Carbon dioxide assisted metal-oxygen battery and related method
A non-aqueous Na-oxygen battery utilizes a gas mixture of CO 2 and O 2 as fuel. The battery exhibits a comparatively high specific energy of 6500-7000 Whkg −1 over a range of CO 2 feed compositions. The energy density achieved is higher, by 200% to 300%, than obtained with pure oxygen feed. Ex-situ FTIR and XRD analysis confirm Na2O2, Na 2 C 2 O 4 and Na 2 CO 3 as discharge products. The Na—O 2 /CO 2 battery provides a promising approach for CO 2 capture and conversion into electrical energy. The Na—O 2 /CO 2 battery may be extended to other metals. In addition, operation of a metal battery fueled at least in-part by carbon dioxide within an optimal temperature range is considered.
1. A rechargeable battery comprising:
a positive electrode contacted by an oxygen and carbon dioxide containing fuel mixture;
a negative electrode comprising a metal material selected from the group consisting of sodium, magnesium, aluminum, zinc, calcium, copper and iron containing metal materials; and
an electrolyte separating the positive electrode and the negative electrode, wherein the battery reduces at least a portion of CO 2 to CO 4 2− in an electroreduction reaction.
2. The battery of claim 1 wherein the oxygen and carbon dioxide containing fuel mixture has an oxygen:carbon dioxide fuel volume ratio from about 10:90 to about 90:10.
3. The battery of claim 1 wherein the oxygen and carbon dioxide containing fuel mixture has an oxygen:carbon dioxide fuel volume ratio from about 20:80 to about 80:20.
4. The battery of claim 1 wherein the oxygen and carbon dioxide containing fuel mixture has an oxygen:carbon dioxide fuel volume ratio from about 30:70 to about 70:30.
5. The battery of claim 1 further comprising a separator also separating the positive electrode and the negative electrode.
6. The battery of claim 1 wherein the positive electrode comprises a carbon material and optionally a binder.
7. The battery of claim 1 wherein the negative electrode comprises sodium metal.
8. The battery of claim 1 wherein the metal material consists of at least one of a pure metal and a metal alloy including at least one metal selected from the group consisting of sodium, magnesium, aluminum, zinc, calcium, copper and iron metals.
9. The battery of claim 1 wherein the metal material comprises a metal oxyanion salt including at least one metal selected from the group consisting of sodium, magnesium, aluminum, zinc, calcium, copper and iron metals.
10. The battery of claim 1 wherein the electrolyte comprises an ionic liquid.
11. The battery of claim 1 , wherein the battery is stably rechargeable for over 20 cycles.
12. The battery of claim 1 wherein C 2 O 4 2− is a dominate reduction product of CO 2 in the electroreduction reaction.
13. The battery of claim 1 wherein the cathode has:
a surface area from about 800 to about 1500 m 2 /g;
a pore volume from about 1.5 to about 3 cm 3 /g; and
an average pore size from about 50 to about 100 Å.
14. A rechargeable battery comprising:
a positive electrode contacted by an oxygen and carbon dioxide containing fuel mixture;
a negative electrode comprising a metal material selected from the group consisting of sodium, magnesium, aluminum, zinc, calcium, copper and iron containing metal materials; and
an ionic liquid electrolyte separating the positive electrode and the negative electrode, wherein the battery reduces at least a portion of CO 2 to C 2 O 4 2− in an electroreduction reaction.