HERMETIC SEAL STRUCTURE
A cell that includes a housing, a current collector placed in the housing, and a cap assembly that closes the housing. The cap assembly includes a terminal block, a cap plate, and a terminal insulator disposed between the terminal block and the cap plate. The terminal insulator is brazed at one side to the terminal block and at another side opposite to the one side to the cap plate.
1 . A cell comprising:
a housing extending along a first axis to define a width, a second axis orthogonal to the first axis to define a height, and a third axis orthogonal to the first and second axes to define a thickness;
a current collector disposed in the housing, and
a cap assembly that closes the housing, the cap assembly comprising:
a terminal block comprising a top side, and a bottom side,
a cap plate; and
a terminal insulator comprising another top side, another bottom side, the terminal insulator disposed between the terminal block and the cap plate, the terminal insulator brazed at the another top side to the terminal block and also brazed at the another bottom side to the cap plate.
2 . The cell of claim 1 , wherein the terminal insulator is a ceramic material.
3 . The cell of claim 2 , wherein the ceramic material comprises Al 2 O 3 .
4 . The cell of claim 1 , wherein the cap plate or housing or terminal block comprises an Al alloy.
5 . The cell of claim 1 , wherein at an anode side of the cell the terminal block is coated with Ni or Cu and the cap plate is coated with Sn.
6 . The cell of claim 1 , wherein at a cathode side of the cell the terminal block and the cap plate are coated with Sn.
7 . The cell of claim 1 , wherein the terminal insulator is an electrical insulator.
8 . The cell of claim 1 , wherein:
the current collector further comprises a protrusion,
the terminal block further comprises, a first opening at the top side and a terminal partition material at the bottom side,
the terminal insulator further comprises a second opening disposed beneath the terminal partition material, a volume of the second opening being larger than a volume of the first opening,
the cap plate further comprises a third opening, disposed beneath the second opening and configured to receive the protrusion; and
the cap plate insulator further comprises a fourth opening and a position fixing extension configured to confine the protrusion.
9 . The cell of claim 8 , wherein the current collector is disposed in the second opening and welded to the terminal at the first opening to form a terminal-to-current collector weld at an external area of the cell.
10 . The cell of claim 1 , wherein the terminal block further comprises an extension at the bottom side that extends downwards and electrically connects the terminal block to the current collector.
11 . The cell of claim 1 , wherein at least a portion of the terminal insulator is disposed in a depressed volume of the cap plate.
12 . The cell of claim 11 , wherein both the whole terminal insulator is disposed in the depressed volume of the cap plate.
13 . A battery pack comprising the cell of claim 1 and a plurality of other cells each designed based on the cell.
14 . The cell of claim 1 , wherein the protrusion is a pillar shaped protrusion.
15 . The cell of claim 1 , wherein the cell is a prismatic cell.
16 . A method of producing a cell comprising:
providing a housing extending along a first axis to define a width, a second axis orthogonal to the first axis to define a height, and a third axis orthogonal to the first and second axes to define a thickness;
disposing a current collector in the housing;
generating a cap assembly to close the housing by:
providing a terminal block comprising a top side and a bottom side, a cap plate, and a terminal insulator comprising another top side and another bottom side;
disposing the terminal insulator between the terminal block and the cap plate;
brazing the terminal insulator at the another top side to the terminal block and at the at the another bottom side to the cap plate; and
closing the housing with the cap assembly.
17 . The method of claim 16 , wherein the brazing comprises at least one of active brazing and vacuum brazing.
18 . The method of claim 16 , wherein:
the terminal insulator is a ceramic and the brazing is performed between a metal surface and the ceramic.
19 . The method of claim 16 , further comprising:
minimizing a height of the cap assembly by disposing at least a portion of the terminal insulator in a depressed volume of the cap plate.
20 . The method of claim 16 , welding, from an area external to the cell and through a first opening, a terminal partition material of the terminal block to the current collector.