film winding stack.In the prior art, secondary cell in some cases its wrapped The electrode assembly included can expand itself, so that very big expansive force can be discharged to external.

Multiple secondary cells as included by battery modules are arranged side by side along a direction, and the expansion of electrode assembly release Power, therefore can shape after the expansive force superposition of the release of electrode assembly included by multiple secondary cells along the arragement direction of secondary cell At biggish resultant force, so that the electrical property for not only resulting in secondary cell deteriorates, and connector structure with higher is required Intensity constrains counteracting expansive force, this just needs the volume by increasing connector to be achieved, and thereby reduces secondary cell Energy density and space utilization rate.

Utility model content

The utility model embodiment provides a kind of secondary cell and battery modules.Secondary cell is on thickness direction Swell increment it is smaller, to require when forming battery modules in groups the stiffness and strength of external fixator lower, be conducive to Improve energy density.

On the one hand, the utility model embodiment proposes a kind of secondary cell, comprising:

Shell, shell include bottom plate and the side plate that is connected with bottom plate, bottom plate and side plate formed receiving hole and with appearance Receive the opening that hole is connected, opening and bottom plate should be arranged along the axially opposing of receiving hole, and the thickness of bottom plate is greater than the thickness of side plate； Cap assembly, cap assembly and side plate are tightly connected with lid make and break mouth；Electrode assembly, electrode assembly are set in receiving hole, electricity Pole component includes more than two electrode units, and electrode unit is formed by the first pole piece, the second pole piece and membrane winding, electrode list Member has wide face and a leptoprosopy, and more than two electrode units are along axially stacked, and the wide face of each electrode unit and bottom plate phase It is correspondingly arranged, the leptoprosopy of each electrode unit is towards side plate.

According to the one aspect of the utility model embodiment, the ratio of the thickness of the width and bottom plate in wide face is more than or equal to 20 And it is less than or equal to 69.

According to the one aspect of the utility model embodiment, the width in wide face is 40mm to 60mm, bottom plate with a thickness of 0.87mm to 1.8mm.

According to the one aspect of the utility model embodiment, the thickness of bottom plate and the height of electrode assembly are to be positively correlated.

Have according to the one aspect of the utility model embodiment, between the first pole piece of adjacent two layers corresponding with leptoprosopy position The first gap and the second gap corresponding with wide face position, the size in the first gap is greater than the size in the second gap.

Have according to the one aspect of the utility model embodiment, between the first pole piece of adjacent two layers corresponding with leptoprosopy position The first gap, the size in the first gap is 5um to 50um.

According to the one aspect of the utility model embodiment, side plate, which includes that two thickness directions along secondary cell are opposite, to be set The first plate set and two are for connecting second plate of two the first plates, the setting corresponding with leptoprosopy of the first plate, The setting corresponding with the winding end face of electrode unit of second plate, the thickness of the thickness of the first plate less than the second plate.

According to the one aspect of the utility model embodiment, there is third space, between third between leptoprosopy and the first plate The size of gap is 0.3mm to 0.9mm.

According to the one aspect of the utility model embodiment, winding has the 4th gap between end face and the second plate, the The size in four gaps is 0.3mm to 0.9mm.

According to the one aspect of the utility model embodiment, interval setting is between cap assembly and electrode assembly to form the One buffer gap, the first buffer gap are used for buffer electrode component dilatancy amount.

According to the one aspect of the utility model embodiment, the height of the first buffer gap is 0.5mm to 12mm.

According to the one aspect of the utility model embodiment, in the axial direction, the height and electrode assembly of the first buffer gap Height ratio be 0.05 to 0.3.

According to the one aspect of the utility model embodiment, interval setting is slow to form second between bottom plate and electrode assembly Gap is rushed, the second buffer gap is used for buffer electrode component dilatancy amount.

According to the secondary cell of the utility model embodiment comprising there is the shell of receiving hole, be set in receiving hole Electrode assembly.When the electrode unit of the present embodiment expands, electrode unit is mainly expanded in the axial direction of receiving hole, To which electrode unit can discharge the axial expansive force along receiving hole, and the expansive force discharged in a thickness direction is smaller, into Excessive compression is generated without the side plate to shell.In this way, the present embodiment more than two secondary cells along itself When thickness direction assembling arranged side by side forms battery modules, generated main expansion when being expanded due to each secondary cell Power intersects with thickness direction, thus each secondary cell generate main expansion power will not accumulate in a thickness direction and formed compared with Big resultant force.It is right when using the battery modules of the fixed secondary cell including more than two the present embodiment of external fixator The stiffness and strength requirement of fixing piece itself is lower, to favorably reduce the volume or weight of fixing piece, and then is conducive to improve The energy density and space utilization rate of secondary cell and battery modules entirety.

On the other hand, a kind of battery modules are provided according to the utility model embodiment, including more than two as above-mentioned The secondary cell of embodiment, more than two secondary cells are arranged side by side.

Detailed description of the invention

The feature, advantage and technical effect of the utility model exemplary embodiment are described below by reference to attached drawing.

Fig. 1 is the structural schematic diagram of the battery modules of an embodiment of the present invention；

Fig. 2 is the decomposition texture schematic diagram of the secondary cell of an embodiment of the present invention；

Fig. 3 is the structural schematic diagram of the electrode unit of an embodiment of the present invention；

Fig. 4 is the schematic cross-sectional view of the secondary cell of an embodiment of the present invention；

Fig. 5 is the schematic cross-sectional view of the secondary cell of another embodiment of the utility model；

Fig. 6 is enlarged drawing at A in Fig. 5；

Fig. 7 is the schematic cross-sectional view of the secondary cell of another embodiment of the utility model.

In the accompanying drawings, the attached drawing is not drawn according to the actual ratio.

Description of symbols:

10, secondary cell；

11, shell；11a, receiving hole；111, bottom plate；112, side plate；112a, the first plate；112b, the second plate；

12, electrode assembly；121, electrode unit；12a, the first pole piece；12b, the second pole piece；12c, diaphragm；12d, first Gap；12e, the second gap；12f, third space；12g, the 4th gap；121a, wide face；121b, leptoprosopy；121c, winding end Face；

13, cap assembly；131, lamina tecti；132, electrode terminal；

14, the first buffer gap；

15, the second buffer gap；

20, battery modules；

X, width direction；Y, thickness direction；Z, axial direction.

Specific embodiment

The embodiments of the present invention is described in further detail with reference to the accompanying drawings and examples.Following embodiment The detailed description and the accompanying drawings for illustratively illustrating the principles of the present invention, but cannot be used to limit the model of the utility model It encloses, i.e., the utility model is not limited to described embodiment.

In the description of the present invention, it should be noted that unless otherwise indicated, the meaning of " plurality " is two or two More than a；The orientation or positional relationship of the instructions such as term " on ", "lower", "left", "right", "inner", "outside" is merely for convenience of retouching State the utility model and simplify description, rather than the device or element of indication or suggestion meaning must have a particular orientation, with Specific orientation construction and operation, therefore should not be understood as limiting the present invention.In addition, term " first ", " second ", " third ", " 4th " etc. are used for descriptive purposes only and cannot be understood as indicating or suggesting relative importance.

In the description of the present invention, it should also be noted that, unless otherwise clearly defined and limited, term " is pacified Dress ", " connected ", " connection " shall be understood in a broad sense, for example, it may be being fixedly connected, may be a detachable connection, or integrally Connection；It can be directly connected, it can also be indirectly connected through an intermediary.For the ordinary skill in the art, Visual concrete condition understands the concrete meaning of above-mentioned term in the present invention.

The utility model in order to better understand, below with reference to Fig. 1 to Fig. 7 according to the secondary electricity of the utility model embodiment Pond 10 and battery modules 20 are described in detail.

Shown in Figure 1, the utility model embodiment also provides a kind of battery modules 20 comprising: more than two The secondary cell 10 of embodiment and busbar connector for connecting two secondary cells 10.More than two secondary cells 10 are along same One direction is arranged side by side.One end of busbar connector is connected and fixed with a secondary cell 10 in two secondary cells 10, the other end It is connected and fixed with another secondary cell 10.More than two secondary cells 10 of the present embodiment can be along thickness direction Y It is arranged side by side to form battery modules 20.

Shown in Figure 2, the secondary cell 10 of the utility model embodiment includes shell 11, the electricity being set in shell 11 Pole component 12 and the cap assembly 13 being tightly connected with shell 11.

The shell 11 of the present embodiment can be four prisms cylinder shape or other shapes.Shell 11 has accommodate electrod component 12 With the inner space of electrolyte.Shell 11 can be manufactured by such as aluminium, aluminium alloy or plastic or other material.Shell 11 includes bottom plate 111 and the side plate 112 that is connected with bottom plate 111.Bottom plate 111 and side plate 112 formed receiving hole 11a and with receiving hole 11a The opening being connected.Opening is with bottom plate 111 along the corresponding setting of axial Z of receiving hole 11a, axial Z and the receiving of receiving hole 11a The extending direction of hole 11a is parallel.The thickness M of bottom plate 111 thickness (shown in Figure 4) greater than side plate 112.Electrode assembly 12 is set It is placed in receiving hole 11a.Cap assembly 13 and side plate 112 are tightly connected with lid make and break mouth, so that electrode assembly 12 is sealed in In shell 11.In one example, cap assembly 13 includes lamina tecti 131 and electrode terminal 132.Lamina tecti 131 and electrode tip Son 132 is respectively positioned on electrode assembly 13 along the side of axial Z.Cap assembly 13 is sealedly attached to shell 11 by lamina tecti 131.Electricity Extreme son 132 is set to lamina tecti 131 and is electrically connected with electrode assembly 13.

Shown in Figure 3, electrode unit 121 is wound and is formed by the first pole piece 12a, the second pole piece 12b and diaphragm 12c.Electricity Whole pole unit 121 is in pancake-like structure.Electrode unit 121 has width face 121a and leptoprosopy 121b.The electrode of the present embodiment Component 12 includes more than two electrode units 121.More than two electrode units 121 are laminated along the axial Z of receiving hole 11a, And the wide face 121a setting corresponding with bottom plate 111 of each electrode unit 121, and the leptoprosopy 121b of each electrode unit 121 Towards side plate 112.The axial Z of receiving hole 11a intersects with the thickness direction Y of secondary cell 10.Electrode unit 121 includes main part And tab.Diaphragm 12c is the insulator between the first pole piece 12a and the second pole piece 12b.The electrode unit of the present embodiment 121 are wound and are formed by diaphragm 12c, the first pole piece 12a and the second pole piece 12b.In the present embodiment, illustratively with the first pole piece 12a is positive plate, and the second pole piece 12b is illustrated for negative electrode tab.Similarly, in other examples, the first pole piece 12a is also It can be negative electrode tab, and the second pole piece 12b is positive plate.In addition, positive active material is applied on the coating area of positive plate, And negative electrode active material is applied on the coating area of negative electrode tab.The multiple uncoated areas extended from main part are then used as pole Ear.Electrode unit 121 includes two tabs, i.e. anode ear and negative electrode lug, anode ear extends from the coating area of positive plate；Cathode Ear extends from the coating area of negative electrode tab.The electrolyte infiltration process of process is manufactured in secondary cell 10 or the later period uses In the process, active material layer included by the electrode unit 121 of the present embodiment can expand, so as to cause electrode unit 121 Entirety expands.Optionally, the capacity of the electrode unit of the present embodiment is 100Ah to 180Ah.

The secondary cell 10 of the utility model embodiment includes the shell 11 with receiving hole 11a, is set to receiving hole 11a Interior electrode assembly 12.When the electrode unit 121 of the present embodiment expands, electrode unit 121 is mainly in the axis of receiving hole 11a It is expanded on Z, so that electrode unit 121 can discharge the expansive force of the axial Z along receiving hole 11a, and in thickness direction Y The expansive force of upper release is smaller, so will not the side plate 112 to shell 11 generate excessive compression.In this way, in the present embodiment More than two secondary cells 10 along thickness direction Y be arranged side by side assembling form battery modules 20 when, due to each two Primary cell 10 when expanding generated main expansion power intersect with thickness direction Y, therefore each secondary cell 10 generate Main expansion power will not accumulate on thickness direction Y and form biggish resultant force.Fixed including two using external fixator It is lower to the stiffness and strength requirement of fixing piece itself when the battery modules 20 of the secondary cell 10 of above the present embodiment, from And favorably reduce the volume or weight of fixing piece, and then the energy for being conducive to improve 20 entirety of secondary cell 10 and battery modules is close Degree and space utilization rate.

When the electrode unit 121 of the utility model embodiment is expanded in the case where not constrained by shell 11, electrode The swell increment for the wide face 121a and leptoprosopy 121b that unit 121 includes is different, and the swell increment of width face 121a is greater than leptoprosopy 121b Swell increment.But after electrode unit 121 is loaded into shell 11, the bottom plate 111 and electrode unit of the shell 11 of the present embodiment The 121 wide corresponding setting of face 121a, and the setting corresponding with leptoprosopy 121b of side plate 112.It is expanded in electrode unit 121 When, constraint of the electrode unit 121 by shell 11, so as to be applied to 111 upper stress of bottom plate big by the wide face 121a of electrode unit 121 The stress on side plate 112 is applied in leptoprosopy 121b.Since 111 thickness of bottom plate of the present embodiment is greater than the thickness of side plate 112, because The deflection of this bottom plate 111 is less than the deflection of side plate 112, so as to limit the swell increment of electrode unit 121, reduces electrode Unit 121 and then advantageously ensures that electrode unit 121 is each in the difference of wide face 121a and each region leptoprosopy 121b degrees of expansion The infiltration consistency in region, effectively promotion effect of impregnation, improve the electric property of secondary cell 10.

The thickness M's of the width C (shown in Figure 3) and bottom plate 111 of the wide face 121a of the electrode unit 121 of the present embodiment Ratio is more than or equal to 20 and is less than or equal to 69.After electrode unit 121 expands, the wide face 121a meeting of electrode unit 121 Axial Z protuberance along receiving hole 11a is to have certain radian.As C/M > 69, the width C of wide face 121a is larger, that is, exists In the case that 121 thickness of electrode unit is constant, when electrode unit 121 expands, included by wide face 121a the bottom of to The active force of plate 111 is bigger, and since the thickness M of bottom plate 111 is smaller, so as to cause bottom plate 111 can not to wide face 121a into Row operative constraint, and then lead to that 111 deformation extent of bottom plate is serious and 121 swell increment of electrode unit is larger, so that electrode unit 121 Outermost layer the first pole piece 12a or 12b stress are concentrated and are broken；As C/M < 20, the thickness M of bottom plate 111 is larger, from And itself be not susceptible to deform, although so that bottom plate 111 can constrain wide face 121a, simultaneously also to electrode unit 121 wide face 121a is applied with biggish reaction force, and since the width C of wide face 121a is smaller, i.e., in electrode unit 121 In the case that thickness is constant, so that the leptoprosopy 121b of electrode unit 121 is to the constraint tensile stress of wide face 121a in electrode list Component on 121 thickness direction Y of member is bigger so that the first pole piece 12a, diaphragm 12c included by electrode unit 121 and Gap between second pole piece 12b becomes smaller, so cause the corresponding first pole piece 12a of wide face 121a, diaphragm 12c and The electrolyte in gap between second pole piece 12b can be extruded discharge, can lead to electroless liquid in gap when serious, easily Lithium phenomenon is analysed in generating.The ratio of the thickness M of the width C and bottom plate 111 of the wide face 121a of electrode unit 121 is in above range When, it is capable of the swell increment of counter electrode unit 121 and the effect of impregnation of electrode unit 121, the electricity of secondary cell 10 is promoted with this Gas performance.In one embodiment, the width of wide face 121a is 40mm to 60mm, the thickness M of bottom plate 111 be 0.87mm extremely 1.8mm。

The thickness M of the bottom plate 111 of the present embodiment and height T of electrode assembly 12 is (shown in Figure 4) for positive correlation.This In, it is positively correlated the height T proportional of the thickness M and electrode assembly 12 that refer to bottom plate 111.The thickness M of bottom plate 111 is got over Greatly, then the height T of electrode assembly 12 is bigger.The thickness M of bottom plate 111 is smaller, then the height T of electrode assembly 12 is smaller.In this way, this The secondary cell 10 of embodiment can take into account the requirement of energy density and the constraint requirements to 121 expansive force of electrode unit.In energy Two aspects of metric density and constraint expansive force are effectively kept in balance.

Shown in Figure 3, the electrode unit 121 that the winding of the present embodiment is formed itself is radially forming the first pole of multilayer Piece 12a.There is first gap 12d corresponding with the position leptoprosopy 121b between the first pole piece of adjacent two layers 12a.Adjacent two layers first There is second gap 12e corresponding with the position wide face 121a between pole piece 12a.Here, the size L1 of the first gap 12d and The size L2 of two gap 12e refers to gap between diaphragm 12c and the first pole piece 12a and diaphragm 12c and the second pole piece The sum of gap between 12b.The active material coated on the first pole piece 12a or the second pole piece 12b of electrode unit 121 occurs When expansion, due to the effect of expansive force, every layer of first pole piece 12a can be subjected to displacement along the radial direction of electrode unit 121, and between first Gap 12d and the second gap 12e can absorb the displacement of every layer of first pole piece 12a, therefore effectively reduce electrode unit 121 The expansion displacement amount of leptoprosopy 121b and width face 121a, to effectively reduce, electrode unit 121 is whole to be released in all directions Expansive force.In one embodiment, the size L1 of the first gap 12d is greater than the size L2 of the second gap 12e, thus relative to Second gap 12e, the first gap 12d can absorb the first pole piece 12a expansion displacement amount to a greater degree, electrode unit 121 The expansion displacement amount of leptoprosopy 121b is less than the expansion displacement amount of the wide face 121a of electrode unit 121.In one embodiment, first Gap 12d and the second gap 12e is formed by identical two layers of first pole piece 12a.In one embodiment, the first gap 12d Size L1 is 5um to 50um.When the size L1 of the first gap 12d is less than 5um, when electrode unit 121 expands, electrode unit 121 leptoprosopy 121b can touch shell 11 earlier, so that electrode unit 121 continues after leptoprosopy 121b touches shell 11 When expansion, biggish reaction force will receive, and then the electrolyte in the first gap 12d can be extruded discharge, lead to lithium ion Can not normal transmission, influence the service life of secondary cell 10.Simultaneously as the leptoprosopy 121b of electrode unit 121 is by shell 11 constraints, so that expansive force can be shifted to wide face 121a, accumulate on thickness direction Y too much so as to cause expansive force. When the size L1 of the first gap 12d is greater than 50um, the first gap 12d between the first pole piece of adjacent two layers 12a can be excessive, makes At lithium ion transport overlong time, to cause leptoprosopy 121b dynamic performance poor, it is easy to occur analysing lithium phenomenon.

The material of the shell 11 of the present embodiment is preferably metal material.Side plate 112 includes two thickness along secondary cell 10 The first plate 112a for being oppositely arranged of degree direction Y and two are for connecting the second plate 112b of two the first plate 112a. First plate 112a and the second plate 112b are arranged alternately, to be configured to the tubular structure that cross section is rectangle.Bottom plate 111 is Rectangular plate-like structure is tightly connected with the first plate 112a and the second plate 112b.First plate 112a and electrode unit 121 The corresponding setting of leptoprosopy 121b.The corresponding setting of axial Z of cap assembly 13 and bottom plate 111 along receiving hole 11a.Cap assembly 13 It is tightly connected with the first plate 112a and the second plate 112b.Under specific circumstances, the leptoprosopy 121b of electrode unit 121 can also be sent out Raw expansion, but its swell increment is smaller, therefore smaller to the compression of the first plate 112a application, so that each secondary cell 10 expansive forces accumulated on the Y of thickness direction are smaller with joint efforts.Meanwhile the swell increment of electrode unit 121 is bigger, and between first The size L2 of gap 12d and the second gap 12e will be smaller.In 121 use process of electrode unit, the electrolysis of therein can be consumed Liquid, it is therefore desirable to constantly from external complement electrolyte.When electrode unit 121 expands, the first plate 112a can be right Leptoprosopy 121b plays effect of contraction, so that the first gap 12d can become smaller, is difficult to so as to cause the electrolyte in shell 12 by One gap 12d is added to inside electrode unit 121, influences the electric property of electrode unit 121.In addition, when electrode unit 121 is sent out When raw expansion, biggish tensile stress can be born positioned at outermost first pole piece 12a or the second pole piece 12b, to be easy to cause First pole piece 12a or the second pole piece 12b fracture.The first plate 112a of the present embodiment can play constraint to leptoprosopy 121b and make With prevention leptoprosopy 121b swell increment is excessive, so that the possibility that the first pole piece 12a or the second pole piece 12b are broken be effectively reduced Property.

In one embodiment, shown in referring to figs. 5 and 6, between third between leptoprosopy 121b and the first plate 112a Gap 12f.The size L3 of third space 12f is 0.3mm to 0.9mm.When the size L3 of third space 12f is less than 0.3mm, electrode The degree that the leptoprosopy 121b of unit 121 is expanded will be occupied completely when smaller third space 12f and with the first plate 112a It contacts and stress simultaneously is applied to the first plate 112a, so as to cause when the leptoprosopy 121b of electrode unit 121 reaches maximum swelling amount, Electrode unit 121 can be excessive to the first plate 112a compression applied, so cause the first plate 112a deform or Entire battery modules 20 are caused to deform in the thickness direction Y of secondary cell 10, furthermore, the first plate 112a can be to electrode list The leptoprosopy 121b of member 121 applies biggish reaction force, is occupied and disappears by complete extruding so as to cause the first gap 12d, makes Obtaining electrolyte can not be immersed inside electrode unit 121 by the first gap 12d well, influence effect of impregnation consistency.When When the size L3 of third space 12f is greater than 0.9mm, the degree that the leptoprosopy 121b of electrode unit 121 is expanded could when larger It is enough to occupy third space 12f completely and contacted with the first plate 112a, it can not be to electrode unit so as to cause the first plate 112a 121 form operative constraint, and then cause when the leptoprosopy 121b of electrode unit 121 reaches maximum swelling amount, electrode unit 121 Leptoprosopy 121b swell increment is excessive, so as to cause corresponding outermost layer the first pole piece 12a or second of leptoprosopy 121b of electrode unit 121 There is stress concentration in pole piece 12b, has the risk being broken.

Shown in Figure 7, the electrode unit 121 of the present embodiment includes opposite two of width direction X along secondary cell Wind end face 121c and the winding axis perpendicular with winding end face 121c.The second plate 112b and electrode list of the present embodiment The corresponding setting of winding end face 121c of member 121.Thickness of the thickness of first plate 112a less than the second plate 112b.In electrode When unit 121 is in hot environment, a large amount of high-temperature gases can be quickly generated inside electrode unit 121.Inside electrode unit 121 High-temperature gas can be sprayed by winding end face 121c, to cause instantaneous high-temperature impact force to the second plate 112b, be easy to cause Second plate 112b is damaged or melts.Therefore, it is necessary to suitably increase the thickness of the second plate 112b, to enhance itself intensity And rigidity, it is effective against high temperature impact power, guarantees the safety of secondary cell 10.The first plate 112a of the present embodiment and second Plate 112b advantageously ensures that shell 11 is whole and is meeting use according to self-position progress specific structure design different with effect Reasonable lightweight is carried out under the premise of it is required that, is conducive to the energy density for promoting secondary cell 10.

In one embodiment, winding has the 4th gap 12g between end face 121c and the second plate 112b.4th gap The size L4 of 12g is 0.3mm to 0.9mm.4th gap 12g can be used in inside buffer electrode unit 121 releasing High Temperature Gas Body impact force caused by the second plate 112b improves two to reduce a possibility that damaged or fusing occurs for the second plate 112b The safety in utilization of primary cell 10.When the size L4 of the 4th gap 12g is less than 0.3mm, to being released inside electrode unit 121 The buffering effect of high-temperature gas can reduce, and can not effectively play buffer function.When the size L4 of the 4th gap 12g is greater than 0.9mm When, the gap between electrode unit 121 and the second plate 112b can be excessive, becomes so as to cause the overall dimensions of secondary cell 10 Greatly, and then cause to generate adverse effect to the energy density of secondary cell 10.

It is shown in Figure 4, between the cap assembly 13 and electrode assembly 12 of the present embodiment between the axial Z of receiving hole 11a Every setting to form the first buffer gap 14.First buffer gap 14 is used for the dilatancy amount of buffer electrode component 12.Electrode When bad expansion occurs at least one electrode unit 121 in electrode unit 121 included by component 12, electrode assembly 12 is whole high Degree will increase.But the constraint due to electrode assembly 12 by bottom plate 111, the expansion direction of electrode assembly 12 mainly towards Cap assembly 13, thus the swell increment of electrode assembly 12 can preferentially occupy squeeze the first buffer gap 14, without directly with top Cap assemblies 13 are in contact and apply compression to cap assembly 13.In this way, when electrode assembly 12 expands, electrode assembly 12 Excessive compression will not be applied to cap assembly 13 and cap assembly 13 and shell 11 is caused to be disconnected state, to avoid There is a situation where electrolyte to leak, and guarantees the structural intergrity and safety of secondary cell 10.In one embodiment, it is accommodating On the axial Z of hole 11a, the height L (along the measured value of the axial Z of receiving hole 11a) and electrode assembly 12 of the first buffer gap 14 Height T ratio be 0.05 to 0.3.When the height L of the first buffer gap 14 and the height T ratio of electrode assembly 12 are less than 0.05 When, the first buffer gap 14 can reduce the buffering effect of the swell increment of electrode assembly 12, can not effectively play buffer function.When When the height L of first buffer gap 14 and the height T ratio of electrode assembly 12 are greater than 0.3, electrode assembly 12 and cap assembly 13 Between gap can be excessive, the overall dimensions so as to cause secondary cell 10 become larger, and then lead to the energy to secondary cell 10 Density generates adverse effect.In one embodiment, the height L of the first buffer gap 14 is 0.5mm to 12mm.

Shown in Figure 5, interval setting is between the bottom plate 111 and electrode assembly 12 of the shell 11 of the present embodiment to form the Two buffer gaps 15.Second buffer gap 15 is used for 12 dilatancy amount of buffer electrode component.Electricity included by electrode assembly 12 When bad expansion occurs at least one electrode unit 121 in pole unit 121,12 whole height of electrode assembly be will increase.But by It will receive the constraint of cap assembly 13 in electrode assembly 12, therefore the expansion direction of electrode assembly 12 is mainly towards bottom plate 111, from And the swell increment of electrode assembly 12 can be occupied preferentially and squeeze the second buffer gap 15, be pressed without directly applying to cap assembly 13 Stress.In this way, electrode assembly 12 will not apply huge pressing stress to cap assembly 13 and cause when electrode assembly 12 expands Cap assembly 13 and shell 11 are disconnected state, thus avoid that theres is a situation where electrolyte leaks, guarantee secondary cell 10 Structural intergrity and safety.

In one embodiment, interval is arranged to form the first buffer gap between cap assembly 13 and electrode assembly 12 14, and interval is arranged to form the second buffer gap 15 between the bottom plate 111 of shell 11 and electrode assembly 12.12 institute of electrode assembly Including electrode unit 121 at least one electrode unit 121 bad expansion occurs when, 12 whole height of electrode assembly can increase Greatly.The swell increment of electrode assembly 12, which can be occupied preferentially, squeezes the first buffer gap 14 and the second buffer gap 15, without direct Compression is applied to cap assembly 13 or bottom plate 111, further increases 10 buffer electrode component 12 of secondary cell along receiving hole 11a Axial Z swell increment ability, improve structural stability and peace of the secondary cell 10 when electrode assembly 12 expands Quan Xing.

The battery modules 20 of the utility model above-described embodiment include more than two secondary cells 10.More than two two Primary cell 10 is arranged side by side along thickness direction Y.Appearance of the electrode unit 121 included by each secondary cell 10 along shell 11 The axial Z of hole 11a of receiving is stacked.When the electrode unit 121 of the present embodiment expands, mainly along the axial Z of receiving hole 11a Dilatancy, and the swell increment on thickness direction Y is smaller.In this way, each secondary cell 10 is accumulated on the Y of thickness direction Expansion resultant force it is smaller.On thickness direction Y, battery modules 20 do not need to constrain using the structural member with higher-strength to Disappearing expansive force or can constrain counteracting expansive force using more low intensive structural member, so that the entirety of battery modules 20 be effectively reduced Quality effectively promotes the energy density of battery modules 20 so that 20 self structure of battery modules is more compact.Meanwhile battery mould Group 20 from 10 thickness direction Y of secondary cell swell increment it is smaller or without swell increment, can effectively promote use process Safety.

Although the present utility model has been described by reference to the preferred embodiments, but in the model for not departing from the utility model In the case where enclosing, various improvement can be carried out to it and can replace component therein with equivalent, especially, as long as not depositing In structural conflict, items technical characteristic mentioned in the various embodiments be can be combined in any way.The utility model It is not limited to specific embodiment disclosed herein, but is included all technical solutions falling within the scope of the claims.

Claims (14)

1. a kind of secondary cell characterized by comprising

Shell, the shell include bottom plate and the side plate that is connected with the bottom plate, and the bottom plate and the side plate form and hold Receive hole and the opening that is connected with the receiving hole, the opening should be set with the bottom plate along the axially opposing of the receiving hole It sets, the thickness of the bottom plate is greater than the thickness of the side plate；

Cap assembly, the cap assembly and the side plate, which are tightly connected, closes the opening to cover；

Electrode assembly, the electrode assembly are set in the receiving hole, and the electrode assembly includes more than two electrode lists Member, the electrode unit include the first pole piece, the second pole piece and diaphragm, and the electrode unit has wide face and a leptoprosopy, two with On the electrode unit along described axially stacked, and wide face is opposite with the bottom plate sets for each electrode unit described It sets, the leptoprosopy of each electrode unit is towards the side plate.

2. secondary cell according to claim 1, which is characterized in that the thickness of the width and bottom plate in the width face Ratio is more than or equal to 20 and is less than or equal to 69.

3. secondary cell according to claim 2, which is characterized in that the width in the width face is 40mm to 60mm, described Bottom plate with a thickness of 0.87mm to 1.8mm.

4. secondary cell according to claim 1, which is characterized in that the height of the thickness of the bottom plate and the electrode assembly Degree is positive correlation.

5. secondary cell according to claim 1, which is characterized in that have and institute between the first pole piece described in two adjacent rings It states corresponding first gap in leptoprosopy position and the second gap corresponding with the wide face position, the size in first gap is big Size in second gap.

6. secondary cell according to claim 1, which is characterized in that have and institute between the first pole piece described in two adjacent rings Corresponding first gap in leptoprosopy position is stated, the size in first gap is 5um to 50um.

7. secondary cell according to claim 1, which is characterized in that the side plate includes two along the secondary cell The first plate that thickness direction is oppositely arranged and two are for connecting the second plate of two first plates, and described first Plate setting corresponding with the leptoprosopy, second plate setting corresponding with the winding end face of the electrode unit are described The thickness of first plate is less than the thickness of second plate.

8. secondary cell according to claim 7, which is characterized in that have the between the leptoprosopy and first plate Three gaps, the size of the third space are 0.3mm to 0.9mm.

9. secondary cell according to claim 7, which is characterized in that have between the winding end face and second plate There is the 4th gap, the size in the 4th gap is 0.3mm to 0.9mm.

10. secondary cell according to any one of claims 1 to 9, which is characterized in that the cap assembly and the electrode To form the first buffer gap, first buffer gap is used to buffer the expansion of the electrode assembly for interval setting between component Deflection.

11. secondary cell according to claim 10, which is characterized in that the height of first buffer gap is 0.5mm To 12mm.

12. secondary cell according to claim 10, which is characterized in that in the axial direction, first buffer gap Height and the electrode assembly height ratio be 0.05 to 0.3.

13. secondary cell according to any one of claims 1 to 9, which is characterized in that the bottom plate and the electrode assembly Between interval setting to form the second buffer gap, second buffer gap is used to buffer the dilatancy of the electrode assembly Amount.

14. a kind of battery modules, which is characterized in that including more than two as claim 1 to 13 is described in any item secondary Battery, more than two secondary cells are arranged side by side.