Description:BACKGROUND
[0001] Secondary cells, also known as rechargeable batteries, are
widely used in various applications including electric vehicles (EVs),
consumer electronics, and energy storage systems due to their ability to
be recharged and reused multiple times. 5 Secondary cells (hereinafter
referred to as “cells”) typically consist of a positive electrode, a negative
electrode, a separator, and an electrolyte that facilitates ion movement
during charge and discharge cycles. The electrodes are housed within
a casing and connected to current collectors to enable efficient electron
10 flow through an external circuit. A bottom lid is welded to the casing of
the cell, providing support to the internal components and ensuring a
secure seal for the electrolyte and internal components. Further, a
closing pin is inserted into the bottom lid to prevent leakage of the
electrolyte and ensure the structural and thermal stability of the cell
15 during repeating cycling.
BRIEF DESCRIPTION OF FIGURES
[0002] Systems and/or methods, in accordance with examples of the
present subject matter are described and with reference to the
20 accompanying figures, in which:
[0003] FIG. 1 illustrates an exploded view of a secondary cell, in
accordance with an example of the present subject matter;
[0004] FIG. 2 illustrates various views of the bottom lid, in accordance
with an example of the present subject matter;
25 [0005] FIG. 3 illustrates a lid assembly for a secondary cell (not
shown), in accordance with an example of the present subject matter;
and
[0006] FIG. 4 illustrates a perspective view of a secondary cell with a
lid assembly positioned on top of the secondary cell, in accordance with
30 an example of the present subject matter.
2
[0007] It may be noted that throughout the drawings, identical
reference numbers designate similar, but not necessarily identical,
elements. The figures are not necessarily to scale, and the size of some
parts may be exaggerated to more clearly illustrate the example shown.
Moreover, the drawings provide examples 5 and/or implementations
consistent with the description; however, the description is not limited to
the examples and/or implementations provided in the drawings.
DETAILED DESCRIPTION
10 [0008] During the manufacturing process of the cell, the cell is sealed
after filing the electrolyte to prevent leakage and to protect the internal
components from environmental exposure. In many designs, the closing
pin is inserted into a sealing plug or aperture present in the bottom lid
and then welded to form a permanent closure. However, any defect at
15 this stage leads to the rejection of the entire cell, resulting in significant
material and cost losses, particularly in mass production environments.
Such defects may include improper weld formation, incomplete sealing,
contamination during the welding process, or misalignment of the
closing pin with the sealing aperture. When these defects occur, the
20 entire assembled cell, which has already undergone multiple
manufacturing steps including electrode preparation, electrolyte filling,
and preliminary assembly, must be discarded.
[0009] Many of such defects may be attributed to limitations in
conventional closing pin designs. For example, the closing pin is typically
25 inserted into an inner bore of the sealing plug with some clearance
provided to accommodate manufacturing tolerances. While this
clearance is necessary for assembly purposes, the clearance creates a
loose fit configuration, especially in cases where the closing pin is devoid
of mechanical locking or interlocking features that may secure the
30 closing pin firmly in place prior to welding. As a result, during the welding
process, thermal expansion, vibrations, or welding forces may cause the
3
closing pin to shift or tilt, leading to misalignment or incomplete sealing.
Such movement may result in electrolyte leakage, poor weld strength,
or cell failure, therefore severely impacting the manufacturing reliability
and cell quality.
[0010] To this end, examples of a lid 5 assembly for a secondary cell
(hereinafter referred to as “cell”) are described. The present subject
matter pertains to a lid assembly for being disposed in the cell to enable
precise positioning and mechanical stability of the lid assembly while
welding the lid assembly onto the cell bottom, ensuring manufacturing
10 reliability and cell quality.
[0011] In an embodiment, the lid assembly includes a base plate
having a threaded aperture and a closing pin configured to close the
threaded aperture. In an example, the base plate includes a first surface
and a second surface. The base plate may be configured to be coupled
15 with an open end of a battery casing. In an example, the first surface
faces towards an electrode assembly accommodated inside the battery
casing and the second surface may face away from the electrode
assembly. Further, the threaded aperture may be disposed at a central
portion of the base plate, extending from the second surface to the first
20 surface. In an example, the threaded aperture may have a tapered
profile. Continuing further, the closing pin may comprise a flat portion
and a threaded protrusion extending away from the flat portion. In an
assembled state, the threaded protrusion may engage with the threaded
aperture, and the flat portion flushes with the second surface of the base
25 plate.
[0012] In another embodiment, the present subject matter discloses
a bottom lid. The bottom lid discloses a base plate having a threaded
aperture. The base plate includes a first surface and a second surface.
The base plate is configured to be coupled with an open end of a battery
30 casing. In an example, the first surface faces towards an electrode
4
assembly accommodated inside the battery casing and the second
surface faces away from the electrode assembly. Further, the threaded
aperture is disposed at a central portion of the base plate, extending
from the second surface to the first surface. In an example, the threaded
aperture may have a tapered profile. 5 The threaded aperture is
configured to receive a closing pin in an assembled state.
[0013] Accordingly, the proposed bottom lid and lid assembly
ensures a smooth laser welding process through the incorporation of
complementary threads at the aperture and closing pin. The threaded
10 aperture in the bottom lid and the threaded protrusion at the closing pin
facilitates proper sealing of the closing pin with the bottom lid by creating
a zero-tolerance interface between the bottom lid and the closing pin,
thereby ensuring that the closing pin is mechanically interlocked with
the bottom lid, holding it firmly in place during welding.
15 [0014] In some cases, this enhanced contact eliminates gaps that
compromise sealing integrity during subsequent manufacturing
operations. The threaded connection constrains all degrees of freedom
of the closing pin relative to the base plate, preventing any rotational or
translational movement that could occur during welding operations. This
20 constraint mechanism allows for controlled positioning of the closing pin
without the risk of displacement during handling or welding operations.
Laser welding may be performed from the outside of the assembly after
the closing pin is fitted, with the threaded engagement maintaining
precise alignment throughout the welding process. The design creates
25 a leak-proof joint by preventing any allowable movement between the
threaded closing pin and bottom lid, which eliminates potential leak
paths that could develop from component shifting during manufacturing
or service.
[0015] The above-mentioned implementations are further described
30 herein with reference to the accompanying figures. It should be noted
5
that the description and figures relate to exemplary implementations
and should not be construed as a limitation to the present subject
matter. It is also to be understood that various arrangements may be
devised that, although not explicitly described or shown herein, embody
the principles of the present subject matter. 5 Moreover, all statements
herein reciting principles, aspects, and embodiments of the present
subject matter, as well as specific examples, are intended to
encompass equivalents thereof.
[0016] FIG. 1 illustrates an exploded view of a secondary cell 100, in
10 accordance with an example of the present subject matter. In an
example, the secondary cell 100 (hereinafter referred to as the cell 100)
may be a cylindrical cell suitable for use in battery packs for electric
vehicles, portable electronics, energy storage systems, or other
applications requiring rechargeable electrochemical energy storage. As
15 may be noted, the cell 100 may be of any known type. Also, the cell 100
may be of any known design format.
[0017] The cell 100 includes a battery casing 102, an electrode
assembly 104, a bottom lid 106, and a closing pin 108. The battery
casing 102 is configured to provide structural support and containment
20 for internal components of the cell 100. Together, the battery casing 102
and the bottom lid 106 form an outer enclosure for the internal
components of the cell 100. The exploded configuration shown in FIG.
1 demonstrates the assembly sequence and spatial relationships
between these components during manufacturing operations.
25 [0018] In an example, the battery casing 102 may be a hollow
cylindrical structure that defines an internal cavity for housing the
electrode assembly 104 and other internal components. The internal
cavity defined by the hollow cylindrical structure may be dimensioned
to accommodate the electrode assembly 104 with appropriate
30 clearances for thermal expansion and electrolyte distribution. The
6
battery casing 102 may be manufactured of durable and conductive
materials. For example, the battery casing 102 may be manufactured
using stainless steel, nickel-plated steel, or aluminum alloy. However,
the materials used for manufacturing the battery casing 102 are
exemplary and any other material may be 5 used without deviating from
the scope of the present subject matter.
[0019] In an example, the battery casing 102 may include an open
end 110 and a closed end 112. The open end 110 may be configured
to allow insertion of the internal components of the cell 100 and the
10 closed end 112 may be structured to interface with an external terminal,
thereby enabling electrical connectivity while maintaining integrity of the
battery casing 102. As may be understood, the open end 110 may have
a shape corresponding to a cross-sectional shape of the battery casing
102.
15 [0020] Continuing further, the electrode assembly 104 is inserted
within the battery casing 102 via the open end 110. The electrode
assembly 104 may be a jelly roll, including a positive electrode (not
shown) and a negative electrode (not shown) with a separator layer (not
shown) interposed between the positive electrode and the negative
20 electrode. The electrode assembly 104 may be positioned within the
battery casing 102 such that the electrode assembly maintains proper
spacing from the internal walls and allows for electrolyte distribution
throughout the cell interior.
[0021] Upon positioning of the electrode assembly 104 inside the
25 battery casing 102, the bottom lid 106 is placed at the open end 110 of
the battery casing 102. In an example, the bottom lid 106 may be made
from a conductive material, such as nickel-plated steel, aluminum alloy,
or stainless steel, to allow for electrical connectivity within the
secondary cell. In an example, the bottom lid 106 includes an aperture
30 114 disposed at a central portion of the bottom lid 106. The aperture
7
114 may include a threaded inner surface (not shown in the figure). In
an example, the threaded surface may be a single thread formed inside
the aperture 114. In another example, the threaded aperture may have
a tapered profile in a longitudinal direction. The tapered profile of the
threaded aperture 114 may facilitate enhanced 5 sealing characteristics
and improved engagement with the closing pin 108. The single thread
configuration may simplify manufacturing while providing adequate
mechanical engagement for sealing purposes.
[0022] Once the bottom lid 106 is properly positioned at the open end
10 110 of the battery casing 102, the bottom lid 106 may be coupled with
the battery casing 102, such as by laser welding. The laser welding is
performed along a periphery of the bottom lid 106, thereby securing the
internal components of the cell 100, such as the electrode assembly
104, inside the battery casing 102. The welding process may create a
15 hermetic seal between the bottom lid 106 and the battery casing 102,
preventing electrolyte leakage and maintaining the integrity of the cell
enclosure. In some cases, the peripheral welding configuration may
distribute stress evenly around the joint interface. It would be evident to
a person skilled in the art that the bottom lid 106 may be coupled with
20 the battery casing 102 using any other techniques such as adhesive
bonding, mechanical fastening, crimping, or thermal sealing, depending
on the design requirements, material compatibility, and intended
application of the cell.
[0023] Upon coupling, an electrolyte is filled through the aperture 114
25 present on the bottom lid 106, and then the aperture 114 is sealed with
the help of the closing pin 108. In an example, the electrolyte may
comprise one or more of sodium chloride (NaCl), potassium chloride
(KCl), or calcium chloride (CaCl2), depending on the specific
electrochemical requirements of the cell 100. The electrolyte filling
30 process may be performed under controlled atmospheric conditions to
8
prevent contamination and ensure optimal electrochemical
performance.
[0024] Continuing further, the closing pin 108 may be understood as
a sealing body configured to fit within the aperture 114 present on the
closing lid 106 to mechanically seal the 5 internal components of the
battery casing 102. The closing pin 108 includes a flat portion and a
threaded protrusion extending away from the flat portion in a
longitudinal direction. The threaded protrusion may have a
complementary tapered profile that matches the tapered profile of the
10 threaded aperture 114. On assembly with the bottom lid 106, the
threaded protrusion of the closing pin 108 is threadedly engaged with
the aperture 114 of the bottom lid 106 to secure the components in a
locked configuration. Further, the flat portion of the closing pin 108 is
flush with the bottom lid 106. This flush configuration creates a
15 continuous surface profile that facilitates subsequent manufacturing
operations and prevents any gaps that could compromise sealing
integrity. The threaded engagement constrains all degrees of freedom
of the closing pin 108 relative to the bottom lid 106, preventing
movement during welding operations and ensuring consistent
20 positioning throughout the manufacturing process.
[0025] FIGS. 2A-2C illustrate various views of the bottom lid 200, in
accordance with an example of the present subject matter. The bottom
lid 200 is structurally and functionally similar to the bottom lid 106. In an
example, the bottom lid 200 may be configured to enclose a battery
25 casing of a cell (for example, cell 100). Particularly, FIG. 2(A) illustrates
an isometric view of the bottom lid 200 depicting three-dimensional
configuration and surface features of the bottom lid 200. FIG. 2(B)
illustrates a side view of the bottom lid 200. FIG. 2(C) illustrates a
magnified portion of an aperture 208 of the bottom lid 200.
9
[0026] The bottom lid 200 includes a base plate 202 including a first
surface 204 and a second surface 206. The base plate 202 may form a
main structure of the bottom lid 200 and may be configured to cover an
open end of the battery casing of the cell. In an example, the base plate
202 may be made from a conducive material, 5 such as aluminum alloy,
nickel-plated steel, or stainless steel, to allow for electrical connectivity
within the secondary cell. In an example, a diameter of the base plate
202 may correspond to a diameter of a cross-section of the battery
casing. The size configuration may also accommodate manufacturing
10 tolerances while ensuring consistent fitment across production units. In
an example, the base plate may have mechanisms to couple with the
open end of the cell. In another example, the base plate 202 may have
mechanisms such as welding interfaces or mechanical features to
couple with the open end of the cell.
15 [0027] In an example, upon coupling with the battery casing, the first
surface 204 faces towards an electrode assembly accommodated
inside the battery casing. For example, the first surface 204 comes in
contact with the internal components of the cell and may be configured
to provide electrical connectivity to the electrode assembly. The second
20 surface 206, on the other hand, faces away from the electrode
assembly and may be configured to act as a terminal of the cell. For
example, the second surface 206 may provide an external interface for
electrical connections and may be designed to accommodate terminal
attachments or welding operations during cell assembly.
25 [0028] Further, the aperture 208 is positioned at the center of the
base plate 202 of the bottom lid 200. As depicted in FIG. 2(C), the
aperture 208 extends from the second surface 206 to the first surface
204 and serves as an access port for electrolyte filling during
manufacturing operations. In an example, the aperture 208 includes a
30 threaded surface 210 formed on an inner surface of the aperture 208.
10
The threaded surface 210 may have a tapered profile 212 that facilitates
enhanced sealing characteristics and improved engagement with a
corresponding closing pin. In an example, the threaded surface 210
may include a single pitch thread. The single pitch thread may be
manufactured using a turret punch press. 5 In some cases, the singlepitch
thread configuration may simplify the manufacturing process while
providing adequate mechanical engagement for sealing purposes. In
some cases, the single pitch thread may be formed by developing a prepierced
aperture in the base plate 202 through a forming process,
10 allowing for precise control of the aperture geometry and thread profile.
[0029] The single-pitch thread may be configured to receive a closing
pin (such as the closing pin 108) upon electrolyte filing. The closing pin
may include complementary threads configured to fit into the threaded
surface 210 formed in the aperture 208. The threaded engagement
15 between the closing pin and the aperture 208 creates a zero-tolerance
interface that eliminates gaps and prevents movement during
subsequent manufacturing operations such as welding processes. This
forming approach allows for precise control of the aperture geometry
and thread profile without requiring additional machining operations.
20 Further, the threaded aperture comprises a single pitch thread. The
single pitch thread configuration reduces the complexity of the forming
operation while maintaining the structural integrity needed for the
sealing application. The assembly of the closing pin with the bottom lid
200 is described with reference to FIG. 3.
25 [0030] FIG. 3 illustrates a lid assembly 300 for a secondary cell (not
shown), in accordance with an example of the present subject matter.
The figure shows a side view that reveals the internal configuration and
dimensional relationships between the components. The lid assembly
300 is formed by mechanical coupling of a bottom lid 302 and a closing
30 pin 304. In particular, after an electrolyte filing process is completed, the
11
closing pin 304 is mechanically coupled with the bottom lid 302 to
ensure effective sealing of the secondary cell to avoid spillage. For
example, the bottom lid 302 may be structurally and functionally the
same as the bottom lid 106 and the closing pin 304 may be structurally
and functionally the 5 same as the pin 108.
[0031] As discussed above, the bottom lid 302 may include a first
surface 306 and a second surface 308. The first surface 306 may be
configured to face towards an electrode assembly accommodated
inside the secondary cell and the second surface 308 may be
10 configured to face away from the electrode assembly. Further, the
bottom lid 302 includes an aperture (such as the aperture 208)
positioned at a center portion of the bottom lid 302. The aperture is used
to fill electrolyte into the secondary cell once the battery casing is sealed
with the bottom lid 302. In accordance with the present subject matter,
15 the aperture may be a threaded aperture, i.e., the aperture may include
threads at an inside surface at a periphery of the aperture. The threaded
aperture may extend from the second surface 308 towards the first
surface 306, the extension manifesting in the form of a protrusion
having a tapered profile 310.
20 [0032] In an example, the bottom lid 302 may have a substantially
circular configuration having concentric circles that define the threaded
aperture at the central portion. The threaded aperture may have a depth
of approximately 1.3 – 1.5 millimeters (mm), extending in a longitudinal
direction. Further, a diameter of a sitting face of the closing pin may
25 range between 11 to 12 mm, corresponding to the area where the
closing pin 304 is configured to make contact with the bottom lid 302.
[0033] Further, as discussed above, the closing pin 304 is configured
to be mechanically coupled with the bottom lid 302. The closing pin 304
includes a flat portion 312 and a threaded protrusion 314 extending
30 away from the flat portion 312 in a longitudinal direction. As depicted in
12
FIG. 3, the threaded protrusion 314 includes external threading that
corresponds to internal threading formed within the aperture. The flat
portion 312 may be formed with a circular configuration having a
diameter that may range from approximately 11mm to 12mm, providing
adequate surface area for contact with the 5 bottom lid 302. In some
cases, the flat portion 312 may have a thickness that allows for flush
positioning with the outer surface of the bottom lid 302 when the closing
pin 304 is fully engaged.
[0034] The threaded protrusion 314 of the closing pin 304 may have
10 a thread diameter of approximately 5.8 mm and may be configured with
a single pitch thread having a pitch specification ranging from 0.65mm
to 0.75mm. The threaded protrusion 314 may extend from the flat
portion 312 with a length that corresponds to the thickness of the bottom
lid 302 and the depth of the threaded aperture. In some aspects, the
15 threaded protrusion 314 may have a tapered profile that complements
the tapered profile 310 of the aperture in the bottom lid 302.
[0035] In some examples, the closing pin 304 may be manufactured
from materials such as nickel-plated steel, stainless steel, or aluminum
to provide corrosion resistance and compatibility with battery
20 electrolytes. The material selection may also ensure adequate strength
for the threaded engagement while maintaining dimensional stability
during manufacturing operations such as welding processes. The
material compatibility between the closing pin 304 and the bottom lid
302 prevents galvanic corrosion and ensures long-term reliability of the
25 sealed joint.
[0036] During assembly, the threaded protrusion 314 of the closing
pin 304 is inserted into the threaded aperture of the bottom lid 302. As
the closing pin 304 is rotated, the threaded surfaces (of the threaded
protrusion 314 and the bottom lid 302) may progressively engage,
30 causing the closing pin 304 to advance into the aperture until a desired
13
engagement depth is achieved. Accordingly, the closing pin 304 is
fastened with the bottom lid 302 to create a firm and stable fixture. Upon
fastening, the closing pin 304 becomes fixedly attached to the bottom
lid 302. Subsequently, the closing pin 304 is hermetically sealed with
the aperture with various means, 5 such as by laser welding. For
example, the flat portion 312 of the closing pin 304 is laser welded to
the threaded aperture from outside, post electrolyte filling operation.
The threaded engagement of the closing pin 304 at the aperture
provides a secure mechanical interlock that resists inadvertent
10 disengagement while allowing for controlled release when the closing
pin 304 is counter-rotated, thus avoiding unwanted gaps to remain
between the bottom lid 302 and the closing pin 304. The threaded
engagement may also allow for fine adjustment of the closing pin 304
position relative to the bottom lid 302, enabling precise alignment of
15 associated components.
[0037] FIG. 4 illustrates a perspective view of a secondary cell 400
with a lid assembly 402 positioned on top of the secondary cell, in
accordance with an example of the present subject matter. The figure
shows a cylindrical battery casing 404 having a closed end (not shown
20 in the figure) and an open end that is sealed by the lid assembly 402.
The lid assembly 402 is shown in its assembled configuration, as
discussed in conjunction with FIG. 3. The lid assembly 402 includes a
bottom lid 406 and a closing pin 408. The closing pin 408 is positioned
at the central portion of the bottom lid 406 and appears as a circular
25 feature flush with an outer surface of the lid assembly 402, creating a
continuous surface profile across the lid assembly 402.
[0038] The assembled secondary cell demonstrates the complete
integration of all components in their operational configuration. The
secondary cell 400 includes a battery casing 404 housing an electrode
30 assembly within its interior that is not visible in this external view but is
14
contained within the sealed enclosure. The lid assembly 402 serves as
the primary sealing mechanism to prevent electrolyte leakage and
maintain the integrity of the cell components. The lid assembly 402
covers the open end of the battery casing and creates a hermetic seal
that protects the internal electrochemical 5 components from
environmental contamination. As may be seen from the assembled
view, a diameter of the closing lid 406 corresponds to a diameter for a
cross-section of the battery casing 404, creating a proper fit between
the components. The dimensional correspondence ensures that the lid
10 assembly 402 provides complete coverage of the battery casing 404
opening and maintains structural continuity between the components.
[0039] As discussed in conjunction with FIG. 3, the closing pin 408 is
threadedly engaged with an aperture in the bottom lid 406. Thereafter,
the closing pin is sealed through welding operations. The flush
15 positioning of the closing pin 408 with the bottom lid 406 creates a
continuous outer profile that facilitates manufacturing operations and
provides a smooth external surface for the completed cell. The
assembled lid assembly 402 provides a complete sealing solution that
maintains the structural integrity of the secondary cell 400 during
20 manufacturing and operational use.
[0040] Although examples for the present disclosure have been
described in language specific to structural features and/or methods, it
is to be understood that these examples are not necessarily limited to
the specific features or methods described. Rather, the specific features
25 and methods are disclosed and explained as examples of the present
description.
15
I/We Claim:
1. A lid assembly (300, 402) for a secondary cell (100, 400), the lid assembly
(300, 402) comprising:
a base plate (202) having a first surface (2 5 04, 306) and a second
surface (206, 308), the base plate (202) is configured to be coupled with an
open end (110) of a battery casing (102, 404), wherein the first surface (204,
306) faces towards an electrode assembly (104) accommodated inside the
battery casing (102, 404) and the second surface (206, 308) is to face away
10 from the electrode assembly (104);
a threaded aperture (114, 208) disposed at a central portion of the
base plate (202), the threaded aperture (114, 208) extends from the second
surface (206, 308) to the first surface (204, 306) and having a tapered profile
(212, 310); and
15 a closing pin (108, 304, 408) configured to close the threaded aperture
(114, 208), wherein the closing pin (108, 304, 408) comprises a flat portion
(312) and a threaded protrusion (314) extending away from the flat portion
(312), in an assembled state, the threaded protrusion (314) is engaged with
the threaded aperture (114, 208) and the flat portion (312) is flush with the
20 second surface (206, 308) of the base plate (202).
2. The lid assembly (300, 402) as claimed in claim 1, wherein the threaded
protrusion (314) has a complementary tapered profile (212, 310) to match
the tapered profile (212, 310) of the threaded aperture (114, 208).
3. The lid assembly (300, 402) as claimed in claim 1, wherein a diameter of
25 the base plate (202) corresponds to a diameter of a cross-section of the
battery casing (102, 404).
4. The lid assembly (300, 402) as claimed in claim 1, wherein the base plate
(202) is made of a material selected from one of an aluminum alloy, nickelplated
steel, and stainless steel.
16
5. The lid assembly (300, 402) as claimed in claim 1, wherein the threaded
aperture (114, 208) comprises a single pitch thread.
6. The lid assembly (300, 402) as claimed in claim 5, wherein the single
pitch thread is formed by developing a pre-pierced aperture in the base plate
5 (202).
7. The lid assembly (300, 402) as claimed in claim 6, wherein the single
pitch thread is manufactured using a turret punch press.
8. The lid assembly (300, 402) as claimed in claim 2, wherein the flat portion
(312) of the closing pin (108, 304, 408) is laser welded to the threaded
10 aperture (114, 208) from outside, post electrolyte filling operation.
9. A bottom lid (106, 200, 302, 406) for a secondary cell (100, 400), the
bottom lid (106, 200, 302, 406) comprising:
a base plate (202) having a first surface (204, 306) and a second
surface (206, 308), the base plate (202) is configured to be coupled with an
15 open end (110) of a battery casing (102, 404), wherein the first surface (204,
306) faces towards an electrode assembly (104) accommodated inside the
battery casing (102, 404) and the second surface (206, 308) is to face away
from the electrode assembly (104);
a threaded aperture (114, 208) disposed at a central portion of the
20 base plate (202), the threaded aperture (114, 208) extending from the
second surface (206, 308) to the first surface (204, 306) and having a
tapered profile (212, 310), wherein the threaded aperture (114, 208) is
configured to receive a closing pin (108, 304, 408) in an assembled state.
10. The bottom lid (106, 200, 302, 406) as claimed in claim 9, wherein a
25 diameter of the base plate (202) corresponds to a diameter of a crosssection
of the battery casing (102, 404).
11. The bottom lid (106, 200, 302, 406) as claimed in claim 9, wherein the
base plate (202) is made of a material selected from one of an aluminum
alloy, nickel-plated steel, and stainless steel.
17
12. The bottom lid (106, 200, 302, 406) as claimed in claim 9, wherein the
threaded aperture (114, 208) comprises a single pitch thread.
13. The bottom lid (106, 200, 302, 406) as claimed in claim 12, wherein the
single pitch thread is formed by developing a pre-pierced aperture in the
5 base plate (202).
14. The bottom lid (106, 200, 302, 406) as claimed in claim 13, wherein the
single pitch thread is manufactured using a turret punch press.
15. The bottom lid (106, 200, 302, 406) as claimed in claim 9, wherein the
closing pin (108, 304, 408) is laser welded to the threaded aperture (114,
10 208) from outside post electrolyte filling operation.
16. A secondary cell (100, 400) comprising:
a battery casing (102, 404) having an open end (110) and a closed
end (112);
an electrode assembly (104) positioned within the battery casing
15 (102, 404); and
the lid assembly (300, 402) as claimed in one of claims 1 to 8.
18
ABSTRACT
BOTTOM LID FOR A SECONDARY CELL
Examples of a lid assembly (300, 402) for a secondary cell (100, 400)
are described in the present subject matter. The lid assembly (300, 402)
includes a base plate (202) configured to be coupled 5 with a battery casing
(102, 404). The base plate includes a threaded aperture (114, 208)
disposed at a central position of the base plate (202). The threaded aperture
(114, 208) extends from an outer surface of the base plate to an inner
surface, upon coupling with the battery casing. The threaded aperture has
10 a tapered profile. The lid assembly further includes a closing pin (108, 304,
408) configured to close the threaded aperture wherein the closing pin
includes a threaded protrusion (314) configured to engage with the threaded
aperture ensuring fixed attachment for preventing displacement while
welding.
19 , Claims:I/We Claim:
1. A lid assembly (300, 402) for a secondary cell (100, 400), the lid assembly
(300, 402) comprising:
a base plate (202) having a first surface (2 5 04, 306) and a second
surface (206, 308), the base plate (202) is configured to be coupled with an
open end (110) of a battery casing (102, 404), wherein the first surface (204,
306) faces towards an electrode assembly (104) accommodated inside the
battery casing (102, 404) and the second surface (206, 308) is to face away
10 from the electrode assembly (104);
a threaded aperture (114, 208) disposed at a central portion of the
base plate (202), the threaded aperture (114, 208) extends from the second
surface (206, 308) to the first surface (204, 306) and having a tapered profile
(212, 310); and
15 a closing pin (108, 304, 408) configured to close the threaded aperture
(114, 208), wherein the closing pin (108, 304, 408) comprises a flat portion
(312) and a threaded protrusion (314) extending away from the flat portion
(312), in an assembled state, the threaded protrusion (314) is engaged with
the threaded aperture (114, 208) and the flat portion (312) is flush with the
20 second surface (206, 308) of the base plate (202).
2. The lid assembly (300, 402) as claimed in claim 1, wherein the threaded
protrusion (314) has a complementary tapered profile (212, 310) to match
the tapered profile (212, 310) of the threaded aperture (114, 208).
3. The lid assembly (300, 402) as claimed in claim 1, wherein a diameter of
25 the base plate (202) corresponds to a diameter of a cross-section of the
battery casing (102, 404).
4. The lid assembly (300, 402) as claimed in claim 1, wherein the base plate
(202) is made of a material selected from one of an aluminum alloy, nickelplated
steel, and stainless steel.
16
5. The lid assembly (300, 402) as claimed in claim 1, wherein the threaded
aperture (114, 208) comprises a single pitch thread.
6. The lid assembly (300, 402) as claimed in claim 5, wherein the single
pitch thread is formed by developing a pre-pierced aperture in the base plate
5 (202).
7. The lid assembly (300, 402) as claimed in claim 6, wherein the single
pitch thread is manufactured using a turret punch press.
8. The lid assembly (300, 402) as claimed in claim 2, wherein the flat portion
(312) of the closing pin (108, 304, 408) is laser welded to the threaded
10 aperture (114, 208) from outside, post electrolyte filling operation.
9. A bottom lid (106, 200, 302, 406) for a secondary cell (100, 400), the
bottom lid (106, 200, 302, 406) comprising:
a base plate (202) having a first surface (204, 306) and a second
surface (206, 308), the base plate (202) is configured to be coupled with an
15 open end (110) of a battery casing (102, 404), wherein the first surface (204,
306) faces towards an electrode assembly (104) accommodated inside the
battery casing (102, 404) and the second surface (206, 308) is to face away
from the electrode assembly (104);
a threaded aperture (114, 208) disposed at a central portion of the
20 base plate (202), the threaded aperture (114, 208) extending from the
second surface (206, 308) to the first surface (204, 306) and having a
tapered profile (212, 310), wherein the threaded aperture (114, 208) is
configured to receive a closing pin (108, 304, 408) in an assembled state.
10. The bottom lid (106, 200, 302, 406) as claimed in claim 9, wherein a
25 diameter of the base plate (202) corresponds to a diameter of a crosssection
of the battery casing (102, 404).
11. The bottom lid (106, 200, 302, 406) as claimed in claim 9, wherein the
base plate (202) is made of a material selected from one of an aluminum
alloy, nickel-plated steel, and stainless steel.
17
12. The bottom lid (106, 200, 302, 406) as claimed in claim 9, wherein the
threaded aperture (114, 208) comprises a single pitch thread.
13. The bottom lid (106, 200, 302, 406) as claimed in claim 12, wherein the
single pitch thread is formed by developing a pre-pierced aperture in the
5 base plate (202).
14. The bottom lid (106, 200, 302, 406) as claimed in claim 13, wherein the
single pitch thread is manufactured using a turret punch press.
15. The bottom lid (106, 200, 302, 406) as claimed in claim 9, wherein the
closing pin (108, 304, 408) is laser welded to the threaded aperture (114,
10 208) from outside post electrolyte filling operation.
16. A secondary cell (100, 400) comprising:
a battery casing (102, 404) having an open end (110) and a closed
end (112);
an electrode assembly (104) positioned within the battery casing
15 (102, 404); and
the lid assembly (300, 402) as claimed in one of claims 1 to 8.