Patent ID: 11876270
Assignee: FUNDACIóN IMDEA ENERGíA
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  Y | IPC H

Claim 11:
12. A method of storing electricity comprising the steps of:
a) providing a redox-flow battery (1) comprising:
(i) a positive compartment (10) comprising a positive electrode (11) and a catholyte, wherein said catholyte is an alkaline ferrocyanide solution comprising ferrocyanide species;
(ii) a catholyte reservoir container (12) connected in fluid communication with the positive compartment (10) through at least one conduct (13) and said container (12) comprising:
catholyte and
a solid electroactive material (14),
wherein said solid electroactive material is confined within the container; wherein the solid electroactive material is a metal hydroxide selected from Ni(OH)2, Co(OH)2, Mn(OH)2 or NixMnyCoz(OH)2, wherein x, y and z varies between 0 and 1;

(iii) a negative compartment (20) comprising a negative electrode (21) and an anolyte, wherein said anolyte is an alkaline solution; and wherein said anolyte comprises anolyte active species;
(iv) an anolyte reservoir container (22) connected in fluid communication with the negative compartment (20) through at least one conduct (23) and said container (22) comprising anolyte; and
(v) a power/load source (40);

b) oxidizing the ferrocyanide species of the catholyte at the positive compartment (10) to ferricyanide to obtain an oxidized catholyte, while the anolyte active species are reduced to their corresponding reduced state at the negative compartment (20) to obtain a reduced anolyte;
c) letting flow the oxidized catholyte of step (b) into the catholyte reservoir container (12) and the reduced anolyte of step (b) into the anolyte reservoir container (22); and
d) storing charge in the solid electroactive material at the catholyte reservoir container by charge transfer between the oxidized catholyte and the solid electroactive material (14) so that ferricyanide species of the oxidized catholyte of step (c) are reduced back to ferrocyanide by oxidation of the solid electroactive material at the catholyte reservoir container (12).