High energy density redox flow device
Redox flow devices are described including a positive electrode current collector, a negative electrode current collector, and an ion-permeable membrane separating said positive and negative current collectors, positioned and arranged to define a positive electroactive zone and a negative electroactive zone; wherein at least one of said positive and negative electroactive zone comprises a flowable semi-solid composition comprising ion storage compound particles capable of taking up or releasing said ions during operation of the cell, and wherein the ion storage compound particles have a polydisperse size distribution in which the finest particles present in at least 5 vol % of the total volume, is at least a factor of 5 smaller than the largest particles present in at least 5 vol % of the total volume.
1. An electrochemical cell comprising:
an anode;
a cathode; and
an ion-permeable membrane disposed between the anode and the cathode;
wherein at least one of the anode or the cathode includes an electrode composition comprising solid ion storage compound particles in a liquid electrolyte; and
wherein the solid ion storage compound particles are capable of taking up or releasing ions and have a polydisperse size distribution in which the finest particles present in at least 5 vol % of the total volume, is at least a factor of 5 smaller than the largest particles present in at least 5 vol % of the total volume.
2. The electrochemical cell of claim 1 , wherein the liquid electrolyte is a non-aqueous liquid electrolyte.
3. The electrochemical cell of claim 1 , wherein the particle packing fraction is at least 55 vol %.
4. The electrochemical cell of claim 3 , wherein the particle packing fraction is at least 70 vol %.
5. The electrochemical cell of claim 1 , wherein the solid ion storage compound particles have a bidisperse size distribution in which the two maxima differ in size by at least a factor of 5.
6. The electrochemical cell of claim 5 , wherein the particle size of the maxima for the larger particles is at least 1 micrometer.
7. The electrochemical cell of claim 1 , wherein the volume percentage of the solid ion storage compound particles is between 5% and 70%.
8. The electrochemical cell of claim 1 , wherein of the electrode composition further an electronically conductive material.
9. The electrochemical cell of claim 8 , wherein the electrode composition comprises 0.5% to 10% by volume of the electronically conductive material.
10. An electrochemical cell comprising:
an anode;
a cathode; and
a separator disposed between the anode and the cathode;
wherein at least one of the anode or the cathode includes an electrode composition comprising solid ion storage compound particles in a liquid electrolyte; and
wherein the solid ion storage compound particles are capable of taking up or releasing ions and have a polydisperse size distribution in which the finest particles present in at least 5 vol of the total volume, is at least a factor of 5 smaller than the largest particles present in at least 5 vol % of the total volume.
11. The electrochemical cell of claim 10 , wherein the liquid electrolyte is a non-aqueous liquid electrolyte.
12. The electrochemical cell of claim 10 , wherein the particle packing fraction is at least 55 vol %.
13. The electrochemical cell of claim 12 , wherein the particle packing fraction is at least 70 vol %.
14. The electrochemical cell of claim 10 , wherein the solid ion storage compound particles have a bidisperse size distribution in which the two maxima differ in size by at least a factor of 5.
15. The electrochemical cell of claim 14 , wherein the particle size of the maxima for the larger particles is at least 1 micrometer.
16. The electrochemical cell of claim 10 , wherein the volume percentage of the solid ion storage compound particles is between 5% and 70%.
17. The electrochemical cell of claim 10 , wherein of the electrode composition further an electronically conductive material.
18. The electrochemical cell of claim 17 , wherein the electrode composition comprises 0.5% to 10% by volume of the electronically conductive material.