Passivating agents for electrochemical cells
Articles and methods involving electrochemical cells and/or electrochemical cell preproducts comprising passivating agents are generally provided. In certain embodiments, an electrochemical cell includes first and second passivating agents. In some embodiments, an electrochemical cell may include a first electrode comprising a first surface, a second electrode (e.g., a counter electrode with respect to the first electrode) comprising a second surface, a first passivating agent configured and arranged to passivate the first surface, and a second passivating agent configured and arranged to passivate the second surface.
1. An electrochemical cell, comprising:
a first electrode comprising lithium, the first electrode comprising a first surface;
a second electrode, the second electrode comprising a second surface;
an electrolyte;
a first passivating agent, wherein the first passivating agent comprises one or more of a xanthate salt and a carbamate salt;
a second passivating agent, wherein the second passivating agent comprises a silane, and
wherein the carbamate salt is present in an amount of less than and equal to 4 wt % in the electrolyte.
2. An electrochemical cell as in claim 1 , wherein the first passivating agent is a solvent.
3. An electrochemical cell as in claim 1 , wherein the first passivating agent is an additive that is soluble or miscible with the electrolyte.
4. An electrochemical cell as in claim 1 , wherein the first passivating agent comprises a lithium salt.
5. An electrochemical cell as in claim 1 , wherein the first passivating agent is derived from a first passivating agent precursor.
6. An electrochemical cell as in claim 1 , wherein the silane comprises a leaving group.
7. An electrochemical cell as in claim 1 , wherein the silane is capable of reacting with —OH and/or —COOH groups.
8. An electrochemical cell as in claim 1 , wherein an average molecular weight of the silane is less than or equal to 1000 g/mol.
9. An electrochemical cell as in claim 1 , wherein the second electrode is a lithium ion intercalation electrode.
10. An electrochemical cell as in claim 1 , wherein the electrolyte comprises a solvent.
11. An electrochemical cell as in claim 10 , wherein the solvent comprises a carbonate group.
12. An electrochemical cell as in claim 10 , wherein the solvent comprises a mixture of dimethyl carbonate and ethylene carbonate.
13. An electrochemical cell as in claim 1 , wherein the electrolyte comprises a lithium salt.
14. An electrochemical cell as in claim 1 , wherein the first passivating agent, in the absence of the second passivating agent, reduces cycle life of an electrochemical cell, compared to a control electrochemical cell that does not include the first or the second passivating agents, all other factors being equal, and wherein the presence of the first and second passivating agents increases cycle life of an electrochemical cell compared to the control electrochemical cell, all other factors being equal.
15. An electrochemical cell as in claim 1 , wherein the second passivating is configured and arranged to reduce or prevent decomposition of the first passivating agent during cycling of the electrochemical cell and/or to reduce or prevent decomposition of an electrolyte component promoted by the first passivating agent during cycling of the electrochemical cell, compared to decomposition in a similar electrochemical cell that does not include the second passivating agent, all other factors being equal.
16. An electrochemical cell as in claim 1 , wherein the first passivating agent is configured and arranged to passivate the first surface.