Lithium sulfur cell with dopant
Among other things, the present disclosure provides a particle comprising a form of sulfur and/or lithium sulfide (Li 2 S) that is doped with a group VIA element, such as selenium (e.g. Se34), tellurium (e.g. Te52), or polonium (e.g. Po84). The present disclosure also provides a cell comprising a negative electrode, a separator, and a positive electrode comprising the particles of the present disclosure.
1. A particle comprising Li 2 S 1−x−y Se x M y ,
wherein M is a Group VIA element, x<0.1, y<0.05, at least one of Se or M is present, and M is not S.
2. The particle of claim 1 , further comprising a coating around the particle.
3. The particle of claim 1 , wherein M is Te or Po.
4. The particle of claim 1 , wherein the coating is a mixed electronic and Li + conductor.
5. The particle of claim 4 , wherein the coating is carbon or Ti 2 S.
6. The particle of claim 1 , wherein the coating is an insulator.
7. The particle of claim 6 , wherein the coating is Al 2 O 3 .
8. A lithium-sulfur cell comprising:
(a) a negative electrode;
(b) a separator; and
(c) a positive electrode comprising the particle of claim 1 .
9. The lithium-sulfur cell of claim 8 , wherein the particle is present in an amount of at least about 40 volume % of the positive electrode.
10. The lithium-sulfur cell of claim 8 , wherein the positive electrode is more than about 30 microns thick.