Patent ID: 8722238

Claim:
An electrochemical cell, comprising: a) a casing; b) an electrode assembly contained within the casing, the electrode assembly comprising: i) an anode composed of an active anode material, a cathode composed of an active cathode material, and a separator membrane residing between the anode and the cathode; and ii) at least one current collector composed of a first metal of a first melting temperature, the current collector comprising a connection tab extending from a current collector body, wherein the current collector body is contacted to one of the active anode or cathode active materials to thereby form the respective anode or cathode; and c) an electrolyte contained within the casing to activate the electrode assembly; d) a terminal pin passing through a feedthrough in a non-conductive relationship with the casing, wherein the terminal pin is of a second metal having a second melting temperature greater than the first melting temperature of the first metal, and wherein the terminal pin extends from a proximal terminal pin portion connected inside the casing to the current collector for the one of the anode and the cathode to a distal terminal pin portion residing outside the casing as a first terminal for the anode or the cathode; e) wherein the proximal terminal pin portion is joined to the connection tab of the current collector by a direct resistance weld, the weld comprising: i) a fusion zone of the first metal having a fusion zone thickness extending from an interface contacting the terminal pin to a distal fusion zone region, wherein the fusion zone is comprised of columnar shaped grains of the first metal radiating from the interface toward the current collector body; and ii) a heat affected zone of the first metal having a heat affected zone thickness extending from the distal fusion zone region to a distal heat affected region at the current collector body, wherein the heat affected zone is comprised of heat affected grains of the first metal, the heat affected grains being at least two times the size of grains of the first metal that are substantially unaffected by heat created during formation of the weld; and f) wherein the casing is a second terminal for the other of the anode and the cathode not connected to the terminal pin.