Additives for electrochemical cells
Articles and methods including additives in electrochemical cells, are generally provided. As described herein, such electrochemical cells may comprise an anode, a cathode, an electrolyte, and optionally a separator. In some embodiments, at least one of the anode, the cathode, the electrolyte, and/or the optional separator may comprise an additive and/or additive precursor. For instance, in some cases, the electrochemical cell comprises an electrolyte and an additive and/or additive precursor that is soluble with and/or is present in the electrolyte. In some embodiments, the additive precursor comprises a disulfide bond. In certain embodiments, the additive is a carbon disulfide salt. In some cases, the electrolyte may comprise a nitrate.
1. An electrochemical cell, comprising:
a first electrode;
a second electrode;
an electrolyte positioned between the first electrode and the second electrode, wherein the electrolyte comprises one or more of a carbonate, a hexafluorophosphate, 1,3-dioxolane, 1,2-dimethoxyethane, a sulfonimide, a sulfone, a sulfolane, an ester of carbonic acid, and/or a nitrate-containing compound;
an additive having a structure as in Formula (I) and/or an additive precursor having a structure as in Formula (II):
wherein:
each occurrence of Q is independently selected from the group consisting of Se, O, S, PR 2 , CR 2 2 , and SiR 2 2 ;
n is 1-6; and
each R 1 and R 2 are the same or different, optionally connected, and are independently selected from the group consisting of hydrogen; oxygen; sulfur; halogen; nitrogen; phosphorus; substituted or unsubstituted, branched or unbranched aliphatic; substituted or unsubstituted cyclic; substituted or unsubstituted, branched or unbranched acyclic; substituted or unsubstituted, branched or unbranched heteroaliphatic; substituted or unsubstituted, branched or unbranched acyl; substituted or unsubstituted aryl; and substituted or unsubstituted heteroaryl.
2. An electrochemical cell, comprising:
a first electrode;
a second electrode;
an electrolyte positioned between the first electrode and the second electrode, wherein the electrolyte comprises one or more of a carbonate, a hexafluorophosphate, 1,3-dioxolane, 1,2-dimethoxyethane, a sulfonimide, a sulfone, a sulfolane, an ester of carbonic acid, and/or a nitrate-containing compound;
an additive having a structure as in Formula (I) and/or an additive precursor having a structure as in Formula (II):
wherein:
each occurrence of Q is independently selected from the group consisting of Se, O, S, PR 2 , NR 2 , CR 2 2 , and SiR 2 2 ;
n is 1-6;
each R 1 and R 2 are the same or different, optionally connected, and are independently selected from the group consisting of hydrogen; oxygen; sulfur; halogen; nitrogen; phosphorus; substituted or unsubstituted, branched or unbranched aliphatic; substituted or unsubstituted cyclic; substituted or unsubstituted, branched or unbranched acyclic; substituted or unsubstituted, branched or unbranched heteroaliphatic; substituted or unsubstituted, branched or unbranched acyl; substituted or unsubstituted aryl; and substituted or unsubstituted heteroaryl; and
the additive and/or the additive precursor is/are present in the electrochemical cell in a total amount of less than or equal to about 20 wt % versus the total weight of the electrolyte and the additive and/or additive precursor, or the additive and/or the additive precursor is/are present in the electrochemical cell in a total amount of less than or equal to about 4 wt % versus the weight of each of the first and second electrodes.
3. An electrochemical cell, comprising:
a first electrode comprising a first active electrode species;
a second electrode comprising a second active electrode species;
an electrolyte positioned between the first electrode and the second electrode, wherein the electrolyte comprises one or more of a carbonate, a hexafluorophosphate, 1,3-dioxolane, 1,2-dimethoxyethane, a sulfonimide, a sulfone, a sulfolane, an ester of carbonic acid, and/or a nitrate-containing compound;
an additive having a structure as in Formula (I) and/or an additive precursor having a structure as in Formula (II):
wherein:
each occurrence of Q is independently selected from the group consisting of Se, O, S, PR 2 , NR 2 , CR 2 2 , and SiR 2 2 ;
n is 1-6;
each R 1 and R 2 are the same or different, optionally connected, and are independently selected from the group consisting of hydrogen; oxygen; sulfur; halogen; nitrogen; phosphorus; substituted or unsubstituted, branched or unbranched aliphatic; substituted or unsubstituted cyclic; substituted or unsubstituted, branched or unbranched acyclic; substituted or unsubstituted, branched or unbranched heteroaliphatic; substituted or unsubstituted, branched or unbranched acyl; substituted or unsubstituted aryl; and substituted or unsubstituted heteroaryl; and
wherein the additive and/or the additive precursor is/are different from the first and second active electrode species.
4. The electrochemical cell of claim 2 , further comprising a lithium salt.
5. The electrochemical cell of claim 2 , wherein the additive and/or additive precursor is polyanionic.
6. The electrochemical cell of claim 2 , wherein the additive is a salt.
7. The electrochemical cell of claim 2 , wherein the additive comprises a cation.
8. The electrochemical cell of claim 7 , wherein the cation is selected from the group consisting of Li + , Na + , K + , Cs + , Rb + , Ca +2 , Mg +2 , substituted or unsubstituted ammonium, guanidinium and imidazolium.
9. The electrochemical cell of claim 2 , wherein the additive and/or additive precursor comprises a xanthate group.
10. The electrochemical cell of claim 2 , wherein at least a portion of the additive and/or additive precursor is in solid form.
11. The electrochemical cell of claim 2 , wherein at least a portion of the additive and/or additive precursor is dissolved in the electrolyte.
12. The electrochemical cell of claim 2 , wherein the additive and/or additive precursor is at least partially soluble in the electrolyte.
13. The electrochemical cell of claim 2 , wherein the additive and/or additive precursor is disposed on and/or within the first electrode.
14. The electrochemical cell of claim 2 , wherein the additive and/or additive precursor is disposed on and/or within the second electrode.
15. The electrochemical cell of claim 2 , wherein the second electrode is an intercalated electrode.
16. The electrochemical cell of claim 2 , wherein the additive and any additive precursor is present in the electrolyte in a total amount ranging between about 0.5 wt % and about 20 wt % versus the total weight of the electrolyte and additive and/or additive precursor.
17. The electrochemical cell of claim 2 , wherein the additive and any additive precursor is present in the electrolyte in a total amount ranging between about 0.5 wt % and about 4 wt % versus the weight of each of the first and second electrodes.
18. The electrochemical cell of claim 2 , wherein the additive and/or additive precursor is disposed on and/or within a separator positioned between the first electrode and the second electrode.
19. The electrochemical cell of claim 2 , wherein the electrolyte comprises a nitrate.
20. The electrochemical cell of claim 19 , wherein the nitrate is selected from the group consisting of LiNO 3 , guanidine nitrate, and pyridine nitrate.