US 9,812,747 B2
Gas-shield-electrode and composite bifunctional air-electrode using the same for use in metal-air batteries
Suren Martirosyan, Yerevan (AM); and Didier Guillonnet, Paris (FR)
Assigned to AZA HOLDING PTE. LTD., Singapore (SG)
Appl. No. 14/415,802
Filed by AZA Holding Pte. Ltd., Singapore (SG)
PCT Filed Jul. 16, 2013, PCT No. PCT/IB2013/055844
§ 371(c)(1), (2) Date Jan. 20, 2015,
PCT Pub. No. WO2014/013433, PCT Pub. Date Jan. 23, 2014.
Claims priority of provisional application 61/672,935, filed on Jul. 18, 2012.
Claims priority of provisional application 61/763,737, filed on Feb. 12, 2013.
Prior Publication US 2015/0200431 A1, Jul. 16, 2015
Int. Cl. H01M 10/052 (2010.01); H01M 12/08 (2006.01); H01M 4/86 (2006.01); H01M 4/88 (2006.01)
CPC H01M 12/08 (2013.01) [H01M 4/8615 (2013.01); H01M 4/8657 (2013.01); H01M 4/8875 (2013.01); H01M 2004/8689 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A method of operating a secondary Metal-Air electrochemical cell with a bulk of liquid electrolyte, a metal anode and an air cathode, the air cathode comprising cavities serving as hollow spaces on a side to be facing the anode, the method comprising the steps of:
a) at start of a charging session, creating in less than 2 seconds an oxygen gas-shield on an electrolyte side of the air cathode to be facing the anode obstructing ion passage between the bulk of the electrolyte and the air cathode, wherein oxygen forming the oxygen gas-shield evolves from the air cathode at a time of charging,
b) charging the cell without anodic polarization of the air cathode with the help of
(i) electric conductive material placed between the electrolyte side of air cathode and the bulk of electrolyte, and,
(ii) the said oxygen gas-shield obstructing passage of ions of the electrolyte between
the electrolyte side of air cathode and the bulk of electrolyte,
c) removing the oxygen gas-shield at start of a discharging session, wherein the step of removing oxygen gas-shield at start of a discharging session is performed by the air cathode consuming oxygen from its electrolyte-side under cathodic polarization.