Over-discharge protection for electrochemical cells
Electrochemical cells and methods of providing over-discharge protection of the same are disclosed. An electrochemical cell may include a cathode, an anode, a separator, and an electrolyte. The cathode may include a cathode current collector and a cathode active material disposed on at least a portion of the cathode current collector. The anode may include an anode current collector and an anode active material disposed on at least a portion of the anode current collector. The anode current collector may include an anode conductive material and a lithophilic metal layer disposed on the anode conductive material. The lithophilic metal layer may define an outer surface of the anode current collector. The separator may be arranged between the anode and the cathode to prevent direct contact between the anode and the cathode. The electrolyte may transport ions between the cathode and the anode.
1 . An electrochemical cell comprising:
a cathode comprising:
a cathode current collector; and
a cathode active material disposed on at least a portion of the cathode current collector;
an anode comprising:
an anode current collector comprising:
an anode conductive material; and
a lithiophilic metal layer disposed on the anode conductive material, the lithiophilic metal layer defining all outer surfaces of the anode current collector;
an anode active material disposed on at least a portion of the anode current collector; and
a separator arranged between the anode and the cathode to prevent direct contact between the anode and the cathode; and
an electrolyte to transport ions between the cathode and the anode, wherein the lithiophilic metal layer is in direct contact with the electrolyte and is configured to prevent dissolution of the anode current collector into the electrolyte.
2 . The electrochemical cell as in claim 1 , wherein the lithiophilic metal layer defines all outer surfaces of the anode current collector that are in direct contact with the electrolyte.
3 . The electrochemical cell as in claim 1 , wherein the lithiophilic metal layer comprises at least one of silver or gold.
4 . The electrochemical cell as in claim 1 , wherein the lithiophilic metal layer comprises a silver alloy or a gold alloy.
5 . The electrochemical cell as in claim 1 , wherein the lithiophilic metal layer consists essentially of silver.
6 . The electrochemical cell as in claim 1 , wherein the lithiophilic metal layer consists of silver.
7 . The electrochemical cell as in claim 1 , wherein the lithiophilic metal layer has a thickness of at least 5 nanometers and no greater than 100 nanometers.
8 . An implantable medical device comprising:
a housing;
one or more electrical components disposed in the housing; and
one or more electrochemical cells electrically coupled to at least one electrical component of the one or more electrical components, each of the one or more electrochemical cells comprising:
a cathode comprising:
a cathode current collector; and
a cathode active material disposed on at least a portion of the cathode current collector;
an anode comprising:
an anode current collector comprising:
an anode conductive material; and
a lithiophilic metal layer disposed on the anode conductive material, the lithiophilic metal layer defining all outer surfaces of the anode current collector;
an anode active material disposed on at least a portion of the anode current collector; and
a separator arranged between the anode and the cathode to prevent direct contact between the anode and the cathode; and
an electrolyte to transport ions between the cathode and the anode, wherein the lithiophilic metal layer is in direct contact with the electrolyte and is configured to prevent dissolution of the anode current collector into the electrolyte.
9 . The implantable medical device as in claim 8 , wherein the implantable medical device comprises an implantable cardioverter defibrillator.
10 . The device as in claim 8 , wherein the lithiophilic metal layer comprises at least one of silver or gold.
11 . The device as in claim 8 , wherein the lithiophilic metal layer comprises a silver alloy or a gold alloy.
12 . The device as in claim 8 , wherein the lithiophilic metal layer consists essentially of silver.
13 . The device as in claim 8 , wherein the lithiophilic metal layer consists of silver.
14 . The device as in claim 8 , wherein the lithiophilic metal layer has a thickness of at least 5 nanometers and no greater than 100 nanometers.
15 . A method for providing over-discharge protection of an electrochemical cell, the electrochemical cell comprising:
a cathode comprising:
a cathode current collector; and
a cathode active material disposed on at least a portion of the cathode current collector;
an anode comprising:
an anode current collector comprising:
an anode conductive material; and
a lithiophilic metal layer disposed on the anode conductive material, the lithiophilic metal layer defining all outer surfaces of the anode current collector;
an anode active material disposed on at least a portion of the anode current collector; and
a separator arranged between the anode and the cathode to prevent direct contact between the anode and the cathode; and
an electrolyte to transport ions between the cathode and the anode, wherein the lithiophilic metal layer is in direct contact with the electrolyte and is configured to prevent dissolution of the anode current collector into the electrolyte; and
the method comprising:
over-discharging the electrochemical cell; and
preventing dissolution of the anode current collector into the electrolyte using the lithiophilic metal layer.
16 . The method as in claim 15 , wherein the lithiophilic metal layer defines all outer surfaces of the anode current collector that are in direct contact with the electrolyte.
17 . The method as in claim 15 , wherein the lithiophilic metal layer comprises at least one of silver or gold.
18 . The method as in claim 15 , wherein the lithiophilic metal layer comprises a silver alloy or a gold alloy.
19 . The method as in claim 15 , wherein the lithiophilic metal layer consists essentially of silver.
20 . The method as in claim 15 , wherein the lithiophilic metal layer consists of silver.