CN214625248U

CN214625248U - Energy storage device

Info

Publication number: CN214625248U
Application number: CN202120418967.7U
Authority: CN
Inventors: 王雷; 陈熙
Original assignee: Shenzhen Zhenghao Zhizao Technology Co ltd
Current assignee: Shenzhen Zhenghao Zhizao Technology Co ltd
Priority date: 2021-02-25
Filing date: 2021-02-25
Publication date: 2021-11-05
Anticipated expiration: 2031-02-25

Abstract

The utility model discloses an energy storage equipment, it includes battery case, electric core subassembly and locking mechanism, and battery case is equipped with the through-hole, and the electric core subassembly is acceptd in battery case inside and accessible through-hole roll-off battery case outside, and locking mechanism installs in battery case, and locking mechanism is used for locking the electric core subassembly inside battery case, and perhaps the unblock makes electric core subassembly part roll-off battery case outside. The utility model discloses an energy storage equipment, through set up through-hole and locking mechanism at battery case, the electric core subassembly charges at low temperature or the in-process of high magnification charge-discharge, can with electric core subassembly roll-off to the battery case outside, heat up and cool down the electric core subassembly in a flexible way, reduce the injury to the electric core subassembly, promote the life of electric core subassembly. And this supplementary intensification cooling mechanism simple structure can effectively reduce the cost of equipment, improve the operating efficiency height and keep energy storage equipment to have great volume energy density moreover.

Description

Energy storage device

Technical Field

The utility model relates to an energy storage technology field especially relates to an energy storage equipment.

Background

At present, due to the material characteristics of the battery core, the energy storage device generally does not allow low-temperature charging, for example, the energy storage device is charged at a temperature below-10 ℃, and charging is started when the heating temperature of the battery core is increased to above 0 ℃. The existing scheme is that the electric core is heated through self-discharge, but the electric core is greatly damaged by large-current discharge. Secondly, the external device heats the battery cell to reach the charging temperature, or the battery cell is directly placed at room temperature for waiting, but the time is long and the cost is high.

In addition, when the battery is charged and discharged at a large multiplying power, the temperature rise of the battery cell is too high, and the service life and the service efficiency of the battery cell are influenced. At present, in order to solve the problem of overhigh charging and discharging temperature, air cooling and liquid cooling modes are mostly adopted. While increasing the cost, the battery also occupies the internal space of the battery, and reduces the volume energy density of the battery.

SUMMERY OF THE UTILITY MODEL

In view of this, the utility model provides an energy storage equipment.

The utility model provides an energy storage equipment, include:

a battery case provided with a through hole;

the battery core assembly is accommodated in the battery shell and can slide out of the battery shell through the through hole;

and the locking mechanism is arranged on the battery shell and used for locking the electric core assembly inside the battery shell or unlocking the electric core assembly to slide out of the battery shell.

According to the technical scheme, the utility model provides an energy storage device, through be equipped with the through-hole in battery case's bottom and set up locking mechanism at battery case, electric core subassembly in the process of low temperature charging or high magnification charge-discharge, can with electric core subassembly roll-off to the battery case outside, heat up and cool down to electric core subassembly in a flexible way, make electric core subassembly all be in the optimum state when low temperature charging and high magnification charge-discharge, reduce the injury to electric core subassembly, promote electric core subassembly's life; moreover, the auxiliary heating and cooling mechanism is simple in structure, and can effectively reduce the cost of equipment; furthermore, the electric core assembly in the arrangement mode has high heating and cooling speed and high working efficiency; in addition, this supplementary intensification cooling mechanism does not occupy the inside great space of energy storage equipment for energy storage equipment can keep great volume energy density.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

Fig. 1 is a schematic structural diagram of an energy storage device according to an embodiment of the present invention;

FIG. 2 is a schematic bottom view of the energy storage device of FIG. 1;

FIG. 3 is an exploded schematic view from the bottom perspective of the energy storage device shown in FIG. 1;

FIG. 4 is an exploded schematic view from a top perspective of the energy storage device shown in FIG. 1;

fig. 5 is a schematic structural diagram of an energy storage device according to another embodiment of the present invention;

fig. 6 is a schematic structural diagram of an energy storage device according to another embodiment of the present invention;

FIG. 7 is a schematic diagram of one embodiment of a locking mechanism of the energy storage device shown in FIG. 6;

FIG. 8 is a schematic view of a variant embodiment of the locking mechanism of the energy storage device shown in FIG. 6;

FIG. 9 is a schematic view of another alternate embodiment of the locking mechanism of the energy storage device shown in FIG. 6;

fig. 10 is a schematic structural diagram of an energy storage device according to another embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, of the embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

It is also to be understood that the terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the specification and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

It should be further understood that the term "and/or" as used in the specification and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes such combinations.

As shown in fig. 1 to 4, an embodiment of the present invention provides an energy storage device 100, including battery case 10, electric core assembly 20 and locking mechanism 30, battery case 10 is equipped with through hole 11, and electric core assembly 20 is accommodated inside battery case 10 and outside accessible through hole 11 roll-off battery case 10, and locking mechanism 30 is installed in battery case 10, and locking mechanism 30 is used for locking electric core assembly 20 inside battery case 10, or the unblock makes electric core assembly 20 roll-off battery case 10 outside.

Alternatively, the through hole 11 is formed at the bottom of the battery case 10, and when the locking mechanism 30 is unlocked, the battery pack assembly 20 slides out from the bottom of the battery case 10. Of course, the through hole 11 is not limited to be provided at the bottom of the battery case 10, and may be provided at the side of the battery case 10, for example.

When energy storage device 100 needs to be charged, but electric core assembly 20 is at a low temperature, for example, lower than-10 ℃, an operator may unlock locking mechanism 30, so that electric core assembly 20 slides out of battery shell 10, then energy storage device 100 is placed in a high temperature environment to be heated, and electric core assembly 20 is charged after rapidly rising to above 0 ℃. When energy storage equipment 100 when high-rate charge-discharge, operating personnel can unblock locking mechanism 30, make electric core subassembly 20 roll-off battery case 10 outside, then arrange energy storage equipment 100 in the low temperature environment and dispel the heat, the heat that electric core subassembly 20 produced can spread out fast.

According to the energy storage device 100 provided by the embodiment, the through hole 11 is formed in the bottom of the battery shell 10, the locking mechanism 30 is arranged on the battery shell 10, the electric core assembly 20 can slide out of the battery shell 10 in the process of low-temperature charging or high-rate charging and discharging, and the electric core assembly 20 is flexibly heated and cooled, so that the electric core assembly 20 is in the best state in both low-temperature charging and high-rate charging and discharging, the damage to the electric core assembly 20 is reduced, and the service life of the electric core assembly 20 is prolonged; moreover, the auxiliary heating and cooling mechanism is simple in structure, and can effectively reduce the cost of equipment; furthermore, the electric core assembly 20 in the arrangement mode has high heating and cooling speed and high working efficiency; in addition, this supplementary intensification cooling mechanism does not occupy the inside great space of energy storage equipment 100 for energy storage equipment 100 can keep great volume energy density.

Optionally, the battery case 10 is provided with a first limiting part 12, the electric core assembly 20 is provided with a second limiting part 21, and the first limiting part 12 and the second limiting part 21 are abutted to limit the electric core assembly 20 to completely slide out of the battery case 10. Through setting up the whole roll-offs of first spacing portion 12 and second spacing portion 21 from battery case 10 with restriction electric core subassembly 20, can avoid later stage intensification or cooling back need assemble electric core subassembly 20 back to battery case 10 inside trouble, reduce the operation degree of difficulty. Of course, the battery case 10 may not be provided with the first limiting portion 12, the electric core assembly 20 is not provided with the second limiting portion 21, and when the locking mechanism 30 is unlocked, the electric core assembly 20 slides out of the through hole 11, and is assembled into the battery case 10 from the through hole 11 after the temperature rise or the temperature decrease is completed.

Optionally, the cell assembly 20 is provided with a sliding groove 22 along the sliding direction E-E of the cell assembly 20, and the battery shell 10 is provided with a protrusion 13, wherein the protrusion 13 is embedded in the sliding groove 22 and can slide along the sliding groove 22. The cooperation of the sliding groove 22 and the protrusion 13 is provided, so that the cell assembly 20 can smoothly slide out and in from the inside of the battery shell 10, and the operation is facilitated. Of course, the energy storage device 100 may not have the structure of the slide groove 22 and the protrusion 13.

Optionally, the projection outlines of the sliding groove 22 and the protrusion 13 in the sliding direction E-E of the electric core assembly 20 are both rectangular. The rectangular shape is simple, and the processing and manufacturing are facilitated. Of course, the projection profile of the sliding groove 22 and the protrusion 13 in the sliding direction of the electric core assembly 20 is not limited to be rectangular, and may be other regular or irregular shapes, such as semicircular, saw-tooth, conical, and other shapes.

Optionally, the outer side wall of the electric core assembly 20 is provided with a sliding groove 22, the side wall of the through hole 11 is provided with a protrusion 13, the protrusion 13 forms a first limiting portion 12, the top end of the sliding groove 22 is provided with a stopping portion 23, and the stopping portion 23 forms a second limiting portion 21. The top end of the chute 22 refers to the upper end of the chute 22 when the energy storage device 100 is in a normal placement state. During the process that the plug assembly 20 slides downwards out of the battery shell 10, the protrusion 13 moves upwards relatively along the sliding groove 22 until the protrusion 13 abuts against the stopping portion 23, and the plug assembly 20 stops sliding downwards.

It is understood that the positions of the sliding groove 22 and the protrusion 13 may be interchanged, that is, the sliding groove 22 is provided on the battery housing 10, and the protrusion 13 is provided on the core assembly 20. It should be noted that, in this embodiment, the stopping portion 23 should be located at the bottom end of the sliding chute 22.

It is also understood that the protrusions 13 are not limited to be provided on the side walls of the through-holes 11, and the protrusions 13 may be provided at other positions on the inner side walls of the battery case 10. As long as the protrusion 13 can form a sliding fit with the sliding groove 22, so that the electric core assembly 20 slides smoothly.

It is also understood that the first position-limiting portion 12 is not limited to being formed by the protrusion 13, and the second position-limiting portion 21 is not limited to being disposed by the above-mentioned stopping portion 23. For example, the battery case 10 may be provided with a first protrusion at a place other than the protrusion 13, and the outer sidewall of the electric core assembly 20 is provided with a second protrusion, as long as the abutment of the first protrusion and the second protrusion can prevent the electric core assembly 20 from sliding out of the battery case 10.

In other embodiments, the battery case 10 is not provided with the protrusion 13, the cell assembly 20 is not provided with the sliding groove 22 and the stopping portion 23, the cell assembly 20 is provided with an inverted trapezoid structure, the bottom profile of the cell assembly 20 is smaller than the profile of the through hole 11, the top profile is larger than the profile of the through hole 11, and the top of the cell assembly 20 can be clamped at the through hole 11, so that only part of the cell assembly 20 can slide out of the battery case 10.

Optionally, the number of the sliding grooves 22 and the number of the protrusions 13 are both multiple, the sliding grooves 22 are arranged at intervals around the outer side wall of the electric core assembly 20, and the protrusions 13 are arranged at intervals around the inner side wall of the through hole 11. The arrangement of the sliding grooves 22 and the protrusions 13 enables the stress between the cell assembly 20 and the battery shell 10 to be balanced and the sliding to be stable.

Optionally, the battery housing 10 includes a bottom plate 14, and a first surrounding wall 15 and a second surrounding wall 16 surrounding the bottom plate 14, where the second surrounding wall 16 is located inside the first surrounding wall 15, the second surrounding wall 16 and the bottom plate 14 surround to form a first chamber 17, the bottom plate 14 is provided with a through hole 11, and the first chamber 17 corresponds to the through hole 11 on the bottom plate 14. The first wall 15, the second wall 16 and the bottom plate 14 enclose and form a second chamber 18, and the electric core assembly 20 is accommodated in the first chamber 17 and can slide out of the first chamber 17 through the through hole 11. The energy storage device 100 also includes a circuit board 40, the circuit board 40 being disposed inside the second chamber 18. By providing the first wall 15 and the second wall 16 to divide the battery case 10 into two chambers, the cell assembly 20 and the circuit control board 40 are disposed in different chambers, so that interference between different components can be avoided.

Optionally, the battery core assembly 20 includes a battery cell casing 24 and a battery cell 25, the battery cell 25 is disposed inside the battery cell casing 24, and a heat-conducting insulating waterproof adhesive is filled between the battery cell casing 24 and the battery cell 25. The heat conduction insulating waterproof glue can not only play the effect of fixed electric core 25, and the heat that produces when heat conduction insulating waterproof glue can make electric core 25 function in addition transmits electric core shell 24 fast to spread away through electric core shell 24, further, the heat conduction insulating waterproof glue can play insulating waterproof effect, avoids electric core 25 to contact liquid to break down.

Optionally, energy storage device 100 further includes a first cover 26, a waterproof panel 27, and a second cover 28. The top of the battery cell shell 24 that first apron 26 lid fitted, equally through heat conduction insulating waterproof glue sealing connection between first apron 26 and the battery cell shell 24, seted up pin hole 261 on the first apron 26, the connecting cable of electricity core can extend to the battery cell shell 24 outside through pin hole 261, and second apron 28 lid fits the top of first leg 15 for the holistic protection of energy storage equipment. The waterproof plate 27 covers the top of the second surrounding wall 16 and is connected with the second surrounding wall 16 in a sealing manner through a sealing waterproof adhesive or a sealing rubber ring, so as to prevent water vapor or dust brought back after the battery pack assembly 20 is installed back to the battery shell 10 from the outside from invading the second cavity 18 to corrode the circuit control board 40.

Optionally, the locking mechanism 30 includes a pin 31, the sidewall of the battery case 10 is provided with a first pin hole 19, the sidewall of the electric core assembly 20 is provided with a second pin hole 29, and when the pin 31 is inserted into the first pin hole 19 and the second pin hole 29, the pin 31 locks the electric core assembly 20 inside the battery case 10.

Specifically, in normal use, the operator inserts the pin 31 into the first pin hole 19 and the second pin hole 29, and the electric core assembly 20 is locked inside the battery shell 10 due to the supporting function of the pin 31. When the electric core assembly 20 needs to slide out of the battery shell 10 for heating or cooling, the operator pulls out the pin 31, and the electric core assembly 20 slides out of the battery shell 10 from the through hole 11.

Optionally, the pin 31 includes a rod portion 311 and a head portion 312 connected to one end of the rod portion 311, the outer side wall of the battery case 10 is provided with a sinking groove 101 communicated with the first pin hole 19, the rod portion 311 is inserted into the first pin hole 19, and the head portion 312 is received in the sinking groove 101. By arranging the sinking groove 101 to accommodate the head 312 of the pin 31, the pin 31 is not exposed, and the whole structure is more concise and beautiful.

Optionally, the first pin hole 19 is disposed near the bottom of the battery case 10, and the bottom of the battery case 10 is provided with a notch 102 communicating with the sink 101. By arranging the notch 102, an operator can conveniently take off the pin 31, and specifically, when the pin 31 needs to be taken off, the operator pushes out the pin 31 at the notch 102 against the head 312 of the pin 31.

Of course, the battery case 10 may not be provided with the sinking groove 101 and the notch 102, and when the rod portion 311 of the pin 31 is inserted into the first pin hole 19, the head portion 312 of the pin 31 is exposed on the surface of the battery case 10, and an operator may hold the head portion 312 of the pin 31 to pull the pin 31 out of the first pin hole 19 and the second pin hole 29.

As shown in fig. 5, another embodiment of the present invention provides an energy storage device 100a, where the energy storage device 100a proposed in this embodiment is different from the energy storage device 100 proposed in the above embodiment in that: in the present embodiment, the locking mechanism 30a includes a stopper 30a1 and a fastener 30a2, the stopper 30a1 is rotatably mounted to the bottom of the battery case 10a by the fastener 30a2, and the stopper 30a1 locks the battery cell assembly 20a inside the battery case 10a when the stopper 30a1 is rotated into the through hole 11 a.

Specifically, during normal use, the operator rotates the stopper 30a1, the stopper 30a1 extends partially into the contour area of the through hole 11a, and the battery pack 20a is locked inside the battery case 10a due to the stopper of the stopper 30a 1. When the electric core assembly 20a needs to slide out of the battery shell 10a for heating or cooling, the operator pulls the stopper 30a1, the stopper 30a1 rotates out of the outline area of the through hole 11a, and the electric core assembly 20a slides out of the battery shell 10a from the through hole 11 a.

In this embodiment, the structure and the connection relationship of other components of the energy storage device 100a may refer to the above embodiments, which are not described herein again.

As shown in fig. 6 to 9, another embodiment of the present invention provides an energy storage device 100b, where the energy storage device 100b proposed in this embodiment is different from the energy storage device 100 proposed in the above embodiments in that: in the present embodiment, the locking mechanism 30b includes a first connecting member 30b1, a second connecting member 30b2 and a driving member 30b3, the first connecting member 30b1 is mounted on the battery case 10b, the second connecting member 30b2 is mounted on the battery cell assembly 20b, the driving member 30b3 is connected with the second connecting member 30b2, and the driving member 30b3 is used for driving the second connecting member 30b2 to move relative to the first connecting member 30b1 so as to slide the battery cell assembly 20b partially out of the battery case 10b through the through hole 11b or to be accommodated in the battery case 10b through the through hole 11 b.

As shown in fig. 7, the first connector 30b1 is a rack, the second connector 30b2 is a gear, the driving member 30b3 is a motor, the rack extends along the sliding direction of the cell assembly 20b, the gear is engaged with the rack, the motor is mounted on the cell assembly 20b and connected with the gear, when the motor is operated, the gear moves along the rack, thereby driving the cell assembly 20b to slide out of the battery case 10b or into the battery case 10 b.

As shown in fig. 8, the first connecting member 30b1 is a lead screw, the second connecting member 30b2 is a lead screw nut, the driving member 30b3 is a motor, the lead screw extends along the sliding direction of the cell assembly 20b, the lead screw nut is sleeved outside the lead screw and is in threaded fit with the lead screw, the motor is installed on the battery case 10b and is connected with the lead screw, when the motor is operated, the lead screw rotates, and the lead screw nut moves along the lead screw, so that the cell assembly 20b is driven to slide out of the battery case 10b or slide into the battery case 10 b.

As shown in fig. 9, the first connector 30b1 is an air cylinder, the electric core assembly 20b is connected to the telescopic rod of the air cylinder through the second connector 30b2, and the air cylinder drives the electric core assembly 20b to slide out of the battery case 10b or slide into the battery case 10b through the telescopic rod. Wherein the cylinder may be gas or hydraulic or electrically driven.

In this embodiment, the structure and connection relationship of other components of the energy storage device 100b may refer to the above embodiments, which are not described herein again.

As shown in fig. 10, another embodiment of the present invention provides an energy storage device 100c, where the energy storage device 100c proposed in this embodiment is different from the energy storage device 100 proposed in the above embodiment in that: in the present embodiment, the locking mechanism 30c includes a stopper 30c1 and a PUSH-PUSH mechanism 30c2, the PUSH-PUSH mechanism 30c2 is mounted on the battery case 10c, the stopper 30c1 is connected to the PUSH-PUSH mechanism 30c2, and the PUSH-PUSH mechanism 30c2 is used to drive the stopper 30c1 to extend into the through hole 11c to block the electric core assembly 20c when pressed, and to drive the stopper 30c1 to withdraw from the through hole 11c to slide the electric core assembly 20c partially out of the battery case 10c when pressed again. The PUSH-PUSH mechanism 30c2 is a conventional mechanism, and is commonly used in a pressing structure of an automatic ball pen and an SD card mounting and dismounting structure of a notebook computer, and will not be described herein.

Specifically, the operator presses PUSH-PUSH mechanism 30c2, PUSH-PUSH mechanism 30c2 drives stopper 30c1 to extend into the contour region of through hole 11c, and electric core assembly 20c is locked inside battery case 10c due to the stopper of stopper 30c 1. When it is desired to slide the electric core assembly 20c out of the battery case 10c for warming or cooling, the operator presses the PUSH-PUSH mechanism 30c2 again, the blocking member 30c1 retracts from the contour region of the through hole 11c, and the electric core assembly 20c slides out of the battery case 10c from the through hole 11 c.

In this embodiment, the structure and connection relationship of other components of the energy storage device 100c may refer to the above embodiments, which are not described herein again.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily think of various equivalent modifications or replacements within the technical scope of the present invention, and these modifications or replacements should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. An energy storage device, comprising:

a battery case provided with a through hole;

2. The energy storage device of claim 1, wherein the battery housing is provided with a first limiting portion, the cell assembly is provided with a second limiting portion, and the first limiting portion and the second limiting portion abut to limit the cell assembly from sliding out of the battery housing entirely.

3. The energy storage device according to claim 2, wherein one of the battery case and the electric core assembly is provided with a slide groove in a sliding direction of the electric core assembly, and the other of the battery case and the electric core assembly is provided with a protrusion that is embedded in the slide groove and is slidable along the slide groove.

4. The energy storage device according to claim 3, wherein the outer side wall of the cell assembly is provided with the sliding groove, the side wall of the through hole is provided with the protrusion, the protrusion forms the first limiting portion, the top end of the sliding groove is provided with a stopping portion, and the stopping portion forms the second limiting portion.

5. The energy storage device according to claim 1, wherein the battery housing comprises a bottom plate and a first wall and a second wall surrounding the bottom plate, the second wall is located at the inner side of the first wall, the second wall and the bottom plate surround to form a first chamber, the first wall, the second wall and the bottom plate surround to form a second chamber, and the battery assembly is accommodated in the first chamber;

the energy storage device further comprises a circuit control board, and the circuit control board is arranged inside the second cavity.

6. The energy storage device of claim 5, wherein the core assembly comprises a cell casing and a cell, the cell is arranged inside the cell casing, and a thermally conductive insulating waterproof adhesive is filled between the cell casing and the cell.

7. The energy storage device of claim 6, further comprising a first cover, a waterproof plate, and a second cover, wherein the first cover covers the top of the cell housing, the waterproof plate covers the top of the first surrounding wall, and the second cover covers the top of the second surrounding wall.

8. The energy storage device of claim 1, wherein the locking mechanism comprises a pin, the side wall of the battery shell is provided with a first pin hole, the side wall of the battery pack is provided with a second pin hole, and when the pin is arranged in the first pin hole and the second pin hole in a penetrating manner, the pin locks the battery pack inside the battery shell; or,

the locking mechanism comprises a blocking piece and a fastening piece, the blocking piece is rotatably arranged at the bottom of the battery shell through the fastening piece, and when the blocking piece is rotated into the through hole, the blocking piece locks the electric core assembly inside the battery shell; or,

the locking mechanism comprises a first connecting piece, a second connecting piece and a driving piece, the first connecting piece is arranged on the battery shell, the second connecting piece is arranged on the cell assembly, the driving piece is connected with the second connecting piece, and the driving piece is used for driving the second connecting piece to move relative to the first connecting piece so that the cell assembly can slide out of the battery shell through the through hole or slide into the battery shell through the through hole; or,

the locking mechanism comprises a blocking piece and a PUSH-PUSH mechanism, the PUSH-PUSH mechanism is installed on the battery shell, the blocking piece is connected with the PUSH-PUSH mechanism, the PUSH-PUSH mechanism is used for driving the blocking piece to extend into the through hole to block the battery core assembly when being pressed, and the blocking piece is driven to exit from the through hole to enable the battery core assembly to partially slide out of the battery shell when being pressed again.

9. The energy storage device of claim 8, wherein the pin comprises a rod portion and a head portion connected to one end of the rod portion, a sunken groove communicated with the first pin hole is formed in an outer side wall of the battery case, the rod portion penetrates through the first pin hole, and the head portion is accommodated in the sunken groove.

10. The energy storage device of claim 9, wherein the first pin hole is disposed proximate a bottom of the battery case, the bottom of the battery case having a notch that communicates with the sink.