Sodium iron(II)-hexacyanoferrate(II) battery electrode
A method is provided for synthesizing sodium iron(II)-hexacyanoferrate(II). A Fe(CN) 6 material is mixed with the first solution and either an anti-oxidant or a reducing agent. The Fe(CN) 6 material may be either ferrocyanide ([Fe(CN) 6 ] 4− ) or ferricyanide ([Fe(CN) 6 ] 3− ). As a result, sodium iron(II)-hexacyanoferrate(II) (Na 1+X Fe[Fe(CN) 6 ] Z . M H 2 O is formed, where X is less than or equal to 1, and where M is in a range between 0 and 7. In one aspect, the first solution including includes A ions, such as alkali metal ions, alkaline earth metal ions, or combinations thereof, resulting in the formation of Na 1+X A Y Fe[Fe(CN) 6 ] Z . M H 2 O, where Y is less than or equal to 1. Also provided are a Na 1+X Fe[Fe(CN) 6 ] Z . M H 2 O battery and Na 1+X Fe[Fe(CN) 6 ] Z . M H 2 O battery electrode.
1. A sodium iron(II)-hexacyanoferrate(II) battery electrode, the battery electrode comprising:
a current collector;
sodium iron(II)-hexacyanoferrate(II) (Na 1+X Fe[Fe(CN) 6 ] Z . M H 2 O) overlying the current collector,
where X and Z are each less than or equal to 1; and,
where M is in a range of 0 to 7.
2. The battery electrode of claim 1 wherein the sodium iron(II)-hexacyanoferrate(II) additionally comprises A ions selected from the group consisting of alkali metal ions, alkaline earth metal ions, and combinations thereof, forming Na 1+X A Y Fe[Fe(CN) 6 ] Z . M H 2 O, where Y is less than or equal to 1.
3. The battery electrode of claim 2 wherein the A ions are selected from the group consisting of lithium ions (Li + ), sodium ions (Na + ), potassium ions (K + ), rubidium ions (Rb + ), cesium ions (Cs + ), beryllium ions (Be + ), magnesium ions (Mg + ), calcium ions (Ca + ), strontium ions (Sr + ), and barium ions (Ba + ).
4. A sodium iron(II)-hexacyanoferrate(II) battery comprising:
a cathode comprising:
a current collector;
sodium iron(II)-hexacyanoferrate(II) (Na 1+X Fe[Fe(CN) 6 ] Z . M H 2 O) overlying the current collector,
where X AND Z are each less than or equal to 1;
where M is in a range of 0 to 7;
an anode;
an electrolyte; and,
an ion-premeable membrane.
5. The battery of claim 4 wherein the sodium iron(II)-hexacyanoferrate(II) additionally comprises A ions selected from the group consisting of alkali metal ions, alkaline earth metal ions, and combinations thereof, forming Na 1+X A Y Fe[Fe(CN) 6 ] Z . M H 2 O, where Y is less than or equal to 1.
6. The battery of claim 5 wherein the A ions are selected from the group consisting of lithium ions (Li + ), sodium ions (Na + ), potassium ions (K + ), rubidium ions (Rb + ), cesium ions (Cs + ), beryllium ions (Be + ), magnesium ions (Mg + ), calcium ions (Ca + ), strontium ions (Sr + ), and barium ions (Ba + ).