Cell connectors for battery
Traditional battery assembly involves welding the vulnerable crimp electrodes after positioning the cells in the pack, which may lead to wastage of the entire pack if a single weld fails. To overcome this, electrode connectors are pre-welded to the crimp terminals of the cells and the welds tested before the cells are assembled in the battery. Electrode connectors for the other cell terminals are pre-assembled in the collector stack. The electrode connectors are generally circular and can be welded in any rotational orientation. The connectors have an upper annulus below which extend legs and a foot or feet. The annuli are welded to the collectors in the stack and the foot or feet to the cells. Compression of the electrode connectors compensates for dimensional differences in the cells. Holes through the collector stack allow for hot gases to escape in the event of a cell failure.
1 . A set of electrode connectors for a cell comprising:
a first electrode connector comprising:
a first annulus;
multiple first legs extending from the first annulus; and
a first foot extending from each first leg, wherein the first feet fit over a crimp of the cell; and
a second electrode connector comprising:
a second annulus;
multiple second legs extending from the second annulus; and
a second foot at which the second legs terminate, the second foot dimensioned to fit inside the first annulus.
2 . The set of electrode connectors of claim 1 wherein there are three equidistant first legs and three equidistant second legs.
3 . The set of electrode connectors of claim 1 wherein:
the first annulus has an outer diameter larger than the second annulus and smaller than the cell; and
the second annulus has a larger inner diameter than the second foot.
4 . The set of electrode connectors of claim 1 wherein:
the first feet have a radius of curvature less than a radius of curvature of the crimp; and
when the first electrode connector is compressed onto the crimp the feet conform to the crimp.
5 . The set of electrode connectors of claim 1 wherein the second foot is planar.
6 . The set of electrode connectors of claim 1 made of a springy material.
7 . The set of electrode connectors of claim 1 wherein:
the second electrode connector is connected to a collector stack and not the cell; and
the first electrode connector is connected to the crimp and not the collector stack.
8 . A battery comprising multiple cells and for each cell:
a first electrode connector comprising:
a first annulus;
a plurality of first legs extending from the first annulus; and
a first foot extending from each first leg, wherein the first feet are connected to a crimp of the cell; and
a second electrode connector comprising:
a second annulus;
a plurality of second legs extending from the second annulus; and
a second foot at which the second legs terminate, the second foot connected to a button terminal of the cell.
9 . The battery of claim 8 wherein:
the cells each have an anode and a cathode;
the crimps are the anodes; and
the button terminals are the cathodes.
10 . The battery of claim 8 comprising a collector stack to which the first annuli are connected to multiple first collectors at a first level thereof and the second annuli are connected to multiple second collectors at a second level thereof.
11 . The battery of claim 10 wherein the collector stack and first and second electrode connectors define venting routes to tops of the cells.
12 . The battery of claim 10 wherein the collector stack defines welding ports via which the first collectors are connected to the first annuli.
13 . The battery of claim 10 wherein at least one of the first collectors is connected to one of the second collectors.
14 . The battery of claim 13 wherein the collector stack defines a collector welding port via which said one first collector is connected to said one second collector.
15 . A method for assembling a battery of multiple cells, the method comprising:
connecting a first electrode connector to each cell by connecting multiple first feet of each first electrode connector to a crimp of each cell, each first electrode connector comprising a first annulus and a plurality of first legs extending from the first annulus and terminating in one of the first feet;
connecting, for each cell, a second electrode connector to a collector stack, each second electrode connector comprising a second annulus, a plurality of second legs extending from the second annulus and a second foot at which the second legs terminate;
connecting the collector stack with the connected second electrode connectors to the first annuli; and
connecting each second electrode connector connected to the collector stack to a button terminal of each cell.
16 . The method of claim 15 comprising compressing the collector stack with the connected second electrode connectors onto the first annuli while connecting the collector stack with the connected second electrode connectors to the first annuli.
17 . The method of claim 15 comprising evaluating the connections of the first electrode connectors to the cells prior to connecting the collector stack with the connected second electrode connectors to the first annuli.
18 . The method of claim 15 , wherein rotational alignment of the first electrode connectors, the second electrode connectors and the cells is unnecessary.