IP Library › Granted Patent US 12695142
Granted Patent B2
US 12695142 · App. 18/507,821 · Granted Jul 28, 2026

Seal assembly for a battery cell

Inventors: Mark T. Ashbolt (Newtown, CT); Daniel G. Allen (New Milford, CT); Oleg Podoprigora (New Milford, CT)
Assignee: DURACELL U.S. OPERATIONS, INC.
H01M50/184H01M50/147H01M50/193H01M50/154H01M50/171H01M50/186
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Quick Facts
Patent No.
US 12695142
App. No.
18/507,821
Granted
Jul 28, 2026
Kind
B2
Abstract

A seal assembly for a battery cell includes a grommet having an opening having an inner surface. A nail has a nail head and a stem extending from the stem. The stem includes a first portion with a larger diameter and a second portion with a smaller diameter and the stem extends through the opening in the grommet. The stem and the grommet form a first interference fit at a distal end of the opening. A trap clearance is formed between the distal end of the opening and the nail head. The trap clearance defines a trap for a sealant. A sealant is disposed on the stem and is located at least partially in the trap.

Claims (39)

1 . A seal assembly for a battery cell, the seal assembly comprising:

a grommet having an opening including an inner surface defining a bore diameter, and an inner annular ring extending inward from the inner surface, the inner annular ring having a ring diameter that is smaller than the bore diameter;

a nail, the nail having a nail head and a stem extending from the nail head, the stem extending through the opening in the grommet, the stem and the grommet forming a first interference fit adjacent a distal end of the opening and a second interference fit between the stem and the grommet adjacent a proximal end of the grommet, a trap clearance being formed between the first interference fit and the second interference fit, and the trap clearance defining a trap for a sealant; and

the sealant disposed on the stem, the sealant being located at least partially in the trap.

2 . The seal assembly of claim 1 , wherein the bore diameter is larger than a portion of a stem diameter.

3 . The seal assembly of claim 2 , wherein the bore diameter is between 0.03 mm and 0.05 mm larger than the portion of the stem diameter.

4 . The seal assembly of claim 1 , wherein the trap is formed between the inner surface and the stem.

5 . The seal assembly of claim 1 , wherein the inner annular ring forms the first interference fit with the stem.

6 . The seal assembly of claim 5 , wherein the trap is located above the inner annular ring, along a length of the stem.

7 . The seal assembly of claim 1 , wherein the trap has a volume of between 0.35 mm 3 and 1.5 mm 3 .

8 . The seal assembly of claim 1 , wherein the stem includes an annular recess.

9 . A seal assembly for a battery cell, the seal assembly comprising:

a grommet having an opening including an inner surface defining a bore diameter, and an inner annular ring extending inward from the inner surface, the inner annular ring having a ring diameter that is smaller than the bore diameter;

a nail, the nail having a nail head and a stem extending from the nail head, the stem extending through the opening in the grommet, the stem and the grommet forming a first interference fit adjacent a distal end of the opening and a trap clearance between the distal end of the opening and the nail head, and the trap clearance defining a trap for a sealant; and

the sealant disposed on the stem, the sealant being located at least partially in the trap,

wherein the stem includes an annular recess, and wherein the trap clearance is formed by the annular recess.

10 . The seal assembly of claim 8 , wherein the stem includes a plurality of annular recesses.

11 . The seal assembly of claim 1 , wherein the grommet comprises a polymer.

12 . The seal assembly of claim 1 , wherein the nail comprises brass or silicon bronze.

13 . The seal assembly of claim 1 , wherein the sealant comprises a polyamide or asphalt based material.

14 . The seal assembly of claim 1 , wherein a head clearance is formed between the nail head and the grommet and sealant is also disposed in the head clearance.

15 . The seal assembly of claim 1 , wherein the grommet includes a lower bore having a larger internal diameter than the ring diameter.

16 . The seal assembly of claim 1 , wherein the stem includes a chamfer and the trap clearance is formed between the inner annular ring and the chamfer.

17 . A battery cell comprising:

a housing, including:

a first cover at a first housing end and a second cover at a second housing end, and an anode and a cathode disposed within the housing; and

a seal assembly proximate the first cover, the seal assembly including:

a grommet having an opening including an inner surface defining a bore diameter, and an inner annular ring extending inward from the inner surface, the inner annular ring having a ring diameter that is smaller than the bore diameter;

a nail, the nail having a nail head and a stem extending from the nail head, the stem extending through the opening in the grommet, the stem and the grommet forming a first interference fit adjacent a distal end of the opening and a second interference fit between the stem and the grommet adjacent a proximal end of the grommet, a trap clearance being formed between the first interference fit and the second interference fit, and the trap clearance defining a trap for a sealant; and

the sealant disposed on the stem, the sealant being located at least partially in the trap.

18 . The battery cell of claim 17 , wherein the trap is located above the inner annular ring, along a length of the stem.

19 . The battery cell of claim 17 , wherein the stem includes an annular recess.

20 . A battery cell comprising:

a housing, including:

a first cover at a first housing end and a second cover at a second housing end, and an anode and a cathode disposed within the housing; and

a seal assembly proximate the first cover, the seal assembly including:

a grommet having an opening including a distal end, a proximal end, and a bore having an inner surface between the distal end and the proximal end, an internal annular ring positioned proximate the distal end, the internal annular ring having a ring diameter, the bore having a bore diameter, and a headspace located at the proximal end, the headspace having a headspace diameter, the ring diameter being smaller than the bore diameter and the headspace diameter, and the bore diameter being smaller than the headspace diameter;

a nail, the nail having a nail head and a stem extending from the nail head, the stem including a first portion with a first stem diameter and a second portion with a second stem diameter, the first stem diameter being larger than the second stem diameter, the stem extending through the opening in the grommet, the stem and the grommet forming a first interference fit between the second portion of the stem and the ring diameter and a second interference fit between the stem and the grommet adjacent the proximal end of the grommet, the stem and the grommet forming a trap clearance between the first interference fit and the second interference fit, the trap clearance defining a trap for a sealant; and

the sealant disposed on the stem, the sealant being located at least partially in the trap.