Cylindrical secondary cell and a method of its manufacture
This disclosure presents an electrode lead plate ( 6 ) for a cylindrical secondary cell ( 1 ) comprising a terminal part ( 4 ) and an electrode roll ( 3 ) comprising a conductive sheet ( 3 a ). The electrode lead plate ( 6 ) comprises an inner contact region ( 6 c ) configured to be arranged in direct electrical contact with the terminal part ( 4 ) and an outer contact region ( 6 e ) configured to be arranged in direct electrical contact with the conductive sheet ( 3 a ), wherein the inner contact region ( 6 c ) is recessed in relation to the outer contact region ( 6 e ). Further, a terminal part ( 4 ) and a cylindrical secondary cell ( 1 ), as well as uses and methods of manufacture, are presented.
1. An electrode lead plate ( 6 ) for a cylindrical secondary cell ( 1 ) comprising a terminal part ( 4 ) and an electrode roll ( 3 ) comprising a conductive sheet ( 3 a ), the electrode lead plate ( 6 ) comprising:
an inner contact region ( 6 c ) configured to be arranged in direct electrical contact with an inner end ( 4 b ) of the terminal part ( 4 ), and
an outer contact region ( 6 e ) configured to be arranged in direct electrical contact with the conductive sheet ( 3 a ), wherein the outer contact region ( 6 e ) radially surrounds the inner contact region ( 6 c ),
wherein:
the inner end ( 4 b ) of the terminal part ( 4 ) extends in a first plane,
the inner contact region ( 6 c ) extends in a second plane non-intersecting with the first plane,
the outer contact region ( 6 e ) extends in a third plane non-intersecting with the first and second planes, and
the first plane is intermediate the second and third planes, such that the inner contact region ( 6 c ) is recessed in relation to the outer contact region ( 6 e ).
2. The electrode lead plate ( 6 ) of claim 1 , comprising a fuse region ( 6 d ) arranged between the inner contact region ( 6 c ) and the outer contact region ( 6 e ), the fuse region ( 6 d ) being adapted to break when a predetermined current passes through the fuse region ( 6 d ).
3. The electrode lead plate ( 6 ) of claim 2 , wherein the fuse region ( 6 d ) optionally comprises a current conducting area that is decreased by an indentation formed in the electrode lead plate ( 6 ).
4. The electrode lead plate ( 6 ) of claim 2 , wherein the fuse region ( 6 d ) optionally comprises at least one through-hole formed through the electrode lead plate ( 6 ) such that at least one fuse element ( 6 f ) is formed in the electrode lead plate ( 6 ) the fuse element ( 6 f ) forming a current conducting area.
5. The electrode lead plate ( 6 ) of claim 1 , wherein the inner and outer contact regions ( 6 c , 6 e ) extend in parallel planes that are distanced from one another.
6. The electrode lead plate ( 6 ) of claim 1 , wherein the outer contact region ( 6 e ) is annular and the inner contact region ( 6 c ) is circular.
7. The electrode lead plate ( 6 ) of claim 1 , wherein the terminal part ( 4 ) is a rivet and wherein the inner contact region ( 6 c ) being recessed provides space to accommodate a rivet head ( 4 e ) of said rivet.
8. The electrode lead plate ( 6 ) of claim 1 , further comprising a number of electrolyte flow holes ( 6 g ).
9. The electrode lead plate ( 6 ) of claim 1 , wherein the holes are arranged in a pattern on the electrode lead plate ( 6 ).
10. The electrode lead plate ( 6 ) of claim 9 , wherein at least one of the pattern has the form of a six-pointed star, or the number of electrolyte flow holes ( 6 g ) is twelve.
11. A method of manufacturing a cylindrical secondary cell ( 1 ) comprising the electrode lead plate ( 6 ) of claim 1 , a terminal part ( 4 ) and an electrode roll ( 3 ) comprising a conductive sheet ( 3 a ), wherein the method comprises
arranging the electrode lead plate ( 6 ) in direct electrical contact with the terminal part ( 4 ) and with the conductive sheet ( 3 a ).
12. A cylindrical secondary cell ( 1 ) comprising:
an electrode roll ( 3 ) comprising a conductive sheet ( 3 a ),
the electrode lead plate ( 6 ) of claim 1 , and
a terminal part ( 4 ) forming an external terminal of the cylindrical secondary cell ( 1 ) and configured to be arranged in direct electrical contact with the electrode lead plate ( 6 ).